EP3621643A1 - Anti-malarial antibodies that bind circumsporozoite protein - Google Patents

Anti-malarial antibodies that bind circumsporozoite protein

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Publication number
EP3621643A1
EP3621643A1 EP18798204.6A EP18798204A EP3621643A1 EP 3621643 A1 EP3621643 A1 EP 3621643A1 EP 18798204 A EP18798204 A EP 18798204A EP 3621643 A1 EP3621643 A1 EP 3621643A1
Authority
EP
European Patent Office
Prior art keywords
antibody
domain
amino acid
sequence
use according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP18798204.6A
Other languages
German (de)
French (fr)
Other versions
EP3621643A4 (en
Inventor
Qi LIANG
Sean Matthew CARROLL
Daniel Eric EMERLING
Allan Bradley
Paul Kellam
pela BINTER
Simon James Watson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kymab Ltd
Atreca Inc
Original Assignee
Kymab Ltd
Atreca Inc
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Filing date
Publication date
Application filed by Kymab Ltd, Atreca Inc filed Critical Kymab Ltd
Publication of EP3621643A1 publication Critical patent/EP3621643A1/en
Publication of EP3621643A4 publication Critical patent/EP3621643A4/en
Pending legal-status Critical Current

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Classifications

    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07KPEPTIDES
    • C07K16/00Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/18Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans
    • C07K16/20Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans from protozoa
    • C07K16/205Plasmodium
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00Medicinal preparations containing antigens or antibodies
    • A61K2039/505Medicinal preparations containing antigens or antibodies comprising antibodies
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07KPEPTIDES
    • C07K2317/00Immunoglobulins specific features
    • C07K2317/30Immunoglobulins specific features characterized by aspects of specificity or valency
    • C07K2317/34Identification of a linear epitope shorter than 20 amino acid residues or of a conformational epitope defined by amino acid residues
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07KPEPTIDES
    • C07K2317/00Immunoglobulins specific features
    • C07K2317/70Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
    • C07K2317/76Antagonist effect on antigen, e.g. neutralization or inhibition of binding
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07KPEPTIDES
    • C07K2317/00Immunoglobulins specific features
    • C07K2317/90Immunoglobulins specific features characterized by (pharmaco)kinetic aspects or by stability of the immunoglobulin
    • C07K2317/92Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/30Against vector-borne diseases, e.g. mosquito-borne, fly-borne, tick-borne or waterborne diseases whose impact is exacerbated by climate change

Definitions

  • This invention relates to treating or preventing malaria, and to antibodies conferring protection against infection by malarial parasites such as Plasmodium falciparum by insect vector transmission.
  • the invention also relates to treating, preventing or diagnosing
  • the causative agent of malaria is a protozoal parasite, which is transmitted by mosquitos.
  • Plasmodium parasites such as P. falciparum
  • the infective stage is the sporozoite, which is transmitted from the mosquito to the vertebrate host, e.g., human.
  • Preventing infection will involve preventing sporozoite transmission from the insect vector to humans. Decreasing infection by P. falciparum will depend on blocking transmission, or inhibiting the pre-erythrocytic phase of infection.
  • Targeting the asexual phases involved in the erythrocytic cycle (and disease) may only mimic naturally acquired immunity - that is, immunity to disease rather than immunity to infection.
  • Circumsporozoite protein is an antigen that is highly expressed on the P. falciparum sporozoite. CSP is displayed on the surface of the sporozoite and is involved in key parasite functions. Human antibodies against P. falciparum sporozoites have been described. Del Giudice et al synthesised a peptide of about 40 repeats of NANP (Asn-Ala- Asn-Pro) from CSP, (NANP) 40 . This was recognised by monoclonal antibodies produced against P.
  • 3 individuals with the highest anti NANP antibody titres were challenged by experimental mosquito mediated infection with Plasmodium falciparum sporozoites.
  • 2 of the vaccines showed delayed parasitaemia and one showed no parasitaemia (Herington et al, Nature. 328: 257-259 1987), indicating that antibodies to NANP could be protective to infection.
  • a first generation vaccine has been developed using portions of CSP, including part of the NANP repeats.
  • CSP-based vaccines have consistently shown 30-50% efficacy in prevention of erythrocytic-stage infection. This level of efficacy is not sufficient for eradication and new pre-erythrocytic treatments will need superior efficacy.
  • anti-malarial products include mefloquinine, doxycycline and
  • Atovaquone/proguanil which are used for chemoprophylaxis by travellers and the military.
  • Artemisinin and its derivatives also have anti-malarial action, and artemisinin combination therapies are a standard treatment worldwide for malaria.
  • sulphadoxine-pyrimethanime SP was initially almost 100% effective in curing malaria when introduced in 1977, but within five years was curing only 10% of cases due to drug resistance.
  • the once-popular chloroquine has lost its effectiveness in almost every part of the world.
  • 95% of African children treated for malaria were given chloroquine, even though the drug only cured half of malaria cases in many countries.
  • the invention provides novel anti-parasitic therapeutic and diagnostic agents, including prophylactic agents, especially antibodies.
  • the antibodies may be employed for diagnosing, treating, or preventing malaria or Plasmodium infection in humans and other mammals, or for reducing the risk of malaria or Plasmodium infection in humans and other mammals. Methods of diagnosis and treatment are described herein, including methods of administration to a mammal.
  • the antibodies may be used to confer protection against infection by malarial parasites such as Plasmodium falciparum by insect vector transmission.
  • Desirable features of the antibodies include inhibiting the pre-erythrocytic stage (e.g., sporozoite) of Plasmodium infection, reducing progression of Plasmodium infection in a mammal, reducing one or more symptoms of malaria, and reducing transmission or risk of transmission of Plasmodium to and/or from a mammal.
  • Inhibition of transmission of malarial Plasmodium parasites between mammals (especially humans) is of particular value in lessening spread of disease, limiting malaria and controlling reservoirs of infectious malarial parasites in populations. This invention offers particular advantages for use in countries and regions where malaria is prevalent, and for travellers, military personnel and health workers visiting or operating in such countries or regions.
  • This invention also relates to the use of antibody sequences as correlates of protection following vaccination to protect from malaria infection, which has utility in vaccine development programs, including pre-clinical and clinical trials, and in determining the level of protection achieved in individuals vaccinated against Plasmodium infection.
  • This invention also relates to the use of such antibodies to diagnose malaria infection, and diagnostic methods and kits are described herein.
  • Pharmaceutical compositions comprising the antibodies are also provided. Exemplary embodiments of the invention are set out in the appended claims. Exemplary antibodies include antibodies 666, 667, 668 and 669, the sequences of which are set out herein. Antibodies having close structural similarity with these antibodies, are also described.
  • antibodies 666-1 , 666-2, 666-3, 666-4 antibody 666 lineage
  • 667-1 , 667-2, 667-3 antibody 667 lineage
  • 668-1 antibody 668 lineage
  • 669-1 , 669-2, 669- 3, 669-4, 669-5 and 669-6 antibodies having the sets of CDRs shown in Tables 5 to 7.
  • Further exemplary antibodies are described in Example 1 1 and include antibodies having the sets of CDRs, and optionally the VH domain and/or VL domains, shown in Table 16.
  • Still further exemplary antibodies are described in Example 13 and include antibodies having the sets of CDRs, and optionally the VH domain and/or VL domains, shown in Table 18.
  • Antibody 667 and antibody 668 are believed to bind the NANP repeat region of the CSP polypeptide sequence and/or to bind within a region of up to 12 amino acids preceding the NANP repeat region.
  • the NANP repeat region starts with a sequence
  • NANPNVDPNANP which may provide at least part of the epitope recognised by these antibodies.
  • a sequence of 12 amino acids KLKQPGDGNPDP which may also provide or contribute to the epitope recognised by antibody 667 and antibody 668.
  • the antibodies may bind the NPDP motif within this sequence.
  • the epitope recognised by antibody 667 and antibody 668 may lie within, or include, the 8-mer sequence NPDPNANP, i.e., the sequence comprising the first NANP motif and the residues that immediately precede it.
  • Antibody 667 and antibody 668 have been characterised both in vitro and in vivo and found to inhibit pathologically relevant sporozoite functions and to protect against sporozoite infection as described in the appended Examples.
  • Antibody 666 and antibody 669 are related in sequence to both antibody 667 and antibody 668, indicating they may share useful functional properties in common and that they may also bind the same region(s) of CSP, e.g., the NANP region and/or upstream sequences of CSP as described above. Targeting an epitope within the NANP repeat region and/or upstream sequence as described may confer particular advantages for inhibiting sporozoite infection.
  • the invention also relates to antibodies that neutralise CSP.
  • An antibody according to the invention may be one that competes for binding to CSP of Plasmodium falciparum with an antibody (e.g., human lgG1 , or an scFv) comprising the heavy and light chain complementarity determining regions (CDRs) of antibody 666, antibody 667, antibody 668 or antibody 669.
  • An antibody according to the present invention may comprise one or more CDRs of any of antibody 666, 667, 668 or 669 (e.g., all 6 CDRs of any such antibody, or a set of HCDRs and/or LCDRs) or variants thereof as described herein.
  • An antibody according to the present invention may comprise one or more CDRs of an antibody of the "antibody 666 lineage", an antibody of the "antibody 667 lineage", an antibody of the “antibody 668 lineage” or an antibody of the "antibody 669 lineage” (e.g., all 6 CDRs of any such antibody, or a set of HCDRs and/or LCDRs) or variants thereof as described herein.
  • the "antibody 666 lineage” comprises antibody 666, antibody 666-1 , antibody 666-2, antibody 666-3 and antibody 666-4.
  • the "antibody 667 lineage” comprises antibody 667, antibody 667-1 , antibody 667-2 and antibody 667-3.
  • the "antibody 668 lineage” comprises antibody 668 and antibody 668-1.
  • the "antibody 669 lineage” comprises antibody 669, antibody 669-1 , antibody 669-2, antibody 669-3, antibody 669-4, antibody 669-5 and antibody 669-6.
  • An antibody according to the present invention may comprise one or more CDRs as shown in Tables 5 to 7.
  • the antibody may comprise a set of 6 CDRs shown in Table 5 or Table 6, it may comprise a VH domain having a set of HCDRs as indicated in any of Tables 5 to 7, and/or it may comprise a VL domain having a set of LCDRs as indicated in Table 5 or Table 6.
  • An antibody according to the present invention may comprise one or more CDRs as shown in Table 16.
  • the antibody may comprise HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 as shown in Table 16, it may comprise a VH domain having the HCDR1 , HCDR2 and HCDR3 shown in Table 16 and/or it may comprise a VL domain having the LCDR1 , LCDR2 and LCDR3 shown in Table 16.
  • An antibody according to the present invention may comprise one or more CDRs as shown in Table 18.
  • the antibody may comprise HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 as shown in Table 18, it may comprise a VH domain having the HCDR1 , HCDR2 and HCDR3 shown in Table 18 and/or it may comprise a VL domain having the LCDR1 , LCDR2 and LCDR3 shown in Table 18.
  • the antibody may comprise an antibody VH domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein the HCDR3 is an HCDR3 of an antibody selected from antibody 666, 667, 668 or 669 or comprises that HCDR3 with 1 , 2, 3, 4 or 5 amino acid alterations.
  • the HCDR2 may be the HCDR2 of the selected antibody or it may comprise that HCDR2 with 1 , 2, 3, 4 or 5 amino acid alterations.
  • the HCDR1 may be the HCDR1 of the selected antibody or it may comprise that HCDR1 with 1 , 2, 3, 4 or 5 amino acid alterations.
  • the antibody may comprise an antibody VL domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein the LCDR3 is an LCDR3 of an antibody selected from antibody 666, 667,
  • the LCDR2 may be the LCDR2 of the selected antibody or it may comprise that LCDR2 with 1 , 2, 3, 4 or
  • the LCDR1 may be the LCDR1 of the selected antibody or it may comprise that LCDR1 with 1 , 2, 3, 4 or 5 amino acid alterations.
  • An antibody may comprise:
  • an antibody VH domain comprising complementarity determining regions HCDR1 , HCDR2 and HCDR3, and
  • an antibody VL domain comprising complementarity determining regions LCDR1 , LCDR2 and LCDR3,
  • heavy chain complementarity determining regions are those of antibody 666, antibody 667, antibody 668 or antibody 669, or comprise the antibody 666, 667, 668 or 669 heavy chain complementarity determining regions with 1 , 2, 3, 4 or 5 amino acid alterations; and/or
  • light chain complementarity determining regions are those of antibody 666, antibody 667, antibody 668 or antibody 669, or comprise the antibody 666, 667, 668 or
  • 669 light chain complementarity determining regions with 1 , 2, 3, 4 or 5 amino acid alterations.
  • the antibody may comprise an antibody VH domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein
  • the HCDR1 , HCDR2 and HCDR3 are each independently selected from an antibody of the antibody 666 lineage, and/or wherein
  • the LCDR1 , LCDR2 and LCDR3 are each independently selected from an antibody of the antibody 666 lineage.
  • the HCDR1 may be the HCDR1 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666-4
  • the HCDR2 may be the HCDR2 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666-4
  • the HCDR3 may be the HCDR3 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666- 4.
  • the LCDR1 may be the LCDR1 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666-4
  • the LCDR2 may be the LCDR2 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666- 4
  • the LCDR3 may be the LCDR3 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666- 4.
  • the antibody comprises a set of HCDRs (HCDR1 , HCDR2 and HCDR3) from antibody 666-1 , antibody 666-2, antibody 666-3 or antibody 666-4.
  • the antibody optionally comprises a set of LCDRs (LCDR1 , LCDR2 and LCDR3) from the same antibody.
  • An antibody may comprise an antibody VH domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein
  • the HCDR1 , HCDR2 and HCDR3 are each independently selected from an antibody of the antibody 667 lineage, and/or wherein
  • the LCDR1 , LCDR2 and LCDR3 are each independently selected from an antibody of the antibody 667 lineage.
  • the antibody comprises a set of HCDRs from antibody 667-1 , antibody 667-2 or antibody 667-3.
  • the antibody optionally comprises a set of LCDRs from the same antibody.
  • An antibody may comprise an antibody VH domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein
  • the HCDR1 , HCDR2 and HCDR3 are each independently selected from an antibody of the antibody 668 lineage, and/or wherein
  • the LCDR1 , LCDR2 and LCDR3 are each independently selected from an antibody of the antibody 668 lineage.
  • the antibody comprises a set of HCDRs from antibody 668-1.
  • the antibody optionally also comprises a set of LCDRs from antibody 668-1.
  • An antibody may comprise an antibody VH domain comprising CDRs HCDR1 ,
  • HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein
  • the HCDR1 , HCDR2 and HCDR3 are each independently selected from an antibody of the antibody 669 lineage, and/or wherein
  • the LCDR1 , LCDR2 and LCDR3 are each independently selected from an antibody of the antibody 669 lineage.
  • the antibody comprises a set of HCDRs from antibody 669-1 , 669-2, 669- 3, 669-4, 669-5 or 669-6.
  • the antibody optionally comprises a set of LCDRs from the same antibody.
  • Example antibody CDR sequences for antibodies of the invention are as follows:
  • CSYAGSSAWV SEQ ID NO: 20
  • SSYAGSSTWV SEQ ID NO: 30
  • Residues shown in brackets are alternatives at a given position.
  • position 2 of a sequence Z(X/Y)Z has either residue X or residue Y, so that Z(X/Y)Z designates the sequences ZXZ and ZYZ.
  • the antibody has a HCDR3 sequence
  • the antibody has an LCDR3 sequence CSYAGSSAWV or SSYAGSSTWV, an LCDR1 sequence TGTS(N/S)DVG(I/S)YN (H/YV)S, and an LCDR2 sequence
  • Antibodies of the invention may comprise VH and/or VL domain framework regions corresponding to human germline gene segment sequences.
  • it may comprise one or more framework regions of antibody 666, antibody 667, antibody 668 or antibody 669.
  • the framework region or framework regions may be a FR1 , FR2, FR3 and/or FR4.
  • An antibody of the invention may comprise an antibody VH domain which
  • (i) is derived from recombination of a human heavy chain V gene segment, a human heavy chain D gene segment and a human heavy chain J gene segment, wherein
  • V segment is IGHV1-3;
  • the D gene segment is IGHD3-10, IGHD3-9, IGHD4-1 1 or IGHD2-2; and/or the J gene segment is IGHJ6, or
  • (ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein
  • FR1 aligns with human germline V gene segment IGHV1-3 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations,
  • FR2 aligns with human germline V gene segment IGHV1-3 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations,
  • FR3 aligns with human germline V gene segment IGHV1-3 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations, and/or
  • FR4 aligns with human germline J gene segment IGHJ6 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations.
  • a FR1 , FR2, FR3 or FR4 segment may align perfectly with the germline gene segment, i.e., with no amino acid alterations.
  • the antibody may comprise a VH domain derived from
  • An antibody may comprise VH domain framework regions FR1 , FR2, FR3 and FR4, wherein FR1 , FR2 and FR3 each align with human germline V gene segment IGHV1-3 with 1 , 2, 3, 4 or 5 amino acid alterations, and a FR4 that aligns with human germline J gene segment IGHJ6 with 1 , 2, 3, 4 or 5 amino acid alterations.
  • An antibody of the invention may comprise an antibody VL domain which
  • (i) is derived from recombination of a human light chain V gene segment and a human light chain J gene segment, wherein
  • V segment is IGLV2-23, and/or
  • the J gene segment is IGLJ3; or
  • (ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein
  • FR1 aligns with human germline V gene segment IGLV2-23 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations,
  • FR2 aligns with human germline V gene segment IGLV2-23 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations,
  • FR3 aligns with human germline V gene segment IGLV2-23 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations, and/or
  • FR4 aligns with human germline J gene segment IGLJ3 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations.
  • a FR1 , FR2, FR3 or FR4 segment may align perfectly with the germline gene segment, i.e., with no amino acid alterations.
  • An antibody according to the invention may comprise an antibody VH domain which is the VH domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VH domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669.
  • the VH domain is the VH domain of an antibody in the antibody 666 lineage, an antibody in the antibody 667 lineage, an antibody in the antibody 668 lineage or an antibody in the antibody 669 lineage.
  • the antibody may comprise an antibody VL domain which is the VL domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VL domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669.
  • the VL domain is the VL domain of an antibody in the antibody 666 lineage, an antibody in the antibody 667 lineage, an antibody in the antibody 668 lineage or an antibody in the antibody 669 lineage.
  • An antibody VH domain having the HCDRs of antibody 666, antibody 667, antibody 668 or antibody 669, or having a variant of those CDRs may be paired with an antibody VL domain having the LCDRs of the same antibody, or having a variant of those CDRs.
  • VH domain of any of antibody 666, antibody 667, antibody 668 or antibody 669, or a variant of that VH domain may be paired with a VL domain of the same antibody, or a VL domain variant of the same antibody.
  • the antibody may comprise the antibody 667 VH domain and the antibody 667 VL domain.
  • the antibody may comprise the antibody 668 VH domain and the antibody 668 VL domain.
  • Antibodies may include constant regions, optionally human heavy and/or light chain constant regions.
  • An exemplary isotype is IgG, e.g., human IgGl
  • Antibodies according to the present invention may be administered to human patients, optionally paediatric patients (under 18 years of age), including young children (5 years of age and under), such as to babies and infants (under 36 months of age, e.g., under 24 months of age). Young patients may have greatest need of prevention by prophylaxis or treatment with the antibodies, as they have been reported to have the highest rates of severe malaria (Griffin et al., Proc. R. Soc. B 282:20142657). The antibodies can also be used in adults of any age.
  • the patient may be a male or female aged 50 years or under, e.g., 40 or under, or 30 or under.
  • the antibodies may be optimally used at time of peak malaria transmission, which coincides with the rain seasons in many target populations.
  • Antibodies may be administered to individuals during the rain season in tropical regions where malaria transmission is ongoing, including sub-Saharan Africa, South-East Asia, Latin America or the Middle East.
  • Antibody may also be administered to travellers outside these regions, in preparation for travel to tropical regions affected by malaria.
  • nucleic acid molecules encoding sequences of the antibodies described herein, host cells containing such nucleic acids, and methods of producing the antibodies by culturing the host cells and expressing and optionally isolating or purifying the antibodies. The expressed antibody is thereby obtained.
  • VH and VL domains of antibodies described herein may similarly be produced and are aspects of the present invention.
  • Suitable production methods of antibodies include large-scale expression from host cells (e.g, mammalian cells) in a bioreactor by continuous or batch culture (e.g., fed batch culture).
  • Figure 1 illustrates the life cycle of malarial Plasmodium parasites such as P. falciparum.
  • Figure 2 is an immunisation schedule for Kymice to produce anti-malarial antibodies.
  • Figure 3 is a schematic diagram of antigen binding cross-blocking between antibodies.
  • Figure 4 is a table of data relating to selected anti-malarial antibodies.
  • Figure 5 illustrates a model to test protection of mice from mosquito transmission of
  • Figure 6 shows the synthetic nucleotide sequence for Pf CSP (SEQ ID NO: 41 , encoding SEQ ID NO: 42).
  • Figure 7 shows the amino acid sequence of Pf CSP (SEQ ID NO: 42) used for reverse translation of a synthetic nucleotide sequence. The illustrated sequence includes a hexa- histidine C-terminal tag. The sequence without the his tag is Plasmodium falciparum CSP SEQ ID NO: 43.
  • Figure 8 shows the results of epitope mapping experiments for antibodies 667 and 668 and reference data from other test antibodies.
  • A Dose-dependent ELISA binding towards recombinant CSP from P. falciparum.
  • B Dose-dependent ELISA binding towards EP070034 (NANP peptide).
  • C Dose-dependent ELISA binding towards Pf16 (C-terminal peptide of CSP).
  • Figure 9 shows results obtained for Antibody 667 and Antibody 668 in a murine malaria challenge model as described in Examples 4a and 4b. Protection data is displayed in terms of liver-stage parasite burden, determined by the number of P. berghei 18s RNA copies detected in mouse liver homogenates.
  • Figure 10 shows results obtained in the in vivo mouse protection assay described in
  • Examples 4a and 4b Results are expressed as percent inhibition compared with naive infected mice.
  • Figure 11 shows further results from the work described in Examples 4a and 4b, in terms of parasitemia following sporozoite challenge of mice receiving passive transfer of anti-CSP mAbs. 17 days after blood feeding on Pb-Pf FULL CSP infected mice, the proportion of infected mosquitoes was -85% (26 out of 30 infected salivary glands). Based on this calculation, it was determined that 6 mosquitoes were needed to challenge mice with 5 infected mosquito bites. Upon passive transfer of monoclonal antibodies, mice were anesthetised with 2% Avertin and mosquitoes allowed to feed on mice for -10 minutes.
  • FIG. 12 shows data from the gliding motility assay described in Example 5.
  • P. falciparum sporozoites were pre-incubated with the indicated antibodies for 30 min and then added to wells in the presence of bovine serum albumin and incubated at 37 degrees C for 1 hr. They were then fixed and trails were stained with anti-CSP antibody and counted using a fluorescence microscope. 100 sporozoites were counted and shown is the number associated with the indicated number of circular trails, indicative of their motility.
  • Figure 13 shows ILSDA data from the work described in Example 6.
  • Pf sporozoites were mixed with the indicated mAbs at 20 ⁇ g/ml and inoculated into CPHH.
  • CPHH were harvested after 96 hours incubation.
  • Pf 18s rRNA copy numbers were measured by qRT- PCR.
  • Y axis is copies of Pf18s per well compared to standards. Error bars represent standard deviation. 3 separate wells were tested for each mAb.
  • the tested anti-CSP antibodies are Ab640, Ab643, Ab646, Ab649, Ab662, Ab667 (second from right), Ab668 (far right) and the reference anti-CSP antibody 2A10 (second from left).
  • Figure 14 shows data on inhibition of hepatocyte traversal as described in Example 7.
  • Graph represents traversal inhibition conferred by anti-CSP Antibodies 640, 643, 646, 649, 667 and 668 and antibodies to another antigen (Antibodies 605, 612, 628, 629, 632) tested in this assay at 10 ⁇ g/mL (right hand bar) and 100 ⁇ g/mL (left hand bar). The means of two independent experiments are shown. Only anti-CSP mAbs 667 and 668 appear to mediate traversal.
  • Figure 15 shows data on inhibition of sporozoite invasion as described in Example 7.
  • FIG. 16 shows in vivo protection mediated by passive transfer of antibodies 667 and 668 in challenge of FRG humanized liver (Hu-Hep) mice with Pf-infected mosquito bites as described in Example 8.
  • Ab667 and Ab668 exhibit robust and dose dependent protection from Pf sporozoite liver infection.
  • Figure 17 shows amino acid sequences of the VH and VL domains of Antibody 667 and Antibody 668 with CDR sequences boxed.
  • the HCDR1 (SEQ ID NO: 13), HCDR2 (SEQ ID NO: 14) and HCDR3 (SEQ ID NO: 15) sequences are boxed.
  • the LCDR1 (SEQ ID NO: 18), LCDR2 (SEQ ID NO: 19) and LCDR3 (SEQ ID NO: 20) sequences are boxed.
  • the HCDR1 (SEQ ID NO: 23), HCDR2 (SEQ ID NO: 24) and HCDR3 (SEQ ID NO: 25) sequences are boxed.
  • the LCDR1 (SEQ ID NO: 28), LCDR2 (SEQ ID NO: 29) and LCDR3 (SEQ ID NO: 30) sequences are boxed.
  • Figure 18 is an antibody lineage tree for Ab666, showing the inferred relationship between Ab666 and Ab666-1 , Ab666-2, Ab666-3 and Ab666-4.
  • Figure 19 is an antibody lineage tree for Ab667, showing the inferred relationship between Ab667 and Ab667-1 , Ab667-2 and Ab667-3.
  • Figure 20 is an antibody lineage tree for Ab668, showing the inferred relationship between Ab668 and Ab668-1.
  • Figure 21 is an antibody lineage tree for Ab669, showing the inferred relationship between Ab669 and Ab669-1 , Ab669-2, Ab669-3, Ab669-4, Ab669-5 and Ab669-6.
  • Figure 22 shows (a) the nucleotide sequence and (b) the amino acid sequence of recombinant CSP used for the experimental work in Example 10.
  • the amino acid sequence includes, besides the CSP ectodomain:
  • LHHILDAQKMLWNHR Biotinylation tag BirA enzyme substrate peptide
  • Figure 23 is a multiple sequence alignment of the light chain for all antibodies containing the common IGLV2-23 IGLJ3 genotype. CDRs are highlighted by boxes. Identical amino acids are indicated by a dot.
  • Figure 24 is a multiple sequence alignment of the heavy chain for all antibodies containing the common IGLV2-23 IGLJ3 genotype. CDRs of Ab666, Ab667, Ab668 and Ab669 are highlighted by boxes. Due to differences in CDR lengths, the sequences have different overall lengths. Identical amino acids are indicated by a dot.
  • nucleotide sequence encoding VH domain amino acid sequence of VH domain; VH CDR1 amino acid sequence, VH CDR2 amino acid sequence; VH CDR3 amino acid sequence; nucleotide sequence encoding VL domain; amino acid sequence of VL domain; VL CDR1 amino acid sequence; VL CDR2 amino acid sequence; and VL CDR3 amino acid sequence, respectively.
  • sequence listing includes VH and VL domain sequences for antibodies that were identified as being in the same lineages as antibody 666, 667, 668 and 669 and having different CDR sequences, namely antibodies 666-3, 666-4 (antibody 666 lineage), 667-1 , 667-2, 667-3 (antibody 667 lineage), 668-1 (antibody 668 lineage) 669-1 , 669-2, 669-3, 669-4, 669-5 and 669-6
  • antibody 669 lineage Further sets of antibody CDRs are shown in Table 5, Table 6 and Table 7. Still further sets of antibody CDRs, and antibody VH and VL domains, are shown in Table 16 and Table 18.
  • CDR sequences within antibody variable domains may for example be determined according to the Kabat system, Chothia system, IMGT system, or others.
  • CDR sequence tables we therefore show CDRs for the antibodies, including their CDRs as determined by the IMGT, Kabat and/or Chothia systems respectively.
  • Antibodies according to the present invention are intended for medical use, particularly as anti-malarials, and for diagnostic use.
  • Desirable properties for antibodies according to examples of the present invention include one or more of:
  • an antibody of the present invention may have any one or more, for example all, of these properties.
  • An antibody according to the invention may be a neutralising antibody, neutralising one or more functions of CSP.
  • Anti-CSP antibodies according to the invention may inhibit sporozoite functions in assays in vitro, including gliding motility (Example 5), liver stage development (Example 6) and hepatocyte traversal and/or invasion (Example 7).
  • An antibody of the invention may inhibit the pre-erythrocytic stage of a Plasmodium parasite infection, e.g., P. falciparum infection, thereby reducing infection by mosquito transmitted malaria.
  • An antibody may provide protection from challenge in a malaria challenge mouse model (e.g., in which mice are infected with recombinant Plasmodium berghei expressing Plasmodium falciparum CPS) and the equivalent human challenge model.
  • a malaria challenge mouse model e.g., in which mice are infected with recombinant Plasmodium berghei expressing Plasmodium falciparum CPS
  • An illustrative protocol for such a mouse model is set out in Example 4. Protection from challenge may be quantified as % reduction in liver-stage parasite load determined by the number of P. berghei 18s RNA copies detected in mouse liver homogenates in such a model where the murine P.
  • Protection from challenge may be at least 50 %, at least 60 %, at least 70 %, at least 80 %, at least 90 %, at least 95 %, at least 98 % or at least 99 %.
  • Full protection from challenge may be obtained, i.e., liver-stage parasite load may be eliminated or entirely prevented through treatment.
  • Examples 4 and 8 herein describe in detail two different in vivo mouse challenge models that were used to assess the ability of passively-transferred anti-CSP mAbs to protect mice from sporozoite challenge: a transgenic (Pb-Pf CSP) sporozoite challenge and a human liver (Hu-Hep) mouse challenge model.
  • a transgenic (Pb-Pf CSP) sporozoite challenge and a human liver (Hu-Hep) mouse challenge model.
  • Protocols for challenge models are also described in:
  • Plasmodium falciparum circumsporozoite protein administered with long- chain poly(l « C) or the Toll-like receptor 4 agonist glucopyranosyl lipid adjuvant-stable emulsion elicits potent antibody and CD4+ T cell immunity and protection in mice.
  • Circumsporozoite Protein as a Model for Vaccine Down-Selection in Mice Using Sterile Protection as an Endpoint. Porter et al., Clin Vaccine Immunol. 20(6):803-810 2013.
  • Antibodies according to the present invention bind CSP.
  • exemplary antibodies were raised in KymiceTM immunised with CSP from P. falciparum.
  • the nucleotide and amino acid sequences of CSP are shown in Figures 6 and 7.
  • An antibody may bind the four amino acid repeat region (NANP) of CSP. It may bind one or more residues encoded by nucleotides 368 to 862 as shown in Figure 6.
  • the NANP region is the region of the CSP polypeptide that is characterised by multiple tandem repeats of the amino acid sequence NANP (SEQ ID NO: 47) i.e., Asn - Ala - Asn - Pro.
  • the NANP repeat region starts with a sequence NANPNVDPNANP, which may provide at least part of the epitope for antibodies according to the invention.
  • an antibody may bind one or more residues of this sequence.
  • An antibody may for example bind the initial (N-terminal) NANP motif of this sequence, i.e., it may bind one or more residues of the NANP motif.
  • An antibody according to the present invention may bind the second and or third amino acid residue within a "NANP" motif, i.e., it may bind the Ala or the second Asn residue, as may be determined for example by measuring binding to a peptide comprising the NANP motif and a loss of binding or reduction in binding to a corresponding peptide in which the NANP motif is mutated at the second or third amino acid residue.
  • Peptide mapping methods are described below and in Example 10. Points of contact between antibody and antigen may be determined in other ways, such as by x-ray crystallography.
  • antibodies may bind CSP within a region of up to 12 amino acids preceding the NANP repeat region, in the sequence KLKQPGDGNPDP.
  • antibodies may bind the NPDP motif within this sequence.
  • An antibody may bind to CSP at one or more residues of the sequence NPDPNANP, which is the sequence comprising the first NANP motif and the residues that immediately precede it.
  • the antibody may bind the NPDP motif immediately preceding the NANP repeat region, and/or may bind the first NANP motif of the NANP repeat region.
  • antibodies may bind CSP within a region of up to 15 amino acids preceding the NANP repeat region, in the sequence KHKKLKQPGDGNPDP.
  • An antibody may bind one or more residues within the sequence KHKKLKQPG.
  • An antibody may bind a polypeptide or peptide comprising or consisting of a NANP repeat region (NANP)n where n is 1 to 40, e.g., 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30 or 40, e.g., (NANP)4.
  • NANP NANP repeat region
  • Any suitable method may be used to determine whether an antibody binds to an antigen such as CSP, a fragment thereof (e.g., the NANP region or a fragment comprising the NANP region or a sequence or motif mentioned above), or a polypeptide or peptide comprising a NANP repeat region.
  • a method may comprise surface plasmon resonance (SPR), bio-layer interferometry, or an ELISA to determine specificity of antibodies.
  • An antibody may be said to bind its antigen if the level of binding to antigen is at least 2.5 fold greater, e.g., at least 10 fold greater, than binding to a control antigen. Binding between an antibody and its cognate antigen is often referred to as specific binding.
  • Precise identification of the residues bound by an antibody can usually be obtained using x-ray crystallography. This technique may be used to determine that an antibody of the invention binds one or more residues of the NANP repeat region of CSP and/or other sequences as mentioned above.
  • the antibody epitope may comprise or consist of residues within the NANP repeat region.
  • Antibody binding epitopes can be mapped using one or more of the following methods:
  • ELISA binding of antibodies to linear peptides synthesised chemically can be used for linear epitope identification, with fine mapping achieved through the use of overlapping peptides where each peptide is offset by a minimum of one amino acid.
  • Single alanine substitutions of the binding peptide can be used to fine map internal amino acid contributions to the minimal binding peptide.
  • Full length CSP can be used together with progressive deletions from the N or C— terminus or expression of CSP sub-domains to identify antibody binding epitopes.
  • Site directed mutagenesis of full length CSP, N or C terminal deletions or sub- domains can be used to identify the precise epitope in the native protein.
  • Co-crystallisation, scanning and/or cryoEM can be used to give structural information of antibody bound to CSP including the precise atomic resolution of antibody and CSP binding using either CSP or linear peptides.
  • Biolayer interferometry can be used to analyse binding of antibodies to CSP peptides. Illustrative methods using biolayer interferometry, including fine mapping using single residue substitutions in peptide fragments, are presented in Example 10.
  • Binding to CSP or peptides or residues thereof may be determined with respect to the CSP amino acid sequence shown in Figure 6 or Figure 7 or a fragment thereof. Variant CSP sequences are known, including naturally occurring variants. Figure 23 shows an alternative CSP sequence.
  • An antibody of the present invention may bind CSP having an amino acid sequence shown in Figure 6 or Figure 7. The antibody may additionally bind CSP having an amino acid sequence shown in Figure 22.
  • the invention provides antibodies that compete with antibody 666, 667, 668 or 669 for binding to CSP or a fragment thereof.
  • An antibody may compete with a human lgG1 or with an scFv antibody comprising the VH and VL domain of an antibody selected from 666, 667, 668 or 669, or a human lgG1 or with an scFv antibody comprising the heavy and light chain CDRs of antibody 666, 667, 668 or 669.
  • Competition between antibodies may be assayed in vitro, for example using ELISA and/or by tagging a specific reporter molecule to one antibody, which can be detected in the presence of one or more other untagged antibodies, to enable identification of antibodies that bind the same epitope or an
  • full length CSP In assay methods and methods of administration described herein relating to the CSP antigen, it is optional to use full length CSP.
  • These CSP fragments or synthetic peptides may be provided as isolated sequences, contained within longer polypeptide sequences, and/or provided with one or more tags or detectable labels, as appropriate.
  • Kd ability of an antibody to bind its target antigen, and the specificity and affinity of that binding (Kd, Koff and/or Kon) can be determined by any routine method in the art, including SPR.
  • Kd is intended to refer to the equilibrium dissociation constant of a particular antibody-antigen interaction.
  • Affinity of antibody-antigen binding may be determined, e.g., by surface plasmon resonance. Affinity may also be determined by bio- layer interferometry. An example of affinity determination by bio-layer interferometry is provided in Example 3 herein.
  • An antibody may bind to CSP with an affinity (Kd) of 1 mM or less, usually 1 nM or less, e.g., 0.9 nM or less, 0.8 nM or less, 0.7 nM or less, 0.5 nM or less, or 0.4 nM or less.
  • Kd affinity
  • Determining affinity (Kd) by bio-layer interferometry may comprise:
  • immobilising antibody on biosensors e.g., at a concentration of 20 ⁇ g/mL
  • a first time period e.g. 60 seconds
  • CSP CSP
  • a baseline measurement may be established using dissociation buffer after loading the biosensors (e.g., for 30 seconds).
  • Parallel references may be set up by using unloaded bare sensor and sensor contacted with the dilution series of the antigen, and the parallel reference used for normalisation in data processing.
  • antigen is immobilised on the biosensors and contacted with a dilution series of the antibody (e.g., starting at 33 nM or 133 nM, 1 :3 diluted down).
  • a dilution series of the antibody e.g., starting at 33 nM or 133 nM, 1 :3 diluted down.
  • suitable concentrations for the dilution series can be determined depending on the strength of the affinity being measured. Any suitable bio-layer interferometry machine may be used.
  • SPR is carried out at 25°C.
  • An alternative is 37°C.
  • SPR may be performed at physiological pH, such as about pH 7 or at pH 7.6 (e.g., using Hepes buffered saline at pH 7.6 (also referred to as HBS-EP)).
  • SPR may be carried out at a physiological salt level, eg, 150 mM NaCI.
  • SPR may be carried out at a detergent level of no greater than 0.05 % by volume, e.g., in the presence of P20 (polysorbate 20; eg, Tween-20®) at 0.05 % and EDTA at 3 mM.
  • the SPR is carried out at 25°C or 37°C in a buffer at pH 7.6, 150 mM NaCI, 0.05 % detergent (e.g., P20) and 3 mM EDTA.
  • the buffer can contain 10 mM Hepes.
  • the SPR is carried out at 25°C or 37°C in HBS-EP.
  • HBS-EP is available from Teknova Inc (California; catalogue number H8022).
  • the affinity of the antibody is determined using SPR by
  • GLM chip such as by primary amine coupling
  • SPR can be carried out using any standard SPR apparatus, such as by Biacore® using the ProteOn XPR36® (Bio-Rad®).
  • Regeneration of the capture surface can be carried out with 10 mM glycine at pH 1.7. This removes the captured antibody and allows the surface to be used for another interaction.
  • the binding data can be fitted to 1 : 1 model inherent using standard techniques, e.g., using a model inherent to the ProteOn XPR36® analysis software.
  • Antibodies according to the present invention are immunoglobulins or molecules comprising immunoglobulin domains, whether natural or partly or wholly synthetically produced.
  • Antibodies may be IgG, IgM, IgA, IgD or IgE molecules or antigen-specific antibody fragments thereof (including, but not limited to, a Fab, F(ab')2, Fv, disulphide linked Fv, scFv, single domain antibody, closed conformation multispecific antibody, disulphide- linked scfv, diabody), whether derived from any species that naturally produces an antibody, or created by recombinant DNA technology; whether isolated from serum, B-cells, hybridomas, transfectomas, yeast or bacteria.
  • Antibodies can be humanised using routine technology.
  • antibody covers any polypeptide or protein comprising an antibody antigen-binding site.
  • An antigen-binding site is the part of an antibody that binds to and is complementary to the epitope of its target antigen (NANP, eg, comprised by CSP).
  • NANP target antigen
  • epitopes refers to a region of an antigen that is bound by an antibody.
  • Epitopes may be defined as structural or functional. Functional epitopes are generally a subset of the structural epitopes and have those residues that directly contribute to the affinity of the interaction. Epitopes may also be conformational, that is, composed of nonlinear amino acids.
  • epitopes may include determinants that are chemically active surface groupings of molecules such as amino acids, sugar side chains, phosphoryl groups, or sulfonyl groups, and, in certain embodiments, may have specific three-dimensional structural characteristics, and/or specific charge characteristics.
  • the antigen binding site is a polypeptide or domain that comprises one or more
  • the polypeptide comprises a CDR3 (e.g., HCDR3).
  • the polypeptide comprises CDRs 1 and 2 (e.g., HCDR1 and 2) or CDRs 1-3 of a variable domain of an antibody (e.g., HCDRs1-3).
  • An antibody antigen-binding site may be provided by one or more antibody variable domains.
  • the antibody binding site is provided by a single variable domain, e.g., a heavy chain variable domain (VH domain) or a light chain variable domain (VL domain).
  • the binding site comprises a VH/VL pair or two or more of such pairs.
  • an antibody antigen-binding site may comprise a VH and a VL.
  • the antibody may be a whole immunoglobulin, including constant regions, or may be an antibody fragment.
  • An antibody fragment is a portion of an intact antibody, for example comprising the antigen binding and/or variable region of the intact antibody. Examples of antibody fragments include:
  • Fab fragment a monovalent fragment consisting of the VL, VH, CL and CH1 domains
  • CDR complementarity determining region
  • An antibody normally comprises an antibody VH and/or VL domain.
  • Isolated VH and VL domains of antibodies are also part of the invention.
  • the antibody variable domains are the portions of the light and heavy chains of antibodies that include amino acid sequences of complementarity determining regions (CDRs; ie., CDR1 , CDR2, and CDR3), and framework regions (FRs).
  • CDRs complementarity determining regions
  • FRs framework regions
  • a VH domain comprises a set of HCDRs
  • a VL domain comprises a set of LCDRs.
  • VH refers to the variable domain of the heavy chain.
  • VL refers to the variable domain of the light chain.
  • Each VH and VL is typically composed of three CDRs and four FRs, arranged from amino- terminus to carboxy-terminus in the following order: FR1 , CDR1 , FR2, CDR2, FR3, CDR3, FR4.
  • the amino acid positions assigned to CDRs and FRs may be defined according to Kabat (Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md., 1987 and 1991 )) or according to IMGT nomenclature.
  • An antibody may comprise an antibody VH domain comprising a VH CDR1 , CDR2 and CDR3 and a framework.
  • VL domain comprising a VL CDR1 , CDR2 and CDR3 and a framework.
  • antibody VH and VL domains and CDRs according to the present invention are as listed in the appended sequence listing that forms part of the present disclosure. All VH and VL sequences, CDR sequences, sets of CDRs and sets of HCDRs and sets of LCDRs disclosed herein represent aspects and embodiments of the invention.
  • a "set of CDRs" comprises CDR1 , CDR2 and CDR3.
  • a set of HCDRs refers to
  • HCDR1 , HCDR2 and HCDR3, and a set of LCDRs refers to LCDR1 , LCDR2 and LCDR3.
  • a "set of CDRs" includes HCDRs and LCDRs.
  • An antibody the invention may comprise one or more CDRs as described herein, e.g. a CDR3, and optionally also a CDR1 and CDR2 to form a set of CDRs.
  • the CDR or set of CDRs may be a CDR or set of CDRs of any of antibodies 666, 667 668 or 669, or may be a variant thereof as described herein.
  • the invention provides antibodies comprising an HCDR1 , HCDR2 and/or HCDR3 of any of antibodies 666, 667, 668 and 669 and/or an LCDR1 , LCDR2 and/or LCDR3 of any of these antibodies, e.g. a set of CDRs.
  • the antibody may comprise a set of VH CDRs of one of these antibodies.
  • it may also comprise a set of VL CDRs of one of these antibodies, and the VL CDRs may be from the same or a different antibody as the VH CDRs.
  • a VH domain comprising a disclosed set of HCDRs, and/or a VL domain comprising a disclosed set of LCDRs, are also provided by the invention.
  • a VH domain is paired with a VL domain to provide an antibody antigen- binding site, although as discussed further below a VH or VL domain alone may be used to bind antigen.
  • the antibody 667 VH domain may be paired with the antibody 667 VL domain, so that an antibody antigen-binding site is formed comprising both the antibody 667 VH and VL domains.
  • Analogous embodiments are provided for the other VH and VL domains disclosed herein.
  • the antibody 667 VH is paired with a VL domain other than the antibody 667 VL. Light-chain promiscuity is well established in the art. Again, analogous embodiments are provided by the invention for the other VH and VL domains disclosed herein.
  • VH of any of antibodies 666 to 669 may be paired with the VL of any of antibodies 666 to 669.
  • antibody 667 VH may be paired with antibody 668 VL
  • antibody 668 VH may be paired with antibody 667 VL.
  • An antibody VH domain may optionally be paired with a VH domain of another antibody in the same lineage.
  • the VH domain of antibody 666 may be paired with the VL domain of any of antibodies 666-1 , 666-2, 666-3 and 666-4
  • the VH domain of antibody 666-1 may be paired with the VL domain of any of antibodies 666, 666-2, 666-3 and antibody 666-4, and so on.
  • An antibody may comprise one or more CDRs, e.g. a set of CDRs, within an antibody framework.
  • the framework regions may be of human germline gene segment sequences.
  • the antibody may be a human antibody having a VH domain comprising a set of HCDRs in a human germline framework.
  • the antibody also has a VL domain comprising a set of LCDRs, e.g. in a human germline framework.
  • Figure 4 identifies human germline gene segment sequences that align to the variable domains of antibodies 666, 667, 668 and 669, indicating that these antibodies were derived from recombination of the identified gene segments.
  • Table 17 provides the corresponding information for the antibodies referenced in Table 16 and Example 11 and for the antibodies referenced in Table 18 and Example 13.
  • An antibody "gene segment”, e.g., a VH gene segment, D gene segment, or JH gene segment refers to oligonucleotide having a nucleic acid sequence from which that portion of an antibody is derived, e.g., a VH gene segment is an oligonucleotide comprising a nucleic acid sequence that corresponds to a polypeptide VH domain from FR1 to part of CDR3. Human V, D and J gene segments recombine to generate the VH domain, and human V and J segments recombine to generate the VL domain.
  • the D domain or region refers to the diversity domain or region of an antibody chain.
  • J domain or region refers to the joining domain or region of an antibody chain.
  • Somatic hypermutation may result in an antibody VH or VL domain having framework regions that do not exactly match or align with the corresponding gene segments, but sequence alignment can be used to identify the closest gene segments and thus identify from which particular combination of gene segments a particular VH or VL domain is derived.
  • the antibody amino acid sequence may be aligned with the amino acid sequence encoded by the gene segment, or the antibody nucleotide sequence may be aligned directly with the nucleotide sequence of the gene segment.
  • An antibody of the invention may comprise an antibody VH domain derived from recombination of a human heavy chain V gene segment, a human heavy chain D gene segment and a human heavy chain J gene segment, wherein
  • V segment is IGHV1-3;
  • the D gene segment is IGHD3-10, IGHD3-9, IGHD4-1 1 or IGHD2-2; and/or the J gene segment is IGHJ6.
  • IGHV1-3 is a particularly preferred V gene segment in antibodies and VH domains of the present invention.
  • the selection of IGHV1-3 for recombination to generate antibody VH domains is believed to represent a particularly effective "choice" when the human immune repertoire is challenged with CSP antigen, as shown in the present Examples.
  • Populations of transgenic mice immunised with CSP may generate anti-NANP repeat antibodies utilising the IGHV1-3 gene segment, these antibodies being effective for neutralising CSP.
  • the antibody of the invention comprises an antibody VH domain derived from recombination of a human heavy chain V gene segment, a human heavy chain D gene segment and a human heavy chain J gene segment, wherein the V segment is IGHV1-3 and the antibody neutralises NANP (e.g., neutralises CSP comprising (NANP) 4 ).
  • NANP neutralises CSP comprising (NANP) 4
  • neutralisation is with an IC 50 of 500M or less.
  • An antibody of the invention may comprise an antibody VL domain derived from recombination of a human light chain V gene segment and a human light chain J gene segment, wherein
  • V segment is IGLV2-23, and/or
  • the J gene segment is IGLJ3.
  • An antibody of the invention may be a human antibody or a chimaeric antibody comprising human variable regions and non-human (e.g., mouse) constant regions.
  • the antibody of the invention for example has human variable regions, and optionally also has human constant regions.
  • antibodies optionally include constant regions or parts thereof, e.g., human antibody constant regions or parts thereof.
  • a VL domain may be attached at its C-terminal end to antibody light chain kappa or lambda constant domains.
  • an antibody VH domain may be attached at its C-terminal end to all or part (e.g. a CH1 domain or Fc region) of an immunoglobulin heavy chain constant region derived from any antibody isotype, e.g. IgG, IgA, IgE and IgM and any of the isotype sub-classes, such as lgG1 or lgG4.
  • Antibody constant regions may be engineered to have an extended half life in vivo.
  • YTE YTE
  • the triple mutation YTE is a substitution of 3 amino acids in the IgG CH2 domain, these mutations providing tyrosine at residue 252, threonine at residue 254 and glutamic acid at residue 256, numbered according to the EU index of Kabat.
  • the YTE modification increases the half-life of the antibody compared with the half-life of a corresponding antibody having a human CH2 wild type domain.
  • antibodies of the present invention may include antibody constant regions (e.g., IgG constant regions, e.g., IgG CH2 domains) that have one or more mutations that increase the half life of the antibody compared with the corresponding wild type human constant region (e.g., IgG, e.g., IgG CH2 domain).
  • Half-life may be determined by standard methods, such as are described in WO02/060919.
  • Constant regions of antibodies of the invention may alternatively be non-human constant regions.
  • chimaeric antibodies may be produced comprising human variable regions and non-human (host animal) constant regions.
  • Some transgenic animals generate fully human antibodies.
  • Others have been engineered to generate antibodies comprising chimaeric heavy chains and fully human light chains.
  • these may be replaced with human constant regions to provide antibodies more suitable for administration to humans as therapeutic compositions, as their immunogenicity is thereby reduced.
  • Antibodies may be generated using transgenic mice (eg, the KymouseTM, Velocimouse® , Omnimouse® , Xenomouse®, HuMab Mouse® or MeMo Mouse®), rats (e.g., the Omnirat®), camelids, sharks, rabbits, chickens or other non-human animals immunised with CSP or a fragment thereof or a synthetic peptide comprising NANP tandem repeats (as described elsewhere herein), followed optionally by humanisation of the constant regions and/or variable regions to produce human or humanised antibodies.
  • transgenic mice eg, the KymouseTM, Velocimouse® , Omnimouse® , Xenomouse®, HuMab Mouse® or MeMo Mouse®
  • rats e.g., the Omnirat®
  • display technologies can be used, such as yeast, phage or ribosome display, as will be apparent to the skilled person.
  • Standard affinity maturation e.g., using a display technology, can be performed in a further step after isolation of an antibody lead from a transgenic animal, phage display library or other library.
  • suitable technologies are described in US20120093818 (Amgen, Inc), which is incorporated by reference herein in its entirety, eg, the methods set out in paragraphs [0309] to [0346].
  • a KymouseTM, VELOC IMMUNE® or other mouse or rat can be challenged with the antigen of interest, and lymphatic cells (such as B-cells) are recovered from the mice that express antibodies.
  • lymphatic cells such as B-cells
  • the lymphatic cells may be fused with a myeloma cell line to prepare immortal hybridoma cell lines, and such hybridoma cell lines are screened and selected to identify hybridoma cell lines that produce antibodies specific to the antigen of interest.
  • DNA encoding the variable regions of the heavy chain and light chain may be isolated and linked to desirable isotypic constant regions of the heavy chain and light chain.
  • Such an antibody protein may be produced in a cell, such as a CHO cell.
  • DNA encoding the antigen-specific chimaeric antibodies or the variable domains of the light and heavy chains may be isolated directly from antigen-specific lymphocytes.
  • high affinity chimaeric antibodies are isolated having a human variable region and a mouse constant region.
  • the antibodies are characterised and selected for desirable characteristics, including affinity, selectivity, epitope, etc.
  • the mouse constant regions are optionally replaced with a desired human constant region to generate the fully human antibody of the invention, for example wild-type or modified lgG1 or lgG4 (for example, SEQ ID NO: 751 , 752, 753 in US2011/0065902 (which is incorporated by reference herein in its entirety). While the constant region selected may vary according to specific use, high affinity antigen-binding and target specificity characteristics reside in the variable region.
  • VH and VL domains or CDRs whose sequences are specifically disclosed herein may be employed in accordance with the present invention, as discussed.
  • An antibody may comprise a set of H and/or L CDRs of any of the disclosed antibodies with one or more amino acid mutations within the disclosed set of H and/or L CDRs.
  • the mutation may be an amino acid substitution, deletion or insertion.
  • An antibody may comprise a VH domain that has at least 60, 70, 80, 85, 90, 95, 98 or 99 % amino acid sequence identity with a VH domain of any of the antibodies shown in the appended sequence listing, and/or comprising a VL domain that has at least 60, 70, 80, 85, 90, 95, 98 or 99 % amino acid sequence identity with a VL domain of any of those antibodies.
  • Algorithms that can be used to calculate % identity of two amino acid sequences include e.g. BLAST, FASTA, or the Smith- Waterman algorithm, e.g. employing default parameters.
  • Particular variants may include one or more amino acid sequence alterations (addition, deletion, substitution and/or insertion of an amino acid residue) .
  • Alterations may be made in one or more framework regions and/or one or more CDRs. Variants are optionally provided by CDR mutagenesis.
  • the alterations normally do not result in loss of function, so an antibody comprising a thus-altered amino acid sequence may retain an ability to bind CSP. It may retain the same quantitative binding ability as an antibody in which the alteration is not made, e.g. as measured in an assay described herein.
  • the antibody comprising a thus-altered amino acid sequence may have an improved ability to bind CSP.
  • Alteration may comprise replacing one or more amino acid residue with a non- naturally occurring or non-standard amino acid, modifying one or more amino acid residue into a non-naturally occurring or non-standard form, or inserting one or more non- naturally occurring or non-standard amino acid into the sequence. Examples of numbers and locations of alterations in sequences of the invention are described elsewhere herein.
  • Naturally occurring amino acids include the 20 "standard" L-amino acids identified as G, A, V, L, I, M, P, F, W, S, T, N, Q, Y, C, K, R, H, D, E by their standard single-letter codes.
  • Nonstandard amino acids include any other residue that may be incorporated into a polypeptide backbone or result from modification of an existing amino acid residue.
  • Non-standard amino acids may be naturally occurring or non-naturally occurring.
  • variant refers to a peptide or nucleic acid that differs from a parent polypeptide or nucleic acid by one or more amino acid or nucleic acid deletions, substitutions or additions, yet retains one or more specific functions or biological activities of the parent molecule.
  • Amino acid substitutions include alterations in which an amino acid is replaced with a different naturally-occurring amino acid residue. Such substitutions may be classified as “conservative", in which case an amino acid residue contained in a polypeptide is replaced with another naturally occurring amino acid of similar character either in relation to polarity, side chain functionality or size. Such conservative substitutions are well known in the art.
  • substitutions encompassed by the present invention may also be "non- conservative", in which an amino acid residue which is present in a peptide is substituted with an amino acid having different properties, such as naturally-occurring amino acid from a different group (e.g., substituting a charged or hydrophobic amino; acid with alanine), or alternatively, in which a naturally-occurring amino acid is substituted with a non- conventional amino acid.
  • amino acid substitutions are conservative.
  • variants when used with reference to a polynucleotide or polypeptide, refers to a polynucleotide or polypeptide that can vary in primary, secondary, or tertiary structure, as compared to a reference polynucleotide or polypeptide, respectively (e.g., as compared to a wild- type polynucleotide or polypeptide).
  • synthetic variants can be used as synthetic variants
  • recombinant variants or “chemically modified” polynucleotide variants or polypeptide variants isolated or generated using methods well known in the art.
  • Modified variants can include conservative or non- conservative amino acid changes, as described below.
  • Polynucleotide changes can result in amino acid substitutions, additions, deletions, fusions and truncations in the polypeptide encoded by the reference sequence.
  • Some aspects use include insertion variants, deletion variants or substituted variants with substitutions of amino acids, including insertions and substitutions of amino acids and other molecules) that do not normally occur in the peptide sequence that is the basis of the variant, for example but not limited to insertion of ornithine which do not normally occur in human proteins.
  • the term "conservative substitution,” when describing a polypeptide, refers to a change in the amino acid composition of the polypeptide that does not substantially alter the polypeptide's activity.
  • a conservative substitution refers to substituting an amino acid residue for a different amino acid residue that has similar chemical properties (e.g., acidic, basic, positively or negatively charged, polar or nonpolar, etc.).
  • Conservative amino acid substitutions include replacement of a leucine with an isoleucine or valine, an aspartate with a glutamate, or a threonine with a serine.
  • Conservative substitution tables providing functionally similar amino acids are well known in the art.
  • the following six groups each contain amino acids that are conservative substitutions for one another: 1) Alanine (A), Serine (S), Threonine (T); 2) Aspartic acid (D), Glutamic acid (E); 3) Asparagine (N), Glutamine (Q); 4) Arginine (R), Lysine (K); 5) Isoleucine (I), Leucine (L), Methionine (M), Valine (V); and 6) Phenylalanine (F), Tyrosine (Y), Tryptophan (W). (See also Creighton, Proteins, W. H.
  • substitutions suitable for amino acids on the exterior of a protein or peptide for example, but not limited to, the following substitutions can be used: substitution of Y with F, T with S or K, P with A, E with D or Q, N with D or G, R with K, G with N or A, T with S or K, D with N or E, I with L or V, F with Y, S with T or A, R with K, G with N or A, K with R, A with S, K or P.
  • substitutions encompassed suitable for amino acids on the interior of a protein or peptide for example one can use suitable conservative substitutions for amino acids is on the interior of a protein or peptide (i.e. the amino acids are not exposed to a solvent), for example but not limited to, one can use the following conservative substitutions: where Y is substituted with F, T with A or S, I with L or V, W with Y, M with L, N with D, G with A, T with A or S, D with N, I with L or V, F with Y or L, S with A or T and A with S, G, T or V.
  • non-conservative amino acid substitutions are also encompassed within the term of variants.
  • the invention includes methods of producing antibodies containing VH and/or VL domain variants of the antibody VH and/or VL domains shown in the appended sequence listing.
  • Such antibodies may be produced by a method comprising
  • parent antibody VH domain is the VH domain of any of antibodies 666
  • VH domain comprising the heavy chain complementarity determining regions of any of those antibodies
  • Desired characteristics include binding to CSP, for example binding to the four amino acid repeat region NANP of the circumsporozoite protein (CSP) of Plasmodium parasites such as Plasmodium falciparum and optionally other malarial Plasmodium species as mentioned herein. Antibodies with comparable or higher affinity for binding CSP may be identified. Other desired characteristics include inhibiting the pre-erythrocytic stage of infection by Plasmodium, e.g, P. falciparum, which may be determined in an assay as described herein.
  • CSP circumsporozoite protein
  • the VL domain may be a VL domain of any of antibodies 666, 667, 668 or 669, or may be a variant provided by way of addition, deletion, substitution or insertion of one or more amino acids in the amino acid sequence of a parent VL domain, wherein the parent VL domain is the VL domain of any of antibodies 666, 667, 668 and 669 or a VL domain comprising the light chain complementarity determining regions of any of those antibodies.
  • an amino acid mutation may be introduced in an antibody variable domain at a position corresponding to a point of sequence variation across multiple antibodies in an antibody lineage.
  • an amino acid in a variable domain (VH or VL domain) of an antibody in a lineage e.g., 666 lineage, 667 lineage, 668 lineage or 669 lineage
  • the antibody 666 VH domain comprises a C terminal sequence VTS
  • certain other antibodies of the same lineage (666 lineage) comprise C terminal sequence VSS.
  • the 666 VH domain may be engineered to have the substitution T>S in this C terminal motif.
  • Comparison of antibody variable domain sequences with human germline gene segment sequences can also identify amino acid residues (e.g., within framework regions) that differ from the germline sequence and may optionally be reverted. Such "germlining" methods are known in the art and comparison with germline gene segment sequences is discussed elsewhere herein.
  • Methods of generating variant antibodies may optionally comprise producing copies of the antibody or VH/VL domain combination. Methods may further comprise expressing the resultant antibody. It is possible to produce nucleotide sequences corresponding to a desired antibody VH and/or VL domain, optionally in one or more expression vectors. Suitable methods of expression, including recombinant expression in host cells, are set out in detail herein.
  • nucleic acids and methods of expression Isolated nucleic acid may be provided, encoding antibodies according to the present invention.
  • Nucleic acid may be DNA and/or RNA. Genomic DNA, cDNA, mRNA or other RNA, of synthetic origin, or any combination thereof can encode an antibody.
  • the present invention provides constructs in the form of plasmids, vectors, transcription or expression cassettes which comprise at least one polynucleotide as above.
  • nucleotide sequences are included in the sequence listing.
  • Reference to a nucleotide sequence as set out herein encompasses a DNA molecule with the specified sequence, and encompasses a RNA molecule with the specified sequence in which U is substituted for T, unless context requires otherwise.
  • the present invention also provides a recombinant host cell that comprises one or more nucleic acids encoding the antibody.
  • Methods of producing the encoded antibody may comprise expression from the nucleic acid, e.g., by culturing recombinant host cells containing the nucleic acid.
  • the antibody may thus be obtained, and may be isolated and/or purified using any suitable technique, then used as appropriate.
  • a method of production may comprise formulating the product into a composition including at least one additional component, such as a pharmaceutically acceptable excipient.
  • Suitable host cells include bacteria, mammalian cells, plant cells,
  • filamentous fungi filamentous fungi, yeast and baculovirus systems and transgenic plants and animals.
  • Vectors may contain appropriate regulatory sequences, including promoter sequences, terminator sequences, polyadenylation sequences, enhancer sequences, marker genes and other sequences as appropriate.
  • Nucleic acid encoding an antibody can be introduced into a host cell.
  • Nucleic acid can be introduced to eukaryotic cells by various methods, including calcium phosphate transfection, DEAE-Dextran, electroporation, liposome-mediated transfection and transduction using retrovirus or other virus, e.g. vaccinia or, for insect cells, baculovirus.
  • Introducing nucleic acid in the host cell, in particular a eukaryotic cell may use a viral or a plasmid based system.
  • the plasmid system may be maintained episomally or may be incorporated into the host cell or into an artificial chromosome. Incorporation may be either by random or targeted integration of one or more copies at single or multiple loci.
  • suitable techniques include calcium chloride transformation, electroporation and transfection using bacteriophage.
  • the introduction may be followed by expressing the nucleic acid, e.g., by culturing host cells under conditions for expression of the gene, then optionally isolating or purifying the antibody.
  • Nucleic acid of the invention may be integrated into the genome (e.g. chromosome) of the host cell. Integration may be promoted by inclusion of sequences that promote recombination with the genome, in accordance with standard techniques.
  • the present invention also provides a method that comprises using nucleic acid described herein in an expression system in order to express an antibody.
  • antibodies can be produced on a large scale, for instance in cell culture volumes of at least 100 litres or at least 200 litres, e.g., between 100-250 litres.
  • Batch culture, particularly fed-batch culture is now commonly used for production of biotherapeutics for clinical and commercial use, and such methods may suitably be used in the present invention to generate the antibodies, followed by purification and formulation steps as noted herein.
  • Bioreactors may be metal (e.g., stainless steel) vessels or may be single-use bioreactors.
  • Antibodies may be monoclonal or polyclonal, but are preferably provided as monoclonal antibodies for therapeutic use. They may be provided as part of a mixture of other antibodies, optionally including antibodies of different binding specificity, such as one or more antibodies that bind to different antigens of a Plasmodium parasite, e.g., P.
  • Antibodies according to the invention, and encoding nucleic acid will usually be provided in isolated form.
  • the antibodies, VH and/or VL domains, and nucleic acids may be provided purified from their natural environment or their production environment.
  • Isolated antibodies and isolated nucleic acid will be free or substantially free of material with which they are naturally associated, such as other polypeptides or nucleic acids with which they are found in vivo, or the environment in which they are prepared (e.g. cell culture) when such preparation is by recombinant DNA technology in vitro.
  • an isolated antibody or nucleic acid (1) is free of at least some other proteins with which it would normally be found, (2) is essentially free of other proteins from the same source, e.g., from the same species, (3) is expressed by a cell from a different species, (4) has been separated from at least about 50 percent of polynucleotides, lipids, carbohydrates, or other materials with which it is associated in nature, (5) is operably associated (by covalent or noncovalent interaction) with a polypeptide with which it is not associated in nature, or (6) does not occur in nature.
  • Antibodies or nucleic acids may be formulated with diluents or adjuvants and still for practical purposes be isolated - for example they may be mixed with carriers if used to coat microtitre plates for use in immunoassays, and may be mixed with pharmaceutically acceptable carriers or diluents when used in therapy. As described elsewhere herein, other active ingredients may also be included in therapeutic preparations.
  • Antibodies may be glycosylated, either naturally in vivo or by systems of heterologous eukaryotic cells such as CHO cells, or they may be (for example if produced by expression in a prokaryotic cell) unglycosylated.
  • the invention encompasses antibodies having a modified glycosylation pattern.
  • modification to remove undesirable glycosylation sites may be useful, or e.g., removal of a fucose moiety to increase antibody dependent cellular cytotoxicity (ADCC) function (see Shields et al. (2002) JBC 277:26733).
  • ADCC antibody dependent cellular cytotoxicity
  • an isolated product constitutes at least about 5%, at least about 10%, at least about 25%, or at least about 50% of a given sample.
  • An antibody may be substantially free from proteins or polypeptides or other contaminants that are found in its natural or production environment that would interfere with its therapeutic, diagnostic, prophylactic, research or other use.
  • An antibody may have been identified, separated and/or recovered from a component of its production environment (eg, naturally or recombinantly).
  • the isolated antibody may be free of association with all other components from its production environment, eg, so that the antibody has been isolated to an FDA-approvable or approved standard.
  • Contaminant components of its production environment such as that resulting from recombinant transfected cells, are materials that would typically interfere with research, diagnostic or therapeutic uses for the antibody, and may include enzymes, hormones, and other proteinaceous or non-proteinaceous solutes.
  • the antibody will be purified: (1) to greater than 95% by weight of antibody as determined by, for example, the Lowry method, and in some embodiments, to greater than 99% by weight; (2) to a degree sufficient to obtain at least 15 residues of N-terminal or internal amino acid sequence by use of a spinning cup sequenator, or (3) to homogeneity by SDS-PAGE under non-reducing or reducing conditions using Coomassie blue or silver stain.
  • Isolated antibody includes the antibody in situ within recombinant cells since at least one component of the antibody's natural environment will not be present. Ordinarily, however, an isolated antibody or its encoding nucleic acid will be prepared by at least one purification step.
  • the invention provides therapeutic compositions comprising the antibodies described herein.
  • Therapeutic compositions comprising nucleic acid encoding such antibodies are also provided.
  • Encoding nucleic acids are described in more detail elsewhere herein and include DNA and RNA, e.g., mRNA.
  • Nucleic acid encoding the antibody of the invention may be provided as naked DNA, mRNA, replicon RNA or in a viral vector (e.g., adenoviral vector or lentiviral vector, or retroviral vector or poxvirus vector or herpesvirus vector) for administration in a therapeutic method that allows direct expression of the antibody.
  • a viral vector e.g., adenoviral vector or lentiviral vector, or retroviral vector or poxvirus vector or herpesvirus vector
  • nucleic acid will then be expressed in vivo by the recipient eukaryotic cells, providing an in vivo source of the therapeutic antibody, suitable for provision of long term protection against the malarial parasite.
  • a nucleic acid composition (optionally naked DNA, mRNA, replicon RNA) may be administered by intramuscular injection, or via a 'gene gun'.
  • viral delivery a range of viral vectors are known in the art (including gene therapy vectors) and any suitable vector may be used for transient expression, episomal expression (persistent but not integrated into the host genome) or integration of the encoding nucleic acid into cells of the recipient (e.g., liver cells and/or cells of the haematopoietic system).
  • compositions may contain suitable carriers, excipients, and other agents that are incorporated into formulations to provide improved transfer, delivery, tolerance, and the like.
  • suitable carriers excipients, and other agents that are incorporated into formulations to provide improved transfer, delivery, tolerance, and the like.
  • a multitude of appropriate formulations can be found in the formulary known to all pharmaceutical chemists: Remington's Pharmaceutical Sciences, Mack Publishing
  • formulations include, for example, powders, pastes, ointments, jellies, waxes, oils, lipids, lipid (cationic or anionic) containing vesicles (such as
  • compositions may comprise the antibody or nucleic acid in combination with medical injection buffer and/or with adjuvant.
  • a composition may comprise the antibody in an aqueous buffered solution at a pH of between 6 and 8, e.g., 6.0 to 6.6, 6.4 to 7.1 , 6.9 to 7.6 or 7.4 to 8.0.
  • Such compositions can be included in medical containers and/or in kits.
  • Antibodies, or their encoding nucleic acids may be formulated for the desired route of administration to a patient, e.g., in liquid (optionally aqueous solution) for injection.
  • compositions of the invention include, but are not limited to, intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous, intranasal, epidural, and oral routes.
  • the composition may be administered by any convenient route, for example by infusion or bolus injection, by absorption through epithelial or mucocutaneous linings (e.g., oral mucosa, rectal and intestinal mucosa, etc.) and may be administered together with other biologically active agents. Administration can be systemic or local.
  • the pharmaceutical composition can be also delivered in a vesicle, in particular a liposome (see Langer (1990) Science 249: 1527-1533 ; Treat et al. (1989) in Liposomes in the Therapy of Infectious Disease and Cancer, Lopez Berestein and Fidler (eds.), Liss, New York, pp. 353-365 ; Lopez-Berestein, ibid., pp. 317-327 ; see generally ibid.).
  • the pharmaceutical composition can be delivered in a controlled release system.
  • a pump may be used (see Langer, supra; Sefton (1987) CRC Crit. Ref. Biomed. Eng. 14:201 ).
  • polymeric materials can be used; see, Medical Applications of Controlled Release, Langer and Wise (eds.), CRC Pres., Boca Raton, Fla. (1974 ).
  • a controlled release system can be placed in proximity of the composition's target, thus requiring only a fraction of the systemic dose (see, e.g., Goodson, in Medical Applications of Controlled Release, supra, vol. 2, pp. 115-138, 1984 ).
  • the injectable preparations may include dosage forms for intravenous,
  • injectable preparations may be prepared by methods publicly known.
  • the injectable preparations may be prepared, e.g., by dissolving, suspending or emulsifying the antibody or its salt described above in a sterile aqueous medium or an oily medium conventionally used for injections.
  • aqueous medium for injections there are, for example, physiological saline, an isotonic solution containing glucose and other auxiliary agents, etc., which may be used in combination with an appropriate solubilizing agent such as an alcohol (e.g., ethanol), a polyalcohol (e.g., propylene glycol, polyethylene glycol), a nonionic surfactant [e.g., polysorbate 80, HCO-50 (polyoxyethylene (50 mol) adduct of hydrogenated castor oil)], etc.
  • an alcohol e.g., ethanol
  • a polyalcohol e.g., propylene glycol, polyethylene glycol
  • a nonionic surfactant e.g., polysorbate 80, HCO-50 (polyoxyethylene (50 mol) adduct of hydrogenated castor oil
  • a pharmaceutical composition of the present invention can be delivered subcutaneously or intravenously with a standard needle and syringe. It is envisaged that treatment will not be restricted to use in the clinic. Therefore, subcutaneous injection using a needle-free device is also advantageous.
  • a pen delivery device readily has applications in delivering a pharmaceutical composition of the present invention. Such a pen delivery device can be reusable or disposable.
  • a reusable pen delivery device generally utilizes a replaceable cartridge that contains a pharmaceutical composition. Once all of the pharmaceutical composition within the cartridge has been administered and the cartridge is empty, the empty cartridge can readily be discarded and replaced with a new cartridge that contains the pharmaceutical composition. The pen delivery device can then be reused. In a disposable pen delivery device, there is no replaceable cartridge. Rather, the disposable pen delivery device comes prefilled with the pharmaceutical composition held in a reservoir within the device. Once the reservoir is emptied of the pharmaceutical composition, the entire device is discarded. Numerous reusable pen and autoinjector delivery devices have applications in the subcutaneous delivery of a pharmaceutical composition of the present invention.
  • Examples include, but certainly are not limited to AUTOPENTM (Owen Mumford, Inc., Woodstock, UK), DISETRONICTM pen (Disetronic Medical Systems, Burghdorf, Switzerland), HUMALOG MIX 75/25TM pen, HUMALOGTM pen, HUMALIN 70/30TM pen (Eli Lilly and Co., Indianapolis, Ind.), NOVOPENTM!, II and III (Novo Nordisk, Copenhagen, Denmark), NOVOPEN JUNIORTM (Novo Nordisk, Copenhagen, Denmark), BDTM pen (Becton Dickinson, Franklin Lakes, N.J.), OPTIPENTTM, OPTIPEN PROTM, OPTIPEN STARLETTM, and OPTICLIKTTM (Sanofi- Aventis, Frankfurt, Germany), to name only a few.
  • Examples of disposable pen delivery devices having applications in subcutaneous delivery of a pharmaceutical composition of the present invention include, but certainly are not limited to the SOLOSTARTM pen (Sanofi- Aventis), the FLEXPENTM (Novo Nordisk), and the KWIKPENTM (Eli Lilly).
  • the pharmaceutical compositions for oral or parenteral use described above are prepared into dosage forms in a unit dose suited to fit a dose of the active ingredients.
  • dosage forms in a unit dose include, for example, tablets, pills, capsules, injections (ampoules), suppositories, etc.
  • the amount of the aforesaid antibody contained is generally about 5 to about 500 mg per dosage form in a unit dose; especially in the form of injection, the aforesaid antibody may be contained in about 5 to about 100 mg and in about 10 to about 250 mg for the other dosage forms.
  • the antibody, nucleic acid, or composition comprising it may be contained in a medical container such as a phial, syringe, IV container or an injection device.
  • the antibody, nucleic acid or composition is in vitro, and may be in a sterile container.
  • a kit is provided comprising the antibody, packaging and instructions for use in a therapeutic method as described herein.
  • the kit may comprise an insert (e.g., paper) and/or a label on a container containing the antibody or on the outer packaging of the kit, carrying the instructions for use in the therapeutic method, for example specifying use for prevention or treatment of malaria or of infection by Plasmodium such as P. falciparum.
  • the insert or label may bear a marketing authorisation number, e.g., an FDA or EMA authorisation number.
  • the antibody may be within a medical container comprising plastics material. Alternative medical grade materials include metal or glass.
  • the medical container e.g., phial, syringe, intravenous container or injection device
  • compositions comprising an antibody or nucleic acid of the invention and one or more pharmaceutically acceptable excipients, examples of which are listed above.
  • “Pharmaceutically acceptable” refers to approved or approvable by a regulatory agency of the USA Federal or a state government or listed in the U.S.
  • a pharmaceutically acceptable carrier, excipient, or adjuvant can be administered to a patient, together with an agent, e.g., any antibody or antibody chain described herein, and does not destroy the pharmacological activity thereof and is nontoxic when administered in doses sufficient to deliver a therapeutic amount of the agent.
  • compositions according to the present invention optionally include one or more additional active ingredients.
  • Further therapeutic agents may be anti-malarial agents such as other antibodies that bind antigens of P. falciparum or other malarial Plasmodium species.
  • such compositions contain multiple antibodies (or encoding nucleic acids) in a combined preparation, e.g., a single formulation comprising the anti-CSP antibody and one or more other antibodies to the same or different antigens of malarial Plasmodium species such as P. falciparum.
  • a composition may include an antibody to Pfs25, an antigen of P. falciparum.
  • antibodies to Plasmodium antigens are antibodies to MSP-1 , MSP-2, TRAP, CelTOS, AMA1 , Rh5 or LSA1 , e.g., from P. falciparum.
  • Other antimalarial agents include chemoprophylactic drugs such as mefloquinine, doxycycline, atovaquone, proguanil, quinine, artemether, lumefantrine, clindamycin, primaquine, artemisinin, sulphadoxine-pyrimethamine and chloroquine. Atovaquone and proguanil are usually administered in combination.
  • anti-malarial drug combinations include artemether with lumefantrine, quinine plus doxycycline, and quinine plus clindamycin.
  • Other therapeutic agents that it may be desirable to administer with antibodies or nucleic acids according to the present invention include antibiotics such as amikacin, and analgaesic agents. Any such agent or combination of agents may be administered in combination with, or provided in compositions with antibodies or nucleic acids according to the present invention, whether as a combined or separate preparation.
  • the antibody or nucleic acid according to the present invention may be administered separately and sequentially, or concurrently and optionally as a combined preparation, with another therapeutic agent or agents such as those mentioned.
  • compositions can be administered separately or simultaneously. Separate administration refers to the two compositions being administered at different times, e.g. at least 10, 20, 30, or 10-60 minutes apart, or 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 12 hours apart. One can also administer compositions at 24 hours apart, or even longer apart. Alternatively, two or more compositions can be administered simultaneously, e.g. less than 10 or less than 5 minutes apart. Compositions administered simultaneously can, in some aspects, be administered as a mixture, with or without similar or different time release mechanism for each of the components.
  • Antibodies, and their encoding nucleic acids can be used as anti-malarial agents. They may be used for passive immunisation of mammals. An antibody or nucleic acid may be administered to a mammal, e.g., by any route of administration mentioned herein.
  • Mammals may be humans, including humans at risk of malaria or humans diagnosed with malaria.
  • the human or other mammal to whom the composition is administered may be one who has been, or is suspected of having been, infected with a malarial Plasmodium parasite, and/or who exhibits one or more symptoms of malaria.
  • An antibody molecule of the present invention may be provided for use in a method of: treating or preventing malaria in a mammal;
  • the method comprises administering the antibody or composition to a mammal.
  • the invention also provides a method of:
  • the method comprising administering an antibody of the invention, or a composition comprising the antibody or its encoding nucleic acid, to the mammal
  • Administration is normally in a "therapeutically effective amount", this being an amount that produces the desired effect for which it is administered, sufficient to show benefit to a patient.
  • the exact amount will depend on the purpose of the treatment, and will be ascertainable by one skilled in the art using known techniques (see, for example, Lloyd (1999) The Art, Science and Technology of Pharmaceutical Compounding).
  • Benefit to the patient may be at least amelioration of at least one symptom of malaria, e.g., reduction in liver-stage parasite load, or protection against malaria or infection by malarial Plasmodium species such as P. falciparum.
  • Prescription of treatment e.g. decisions on dosage etc, is within the responsibility of general practitioners and other medical doctors and may depend on the severity of the symptoms and/or progression of a disease being treated.
  • therapeutically effective amount or suitable dose of antibody or nucleic acid can be determined by comparing its in vitro activity and in vivo activity in an animal model. Methods for extrapolation of effective dosages in mice and other test animals to humans are known.
  • one or more doses may be administered. In some cases, a single dose may be effective to achieve a long-term benefit.
  • the method may comprise administering a single dose of the antibody, its encoding nucleic acid, or the composition. Alternatively, multiple doses may be administered, usually sequentially and separated by a period of days, weeks or months.
  • the terms “treat,” “treatment,” “treating,” or “amelioration” refer to therapeutic treatments, wherein the object is to reverse, alleviate, ameliorate, inhibit, slow down or stop the progression or severity of a condition associated with a disease or disorder.
  • the term “treating” includes reducing or alleviating at least one adverse effect or symptom of a condition, disease or disorder.
  • Treatment is generally “effective” if one or more symptoms or clinical markers are reduced.
  • treatment is “effective” if the progression of a disease is reduced or halted. That is, “treatment” includes not just the improvement of symptoms or markers, but also a cessation of, or at least slowing of, progress or worsening of symptoms compared to what would be expected in the absence of treatment.
  • Beneficial or desired clinical results include, but are not limited to, alleviation of one or more symptom(s), diminishment of extent of disease, stabilised (i.e., not worsening) state of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, remission (whether partial or total), and/or decreased mortality, whether detectable or undetectable.
  • treatment also includes providing relief from the symptoms or side- effects of the disease (including palliative treatment). For treatment to be effective a complete cure is not contemplated. The method can in certain aspects include cure as well.
  • treatment may be preventative treatment, optionally the prevention or reduction of infection by Plasmodium such as P. falciparum, and/or the prevention of malaria, or reduction of at least one symptom of malaria. Diagnostics
  • a further aspect of the invention relates to diagnostic uses of the antibodies described herein.
  • the antibodies offer advantages for point of care diagnostics in mammals, and are especially envisaged for use in humans, where rapid diagnosis of malaria and/or Plasmodium infection is of significant clinical benefit.
  • An antibody according to the invention may be used to detect Plasmodium, e.g., Plasmodium falciparum.
  • an antibody may comprise or be conjugated to a detectable label, such as a radioisotope or a fluorescent label.
  • a detectable label such as a radioisotope or a fluorescent label.
  • An antibody according to the invention may be used for determining the presence or absence of CSP or Plasmodium in a sample.
  • a method of determining the presence or absence of CSP or Plasmodium in a sample may comprise contacting the sample with the antibody;
  • Detection of binding indicates the presence of CSP or Plasmodium in the sample, whereas absence of binding indicates the absence of CSP or Plasmodium in the sample.
  • Methods may further comprise quantifying the level of binding, for example by comparing the level of binding with a control.
  • Control assays may be run in parallel, or the level of binding may be compared with previously obtained control values.
  • Suitable controls include negative control samples in which no CSP or Plasmodium is present, thus establishing a level of background signal, which can be subtracted from the signal obtained from the test assay.
  • Positive controls may also be conducted, by contacting the antibody with a sample known to contain a pre-determined amount of CSP or Plasmodium.
  • Determining the level of binding in the test sample compared with the level of binding in one or more positive controls is one method of quantifying the amount of CSP or Plasmodium in the sample.
  • the sample may be one that has been obtained from a mammal who has been, or is suspected of having been, infected with a malarial Plasmodium parasite, and/or who exhibits one or more symptoms of malaria. It may be a blood sample, e.g., serum or whole blood. Peripheral blood samples are routinely obtainable from mammals, including human patients, in a clinical setting.
  • kits may comprise the antibody, or a composition as described herein, and optionally one or more buffering solutions.
  • the antibody may comprise or be conjugated to a detectable label.
  • Labelled antibodies allow for detection of the antibody, facilitating detection of binding of the antibody to its target.
  • an antibody may be used in combination with a secondary antibody or other labelled agent, the secondary antibody comprising or carrying a detectable label.
  • a kit may comprise a first reagent comprising an antibody according to the present invention, plus a second reagent comprising a detector molecule that binds to the first reagent.
  • the detector molecule may be an antibody that comprises or is conjugated to a detectable label.
  • mammals may be humans or other mammalian subjects such as wild animals, livestock or test (laboratory) animals.
  • the mammal may be one who has been, or is suspected of having been, infected with a malarial Plasmodium parasite, and/or who exhibits one or more symptoms of malaria.
  • Such mammals represent potential subjects for treatment with antibodies and compositions of the invention, and subjects from whom it may be of value to obtain samples for performing the diagnostic methods described herein.
  • a mammal may be a non-human mammal comprising a human immunoglobulin variable region that is capable of generating antibodies comprising human variable regions.
  • the KymouseTM is a transgenic mouse containing a humanised antibody heavy chain locus and a humanised antibody light chain locus. It is described in Lee et al., Nature Biotechnology 32(4): 356-367 2014 and in WO2011004192.
  • KymiceTM A number of different KymiceTM have been developed, including mice with humanised kappa light chain variable regions, humanised lambda light chain variable regions, and mice in which the heavy chain variable regions and both lambda and kappa light chain variable regions are fully humanised and comprise the full repertoire of human immunoglobulin gene segments, reflecting the full diversity of the human antibody repertoire.
  • mice such as Velocimouse® , Omnimouse® , Xenomouse®, HuMab Mouse® and MeMo Mouse®, and rats such as the Omnirat®.
  • these animals Owing to their ability to mirror aspects of the human antibody immune response, these animals - especially the KymouseTM - are of particular value in a pre-clinical setting for the development of vaccines and for testing compositions to determine efficacy of immunisation against infection by malarial Plasmodium parasites. They find use in many aspects of the invention, such as in testing anti-malarial vaccines as described in more detail elsewhere herein.
  • Plasmodium Plasmodium is a genus of parasitic protozoa. Infection with Plasmodium results in the disease malaria, which can be fatal.
  • the malarial Plasmodium parasite has two hosts in its life cycle - a Dipteran insect host and a vertebrate host. The life-cycle is complex, involving a sequence of different stages both in the vector and the vertebrate host.
  • sporozoites which are injected by the insect vector into the vertebrate host's blood; latent hypnozoites, which may rest undetected in the liver for up to 30 years; merosomes and merozoites, which infect the red cells (erythrocytes) of the blood; trophozoites, which grow in the red cells, and schizonts, which divide in red blood cells. Schizonts produce merozoites, which leave to infect more red cells.
  • the sexual forms, gametocytes are taken up by other insect hosts during feeding. Gametocytes develop into gametes in the insect midgut, and then fertilise each other to form motile zygotes, which escape the gut.
  • Plasmodium may be any Plasmodium species, such as P. falciparum, P. vivax, P. ovale, or P. malariae. It may be a naturally occuring Plasmodium species, or a laboratory-engineered Plasmodium such as P. berghei that has been engineered to express CSP from Plasmodium falciparum. Such engineered protozoa are useful in animal models, especially with mice as described herein.
  • Antibodies according to the present invention may target or bind Plasmodium sporozoites. Antibodies may inhibit or reduce the risk of Plasmodium infection, specifically the pre-erythrocytic or sporozoite stage of infection. This provides the advantage of targeting the Plasmodium at an early stage of entry to the vertebrate host body, offering the possibility of preventing infection from taking place. Where a body is already infected with Plasmodium, inhibition of sporozoites nevertheless has the advantage of reducing progression of
  • Plasmodium infection and of inhibiting sporozoites in the blood stream thereby lessening the risk of transmission of Plasmodium from that individual to another via insect feeding e.g., mosquito bite or via contact with infected blood.
  • Anti-Malarial Vaccines and Immunisation Efforts to produce effective vaccines against malarial Plasmodium parasites are ongoing. It is desirable to eradicate malaria, or at least to reduce its prevalence, and improving the efficacy of anti-malarial vaccines offers a route to achieving this goal.
  • Fragments of CSP or synthetic peptides comprising other epitopes identified herein, e.g., NPDPNANP may be used for such immunisations and also represent potential components for vaccine compositions.
  • a synthetic repeat peptide may be generated, comprising repeats of the motif NPDPNANP, optionally including one or more additional amino acids at one or both ends of the repeated motif.
  • a vaccine composition may optionally include part but not all of the NANP repeat region, e.g., may be a fragment or C-terminal truncated CSP, including the sequence NPDPNANP and optionally upstream sequence, but lacking a C-terminal and/or central portion of the NANP repeat region.
  • Such peptide vaccines could be coupled to carrier proteins or virus like nanoparticles to achieve a more optimal and long lived immune response.
  • compositions may further comprise one or more additional antigens or antigen fragments from one or more malarial Plasmodium parasites, optionally P. falciparum.
  • Efficacy may be measured in pre-clinical models, such as in mice, and in human clinical trials.
  • One way to measure the ability of a composition to confer protection against a malarial Plasmodium parasite is to administer the composition to a mammal and determine the efficacy of immunisation of that mammal resulting from the administration.
  • Measures of efficacy of immunisation include strength of immune response generated, e.g., antibody titre, and quality of antibodies generated, e.g., in terms of their binding specificity, neutralising ability, or sequence and/or epitope-binding diversity.
  • Efficacy of immunisation can also be determined by subsequently challenging the individual with a malarial Plasmodium parasite and observing the degree to which the individual develops, or is protected from, Plasmodium infection and/or symptoms of malaria. It is useful to measure efficacy of immunisation in populations of individuals, such as cohorts of mice, and to determine protection against challenge in terms of length of survival of the individuals following challenge. It will be appreciated that individuals, or populations of individuals, will usually be compared with control individuals or populations of individuals that receive the same challenge without having previously been immunised with the candidate composition. Control individuals may be placed in the same experimental conditions except that they do not receive the administration of candidate composition. They may for example receive a mock injection - injection of buffer/saline in place of an injection of the test composition. Efficacy of immunisation, and protection from challenge, are thus usually compared with control data.
  • Antibodies according to the present invention may be used to determine the efficacy of immunisation against a malarial Plasmodium parasite. They may be used as diagnostic reagents for determining the level of CSP or Plasmodium in a sample, this being indicative of the level of P. falciparum (or of other Plasmodium species that express CSP, such as P. berghei engineered to express P. falciparum CSP) in the sample, and thus the level of infection in the mammal from whom the sample is obtained, particularly the pre-erythrocytic or sporozoite stage of the parasite. Methods of detecting CSP or Plasmodium with antibodies are described in detail elsewhere herein.
  • a method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite may comprise:
  • CSP CSP
  • a fragment thereof comprising the NANP repeat region, or a synthetic NANP repeat peptide, and optionally one or more other antigens of the Plasmodium parasite to a mammal, allowing time for development of an immune response in the mammal;
  • a malarial Plasmodium parasite for example by exposing the mammal to biting by a mosquito infected with the parasite, and allowing time for development of an immune response in the mammal, to provide a challenged mammal; obtaining a sample from the challenged mammal;
  • the level of binding being negatively correlated with the efficacy of immunisation.
  • a method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite may comprise:
  • the level of binding being negatively correlated with the efficacy of immunisation.
  • binding may be quantified relative to binding in samples obtained from control individuals, or relative to positive and/or negative control samples.
  • the CSP (or fragment thereof, or NANP repeat peptide) or the Plasmodium may be administered by any method suitable to generate an immune response in the mammal. Common methods of delivering vaccines include by intramuscular, subcutaneous or intravenous injection, and any such method may be used here. Other possible methods of administration are described elsewhere herein, and may be applied to methods of administering the CSP (or fragment thereof, or NANP repeat peptide) or the Plasmodium.
  • Administering the candidate vaccine composition comprising the antigen or antigens may comprise injecting live or killed Plasmodium, or antigen or antigens purified from
  • the antigen or antigens may be administered in combination with an adjuvant.
  • mice are a suitable test animal for vaccine development.
  • the mammal in these methods may thus be a mouse.
  • a suitable Plasmodium parasite is P. berghei, which can be engineered to express P. falciparum CSP or a fragment thereof comprising the NANP repeat region, ensuring that the P. berghei is bound by antibodies according to the present invention.
  • transgenic mice containing a human antibody repertoire are employed, this provides a model of infection of humans by P. falciparum, the antibody response in the mice representing a model antibody response generated by the human immune system.
  • the KymouseTM is especially suitable for use in such models. It is possible to use other transgenic mice or other test animals engineered to express antibodies with human variable regions, and examples of these are mentioned elsewhere herein.
  • the generation of antibodies according to the present invention provides an indication that the mouse generates an effective immune response.
  • generation of antibodies according to the present invention is an indication that the human generates an effective immune response against P. falciparum.
  • Antibodies according to the invention may thus be used as a measure of vaccine efficacy in anti-malarial vaccine trials, whether pre-clinical (e.g., in transgenic animals expressing antibodies with human variable domains) or clinical (in humans).
  • a method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite may comprise:
  • CSP CSP
  • a fragment thereof comprising the NANP repeat region, or a NANP repeat peptide, and optionally one or more other antigens of the Plasmodium parasite to a mammal, allowing time for development of an immune response in the mammal, and obtaining a sample from the mammal;
  • a method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite may comprise:
  • a sample obtained from a mammal wherein the mammal has received an administration of CSP, a fragment thereof comprising the NANP repeat region, or a NANP repeat peptide, and optionally one or more other antigens of the Plasmodium parasite, and wherein the sample has been obtained after allowing time for development of an immune response;
  • fragments of CSP or synthetic peptides comprising epitopes identified herein, e.g., NPDPNANP may be administered.
  • a synthetic repeat peptide may be generated, comprising repeats of the motif NPDPNANP, optionally including one or more additional amino acids at one or both ends of the repeated motif.
  • a vaccine composition or a composition used for immunisation or administration to a mammal may optionally contain part but not all of the NANP repeat region, e.g., may be a fragment or C-terminal truncated CSP, including the sequence NPDPNANP and optionally upstream sequence, but lacking a C-terminal and/or central portion of the NANP repeat region.
  • Such vaccines could be coupled to carrier proteins or virus like nanoparticles to achieve a more optimal and long lived immune response.
  • further methods of the invention include methods of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite, comprising:
  • composition comprising CSP, or comprising a fragment of CSP or a synthetic peptide comprising NPDPNANP, to a mammal, allowing time for development of an immune response in the mammal, and obtaining a sample from the mammal;
  • Plasmodium parasite may comprise:
  • compositions may optionally further comprise one or more other antigens of the Plasmodium parasite.
  • Exemplary antibodies are antibodies comprising the antibody 667 or antibody 668 CDRs, and variants thereof, as described herein.
  • Methods of determining efficacy of immunisation may comprise assaying for the presence of, or determining enrichment of, antibody comprising the structural motif as defined herein.
  • the antibody may comprise a VH domain comprising HCDR1 , HCDR2 and HCDR3 in a framework, and a VL domain comprising LCDR1 , LCDR2 and LCDR3 in a framework, wherein LCDR1 , LCDR3, HCDR2 and HCDR3 are as follows:
  • LCDR1 contains an N and a hydrophobic residue.
  • the N is at position 31.
  • the N is either directly preceded or followed by the hydrophobic residue.
  • the hydrophobic residue is preferably Y.
  • LCDR3 contains a Y residue and a W residue.
  • the Y precedes W (in the N to C direction).
  • Y is at position 91.
  • W is at position 96.
  • HCDR2 contains W and N.
  • the W precedes N (in the N to C direction).
  • W is at position 50.
  • N is at at position 52.
  • HCDR3 contains at least one Y residue. Y may be present at any position in the HCDR3.
  • Assaying for the presence of an antibody molecule may comprise identifying whether any B cells in the mammal encode antibodies according to the present invention, for example by sequencing nucleic acid from the B cells. Methods may comprise determining whether antibodies (e.g., VH and VL domains comprising the defined structural motif) according to the present invention are enriched in the mammal following administration of the composition.
  • antibodies e.g., VH and VL domains comprising the defined structural motif
  • a method may comprise determining whether such antibodies are enriched over background frequencies by at least 0.1 %, at least 1 %, at least 2 %, at least 5 % or at least 10 % in the sample from the mammal, compared with a control sample (e.g., from a mammal who has not received the administered composition, e.g., a sample obtained from the same mammal prior to the administration).
  • a sample may be a blood sample, e.g., serum or whole blood. Peripheral blood samples are routinely obtainable from mammals, including human patients, in a clinical setting.
  • the presence of, and especially the enrichment of, the antibody or antibody sequence according to the invention in the sample provides an indication that the administered composition generates a protective immune response against the malarial Plasmodium parasite (e.g., protecting against infection by P. falciparum).
  • the administered composition may be a vaccine or a candidate vaccine, and may comprise one or more adjuvants.
  • the methods described here may be used to determine efficacy of vaccination of a mammal, for example to confirm, predict or test for protection of a vaccinated human individual against infection by a malarial Plasmodium parasite.
  • the methods may also be used in the context of pre-clinical or clinical trials involving a candidate vaccine composition.
  • the method may further comprise challenging the mammal with a malarial
  • Plasmodium parasite by exposing the mammal to biting by a Plasmodium-infected mosquito, and determining the degree of protection against challenge, as described.
  • an antibody VH domain comprising complementarity determining regions (CDRs)
  • an antibody VL domain comprising complementarity determining regions LCDR1 , LCDR2 and LCDR3,
  • the HCDR3 is an HCDR3 of antibody 666, antibody 667, antibody 668 or antibody 669, or comprises the antibody 666, 667, 668 or 669 HCDR3 with 1 , 2, 3, 4 or 5 amino acid alterations.
  • HCDR1 is an HCDR1 of antibody 666, 667, 668 or 669, or comprises the antibody 666, 667, 668 or 669 HCDR1 with 1 , 2, 3, 4 or 5 amino acid alterations.
  • Clause 1 An antibody according to clause 10, wherein the antibody VH domain has the heavy chain CDRs of antibody 667 or antibody 668.
  • an antibody VH domain comprising complementarity determining regions HCDR1 ,
  • an antibody VL domain comprising complementarity determining regions LCDR1 , LCDR2 and LCDR3,
  • LCDR3 is a LCDR3 of antibody 666, antibody 667, antibody 668 or antibody
  • an antibody according to clause 14 wherein the antibody light chain CDRs are those of antibody 666, antibody 667, antibody 668 or antibody 669, or comprise the antibody 666, 667, 668 or 669 light chain CDRs with 1 , 2, 3, 4 or 5 amino acid alterations.
  • Clause 16 An antibody according to clause 15, wherein the antibody VL domain has the light chain CDRs of antibody 667 or antibody 668.
  • (i) is derived from recombination of a human heavy chain V gene segment, a human heavy chain D gene segment and a human heavy chain J gene segment, wherein
  • V segment is IGHV1-3;
  • the D gene segment is IGHD3-10, IGHD3-9, IGHD4-1 1 or IGHD2-2; and/or the J gene segment is IGHJ6, or
  • (ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein
  • FR1 aligns with human germline V gene segment IGHV1-3 with up to 1 , 2, 3, 4 or 5 amino acid alterations
  • FR2 aligns with human germline V gene segment IGHV1-3 with up to 1 , 2, 3, 4 or 5 amino acid alterations
  • FR3 aligns with human germline V gene segment IGHV1-3 with up to 1 , 2, 3, 4 or 5 amino acid alterations, and/or
  • FR4 aligns with human germline J gene segment IGHJ6 with up to 1 , 2, 3, 4 or 5 amino acid alterations.
  • (i) is derived from recombination of a human heavy chain V gene segment IGHV1-3, a human heavy chain D gene segment and a human heavy chain J gene segment, or
  • (ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein FR1 , FR2 and FR3 each align with human germline V segment IGHV1-3 with up to 1 , 2, 3, 4 or 5 amino acid alterations,
  • the antibody inhibits the pre-erythrocytic stage of Plasmodium infection in a mammal, reduces risk of malaria in a mammal, reduces one or more symptoms of malaria in a mammal, reduces progression of Plasmodium infection in a mammal, and/or reduces transmission, or reduces risk of transmission, of Plasmodium between mammals.
  • (i) is derived from recombination of a human light chain V gene segment and a human light chain J gene segment, wherein
  • V segment is IGLV2-23, and/or
  • the J gene segment is IGLJ3; or
  • (ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein
  • FR1 aligns with human germline V gene segment IGLV2-23 with up to 1 , 2, 3, 4 or 5 amino acid alterations
  • FR2 aligns with human germline V gene segment IGLV2-23 with up to 1 , 2, 3, 4 or 5 amino acid alterations
  • FR3 aligns with human germline V gene segment IGLV2-23 with up to 1 , 2, 3, 4 or 5 amino acid alterations, and/or
  • FR4 aligns with human germline J gene segment IGLJ3 with up to 1 , 2, 3, 4 or 5 amino acid alterations.
  • Clause 22 An antibody according to any of the preceding clauses, comprising an antibody VL domain derived from recombination of a human light chain V gene segment and a human light chain J gene segment, wherein
  • V segment is IGLV2-23, and optionally
  • the J gene segment is IGLJ3.
  • An antibody according to any of the preceding clauses comprising an antibody VH domain which is the VH domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VH domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669.
  • An antibody according to any of the preceding clauses comprising an antibody VL domain which is the VL domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VL domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669.
  • An antibody according to clause 24, comprising an antibody VH domain which is selected from the VH domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VH domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669, and
  • an antibody VL domain which is the VL domain of said selected antibody, or which has an amino acid sequence at least 90 % identical to the antibody VL domain sequence of said selected antibody.
  • Clause 26 An antibody according to clause 25, comprising the antibody 667 VH domain and the antibody 667 VL domain.
  • Clause 27 An antibody according to clause 25, comprising the antibody 668 VH domain and the antibody 668 VL domain.
  • Clause 28. An antibody according to any of the preceding clauses, comprising an antibody constant region.
  • Clause 32 An antibody according to clause 30 or clause 31 , wherein the IgG comprises a CH2 domain having "YTE" mutations to extend the in vivo half-life of the antibody, the YTE mutations being tyrosine at residue 252, threonine at residue 254 and glutamic acid at residue 256, numbered according to the EU index of Kabat.
  • Clause 34 A composition comprising an isolated antibody according to any of the preceding clauses and a pharmaceutically acceptable excipient.
  • Clause 35. A composition comprising isolated nucleic acid encoding an antibody according to any of the preceding clauses and a pharmaceutically acceptable excipient.
  • Clause 36. A composition according to clause 34 or clause 35 formulated for intravenous or subcutaneous administration.
  • Clause 37 A composition according to any of clauses 34 to 36, further comprising one or more additional agents that are anti-malarial agents.
  • Clause 38 A composition according to any of clauses 34 to 36, further comprising one or more additional antibodies, or nucleic acid encoding one or more additional antibodies.
  • Clause 39 A composition according to clause 38, wherein the one or more additional antibodies bind one or more antigens of a malarial Plasmodium parasite.
  • Clause 40 A composition according to clause 39, wherein the malarial Plasmodium parasite is P. falciparum.
  • Clause 41. An antibody according to any of clauses 1 to 33, or a composition according to any of clauses 34 to 40, for use in a method of:
  • the method comprises administering the antibody or composition to a mammal.
  • Clause 42 An antibody or composition for use according to clause 41 , wherein the mammal is a human patient aged 50 years or under.
  • Clause 43 An antibody or composition for use according to clause 42, wherein the mammal is a human paediatric patient.
  • Clause 44 An antibody or composition for use according to any of clauses 41 to 43, wherein the method comprises administering a single dose of the antibody or composition.
  • the method comprising administering atherapeutically effective amount of an antibody according to any of clauses 1 to 33 or of a composition according to any of clauses 34 to 40 to the mammal.
  • Clause 46 An antibody or composition for use according to clause 45, wherein the mammal is a human patient aged 50 years or under.
  • Clause 47 An antibody or composition for use according to clause 46, wherein the mammal is a human paediatric patient.
  • Clause 48 A method according to any of clauses 45 to 47, wherein a single dose of the antibody is administered to the mammal.
  • Clause 49 Isolated nucleic acid encoding an antibody, or an isolated VH or VL domain of an antibody according to any of clauses 1 to 33.
  • Clause 50 A host cell in vitro containing nucleic acid according to clause 49.
  • Clause 51 A method of producing an antibody or an antibody VH or VL domain, comprising culturing host cells according to clause 50 under conditions for expression of the antibody or antibody VH or VL domain, and obtaining the expressed antibody or domain.
  • Clause 52 A method according to clause 51 , comprising culturing host cells in a culture medium of at least 100 litres (e.g., 100 - 250 litres) in a bioreactor.
  • Clause 53 A method according to clause 52, wherein the culturing comprises fed-batch culture.
  • Clause 54 A method according to clause 52 or clause 53, wherein the bioreactor comprises a metal (e.g., stainless steel) vessel or is a single-use bioreactor.
  • a metal e.g., stainless steel
  • Clause 55 A method according to any of clauses 51 to 54, further comprising isolating and/or purifying the antibody or antibody VH or VL domain.
  • Clause 56 A method according to any of clauses 51 to 55, further comprising formulating the antibody, or antibody VH or VL domain into a composition comprising at least one additional component, such as one or more additional antibodies and/or a pharmaceutically acceptable excipient.
  • Clause 57 A method according to clause 56, comprising formulating the antibody, or antibody VH or VL domain, into a composition for subcutaneous or intravenous
  • Clause 58 A method for producing an antibody according to any of clauses 1 to 33, the method comprising
  • parent antibody VH domain is the VH domain of any of antibodies 666, 667, 668 and 669 or a VH domain comprising the heavy chain complementarity determining regions of any of those antibodies,
  • VL domain is provided by way of addition, deletion, substitution or insertion of one or more amino acids in the amino acid sequence of a parent VL domain, wherein the parent VL domain is the VL domain of any of antibodies 666, 667, 668 and 669 or a VL domain comprising the light chain
  • Clause 61 A method according to any of clauses 58 to 60, further comprising expressing the antibody comprising the identified VH domain or VH/VL domain combination.
  • Clause 62 Use of an antibody according to any of clauses 1 to 33 for determining the presence or absence of CSP or Plasmodium in a sample.
  • Clause 63 A method of determining the presence or absence of CSP or Plasmodium in a sample, the method comprising
  • Clause 64 A method according to clause 63, wherein the antibody comprises or is conjugated to a detectable label.
  • Clause 65 Use according to clause 62, or a method according to clause 63 or clause 64, wherein the sample has been obtained from a mammal who has been or is suspected of having been infected with a malarial Plasmodium parasite and/or who exhibits one or more symptoms of malaria.
  • Plasmodium is P. falciparum.
  • Clause 67 Use or a method according to any of clauses 62 to 66, wherein the sample is a serum or whole blood sample.
  • Clause 68 A diagnostic kit for the use or method as set out in any of clauses 62 to 67, comprising an antibody according to any of clauses 1 to 33, and optionally one or more buffering solutions.
  • Clause 69 A diagnostic kit according to clause 68, wherein the antibody comprises or is conjugated to a detectable label.
  • Clause 70. A diagnostic kit according to clause 69, comprising
  • a first reagent comprising the antibody according to any of clauses 1 to 33, and a second reagent comprising a detector molecule that binds to the first reagent.
  • Clause 72 Use of an antibody according to any of clauses 1 to 33 or a composition according to any of clauses 34 to 40, for determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite or as a correlate of protection following vaccination to protect from infection by a malarial Plasmodium parasite.
  • Clause 73 An antibody according to any of clauses 1 to 33 or a composition according to any of clauses 34 to 40, for use in determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite or as a correlate of protection following vaccination to protect from infection by a malarial Plasmodium parasite.
  • Clause 74 A method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite, the method comprising:
  • CSP CSP
  • Plasmodium parasite to a mammal
  • a method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite comprising:
  • a sample obtained from a mammal wherein the mammal has received an administration of CSP, a fragment thereof comprising the NANP repeat region, or a synthetic NANP repeat peptide, and optionally one or more other antigens of the Plasmodium parasite, and wherein the sample has been obtained after allowing time for development of an immune response; and assaying for the presence of an antibody according to any clauses 1 to 33 in the sample;
  • Clause 76 A method according to clause 74 or clause 75, wherein administering the antigen or antigens comprises injecting live or killed Plasmodium, or antigen or antigens purified from Plasmodium or recombinantly expressed, into the mammal, optionally together with an adjuvant.
  • Clause 77 A method according to any of clauses 74 to 76, further comprising challenging the mammal with a malarial Plasmodium parasite by exposing the mammal to biting by a Plasmodium-infected mosquito, and determining the degree of protection against challenge.
  • Clause 78 A method according to clause 77, wherein the mammal is a mouse that expresses antibodies comprising human antibody variable regions.
  • Clause 80 A method according to any of clauses 74 to 77, wherein the Plasmodium parasite is P. falciparum.
  • Clause 81 A method according to clause 80, wherein the mammal is a human.
  • Clause 82 A method according to any of clauses 74 to 81 , for evaluating efficacy of a vaccine or candidate vaccine composition.
  • a method according to statement 1 wherein the culturing comprises fed-batch culture.
  • the bioreactor comprises a metal (e.g., stainless steel) vessel or is a single-use bioreactor.
  • a method according to any preceding statement further comprising isolating and/or purifying the antibody.
  • a method according to any preceding statement further comprising formulating the antibody into a composition comprising at least one additional component, such as one or more additional antibodies and/or a pharmaceutically acceptable excipient. 6.
  • a method according to statement 5 comprising formulating the antibody into a composition for subcutaneous or intravenous administration.
  • a method of preventing malaria or reducing risk of malaria in a mammal comprising administering a therapeutically effective amount of an antibody to the mammal, wherein the antibody binds circumsporozoite protein (CSP) of Plasmodium falciparum, wherein the antibody binds within the sequence NPDPNANP of CSP, and wherein the mammal is a human patient aged 50 years or under, e.g., a paediatric patient.
  • CSP circumsporozoite protein
  • the method comprises administering the antibody to the mammal, wherein the mammal is a human patient aged 50 years or under, e.g., a paediatric patient.
  • the mammal is a human patient aged 50 years or under, e.g., a paediatric patient.
  • the antibody binds CSP in the NPDP motif immediately preceding the NANP repeat region.
  • a method or an antibody for use according to any preceding statement wherein the antibody binds the first NANP motif of the NANP repeat region.
  • the antibody comprises
  • an antibody VH domain comprising complementarity determining regions (CDRs) HCDR1 , HCDR2 and HCDR3, and
  • an antibody VL domain comprising complementarity determining regions LCDR1 ,
  • the antibody VH domain is the VH domain of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab-c1281 , Ab-c1315 or Ab-c1731 , or wherein the VH domain has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab-c1281 , Ab-c1315 or Ab-c1731 , and/or wherein the antibody VL domain is the VL domain of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab- c1281 , Ab-c1315 or Ab-c1731 , or wherein the VL domain has an amino acid sequence at least 90 %
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 666, and
  • an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 666.
  • a method or an antibody for use according to any preceding statement wherein the antibody comprises the antibody 666 VH domain and the antibody 666 VL domain.
  • the antibody comprises an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 667, and
  • an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 667.
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 668, and
  • an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 668. 19.
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least
  • an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c82.
  • 26. A method or an antibody for use according to any of statements 1 to 11 or 24 to 25, wherein the antibody comprises the Ab-c82 VH domain and the Ab-c82 VL domain.
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least
  • an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c152.
  • 28. A method or an antibody for use according to any of statements 1 to 11 or statement 27, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c152.
  • 29. A method or an antibody for use according to any of statements 1 to 11 or 27 to 28, wherein the antibody comprises the Ab-c152 VH domain and the Ab-c152 VL domain.
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least
  • an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c194.
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least
  • an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c265.
  • the antibody comprises the Ab-c265 VH domain and the Ab-c265 VL domain.
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab- c1281 , and
  • an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab- C1281. 37. A method or an antibody for use according to any of statements 1 to 11 or statement 36, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c1281.
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab- C1315, and
  • an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab- C1315.
  • an antibody VH domain which has an amino acid sequence at least 90 %, at least
  • IgG comprises a CH2 domain having "YTE" mutations to extend the in vivo half-life of the antibody, the YTE mutations being tyrosine at residue 252, threonine at residue 254 and glutamic acid at residue 256, numbered according to the EU index of Kabat.
  • KymiceTM a transgenic mouse platform capable of generating antibodies with human variable domains, were immunised with CSP to generate anti-CSP antibodies.
  • the KymouseTM platform used in this study is composed of two strains of mice,
  • Kymouse HK and Kymouse HL both of which carry human variable domains and mouse constant domains.
  • the antibody repertoire of these mice are composed of human V, D and J segments.
  • the endogenous mouse variable genes have been silenced and make up a very small portion of the repertoire (less than 0.5 % of all heavy chain variable regions are of mouse origin).
  • the mice display normal B-cell signalling and development. These mice respond robustly to antigen challenge and produce high affinity antibodies with human-like HCDR3 lengths.
  • Kymouse HK includes engineered IgH and IgK loci. It includes inserted human VH- gene segments and human V-kappa gene segments. It has normal mouse heavy and light constant regions.
  • Kymouse HL includes engineered IgH and IgL loci. It includes inserted human VH- gene segments and V-lambda gene segments. It has normal mouse heavy regions and human light constant regions.
  • CSP used for this experiment was sourced from Gennova through the Malaria Vaccine Initiative (MVI). Protein was provided in lyophilised form.
  • the antigen is a 58 kDa protein from P. falciparum strain 3D7; GenBank accession number AL034558.
  • a synthetic nucleotide sequence encoding the full-length, mature translated protein sequence for PfCSP (3D7 strain; GenBank accession number AL034558) was commercially synthesised with codons optimised for maximizing expression of the heterologous gene in E. coli. This synthetic gene encoded the predicted full-length mature protein with a carboxy-terminal hexa-histidine tag, without the signal sequence and putative GPI anchor sequence.
  • E. coli BL21 (DE3). These host cells contain a chromosomal copy of T7 RNA polymerase gene under the control of lacUV5 promoter which is induced by addition of lactose analogue such as isopropyl ⁇ -D-thiogalactopyranoside (IPTG). IPTG induces production of T7 RNA polymerase allowing transcription of the target DNA in the plasmid.
  • BL21 (DE3) strain is deficient in both Ion and ompT proteases, thus improving stability of the recombinant protein expressed in these host cells.
  • the purified antigen has been show to elicit a strong T-cell immune response by Elispot. Nucleotide and amino acid sequences of CSP are shown in Figures 6 and 7. The antigen has also previously been shown to be immunogenic in immunisations in animals (Kastenmuller K, Espinosa DA, Trager L,
  • Post-immunisation antibody responses in the KymiceTM were identified from blasting B cells using the IRCTM sequencing technology.
  • IRCTM technology has been described by Atreca, Inc. in published patent applications. This platform captures full length sequences, enabling detection of somatic mutations across the entire antibody variable region. Natively paired heavy and light chain IgG variable regions are analysed, and constant region isotype assignments can be made.
  • IRC corrects for sequence errors introduced at all steps of a single-cell analysis process and provides unbiased output by correcting for biases from PCR amplification and other sources.
  • IRC can be applied to any B cell type, other isotypes, and any species for which constant region sequences are known, including blasted B cells (e.g.
  • IRC immunosorbent assay for human plasmablasts, mouse splenocytes, etc.
  • antigen sorted B cells e.g. antigen- binding memory B cells.
  • IRC was used here to provide the signal peptide, full variable region, and a portion of the constant region of natively-paired heavy and light chain sequences from individual B cells of the immunised Kymice.
  • Candidate antibody lineages for expression and testing were chosen based on sequence-features such as the degree of lineage dominance, somatic hypermutation levels, and apparent convergence of lineages across multiple CSP-immunised Kymice. Forty-eight antibody sequences representing thirty-seven diverse, putative antibody lineages were produced via gene synthesis and recombinant expression as fully human antibodies.
  • DNA sequences for paired heavy chain (HC) and light chain (LC) IgG variable regions were synthesised and subcloned into expression vector pLEV123 (LakePharma, Inc.). Heavy chain variable region sequences were fused to the signal peptide
  • MDPKGSLSWRILLFLSLAFELSYG SEQ ID NO: 51
  • human lgG1 constant regions The light chain variable region sequences were fused to the signal peptide
  • METDTLLLWVLLLWVPGSTG (SEQ ID NO: 53) for the kappa light chain, followed by the compatible human kappa or lambda light chain constant regions.
  • HEK293 cells were seeded in shake flasks one day before transfection, and were grown using serum-free chemically defined media.
  • the DNA expression plasmids were scaled up and transiently transfected into 10-30 ml of suspension HEK293 cells using LakePharma's standard operating procedure for transient transfection. After 20 hours, cultures were fed and production continued for 5 days. Cells were sampled to obtain the viabilities and viable cell counts, and titers were measured (Octet QKe, ForteBio). On day 5, cells were sampled to obtain the viabilities and viable cell counts, and titers were measured (Octet QKe, ForteBio) before harvesting the cell cultures.
  • Protein A affinity purification
  • the conditioned media from HEK293 cells expressing antibody were harvested from the transient transfection production run by centrifugation. The supernatant was run over a Protein A column and eluted with a low pH buffer. Filtration using a 0.2 ⁇ membrane filter was performed before aliquoting. After purification and filtration, the protein concentration was calculated from the OD280 and the extinction coefficient.
  • Antibodies were formulated in HEPES buffer (200 mM HEPES, 100 mM NaCI, 50 mM NaOac, pH 7.) CE-SDS analysis was performed (LabChip GXII, Perkin Elmer) to ensure antibody quality.
  • ELISA positive lineages Seven of nine ELISA positive lineages were expressed as full-length antibodies with human lgG1 constant region and further characterised using bio-layer interferometry and competitive binding assays to identify distinct binding sites.
  • Binding affinities against rCSP were measured via ForteBio Octet Red69 using two different assay formats. By changing the Octet assay antibody-antigen orientation (see methods section below for two formats), the dose-dependent responses of Ab667 and Ab668 toward Streptavidin-sensor captured biotin/rCSP were obtained and the kinetics constants were calculated. The kinetic analysis of Ab667 and Ab668 binding toward biotin/rCSP by Octet was used to generate the kinetic constants shown in Table 3 and illustrate the high affinity of antibodies 667 and 668 to the CSP antigen. Loading Sample ID KD (M) kon(1/Ms) kdis(1/s) Full R A 2 Full ⁇ ⁇ 2
  • Anti-CSP mAbs 667 and 668 were shown to bind to rPF-CSP and to the NANP repeat region, while lacking binding capacity to the Pf16 motif at the C-terminus region of CSP. See Figure 8.
  • Epitope binning tests antibodies in a pairwise manner; antibodies competing for the same binding region are grouped together into bins.
  • epitope binning was performed on Octet QKe system (ForteBio) using two assay formats. The biosensors were hydrated in sample diluent (0.1 % BSA in PBS and 0.02% Tween 20) and preconditioned in pH 1.9 Glycine.
  • the first assay format (Assay Format 1) used Anti-hFc (AHC) kinetic grade biosensors (ForteBio, #18-5060) to capture rCSP/Ab1 mix (rCSP 100nM, Ab1 300nM, 60 seconds); the sensors were then dipped into high concentration of hFc (150 ug/mL) for 300 seconds to saturate the AHC sensor. Ab1 of 300nM was loaded again for 300 seconds to check for unsaturated Ab1 binding epitope. Lastly, the sensors were dipped into Ab2
  • a second assay format (Assay Format 2) used Streptavidin (SA) kinetic grade biosensors (ForteBio, #18-5021) to immobilize biotinylated rCSP at a concentration of 20 ⁇ g/ml for 120 seconds.
  • SA Streptavidin
  • the antigen-loaded SA biosensors were then dipped into Ab1 ("saturating antibody”) at 20 ug/ml for 600 seconds.
  • Ab1 saturatedating antibody
  • a short baseline (30 seconds) was observed using dissociation buffer after the Ab1 loading.
  • the sensor was then dipped into Ab2 ("competing antibody”) at 5 ug/mL and the association was observed for 120 seconds, followed by 120 seconds of dissociation.
  • EPO70034 (NANP repeat region).
  • Peptide Pf16 was reconstituted with DMSO to 20 mg/mL and then diluted with sterile water to obtain a final concentration of 5 mg/mL.
  • EP070034 was reconstituted with sterile water to obtain a final concentration of 5 mg/mL.
  • 96-well plates were coated overnight with the three antigens (including the full-length Pf CSP antigen) at a final concentration of ⁇ g/mL. The plate was blocked with 1x PBS, 2.5% BSA for 2 hours the next morning at room temperature.
  • Antibody samples were prepared in an 8-point 1 :5 serial dilution series with 1x PBS, 1 % BSA with a starting concentration of 50 ⁇ g/mL.
  • the HRP- goat anti-human Fc was diluted 1 :5,000 for detection as described above.
  • Affinity determination was performed on an Octet QKe system (ForteBio).
  • Anti-hFc (AHC) kinetic grade biosensors (ForteBio, #18-5060) were hydrated in sample diluent (0.1 % BSA in PBS and 0.02% Tween 20) and preconditioned in pH 1.9 Glycine.
  • Antibody was immobilised onto AHC biosensors at a concentration of 20 ⁇ g/mL for 60 seconds.
  • the antibody-loaded AHC biosensors were then dipped into an 8-point dilution series of the Pf CSP antigen (starting at 1000 nM, 1 :3 diluted down). Association was observed for 120 seconds, followed by 180 seconds of dissociation.
  • a short baseline (30 seconds) was established using dissociation buffer after AHC loading.
  • Parallel references were set up by using unloaded bare sensor and sensor dipped into an 8-point dilution series of the antigen. During data processing, the parallel reference was used for normalization.
  • the binding affinity of Pf CSP to each antibody was characterized by fitting kinetic sensorgrams to a monovalent binding model (1 :1 binding). This assay set up was used for five related antibodies (AB-000662, AB-000640, AB-000649, AB000646 and AB000643).
  • Example 4a In vivo protection studies using mouse malaria challenge model
  • Candidate antibodies are tested in a mouse malaria challenge model. This in vivo mouse protection assay uses intravenous passive transfer of selected antibodies (300 ⁇ g/mouse) followed by challenge with chimeric P. berghei encoding full-length P.
  • antibodies are injected intravenously. Sporozoites are injected 30 minutes later by intravenous challenge. Parasite liver burden (measured by PCR) is used as a readout. Antibodies that show protection in this IV challenge are then further tested in a second experiment, using mosquito bite challenge. Parasitaemia can be used as a readout to assess sterile protection.
  • Figure 5 illustrates principles of the challenge model.
  • livers are extracted and RNA is isolated from liver homogenates.
  • Real-time PCR targeting the parasite 18S rRNA sequence, is used to measure the relative level of liver-stage parasites.
  • Liver-stage parasite load can be quantified in terms of the number of P. berghei 18S rRNA copies in liver. % reduction of parasite load can be determined relative to control mice who do not receive the candidate antibody or who receive a control antibody (naive mice).
  • mice may be monitored for a period of, e.g., 7 or 14 days, and % mice remaining free of blood-stage parasites is determined for challenged mice and control mice.
  • Example 4a The mouse challenge described in Example 4a was performed to assess the ability of passively-transferred anti-CSP mAbs to protect mice from sporozoite challenge.
  • these in vivo protection studies involving transgenic sporozoites comprised initial screening by IV injection of 300 ug of Ab per animal followed by measurement of liver stage burden.
  • Results are shown in Figure 9 and Figure 10. The data indicate that antibodies 667 and 668 confer significant and very strong protection relative to the 2A10 positive control.
  • mAbs 667 and 668 confer protection from transgenic sporozoite challenge and evaluate whether such protection could be sterilising.
  • a second challenge was performed using three different concentrations of antibody. The outcome was evaluated by determination of parasitemia at various time points post-challenge.
  • mice Upon passive transfer of monoclonal antibodies, mice were anesthetized with 2% Avertin and mosquitoes allowed to feed on mice for -10 minutes. After feeding, the number of mosquitoes positive for a blood meal was determined. On days 4 - 11 after challenge, blood smears were taken from mice to determine parasitemia. % sterile protection was determined by dividing the number of uninfected mice by the total number of mice challenged. Pre-patent period, the number of days prior to detection of parasites in the blood, was also recorded.
  • the impact of anti-CSP antibodies on sporozoites' gliding motility was assessed using methods previously described by Ejigiri et al. (Ejigiri et al., Shedding of TRAP by a Rhomboid Protease from the Malaria Sporozoite Surface is Essential for Gliding Motility and Sporozoite Infectivity, PLoS Pathog 8(7), 2012). Briefly, P.
  • falciparum sporozoites were pre-incubated with the indicated antibodies (100 ug/ml) for 30 min and then added to wells in the presence of bovine serum albumin and incubated at 37°C for 1 hr. They were then fixed and trails were stained with anti-CSP antibody and counted using a fluorescence microscope.
  • Anti-CSP antibodies mAb667 and mAb668 abolished gliding motility of the sporozoites in this assay. Data are shown in Figure 12.
  • liver stage development assay tests antibodies for the ability to block sporozoite development in hepatocytes.
  • ILSDA is an excellent candidate assay to identify correlates of humoral protection, particularly against the liver stage of malaria infection.
  • the Inhibition of Liver Stage Development Assay (ILSDA) was performed as previously described by Zou et al. (Zou et al, Towards an optimized inhibition of liver stage development assay (ILDSA) for Plasmodium falciparum, Malaria Journal 12:394, 2013).
  • the NF54 strain of Plasmodium falciparum (Pf) sporozoites obtained from salivary gland dissections
  • mAbs monoclonal antibodies
  • the sporozoites-mAbs mixtures were then introduced into the wells containing cryopreserved human hepatocytes (CPHH; BioReclamation IVT, Baltimore MD) and incubated at 37°C for 3 hours to allow sporozoites to infect hepatocytes.
  • the anti- CSP mAb 2A10 was used as a positive control.
  • CPHH were washed with fresh hepatocyte culture media to remove non-invaded sporozoites and incubated at 37°C for 96 hours.
  • the RNA from the cells was then harvested for downstream quantitative real-time PCR (qRT-PCR) analysis. Pf 18s rRNA level were quantified to determine the inhibitive ability of the tested mAbs.
  • Example 7 Inhibition of sporozoite traversal and invasion (ISTI)
  • Anti-CSP antibodies mAb667 and mAb668 dramatically reduced both hepatocyte traversal ( Figure 14) and hepatocyte invasion (Figure 15) in this assay.
  • Antibody 666 and antibody 669 were also tested and were confirmed to be functional hits in the ISTI assay.
  • Example 8 Sporozoite challenge into FRG Hu-Hep mice
  • a human liver (Hu-Hep) mouse challenge model was used to assess the ability of passively-transferred anti-CSP mAbs to protect mice from sporozoite challenge.
  • mice were purchased from Yecuris, Inc. and used in passive transfer experiments as previously described (K. Sack et al., Model for in vivo assessment of humoral protection against malaria sporozoite challenge by passive transfer of monoclonal antibodies and immune serum. Infect Immun 82, 808-817 (2014), and Sack et al., submitted). Briefly, mice were intravenously injected with 150 ⁇ g of mAb or non-specific murine IgG (mock) 16-24 hours prior to infection by bite of 50 mosquitos infected with Pf GFP-luciferase parasites (Vaughan et al. 2012) for 10 minutes. Six days after infection, parasite liver burden was assessed by bioluminescent imaging.
  • Percent of mock liver burden was calculated by normalizing all liver burdens to the average of the mock-injected group within each independent experiment.
  • the 3C1 anti-CSP mAb (Zavala et al., J Exp Med 157: 1947-1957 1983) had previously been shown in this model to mediate higher inhibition of infection than the 2A10 positive control and was therefore used as the positive control in the present experiment.
  • the phylogenetic family of Ab667 contains Ab666 and a number of further antibodies, as shown in Table 5.
  • DQYYDILTPYYYYYYGMDV WINAGNGNTKYSQKFQG GYTFTSYAMH CSYAGSSTWV VVSKRPS TGTSSDVGGYNYVS
  • DSFYDILTGPVYHYYGMDV WINAGNGYTKYSQKFQD GYTFTNYAMH CSYAGSSTWV DVSKRPS TGTSNDVGVYNHVS
  • the phylogenetic family of Ab668 contains Ab669 and a number of further 5 antibodies, as shown in Table 6.
  • antibodies have the same germline gene usage, high identity light chains and high identity in the HCDR1 and HCDR2. It is believed that antibodies comprising VH domains having these CDRs may be functionally active in a similar way to Ab666, 667, 668 and 669. This may be confirmed through assays as described in the above Examples.
  • Ab666 lineage Ab666, Ab666-1 , Ab666-2, Ab666-3, Ab666-4.
  • Ab667 lineage Ab667, Ab667-1 , Ab667-2, Ab667-3.
  • Ab668 lineage Ab668, Ab668-1.
  • Ab669 lineage Ab669, Ab669-1 , Ab669-2, Ab669-3, Ab669-4, Ab669-5, Ab669-6.
  • Lineage trees are shown in Figure 18 (Ab666 lineage), Figure 19 (Ab667 lineage), Figure 20 (Ab668 lineage) and Figure 21 (Ab669 lineage).
  • Example 3 we reported measurements of the affinity of binding between anti-CSP antibodies and the CSP antigen, and showed that binding sites for antibody 667 and antibody 668 were found in the NANP repeat region of the CSP antigen.
  • the antibodies (666, 667, 668 and 669) with CSP, including measuring the kinetics of binding using SPR and determining binding to an array of CSP peptides to provide additional information on epitope recognition by these antibodies.
  • Amino acid sequences of antibodies 666, 667, 668 and 669 are shown in the appended sequence listing. For expression, silent mutations were introduced in certain VH domain nucleotide sequences to remove an AaR1 restriction site.
  • Antibodies 667, 668 and 669 were expressed as human lgG1 in HEK cells
  • lgG1 human lgG1 in CHO cells (ExpiCHO, Gibco Life Technologies).
  • the lgG1 were purified by Protein A and desalting and formulated at a concentration of 1 mg/mL in PBS at pH 7.4. Purity from size exclusion chromatography (SEC) was 92-95 %.
  • Antibodies 666, 667, 668 and 669 were expressed as Fabs in CHO cells (CHO-3E7, National Research Council Canada), purified on HiTrap nickel columns (GE Healthcare) eluted using 250 nM imidazole in PBS, and formulated at a concentration of 1 mg/mL in PBS at pH 7.4. Purity from SEC was >95 %.
  • Recombinant CSP ( Figure 22) was provided by the Wellcome Trust Sanger Institute.
  • P. falciparum strain 3D7 GenBank accession number: CAB38998.2
  • molecular weight 45 kDa The gene construct encoded CSP without the final 21 amino acids (GPI-anchor) to allow for soluble expression.
  • a biotinylation site (BirA enzyme substrate peptide BSP) and histidine tag was also added.
  • Recombinant CSP was expressed in HEK293 cells using a mouse variable ⁇ light chain peptide signal sequence for secretion into the culture medium, nickel-affinity purified and dialyzed into DPBS.
  • Recombinant CSP was used as analyte at 64 nM, 16 nM, 4 nM, 1 nM, 0.25 nM and 0 nM, and injected over the monoclonal mouse lgG2a construct.
  • the assay was carried out at 25°C, with an association step of 240 sec and a dissociation step of 600 sec. Buffer injection (0 nM) was used to double reference the sensorgrams.
  • the analysis was carried out using the 1 :1 binding model inherent to the Bio-Rad ProteOn's analysis software.
  • the monoclonal human lgG1 Abs were diluted to 30 ⁇ g/mL in running buffer.
  • CSP peptides and biotinylated recombinant CSP were diluted to 20 ⁇ g/mL in running buffer.
  • a first set of peptides (#1 to #4) was designed to cover 22 amino acids around the first occurrence of the epitope NPDPNANP, and a second set of peptides (#5 to #17) was designed as an alanine scan replacing one by one all amino acids in the
  • biotinylated peptides and recombinant CSP were captured at 20 ⁇ g/mL on the streptavidin sensors and then the sensors were dipped into the antibody solutions at 30 ⁇ g/mL.
  • Fresh streptavidin sensors were used for each peptide-antibody interaction.
  • the assay was carried out at 25°C. Binding signals were double referenced using a well reference and a sensor reference.
  • Table 15 Summary of 666 human lgG1 interactions with peptides Considering the first set of peptides, all four monoclonal human IgGIs bind the peptide #4 (NPDPNANP) and the longest peptides (#1 and #3) that are including this sequence. 667, 668 and 669 do not bind the peptide #2 which covers the same sequence except for the NPDPNANP sequence. The four tested monoclonal human IgGIs show the same results that correlate with an epitope involving the NPDPNANP sequence. However, 666 lgG1 did show weak binding to peptide #2 which suggests the epitope for this antibody extends into the region further upstream, binding an epitope comprising one or more residues of the sequence KHKKLKQPG.
  • DGNPDPNKNPNV peptide #13
  • 666, 667 and 669 human IgGIs is disrupted on the following peptide as well
  • DGNPDPNAAPNV a refined epitope where the alanine in the NPDPNANP sequence has a role in the binding of the four monoclonal human IgGI s, and the following asparagine is involved in the binding of 666, 667 and 669 human IgGI s.
  • Example 2 Further computational analysis of the antibody lineages identified in Example 2 was performed to group antibodies into evolutionarily-related lineages from their nucleotide sequences. Bioinformatics analysis was used to infer phylogenetic trees of antibodies derived from the same B cell clonal lineage.
  • Antibodies 666, 667, 668 and 669 are derived from IGLV2-23 and IGLJ3 germline genes. An additional 33 antibody sequences were identified which contain the common IGLV2-23 IGLJ3 genotype. These antibodies may therefore also be active against CSP. Alignments of the light and heavy chains of these antibodies are shown in Figures 23 and 24. An additional six antibodies were also selected as they were identified as members of the largest lineages. A large lineage is suggestive of a favoured evolutionary trajectory against an antigen and therefore of greater potential to contain strong antigen binding antibodies. Sequence information for these antibodies is provided in Table 16 and Table 17.
  • Example 11 The antibodies identified in Example 11 were expressed as human lgG1 in HEK cells (Expi293F, Gibco Life Technologies) having the VH and VL domains shown in Table 16 and cell culture supernatants were tested for binding to CSP by SPR at 25 degrees C.
  • Antibody 666 was included as a positive control. Positive binding data were obtained for antibody 666 and for 21 of the Table 16 antibodies. Off-rates could not be resolved so kd (1/s) and KD (nM) values were not calculated. On-rates as represented by ka (1/Ms) were as follows:
  • the human IgGls were transiently expressed in HEK293 cells over a week.
  • supernatants containing the human IgGls were diluted 1/100 in running buffer (1X HBS-EP+ Buffer Technova, cat. No. H8022) and captured on an anti-human IgG capture surface.
  • the full CSP protein was used as analyte at 64nM, 16nM, 4nM, 1 nM, 0.25nM and OnM, and injected over the captured human IgGls.
  • the surface was regenerated between each human lgG1 construct using 100mM P04.
  • the assay was carried out at 25°C, with an association step of 210sec and a dissociation step of 600sec.
  • the buffer injection i.e. OnM
  • the analysis was carried out using the 1 : 1 binding model inherent to the Bio-Rad ProteOn's analysis software.
  • Example 13 Selection of further protective anti-CSP antibodies with structural motif for NPDPNANP binding
  • antibodies that showed strong binding to CSP and effective inhibition in biological assays described herein, and considering their structural interface with the NPDPNANP epitope identified herein, we uncovered a structural pattern that may be considered a structural "signature" or motif indicative of a class of antibodies that confer protection against sporozoite infection.
  • Such antibodies are strong candidates for preventing malaria and may thus be administered to a mammal (e.g., human) to reduce risk of malaria in that mammal, methods for which are described in more detail elsewhere herein.
  • the N is at position 31.
  • the N is either directly preceded or followed by the hydrophobic residue.
  • the hydrophobic residue is preferably Y.
  • LCDR3 containing a Y residue and a W residue.
  • the Y precedes W (in the N to C direction).
  • Y is at position 91.
  • W is at position 96.
  • HCDR2 containing W and N Preferably, the W precedes N (in the N to C direction). Preferably, W is at position 50. Preferably, N is at at position 52.
  • Y may be present at any position in the HCDR3.
  • Antibodies comprising this structural motif represent preferred embodiments of the present invention.

Abstract

Antibodies that bind to the circumsporozoite protein (CSP) of Plasmodium falciparum. Use of such antibodies as anti-malarial agents, to confer protection against infection by malarial parasites such as P. falciparum by insect vector transmission.

Description

ANTI-MALARIAL ANTIBODIES THAT BIND CIRCUMSPOROZOITE PROTEIN
Cross-Reference to Related Applications
This application claims priority to U.S. Provisional Application Nos. 62/504,863, filed May 1 1 , 2017; 62/560,971 , filed September 20, 2017; and 62/564,066, filed September 27, 2017, which are incorporated herein by reference in their entireties.
Reference to Sequencing Listing
The content of the electronically submitted sequence listing (Name:
4010003PC03_st25; Size: 352,741 bytes; and Date of Creation: May 1 1 , 2018) filed with the application is incorporated herein by reference in its entirety. Field of the Invention
This invention relates to treating or preventing malaria, and to antibodies conferring protection against infection by malarial parasites such as Plasmodium falciparum by insect vector transmission. The invention also relates to treating, preventing or diagnosing
Plasmodium infection in a mammal. Background
Malaria causes a large burden of morbidity and mortality, especially in the developing world. The causative agent of malaria is a protozoal parasite, which is transmitted by mosquitos. There are several infectious Plasmodium species that cause malaria, the most deadly of which is Plasmodium falciparum. Others include P. vivax, P. ovale and P.
malariae.
The life cycle of Plasmodium parasites such as P. falciparum is shown in Figure 1. The infective stage is the sporozoite, which is transmitted from the mosquito to the vertebrate host, e.g., human. Preventing infection will involve preventing sporozoite transmission from the insect vector to humans. Decreasing infection by P. falciparum will depend on blocking transmission, or inhibiting the pre-erythrocytic phase of infection.
Targeting the asexual phases involved in the erythrocytic cycle (and disease) may only mimic naturally acquired immunity - that is, immunity to disease rather than immunity to infection.
Circumsporozoite protein (CSP) is an antigen that is highly expressed on the P. falciparum sporozoite. CSP is displayed on the surface of the sporozoite and is involved in key parasite functions. Human antibodies against P. falciparum sporozoites have been described. Del Giudice et al synthesised a peptide of about 40 repeats of NANP (Asn-Ala- Asn-Pro) from CSP, (NANP)40. This was recognised by monoclonal antibodies produced against P. falciparum sporozoites, and was proposed for use in detecting anti-sporozoite antibodies and for epidemiological studies to obtain base-line data concerning the immune status of individuals before their participation in a sporozoite vaccine trial (del Guidice et al., J. Clin. Microbiol. 25(1):91-96 1987). In a study of the structural diversity of antibodies that bind the NANP repeat region of CSP, it was found that the murine antibody response to this immunodominant region is heterogeneous. In that study, hybridomas (2E7, 2A10, 3D6, 2C11 , 1 E9) were created from mice innoculated with whole P. falciparum sporozoites, and the VH and VL domains from the hybridoma antibodies were sequenced. It was found that the different antibodies to the NANP repeat region incorporated a variety of different v, d and j gene segments (Anker, Zavala & Pollok, Eur J Immunol. 20:2757-2761 1990).
The NANP repeat, coupled to Keyhole limpet hemocyanin (KLH), has been used to vaccinate human volunteers and shown to produce an immune response in up to 71 % of volunteers (n=35). 3 individuals with the highest anti NANP antibody titres were challenged by experimental mosquito mediated infection with Plasmodium falciparum sporozoites. Compared with controls (n=10) who had not been vaccinated and who all showed blood stage parasitaemia, 2 of the vaccines showed delayed parasitaemia and one showed no parasitaemia (Herington et al, Nature. 328: 257-259 1987), indicating that antibodies to NANP could be protective to infection.
A first generation vaccine (RTS.S) has been developed using portions of CSP, including part of the NANP repeats. CSP-based vaccines have consistently shown 30-50% efficacy in prevention of erythrocytic-stage infection. This level of efficacy is not sufficient for eradication and new pre-erythrocytic treatments will need superior efficacy.
Other anti-malarial products include mefloquinine, doxycycline and
atovaquone/proguanil, which are used for chemoprophylaxis by travellers and the military. Artemisinin and its derivatives also have anti-malarial action, and artemisinin combination therapies are a standard treatment worldwide for malaria.
In the absence of sufficiently effective vaccines, these drug treatments currently remain at the forefront of anti-malarial medicine. However, resistance to existing anti- malarial treatments is arising. Evidence for resistance to artemisinin in Southeast Asia was first reported in 2008, and more recently it has been reported that Plasmodium falciparum resistant to artemisinin were spreading in the Greater Mekong subregion (Imwong et al., The Lancet, 2017; dx.doi.org/10.1016/S1473-3099(17)30048-8).
The development of drug resistant Plasmodium follows a familiar pattern. In
Thailand, sulphadoxine-pyrimethanime (SP) was initially almost 100% effective in curing malaria when introduced in 1977, but within five years was curing only 10% of cases due to drug resistance. The once-popular chloroquine has lost its effectiveness in almost every part of the world. Between 1999 and 2004, 95% of African children treated for malaria were given chloroquine, even though the drug only cured half of malaria cases in many countries.
Resistance to atovaquone developed within one year of introduction in 1997.
Development of resistance can be reduced through use of combination therapies, and the World Health Organisation has discouraged use of artemisinin monotherapy in favour of combination treatments for this reason. The WHO has also urged the global malaria research community and the pharmaceutical industry to invest in the design of the next generation of antimalarial drugs. Use of further categories of active anti-malarials in combination therapies should slow the development of drug resistance and provide treatment options for cases that are resistant to existing anti-malarial drugs.
Summary of the Invention
The invention provides novel anti-parasitic therapeutic and diagnostic agents, including prophylactic agents, especially antibodies. The antibodies may be employed for diagnosing, treating, or preventing malaria or Plasmodium infection in humans and other mammals, or for reducing the risk of malaria or Plasmodium infection in humans and other mammals. Methods of diagnosis and treatment are described herein, including methods of administration to a mammal. The antibodies may be used to confer protection against infection by malarial parasites such as Plasmodium falciparum by insect vector transmission. Desirable features of the antibodies include inhibiting the pre-erythrocytic stage (e.g., sporozoite) of Plasmodium infection, reducing progression of Plasmodium infection in a mammal, reducing one or more symptoms of malaria, and reducing transmission or risk of transmission of Plasmodium to and/or from a mammal. Inhibition of transmission of malarial Plasmodium parasites between mammals (especially humans) is of particular value in lessening spread of disease, limiting malaria and controlling reservoirs of infectious malarial parasites in populations. This invention offers particular advantages for use in countries and regions where malaria is prevalent, and for travellers, military personnel and health workers visiting or operating in such countries or regions.
This invention also relates to the use of antibody sequences as correlates of protection following vaccination to protect from malaria infection, which has utility in vaccine development programs, including pre-clinical and clinical trials, and in determining the level of protection achieved in individuals vaccinated against Plasmodium infection. This invention also relates to the use of such antibodies to diagnose malaria infection, and diagnostic methods and kits are described herein. Pharmaceutical compositions comprising the antibodies are also provided. Exemplary embodiments of the invention are set out in the appended claims. Exemplary antibodies include antibodies 666, 667, 668 and 669, the sequences of which are set out herein. Antibodies having close structural similarity with these antibodies, are also described. These are antibodies 666-1 , 666-2, 666-3, 666-4 (antibody 666 lineage), 667-1 , 667-2, 667-3 (antibody 667 lineage), 668-1 (antibody 668 lineage) 669-1 , 669-2, 669- 3, 669-4, 669-5 and 669-6 (antibody 669 lineage), and antibodies having the sets of CDRs shown in Tables 5 to 7. Further exemplary antibodies are described in Example 1 1 and include antibodies having the sets of CDRs, and optionally the VH domain and/or VL domains, shown in Table 16. Still further exemplary antibodies are described in Example 13 and include antibodies having the sets of CDRs, and optionally the VH domain and/or VL domains, shown in Table 18.
Antibody 667 and antibody 668 are believed to bind the NANP repeat region of the CSP polypeptide sequence and/or to bind within a region of up to 12 amino acids preceding the NANP repeat region. The NANP repeat region starts with a sequence
NANPNVDPNANP, which may provide at least part of the epitope recognised by these antibodies. Immediately upstream of the NANP repeat region is a sequence of 12 amino acids KLKQPGDGNPDP, which may also provide or contribute to the epitope recognised by antibody 667 and antibody 668. For example, the antibodies may bind the NPDP motif within this sequence. The epitope recognised by antibody 667 and antibody 668 may lie within, or include, the 8-mer sequence NPDPNANP, i.e., the sequence comprising the first NANP motif and the residues that immediately precede it.
Antibody 667 and antibody 668 have been characterised both in vitro and in vivo and found to inhibit pathologically relevant sporozoite functions and to protect against sporozoite infection as described in the appended Examples. Antibody 666 and antibody 669 are related in sequence to both antibody 667 and antibody 668, indicating they may share useful functional properties in common and that they may also bind the same region(s) of CSP, e.g., the NANP region and/or upstream sequences of CSP as described above. Targeting an epitope within the NANP repeat region and/or upstream sequence as described may confer particular advantages for inhibiting sporozoite infection. Antibodies that bind the same part of the CSP polypeptide that is recognised by antibodies 667 and 668, e.g., the NANP repeat region and/or upstream sequences, and the use of such antibodies in therapeutic and prophylactic methods described herein, thus represent an aspect of the present invention. The invention also relates to antibodies that neutralise CSP.
An antibody according to the invention may be one that competes for binding to CSP of Plasmodium falciparum with an antibody (e.g., human lgG1 , or an scFv) comprising the heavy and light chain complementarity determining regions (CDRs) of antibody 666, antibody 667, antibody 668 or antibody 669. An antibody according to the present invention may comprise one or more CDRs of any of antibody 666, 667, 668 or 669 (e.g., all 6 CDRs of any such antibody, or a set of HCDRs and/or LCDRs) or variants thereof as described herein.
An antibody according to the present invention may comprise one or more CDRs of an antibody of the "antibody 666 lineage", an antibody of the "antibody 667 lineage", an antibody of the "antibody 668 lineage" or an antibody of the "antibody 669 lineage" (e.g., all 6 CDRs of any such antibody, or a set of HCDRs and/or LCDRs) or variants thereof as described herein.
The "antibody 666 lineage" comprises antibody 666, antibody 666-1 , antibody 666-2, antibody 666-3 and antibody 666-4.
The "antibody 667 lineage" comprises antibody 667, antibody 667-1 , antibody 667-2 and antibody 667-3.
The "antibody 668 lineage" comprises antibody 668 and antibody 668-1.
The "antibody 669 lineage" comprises antibody 669, antibody 669-1 , antibody 669-2, antibody 669-3, antibody 669-4, antibody 669-5 and antibody 669-6.
An antibody according to the present invention may comprise one or more CDRs as shown in Tables 5 to 7. For example, the antibody may comprise a set of 6 CDRs shown in Table 5 or Table 6, it may comprise a VH domain having a set of HCDRs as indicated in any of Tables 5 to 7, and/or it may comprise a VL domain having a set of LCDRs as indicated in Table 5 or Table 6.
An antibody according to the present invention may comprise one or more CDRs as shown in Table 16. The antibody may comprise HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 as shown in Table 16, it may comprise a VH domain having the HCDR1 , HCDR2 and HCDR3 shown in Table 16 and/or it may comprise a VL domain having the LCDR1 , LCDR2 and LCDR3 shown in Table 16.
An antibody according to the present invention may comprise one or more CDRs as shown in Table 18. The antibody may comprise HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 as shown in Table 18, it may comprise a VH domain having the HCDR1 , HCDR2 and HCDR3 shown in Table 18 and/or it may comprise a VL domain having the LCDR1 , LCDR2 and LCDR3 shown in Table 18.
The antibody may comprise an antibody VH domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein the HCDR3 is an HCDR3 of an antibody selected from antibody 666, 667, 668 or 669 or comprises that HCDR3 with 1 , 2, 3, 4 or 5 amino acid alterations. The HCDR2 may be the HCDR2 of the selected antibody or it may comprise that HCDR2 with 1 , 2, 3, 4 or 5 amino acid alterations. The HCDR1 may be the HCDR1 of the selected antibody or it may comprise that HCDR1 with 1 , 2, 3, 4 or 5 amino acid alterations. The antibody may comprise an antibody VL domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein the LCDR3 is an LCDR3 of an antibody selected from antibody 666, 667,
668 or 669 or comprises that LCDR3 with 1 , 2, 3, 4 or 5 amino acid alterations. The LCDR2 may be the LCDR2 of the selected antibody or it may comprise that LCDR2 with 1 , 2, 3, 4 or
5 amino acid alterations. The LCDR1 may be the LCDR1 of the selected antibody or it may comprise that LCDR1 with 1 , 2, 3, 4 or 5 amino acid alterations.
An antibody may comprise:
an antibody VH domain comprising complementarity determining regions HCDR1 , HCDR2 and HCDR3, and
an antibody VL domain comprising complementarity determining regions LCDR1 , LCDR2 and LCDR3,
wherein the heavy chain complementarity determining regions are those of antibody 666, antibody 667, antibody 668 or antibody 669, or comprise the antibody 666, 667, 668 or 669 heavy chain complementarity determining regions with 1 , 2, 3, 4 or 5 amino acid alterations; and/or
wherein the light chain complementarity determining regions are those of antibody 666, antibody 667, antibody 668 or antibody 669, or comprise the antibody 666, 667, 668 or
669 light chain complementarity determining regions with 1 , 2, 3, 4 or 5 amino acid alterations.
The antibody may comprise an antibody VH domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein
the HCDR1 , HCDR2 and HCDR3 are each independently selected from an antibody of the antibody 666 lineage, and/or wherein
the LCDR1 , LCDR2 and LCDR3 are each independently selected from an antibody of the antibody 666 lineage.
Thus, the HCDR1 may be the HCDR1 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666-4, the HCDR2 may be the HCDR2 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666-4, the HCDR3 may be the HCDR3 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666- 4. Similarly, the LCDR1 may be the LCDR1 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666-4, the LCDR2 may be the LCDR2 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666- 4, and the LCDR3 may be the LCDR3 of any of antibodies 666, 666-1 , 666-2, 666-3 or 666- 4.
Optionally, the antibody comprises a set of HCDRs (HCDR1 , HCDR2 and HCDR3) from antibody 666-1 , antibody 666-2, antibody 666-3 or antibody 666-4. The antibody optionally comprises a set of LCDRs (LCDR1 , LCDR2 and LCDR3) from the same antibody. An antibody may comprise an antibody VH domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein
the HCDR1 , HCDR2 and HCDR3 are each independently selected from an antibody of the antibody 667 lineage, and/or wherein
the LCDR1 , LCDR2 and LCDR3 are each independently selected from an antibody of the antibody 667 lineage.
Optionally, the antibody comprises a set of HCDRs from antibody 667-1 , antibody 667-2 or antibody 667-3. The antibody optionally comprises a set of LCDRs from the same antibody.
An antibody may comprise an antibody VH domain comprising CDRs HCDR1 , HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein
the HCDR1 , HCDR2 and HCDR3 are each independently selected from an antibody of the antibody 668 lineage, and/or wherein
the LCDR1 , LCDR2 and LCDR3 are each independently selected from an antibody of the antibody 668 lineage.
Optionally, the antibody comprises a set of HCDRs from antibody 668-1. The antibody optionally also comprises a set of LCDRs from antibody 668-1.
An antibody may comprise an antibody VH domain comprising CDRs HCDR1 ,
HCDR2 and HCDR3 and an antibody VL domain comprising CDRs LCDR1 , LCDR2 and LCDR3, wherein
the HCDR1 , HCDR2 and HCDR3 are each independently selected from an antibody of the antibody 669 lineage, and/or wherein
the LCDR1 , LCDR2 and LCDR3 are each independently selected from an antibody of the antibody 669 lineage.
Optionally, the antibody comprises a set of HCDRs from antibody 669-1 , 669-2, 669- 3, 669-4, 669-5 or 669-6. The antibody optionally comprises a set of LCDRs from the same antibody.
Example antibody CDR sequences for antibodies of the invention are as follows:
HCDR1 G(Y/F)TFT(N/D)YAMH SEQ ID NO: 134
HCDR2 WINAGNGYTKYSQKFQD SEQ ID NO: 14
HCDR3 DSFYDILSGPVYHYYGMDV SEQ ID NO: 15
LCDR1 TGTS(N/S)DVG(I/S)YN (H/YV)S SEQ ID NO: 135
LCDR2 DVN(T/K)RPS SEQ ID NO: 136
LCDR3 (C/S)SYAGSS(A/T)WV SEQ ID NO: 137,
e.g., CSYAGSSAWV (SEQ ID NO: 20) or SSYAGSSTWV (SEQ ID NO: 30) Residues shown in brackets are alternatives at a given position. Thus, position 2 of a sequence Z(X/Y)Z has either residue X or residue Y, so that Z(X/Y)Z designates the sequences ZXZ and ZYZ.
Thus, in some embodiments, the antibody has a HCDR3 sequence
DSFYDILSGPVYHYYGMDV or DGFCPSNTCSGYYGMDV, a HCDR1 sequence
G(Y/F)TFT(N/D)YAMH, and a HCDR2 sequence WINAGNGYTKYSQKFQD. In some embodiments, the antibody has an LCDR3 sequence CSYAGSSAWV or SSYAGSSTWV, an LCDR1 sequence TGTS(N/S)DVG(I/S)YN (H/YV)S, and an LCDR2 sequence
DVN(T/K)RPS.
Antibodies of the invention may comprise VH and/or VL domain framework regions corresponding to human germline gene segment sequences. For example, it may comprise one or more framework regions of antibody 666, antibody 667, antibody 668 or antibody 669. The framework region or framework regions may be a FR1 , FR2, FR3 and/or FR4.
An antibody of the invention may comprise an antibody VH domain which
(i) is derived from recombination of a human heavy chain V gene segment, a human heavy chain D gene segment and a human heavy chain J gene segment, wherein
the V segment is IGHV1-3;
the D gene segment is IGHD3-10, IGHD3-9, IGHD4-1 1 or IGHD2-2; and/or the J gene segment is IGHJ6, or
(ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein
FR1 aligns with human germline V gene segment IGHV1-3 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations,
FR2 aligns with human germline V gene segment IGHV1-3 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations,
FR3 aligns with human germline V gene segment IGHV1-3 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations, and/or
FR4 aligns with human germline J gene segment IGHJ6 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations. Optionally, a FR1 , FR2, FR3 or FR4 segment may align perfectly with the germline gene segment, i.e., with no amino acid alterations.
Thus, for example, the antibody may comprise a VH domain derived from
recombination of human heavy chain V gene segment IGHV1-3, a human heavy chain D gene segment and a human heavy chain J gene segment IGHJ6. An antibody may comprise VH domain framework regions FR1 , FR2, FR3 and FR4, wherein FR1 , FR2 and FR3 each align with human germline V gene segment IGHV1-3 with 1 , 2, 3, 4 or 5 amino acid alterations, and a FR4 that aligns with human germline J gene segment IGHJ6 with 1 , 2, 3, 4 or 5 amino acid alterations. An antibody of the invention may comprise an antibody VL domain which
(i) is derived from recombination of a human light chain V gene segment and a human light chain J gene segment, wherein
the V segment is IGLV2-23, and/or
the J gene segment is IGLJ3; or
(ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein
FR1 aligns with human germline V gene segment IGLV2-23 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations,
FR2 aligns with human germline V gene segment IGLV2-23 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations,
FR3 aligns with human germline V gene segment IGLV2-23 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations, and/or
FR4 aligns with human germline J gene segment IGLJ3 with up to 5 amino acid alterations, e.g., 1 , 2, 3, 4 or 5 amino acid alterations. Optionally, a FR1 , FR2, FR3 or FR4 segment may align perfectly with the germline gene segment, i.e., with no amino acid alterations.
An antibody according to the invention may comprise an antibody VH domain which is the VH domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VH domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669. Optionally, the VH domain is the VH domain of an antibody in the antibody 666 lineage, an antibody in the antibody 667 lineage, an antibody in the antibody 668 lineage or an antibody in the antibody 669 lineage.
The antibody may comprise an antibody VL domain which is the VL domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VL domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669. Optionally, the VL domain is the VL domain of an antibody in the antibody 666 lineage, an antibody in the antibody 667 lineage, an antibody in the antibody 668 lineage or an antibody in the antibody 669 lineage.
An antibody VH domain having the HCDRs of antibody 666, antibody 667, antibody 668 or antibody 669, or having a variant of those CDRs, may be paired with an antibody VL domain having the LCDRs of the same antibody, or having a variant of those CDRs.
Similary, the VH domain of any of antibody 666, antibody 667, antibody 668 or antibody 669, or a variant of that VH domain, may be paired with a VL domain of the same antibody, or a VL domain variant of the same antibody.
For instance, the antibody may comprise the antibody 667 VH domain and the antibody 667 VL domain. In another example, the antibody may comprise the antibody 668 VH domain and the antibody 668 VL domain. Antibodies may include constant regions, optionally human heavy and/or light chain constant regions. An exemplary isotype is IgG, e.g., human IgGl
Antibodies according to the present invention may be administered to human patients, optionally paediatric patients (under 18 years of age), including young children (5 years of age and under), such as to babies and infants (under 36 months of age, e.g., under 24 months of age). Young patients may have greatest need of prevention by prophylaxis or treatment with the antibodies, as they have been reported to have the highest rates of severe malaria (Griffin et al., Proc. R. Soc. B 282:20142657). The antibodies can also be used in adults of any age. For example, the patient may be a male or female aged 50 years or under, e.g., 40 or under, or 30 or under.
The antibodies may be optimally used at time of peak malaria transmission, which coincides with the rain seasons in many target populations. Antibodies may be administered to individuals during the rain season in tropical regions where malaria transmission is ongoing, including sub-Saharan Africa, South-East Asia, Latin America or the Middle East. Antibody may also be administered to travellers outside these regions, in preparation for travel to tropical regions affected by malaria.
Further aspects of the invention include nucleic acid molecules encoding sequences of the antibodies described herein, host cells containing such nucleic acids, and methods of producing the antibodies by culturing the host cells and expressing and optionally isolating or purifying the antibodies. The expressed antibody is thereby obtained. VH and VL domains of antibodies described herein may similarly be produced and are aspects of the present invention. Suitable production methods of antibodies include large-scale expression from host cells (e.g, mammalian cells) in a bioreactor by continuous or batch culture (e.g., fed batch culture). Brief Description of the Drawings
Figure 1 illustrates the life cycle of malarial Plasmodium parasites such as P. falciparum.
Figure 2 is an immunisation schedule for Kymice to produce anti-malarial antibodies. Figure 3 is a schematic diagram of antigen binding cross-blocking between antibodies.
Figure 4 is a table of data relating to selected anti-malarial antibodies.
Figure 5 illustrates a model to test protection of mice from mosquito transmission of
Plasmodium. Figure 6 shows the synthetic nucleotide sequence for Pf CSP (SEQ ID NO: 41 , encoding SEQ ID NO: 42). Figure 7 shows the amino acid sequence of Pf CSP (SEQ ID NO: 42) used for reverse translation of a synthetic nucleotide sequence. The illustrated sequence includes a hexa- histidine C-terminal tag. The sequence without the his tag is Plasmodium falciparum CSP SEQ ID NO: 43. Figure 8 shows the results of epitope mapping experiments for antibodies 667 and 668 and reference data from other test antibodies. A: Dose-dependent ELISA binding towards recombinant CSP from P. falciparum. B: Dose-dependent ELISA binding towards EP070034 (NANP peptide). C: Dose-dependent ELISA binding towards Pf16 (C-terminal peptide of CSP).
Figure 9 shows results obtained for Antibody 667 and Antibody 668 in a murine malaria challenge model as described in Examples 4a and 4b. Protection data is displayed in terms of liver-stage parasite burden, determined by the number of P. berghei 18s RNA copies detected in mouse liver homogenates.
Figure 10 shows results obtained in the in vivo mouse protection assay described in
Examples 4a and 4b. Results are expressed as percent inhibition compared with naive infected mice. Figure 11 shows further results from the work described in Examples 4a and 4b, in terms of parasitemia following sporozoite challenge of mice receiving passive transfer of anti-CSP mAbs. 17 days after blood feeding on Pb-Pf FULL CSP infected mice, the proportion of infected mosquitoes was -85% (26 out of 30 infected salivary glands). Based on this calculation, it was determined that 6 mosquitoes were needed to challenge mice with 5 infected mosquito bites. Upon passive transfer of monoclonal antibodies, mice were anesthetised with 2% Avertin and mosquitoes allowed to feed on mice for -10 minutes. After feeding, we determined the number of mosquitoes positive for a blood meal. Upper panel data are for mAb667; lower panel data are for mAb668. Figure 12 shows data from the gliding motility assay described in Example 5. P. falciparum sporozoites were pre-incubated with the indicated antibodies for 30 min and then added to wells in the presence of bovine serum albumin and incubated at 37 degrees C for 1 hr. They were then fixed and trails were stained with anti-CSP antibody and counted using a fluorescence microscope. 100 sporozoites were counted and shown is the number associated with the indicated number of circular trails, indicative of their motility. Figure 13 shows ILSDA data from the work described in Example 6. 25k Pf sporozoites were mixed with the indicated mAbs at 20 μg/ml and inoculated into CPHH. CPHH were harvested after 96 hours incubation. Pf 18s rRNA copy numbers were measured by qRT- PCR. Y axis is copies of Pf18s per well compared to standards. Error bars represent standard deviation. 3 separate wells were tested for each mAb. The tested anti-CSP antibodies are Ab640, Ab643, Ab646, Ab649, Ab662, Ab667 (second from right), Ab668 (far right) and the reference anti-CSP antibody 2A10 (second from left).
Figure 14 shows data on inhibition of hepatocyte traversal as described in Example 7. Graph represents traversal inhibition conferred by anti-CSP Antibodies 640, 643, 646, 649, 667 and 668 and antibodies to another antigen (Antibodies 605, 612, 628, 629, 632) tested in this assay at 10 μg/mL (right hand bar) and 100 μg/mL (left hand bar). The means of two independent experiments are shown. Only anti-CSP mAbs 667 and 668 appear to mediate traversal. Figure 15 shows data on inhibition of sporozoite invasion as described in Example 7. Graph represents invasion inhibition conferred by anti-CSP Antibodies 640, 643, 646, 649, 667 and 668 and antibodies to another antigen (Antibodies 605, 612, 628, 629, 632) tested in this assay at 10 μg/mL. The means of two independent experiments are shown. Figure 16 shows in vivo protection mediated by passive transfer of antibodies 667 and 668 in challenge of FRG humanized liver (Hu-Hep) mice with Pf-infected mosquito bites as described in Example 8. Ab667 and Ab668 exhibit robust and dose dependent protection from Pf sporozoite liver infection. Figure 17 shows amino acid sequences of the VH and VL domains of Antibody 667 and Antibody 668 with CDR sequences boxed. In the Ab667 VH domain (SEQ ID NO: 12) the HCDR1 (SEQ ID NO: 13), HCDR2 (SEQ ID NO: 14) and HCDR3 (SEQ ID NO: 15) sequences are boxed. In the Ab667 VL domain (SEQ ID NO: 17), the LCDR1 (SEQ ID NO: 18), LCDR2 (SEQ ID NO: 19) and LCDR3 (SEQ ID NO: 20) sequences are boxed. In the Ab668 VH domain (SEQ ID NO: 22), the HCDR1 (SEQ ID NO: 23), HCDR2 (SEQ ID NO: 24) and HCDR3 (SEQ ID NO: 25) sequences are boxed. In the Ab668 VL domain (SEQ ID NO: 27), the LCDR1 (SEQ ID NO: 28), LCDR2 (SEQ ID NO: 29) and LCDR3 (SEQ ID NO: 30) sequences are boxed.
Figure 18 is an antibody lineage tree for Ab666, showing the inferred relationship between Ab666 and Ab666-1 , Ab666-2, Ab666-3 and Ab666-4.
Figure 19 is an antibody lineage tree for Ab667, showing the inferred relationship between Ab667 and Ab667-1 , Ab667-2 and Ab667-3. Figure 20 is an antibody lineage tree for Ab668, showing the inferred relationship between Ab668 and Ab668-1.
Figure 21 is an antibody lineage tree for Ab669, showing the inferred relationship between Ab669 and Ab669-1 , Ab669-2, Ab669-3, Ab669-4, Ab669-5 and Ab669-6.
Figure 22 shows (a) the nucleotide sequence and (b) the amino acid sequence of recombinant CSP used for the experimental work in Example 10.
The amino acid sequence includes, besides the CSP ectodomain:
LHHILDAQKMLWNHR = Biotinylation tag BirA enzyme substrate peptide
DRNLPPLAPLGP = Biolinker
HHHHHH = Histidine tag
Figure 23 is a multiple sequence alignment of the light chain for all antibodies containing the common IGLV2-23 IGLJ3 genotype. CDRs are highlighted by boxes. Identical amino acids are indicated by a dot.
Figure 24 is a multiple sequence alignment of the heavy chain for all antibodies containing the common IGLV2-23 IGLJ3 genotype. CDRs of Ab666, Ab667, Ab668 and Ab669 are highlighted by boxes. Due to differences in CDR lengths, the sequences have different overall lengths. Identical amino acids are indicated by a dot.
Detailed Description
As described in more detail in the Examples, we isolated and characterised antibodies of particular interest, numbered 666, 667, 668 and 669. Sequences of each of these antibodies are provided in the appended sequence listing, wherein for each antibody the following sequences are shown in order: nucleotide sequence encoding VH domain; amino acid sequence of VH domain; VH CDR1 amino acid sequence, VH CDR2 amino acid sequence; VH CDR3 amino acid sequence; nucleotide sequence encoding VL domain; amino acid sequence of VL domain; VL CDR1 amino acid sequence; VL CDR2 amino acid sequence; and VL CDR3 amino acid sequence, respectively. In addition, the sequence listing includes VH and VL domain sequences for antibodies that were identified as being in the same lineages as antibody 666, 667, 668 and 669 and having different CDR sequences, namely antibodies 666-3, 666-4 (antibody 666 lineage), 667-1 , 667-2, 667-3 (antibody 667 lineage), 668-1 (antibody 668 lineage) 669-1 , 669-2, 669-3, 669-4, 669-5 and 669-6
(antibody 669 lineage). Further sets of antibody CDRs are shown in Table 5, Table 6 and Table 7. Still further sets of antibody CDRs, and antibody VH and VL domains, are shown in Table 16 and Table 18.
It is recognised that different conventions exist for identifying CDR sequences within antibody variable domains, and that CDRs may for example be determined according to the Kabat system, Chothia system, IMGT system, or others. In the appended Antibody CDR sequence tables we therefore show CDRs for the antibodies, including their CDRs as determined by the IMGT, Kabat and/or Chothia systems respectively.
Desirable properties
Antibodies according to the present invention are intended for medical use, particularly as anti-malarials, and for diagnostic use.
Desirable properties for antibodies according to examples of the present invention include one or more of:
(i) binding to the NANP repeat region of CSP and/or to a region of 12 or 15 amino acids immediately preceding the NANP repeat region;
(ii) reducing the risk of malaria in a mammal;
(iii) reducing one or more symptoms of malaria in a mammal;
(v) reducing progression of Plasmodium infection in a mammal; and
(vi) reducing transmisson, or reducing the risk of transmission, of Plasmodium to and/or from a mammal.
Thus, an antibody of the present invention may have any one or more, for example all, of these properties.
An antibody according to the invention may be a neutralising antibody, neutralising one or more functions of CSP. Anti-CSP antibodies according to the invention may inhibit sporozoite functions in assays in vitro, including gliding motility (Example 5), liver stage development (Example 6) and hepatocyte traversal and/or invasion (Example 7).
An antibody of the invention may inhibit the pre-erythrocytic stage of a Plasmodium parasite infection, e.g., P. falciparum infection, thereby reducing infection by mosquito transmitted malaria. An antibody may provide protection from challenge in a malaria challenge mouse model (e.g., in which mice are infected with recombinant Plasmodium berghei expressing Plasmodium falciparum CPS) and the equivalent human challenge model. An illustrative protocol for such a mouse model is set out in Example 4. Protection from challenge may be quantified as % reduction in liver-stage parasite load determined by the number of P. berghei 18s RNA copies detected in mouse liver homogenates in such a model where the murine P. berghei has been engineered to express P. falciparum CSP. Protection from challenge may be at least 50 %, at least 60 %, at least 70 %, at least 80 %, at least 90 %, at least 95 %, at least 98 % or at least 99 %. Full protection from challenge may be obtained, i.e., liver-stage parasite load may be eliminated or entirely prevented through treatment.
Examples 4 and 8 herein describe in detail two different in vivo mouse challenge models that were used to assess the ability of passively-transferred anti-CSP mAbs to protect mice from sporozoite challenge: a transgenic (Pb-Pf CSP) sporozoite challenge and a human liver (Hu-Hep) mouse challenge model.
Protocols for challenge models are also described in:
Development of a chimeric Plasmodium berghei strain expressing the repeat region of the P. vivax circumsporozoite protein for in vivo evaluation of vaccine efficacy.
Espinosa DA1 , Yadava A, Angov E, Maurizio PL, Ockenhouse CF, Zavala F.
Infect Immun. 2013 Aug;81 (8):2882-7. doi: 10.1128/IAI.00461-13. Epub 2013 May 28.
Full-length Plasmodium falciparum circumsporozoite protein administered with long- chain poly(l«C) or the Toll-like receptor 4 agonist glucopyranosyl lipid adjuvant-stable emulsion elicits potent antibody and CD4+ T cell immunity and protection in mice.
Kastenmuller K, Espinosa DA, Trager L, Stoyanov C, Salazar AM, Pokalwar S, Singh S, Dutta S, Ockenhouse CF, Zavala F, Seder RA. Infect Immun. 2013 Mar;81 (3):789-800. doi: 10.1128/IAI.01108-12. Epub 2012 Dec 28.
Transgenic Parasites Stably Expressing Full-Length Plasmodium falciparum
Circumsporozoite Protein as a Model for Vaccine Down-Selection in Mice Using Sterile Protection as an Endpoint. Porter et al., Clin Vaccine Immunol. 20(6):803-810 2013.
Antibodies according to the present invention bind CSP. As described in Example 1 , exemplary antibodies were raised in Kymice™ immunised with CSP from P. falciparum. The nucleotide and amino acid sequences of CSP are shown in Figures 6 and 7. An antibody may bind the four amino acid repeat region (NANP) of CSP. It may bind one or more residues encoded by nucleotides 368 to 862 as shown in Figure 6. The NANP region is the region of the CSP polypeptide that is characterised by multiple tandem repeats of the amino acid sequence NANP (SEQ ID NO: 47) i.e., Asn - Ala - Asn - Pro. The NANP repeat region starts with a sequence NANPNVDPNANP, which may provide at least part of the epitope for antibodies according to the invention. Thus, an antibody may bind one or more residues of this sequence. An antibody may for example bind the initial (N-terminal) NANP motif of this sequence, i.e., it may bind one or more residues of the NANP motif.
An antibody according to the present invention may bind the second and or third amino acid residue within a "NANP" motif, i.e., it may bind the Ala or the second Asn residue, as may be determined for example by measuring binding to a peptide comprising the NANP motif and a loss of binding or reduction in binding to a corresponding peptide in which the NANP motif is mutated at the second or third amino acid residue. Peptide mapping methods are described below and in Example 10. Points of contact between antibody and antigen may be determined in other ways, such as by x-ray crystallography.
In addition, or as an alternative, to binding the NANP repeat region of the CSP polypeptide sequence, antibodies may bind CSP within a region of up to 12 amino acids preceding the NANP repeat region, in the sequence KLKQPGDGNPDP. For example, antibodies may bind the NPDP motif within this sequence.
An antibody may bind to CSP at one or more residues of the sequence NPDPNANP, which is the sequence comprising the first NANP motif and the residues that immediately precede it. Thus, optionally the antibody may bind the NPDP motif immediately preceding the NANP repeat region, and/or may bind the first NANP motif of the NANP repeat region.
In addition, or as an alternative, to binding the NANP repeat region of the CSP sequence, antibodies may bind CSP within a region of up to 15 amino acids preceding the NANP repeat region, in the sequence KHKKLKQPGDGNPDP. An antibody may bind one or more residues within the sequence KHKKLKQPG.
An antibody may bind a polypeptide or peptide comprising or consisting of a NANP repeat region (NANP)n where n is 1 to 40, e.g., 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30 or 40, e.g., (NANP)4.
Any suitable method may be used to determine whether an antibody binds to an antigen such as CSP, a fragment thereof (e.g., the NANP region or a fragment comprising the NANP region or a sequence or motif mentioned above), or a polypeptide or peptide comprising a NANP repeat region. Such a method may comprise surface plasmon resonance (SPR), bio-layer interferometry, or an ELISA to determine specificity of antibodies. An antibody may be said to bind its antigen if the level of binding to antigen is at least 2.5 fold greater, e.g., at least 10 fold greater, than binding to a control antigen. Binding between an antibody and its cognate antigen is often referred to as specific binding. Precise identification of the residues bound by an antibody can usually be obtained using x-ray crystallography. This technique may be used to determine that an antibody of the invention binds one or more residues of the NANP repeat region of CSP and/or other sequences as mentioned above. The antibody epitope may comprise or consist of residues within the NANP repeat region.
Antibody binding epitopes can be mapped using one or more of the following methods:
ELISA binding of antibodies to linear peptides synthesised chemically can be used for linear epitope identification, with fine mapping achieved through the use of overlapping peptides where each peptide is offset by a minimum of one amino acid.
Single alanine substitutions of the binding peptide can be used to fine map internal amino acid contributions to the minimal binding peptide.
Full length CSP can be used together with progressive deletions from the N or C— terminus or expression of CSP sub-domains to identify antibody binding epitopes.
Site directed mutagenesis of full length CSP, N or C terminal deletions or sub- domains can be used to identify the precise epitope in the native protein.
Co-crystallisation, scanning and/or cryoEM can be used to give structural information of antibody bound to CSP including the precise atomic resolution of antibody and CSP binding using either CSP or linear peptides.
Biolayer interferometry can be used to analyse binding of antibodies to CSP peptides. Illustrative methods using biolayer interferometry, including fine mapping using single residue substitutions in peptide fragments, are presented in Example 10.
Any of these techniques, alone or in combination, can be used to determine whether an antibody binds to a CSP sequence of interest, including those mentioned above such as NANPNVDPNANP and/or KLKQPGDGNPDP.
Binding to CSP or peptides or residues thereof may be determined with respect to the CSP amino acid sequence shown in Figure 6 or Figure 7 or a fragment thereof. Variant CSP sequences are known, including naturally occurring variants. Figure 23 shows an alternative CSP sequence. An antibody of the present invention may bind CSP having an amino acid sequence shown in Figure 6 or Figure 7. The antibody may additionally bind CSP having an amino acid sequence shown in Figure 22.
The invention provides antibodies that compete with antibody 666, 667, 668 or 669 for binding to CSP or a fragment thereof. An antibody may compete with a human lgG1 or with an scFv antibody comprising the VH and VL domain of an antibody selected from 666, 667, 668 or 669, or a human lgG1 or with an scFv antibody comprising the heavy and light chain CDRs of antibody 666, 667, 668 or 669. Competition between antibodies may be assayed in vitro, for example using ELISA and/or by tagging a specific reporter molecule to one antibody, which can be detected in the presence of one or more other untagged antibodies, to enable identification of antibodies that bind the same epitope or an
overlapping epitope. One standard assay for competition between antibodies is a
competitive cross-blocking assay using surface plasmon resonance - see Example 3.
In assay methods and methods of administration described herein relating to the CSP antigen, it is optional to use full length CSP. Alternatives to full length CSP include the isolated NANP repeat region, a fragment of CSP comprising this region, or a synthetically generated NANP repeat peptide such as (NANP)n, where n = 4 to 40, e.g., (NANP)40, (NANP)10 or (NANP)4, may be employed. These CSP fragments or synthetic peptides may be provided as isolated sequences, contained within longer polypeptide sequences, and/or provided with one or more tags or detectable labels, as appropriate.
Ability of an antibody to bind its target antigen, and the specificity and affinity of that binding (Kd, Koff and/or Kon) can be determined by any routine method in the art, including SPR. The term "Kd", as used herein, is intended to refer to the equilibrium dissociation constant of a particular antibody-antigen interaction. Affinity of antibody-antigen binding may be determined, e.g., by surface plasmon resonance. Affinity may also be determined by bio- layer interferometry. An example of affinity determination by bio-layer interferometry is provided in Example 3 herein. An antibody may bind to CSP with an affinity (Kd) of 1 mM or less, usually 1 nM or less, e.g., 0.9 nM or less, 0.8 nM or less, 0.7 nM or less, 0.5 nM or less, or 0.4 nM or less.
Determining affinity (Kd) by bio-layer interferometry may comprise:
immobilising antibody on biosensors (e.g., at a concentration of 20 μg/mL) for a first time period, e.g., 60 seconds;
- contacting the antibody-loaded biosensors with a dilution series of antigen (Pf
CSP), e.g., starting at 1000 nM, 1 :3 diluted down;
observing association for a second time period, e.g., 120 seconds, followed by a dissociation period, e.g., 180 seconds of dissociation;
characterising the antibody-antigen binding affinity by fitting kinetic sensorgrams to a monovalent binding model (1 :1 binding).
A baseline measurement may be established using dissociation buffer after loading the biosensors (e.g., for 30 seconds). Parallel references may be set up by using unloaded bare sensor and sensor contacted with the dilution series of the antigen, and the parallel reference used for normalisation in data processing.
In an alternative set-up, antigen is immobilised on the biosensors and contacted with a dilution series of the antibody (e.g., starting at 33 nM or 133 nM, 1 :3 diluted down). In each case, suitable concentrations for the dilution series can be determined depending on the strength of the affinity being measured. Any suitable bio-layer interferometry machine may be used.
An alternative is to use SPR. Optionally, SPR is carried out at 25°C. An alternative is 37°C. SPR may be performed at physiological pH, such as about pH 7 or at pH 7.6 (e.g., using Hepes buffered saline at pH 7.6 (also referred to as HBS-EP)). SPR may be carried out at a physiological salt level, eg, 150 mM NaCI. SPR may be carried out at a detergent level of no greater than 0.05 % by volume, e.g., in the presence of P20 (polysorbate 20; eg, Tween-20®) at 0.05 % and EDTA at 3 mM. In one example, the SPR is carried out at 25°C or 37°C in a buffer at pH 7.6, 150 mM NaCI, 0.05 % detergent (e.g., P20) and 3 mM EDTA. The buffer can contain 10 mM Hepes. In one example, the SPR is carried out at 25°C or 37°C in HBS-EP. HBS-EP is available from Teknova Inc (California; catalogue number H8022).
In an example, the affinity of the antibody is determined using SPR by
1. Coupling anti-mouse (or other relevant human, rat or non-human vertebrate antibody constant region species-matched) IgG (e.g., Biacore® BR-1008-38) to a biosensor chip
(e.g., GLM chip) such as by primary amine coupling;
2. Exposing the anti-mouse IgG (or other matched species antibody) to a test IgG antibody to capture test antibody on the chip;
3. Passing the test antigen over the chip's capture surface at 1024 nM, 256 nM, 64 nM, 16 nM, 4 nM with a 0 nM (i.e. buffer alone); and
4. Determining the affinity of binding of test antibody to test antigen using surface plasmon resonance, eg, under an SPR condition discussed above (e.g., at 25°C in physiological buffer).
SPR can be carried out using any standard SPR apparatus, such as by Biacore® using the ProteOn XPR36® (Bio-Rad®).
Regeneration of the capture surface can be carried out with 10 mM glycine at pH 1.7. This removes the captured antibody and allows the surface to be used for another interaction. The binding data can be fitted to 1 : 1 model inherent using standard techniques, e.g., using a model inherent to the ProteOn XPR36® analysis software. Antibodies
Antibodies according to the present invention are immunoglobulins or molecules comprising immunoglobulin domains, whether natural or partly or wholly synthetically produced. Antibodies may be IgG, IgM, IgA, IgD or IgE molecules or antigen-specific antibody fragments thereof (including, but not limited to, a Fab, F(ab')2, Fv, disulphide linked Fv, scFv, single domain antibody, closed conformation multispecific antibody, disulphide- linked scfv, diabody), whether derived from any species that naturally produces an antibody, or created by recombinant DNA technology; whether isolated from serum, B-cells, hybridomas, transfectomas, yeast or bacteria. Antibodies can be humanised using routine technology. The term antibody covers any polypeptide or protein comprising an antibody antigen-binding site. An antigen-binding site (paratope) is the part of an antibody that binds to and is complementary to the epitope of its target antigen (NANP, eg, comprised by CSP).
The term "epitope" refers to a region of an antigen that is bound by an antibody. Epitopes may be defined as structural or functional. Functional epitopes are generally a subset of the structural epitopes and have those residues that directly contribute to the affinity of the interaction. Epitopes may also be conformational, that is, composed of nonlinear amino acids. In certain embodiments, epitopes may include determinants that are chemically active surface groupings of molecules such as amino acids, sugar side chains, phosphoryl groups, or sulfonyl groups, and, in certain embodiments, may have specific three-dimensional structural characteristics, and/or specific charge characteristics.
The antigen binding site is a polypeptide or domain that comprises one or more
CDRs of an antibody and is capable of binding the antigen. For example, the polypeptide comprises a CDR3 (e.g., HCDR3). For example the polypeptide comprises CDRs 1 and 2 (e.g., HCDR1 and 2) or CDRs 1-3 of a variable domain of an antibody (e.g., HCDRs1-3).
An antibody antigen-binding site may be provided by one or more antibody variable domains. In an example, the antibody binding site is provided by a single variable domain, e.g., a heavy chain variable domain (VH domain) or a light chain variable domain (VL domain). In another example, the binding site comprises a VH/VL pair or two or more of such pairs. Thus, an antibody antigen-binding site may comprise a VH and a VL.
The antibody may be a whole immunoglobulin, including constant regions, or may be an antibody fragment. An antibody fragment is a portion of an intact antibody, for example comprising the antigen binding and/or variable region of the intact antibody. Examples of antibody fragments include:
(i) a Fab fragment, a monovalent fragment consisting of the VL, VH, CL and CH1 domains;
(ii) a F(ab')2 fragment, a bivalent fragment including two Fab fragments linked by a disulfide bridge at the hinge region;
(iii) an Fd fragment consisting of the VH and CH1 domains;
(iv) an Fv fragment consisting of the VL and VH domains of a single arm of an antibody,
(v) a dAb fragment (Ward et al., (1989) Nature 341 :544-546; which is incorporated by reference herein in its entirety), which consists of a VH or VL domain; and
(vi) an isolated complementarity determining region (CDR) that retains specific antigen- binding functionality. Single-chain antibodies (e.g., scFv) are a commonly used fragment. Multispecific antibodies may be formed from antibody fragments. An antibody of the invention may employ any such format, as appropriate.
An antibody normally comprises an antibody VH and/or VL domain. Isolated VH and VL domains of antibodies are also part of the invention. The antibody variable domains are the portions of the light and heavy chains of antibodies that include amino acid sequences of complementarity determining regions (CDRs; ie., CDR1 , CDR2, and CDR3), and framework regions (FRs). Thus, within each of the VH and VL domains are CDRs and FRs. A VH domain comprises a set of HCDRs, and a VL domain comprises a set of LCDRs. VH refers to the variable domain of the heavy chain. VL refers to the variable domain of the light chain. Each VH and VL is typically composed of three CDRs and four FRs, arranged from amino- terminus to carboxy-terminus in the following order: FR1 , CDR1 , FR2, CDR2, FR3, CDR3, FR4. According to the methods used in this invention, the amino acid positions assigned to CDRs and FRs may be defined according to Kabat (Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md., 1987 and 1991 )) or according to IMGT nomenclature. An antibody may comprise an antibody VH domain comprising a VH CDR1 , CDR2 and CDR3 and a framework. It may alternatively or also comprise an antibody VL domain comprising a VL CDR1 , CDR2 and CDR3 and a framework. Examples of antibody VH and VL domains and CDRs according to the present invention are as listed in the appended sequence listing that forms part of the present disclosure. All VH and VL sequences, CDR sequences, sets of CDRs and sets of HCDRs and sets of LCDRs disclosed herein represent aspects and embodiments of the invention. As described herein, a "set of CDRs" comprises CDR1 , CDR2 and CDR3. Thus, a set of HCDRs refers to
HCDR1 , HCDR2 and HCDR3, and a set of LCDRs refers to LCDR1 , LCDR2 and LCDR3. Unless otherwise stated, a "set of CDRs" includes HCDRs and LCDRs. An antibody the invention may comprise one or more CDRs as described herein, e.g. a CDR3, and optionally also a CDR1 and CDR2 to form a set of CDRs. The CDR or set of CDRs may be a CDR or set of CDRs of any of antibodies 666, 667 668 or 669, or may be a variant thereof as described herein.
The invention provides antibodies comprising an HCDR1 , HCDR2 and/or HCDR3 of any of antibodies 666, 667, 668 and 669 and/or an LCDR1 , LCDR2 and/or LCDR3 of any of these antibodies, e.g. a set of CDRs. The antibody may comprise a set of VH CDRs of one of these antibodies. Optionally it may also comprise a set of VL CDRs of one of these antibodies, and the VL CDRs may be from the same or a different antibody as the VH CDRs.
A VH domain comprising a disclosed set of HCDRs, and/or a VL domain comprising a disclosed set of LCDRs, are also provided by the invention. Typically, a VH domain is paired with a VL domain to provide an antibody antigen- binding site, although as discussed further below a VH or VL domain alone may be used to bind antigen. The antibody 667 VH domain may be paired with the antibody 667 VL domain, so that an antibody antigen-binding site is formed comprising both the antibody 667 VH and VL domains. Analogous embodiments are provided for the other VH and VL domains disclosed herein. In other embodiments, the antibody 667 VH is paired with a VL domain other than the antibody 667 VL. Light-chain promiscuity is well established in the art. Again, analogous embodiments are provided by the invention for the other VH and VL domains disclosed herein.
Thus, the VH of any of antibodies 666 to 669 may be paired with the VL of any of antibodies 666 to 669. In particular, antibody 667 VH may be paired with antibody 668 VL, and antibody 668 VH may be paired with antibody 667 VL.
An antibody VH domain may optionally be paired with a VH domain of another antibody in the same lineage. For example, the VH domain of antibody 666 may be paired with the VL domain of any of antibodies 666-1 , 666-2, 666-3 and 666-4, the VH domain of antibody 666-1 may be paired with the VL domain of any of antibodies 666, 666-2, 666-3 and antibody 666-4, and so on.
An antibody may comprise one or more CDRs, e.g. a set of CDRs, within an antibody framework. The framework regions may be of human germline gene segment sequences. Thus, the antibody may be a human antibody having a VH domain comprising a set of HCDRs in a human germline framework. Normally the antibody also has a VL domain comprising a set of LCDRs, e.g. in a human germline framework. Figure 4 identifies human germline gene segment sequences that align to the variable domains of antibodies 666, 667, 668 and 669, indicating that these antibodies were derived from recombination of the identified gene segments. Table 17 provides the corresponding information for the antibodies referenced in Table 16 and Example 11 and for the antibodies referenced in Table 18 and Example 13. An antibody "gene segment", e.g., a VH gene segment, D gene segment, or JH gene segment refers to oligonucleotide having a nucleic acid sequence from which that portion of an antibody is derived, e.g., a VH gene segment is an oligonucleotide comprising a nucleic acid sequence that corresponds to a polypeptide VH domain from FR1 to part of CDR3. Human V, D and J gene segments recombine to generate the VH domain, and human V and J segments recombine to generate the VL domain. The D domain or region refers to the diversity domain or region of an antibody chain. J domain or region refers to the joining domain or region of an antibody chain. Somatic hypermutation may result in an antibody VH or VL domain having framework regions that do not exactly match or align with the corresponding gene segments, but sequence alignment can be used to identify the closest gene segments and thus identify from which particular combination of gene segments a particular VH or VL domain is derived. When aligning antibody sequences with gene segments, the antibody amino acid sequence may be aligned with the amino acid sequence encoded by the gene segment, or the antibody nucleotide sequence may be aligned directly with the nucleotide sequence of the gene segment.
An antibody of the invention may comprise an antibody VH domain derived from recombination of a human heavy chain V gene segment, a human heavy chain D gene segment and a human heavy chain J gene segment, wherein
the V segment is IGHV1-3;
the D gene segment is IGHD3-10, IGHD3-9, IGHD4-1 1 or IGHD2-2; and/or the J gene segment is IGHJ6.
IGHV1-3 is a particularly preferred V gene segment in antibodies and VH domains of the present invention. The selection of IGHV1-3 for recombination to generate antibody VH domains is believed to represent a particularly effective "choice" when the human immune repertoire is challenged with CSP antigen, as shown in the present Examples. Populations of transgenic mice immunised with CSP may generate anti-NANP repeat antibodies utilising the IGHV1-3 gene segment, these antibodies being effective for neutralising CSP. Thus, in one example the antibody of the invention comprises an antibody VH domain derived from recombination of a human heavy chain V gene segment, a human heavy chain D gene segment and a human heavy chain J gene segment, wherein the V segment is IGHV1-3 and the antibody neutralises NANP (e.g., neutralises CSP comprising (NANP)4). In an example, neutralisation is with an IC50 of 500M or less.
An antibody of the invention may comprise an antibody VL domain derived from recombination of a human light chain V gene segment and a human light chain J gene segment, wherein
the V segment is IGLV2-23, and/or
the J gene segment is IGLJ3.
An antibody of the invention may be a human antibody or a chimaeric antibody comprising human variable regions and non-human (e.g., mouse) constant regions. The antibody of the invention for example has human variable regions, and optionally also has human constant regions.
Thus, antibodies optionally include constant regions or parts thereof, e.g., human antibody constant regions or parts thereof. For example, a VL domain may be attached at its C-terminal end to antibody light chain kappa or lambda constant domains. Similarly, an antibody VH domain may be attached at its C-terminal end to all or part (e.g. a CH1 domain or Fc region) of an immunoglobulin heavy chain constant region derived from any antibody isotype, e.g. IgG, IgA, IgE and IgM and any of the isotype sub-classes, such as lgG1 or lgG4. Antibody constant regions may be engineered to have an extended half life in vivo. Examples include "YTE" mutations and other half-life extending mutations (Dall'Acqua, Kiener & Wu, JBC 281 (33):23514-23524 2006 and WO02/060919, incorporated by reference herein). The triple mutation YTE is a substitution of 3 amino acids in the IgG CH2 domain, these mutations providing tyrosine at residue 252, threonine at residue 254 and glutamic acid at residue 256, numbered according to the EU index of Kabat. As described in the referenced publications, the YTE modification increases the half-life of the antibody compared with the half-life of a corresponding antibody having a human CH2 wild type domain. To provide an increased duration of efficacy in vivo, antibodies of the present invention may include antibody constant regions (e.g., IgG constant regions, e.g., IgG CH2 domains) that have one or more mutations that increase the half life of the antibody compared with the corresponding wild type human constant region (e.g., IgG, e.g., IgG CH2 domain). Half-life may be determined by standard methods, such as are described in WO02/060919.
Constant regions of antibodies of the invention may alternatively be non-human constant regions. For example, when antibodies are generated in transgenic animals (examples of which are described elsewhere herein), chimaeric antibodies may be produced comprising human variable regions and non-human (host animal) constant regions. Some transgenic animals generate fully human antibodies. Others have been engineered to generate antibodies comprising chimaeric heavy chains and fully human light chains. Where antibodies comprise one or more non-human constant regions, these may be replaced with human constant regions to provide antibodies more suitable for administration to humans as therapeutic compositions, as their immunogenicity is thereby reduced.
Generating and modifying antibodies Methods for identifying and preparing antibodies are well known. Antibodies may be generated using transgenic mice (eg, the Kymouse™, Velocimouse® , Omnimouse® , Xenomouse®, HuMab Mouse® or MeMo Mouse®), rats (e.g., the Omnirat®), camelids, sharks, rabbits, chickens or other non-human animals immunised with CSP or a fragment thereof or a synthetic peptide comprising NANP tandem repeats (as described elsewhere herein), followed optionally by humanisation of the constant regions and/or variable regions to produce human or humanised antibodies. In an example, display technologies can be used, such as yeast, phage or ribosome display, as will be apparent to the skilled person. Standard affinity maturation, e.g., using a display technology, can be performed in a further step after isolation of an antibody lead from a transgenic animal, phage display library or other library. Representative examples of suitable technologies are described in US20120093818 (Amgen, Inc), which is incorporated by reference herein in its entirety, eg, the methods set out in paragraphs [0309] to [0346].
Generally, a Kymouse™, VELOC IMMUNE® or other mouse or rat can be challenged with the antigen of interest, and lymphatic cells (such as B-cells) are recovered from the mice that express antibodies. The lymphatic cells may be fused with a myeloma cell line to prepare immortal hybridoma cell lines, and such hybridoma cell lines are screened and selected to identify hybridoma cell lines that produce antibodies specific to the antigen of interest. DNA encoding the variable regions of the heavy chain and light chain may be isolated and linked to desirable isotypic constant regions of the heavy chain and light chain. Such an antibody protein may be produced in a cell, such as a CHO cell. Alternatively, DNA encoding the antigen-specific chimaeric antibodies or the variable domains of the light and heavy chains may be isolated directly from antigen-specific lymphocytes.
Initially, high affinity chimaeric antibodies are isolated having a human variable region and a mouse constant region. The antibodies are characterised and selected for desirable characteristics, including affinity, selectivity, epitope, etc. The mouse constant regions are optionally replaced with a desired human constant region to generate the fully human antibody of the invention, for example wild-type or modified lgG1 or lgG4 (for example, SEQ ID NO: 751 , 752, 753 in US2011/0065902 (which is incorporated by reference herein in its entirety). While the constant region selected may vary according to specific use, high affinity antigen-binding and target specificity characteristics reside in the variable region.
Variable domain amino acid sequence variants of any of the VH and VL domains or CDRs whose sequences are specifically disclosed herein may be employed in accordance with the present invention, as discussed.
An antibody may comprise a set of H and/or L CDRs of any of the disclosed antibodies with one or more amino acid mutations within the disclosed set of H and/or L CDRs. The mutation may be an amino acid substitution, deletion or insertion. Thus for example there may be one or more amino acid substitutions within the disclosed set of H and/or L CDRs. For example, there may be up to 12, 11 , 10, 9, 8, 7, 6, 5, 4, 3 or 2 mutations e.g. substitutions, within the set of H and/or L CDRs. For example, there may be up to 6, 5, 4, 3 or 2 mutations, e.g. substitutions, in HCDR3 and/or there may be up to 6, 5, 4, 3, or 2 mutations, e.g. substitutions, in LCDR3.
An antibody may comprise a VH domain that has at least 60, 70, 80, 85, 90, 95, 98 or 99 % amino acid sequence identity with a VH domain of any of the antibodies shown in the appended sequence listing, and/or comprising a VL domain that has at least 60, 70, 80, 85, 90, 95, 98 or 99 % amino acid sequence identity with a VL domain of any of those antibodies. Algorithms that can be used to calculate % identity of two amino acid sequences include e.g. BLAST, FASTA, or the Smith- Waterman algorithm, e.g. employing default parameters. Particular variants may include one or more amino acid sequence alterations (addition, deletion, substitution and/or insertion of an amino acid residue) .
Alterations may be made in one or more framework regions and/or one or more CDRs. Variants are optionally provided by CDR mutagenesis. The alterations normally do not result in loss of function, so an antibody comprising a thus-altered amino acid sequence may retain an ability to bind CSP. It may retain the same quantitative binding ability as an antibody in which the alteration is not made, e.g. as measured in an assay described herein. The antibody comprising a thus-altered amino acid sequence may have an improved ability to bind CSP.
Alteration may comprise replacing one or more amino acid residue with a non- naturally occurring or non-standard amino acid, modifying one or more amino acid residue into a non-naturally occurring or non-standard form, or inserting one or more non- naturally occurring or non-standard amino acid into the sequence. Examples of numbers and locations of alterations in sequences of the invention are described elsewhere herein.
Naturally occurring amino acids include the 20 "standard" L-amino acids identified as G, A, V, L, I, M, P, F, W, S, T, N, Q, Y, C, K, R, H, D, E by their standard single-letter codes. Nonstandard amino acids include any other residue that may be incorporated into a polypeptide backbone or result from modification of an existing amino acid residue. Non-standard amino acids may be naturally occurring or non-naturally occurring.
The term "variant" as used herein refers to a peptide or nucleic acid that differs from a parent polypeptide or nucleic acid by one or more amino acid or nucleic acid deletions, substitutions or additions, yet retains one or more specific functions or biological activities of the parent molecule. Amino acid substitutions include alterations in which an amino acid is replaced with a different naturally-occurring amino acid residue. Such substitutions may be classified as "conservative", in which case an amino acid residue contained in a polypeptide is replaced with another naturally occurring amino acid of similar character either in relation to polarity, side chain functionality or size. Such conservative substitutions are well known in the art. Substitutions encompassed by the present invention may also be "non- conservative", in which an amino acid residue which is present in a peptide is substituted with an amino acid having different properties, such as naturally-occurring amino acid from a different group (e.g., substituting a charged or hydrophobic amino; acid with alanine), or alternatively, in which a naturally-occurring amino acid is substituted with a non- conventional amino acid. In some embodiments amino acid substitutions are conservative. Also encompassed within the term variant when used with reference to a polynucleotide or polypeptide, refers to a polynucleotide or polypeptide that can vary in primary, secondary, or tertiary structure, as compared to a reference polynucleotide or polypeptide, respectively (e.g., as compared to a wild- type polynucleotide or polypeptide). In some aspects, one can use "synthetic variants", "recombinant variants", or "chemically modified" polynucleotide variants or polypeptide variants isolated or generated using methods well known in the art. "Modified variants" can include conservative or non- conservative amino acid changes, as described below. Polynucleotide changes can result in amino acid substitutions, additions, deletions, fusions and truncations in the polypeptide encoded by the reference sequence. Some aspects use include insertion variants, deletion variants or substituted variants with substitutions of amino acids, including insertions and substitutions of amino acids and other molecules) that do not normally occur in the peptide sequence that is the basis of the variant, for example but not limited to insertion of ornithine which do not normally occur in human proteins. The term "conservative substitution," when describing a polypeptide, refers to a change in the amino acid composition of the polypeptide that does not substantially alter the polypeptide's activity. For example, a conservative substitution refers to substituting an amino acid residue for a different amino acid residue that has similar chemical properties (e.g., acidic, basic, positively or negatively charged, polar or nonpolar, etc.). Conservative amino acid substitutions include replacement of a leucine with an isoleucine or valine, an aspartate with a glutamate, or a threonine with a serine. Conservative substitution tables providing functionally similar amino acids are well known in the art. For example, the following six groups each contain amino acids that are conservative substitutions for one another: 1) Alanine (A), Serine (S), Threonine (T); 2) Aspartic acid (D), Glutamic acid (E); 3) Asparagine (N), Glutamine (Q); 4) Arginine (R), Lysine (K); 5) Isoleucine (I), Leucine (L), Methionine (M), Valine (V); and 6) Phenylalanine (F), Tyrosine (Y), Tryptophan (W). (See also Creighton, Proteins, W. H. Freeman and Company (1984), incorporated by reference in its entirety.) In some embodiments, individual substitutions, deletions or additions that alter, add or delete a single amino acid or a small percentage of amino acids can also be considered "conservative substitutions" if the change does not reduce the activity of the peptide. Insertions or deletions are typically in the range of about 1 to 5 amino acids. The choice of conservative amino acids may be selected based on the location of the amino acid to be substituted in the peptide, for example if the amino acid is on the exterior of the peptide and expose to solvents, or on the interior and not exposed to solvents.
One can select the amino acid that will substitute an existing amino acid based on the location of the existing amino acid, including its exposure to solvents (i.e., if the amino acid is exposed to solvents or is present on the outer surface of the peptide or polypeptide as compared to internally localized amino acids not exposed to solvents). Selection of such conservative amino acid substitutions are well known in the art, for example as disclosed in Dordo et al, J. Mol Biol, 1999, 217, 721-739 and Taylor et al, J. Theor. Biol. 119(1986) ;205- 218 and S. French and B. Robson, J. Mol. Evol. 19(1983)171 . Accordingly, one can select conservative amino acid substitutions suitable for amino acids on the exterior of a protein or peptide (i.e. amino acids exposed to a solvent), for example, but not limited to, the following substitutions can be used: substitution of Y with F, T with S or K, P with A, E with D or Q, N with D or G, R with K, G with N or A, T with S or K, D with N or E, I with L or V, F with Y, S with T or A, R with K, G with N or A, K with R, A with S, K or P.
In alternative embodiments, one can also select conservative amino acid
substitutions encompassed suitable for amino acids on the interior of a protein or peptide, for example one can use suitable conservative substitutions for amino acids is on the interior of a protein or peptide (i.e. the amino acids are not exposed to a solvent), for example but not limited to, one can use the following conservative substitutions: where Y is substituted with F, T with A or S, I with L or V, W with Y, M with L, N with D, G with A, T with A or S, D with N, I with L or V, F with Y or L, S with A or T and A with S, G, T or V. In some embodiments, non-conservative amino acid substitutions are also encompassed within the term of variants.
The invention includes methods of producing antibodies containing VH and/or VL domain variants of the antibody VH and/or VL domains shown in the appended sequence listing. Such antibodies may be produced by a method comprising
(i) providing, by way of addition, deletion, substitution or insertion of one or more amino acids in the amino acid sequence of a parent antibody VH domain, an antibody VH domain that is an amino acid sequence variant of the parent antibody VH domain,
wherein the parent antibody VH domain is the VH domain of any of antibodies 666,
667, 668 and 669 or a VH domain comprising the heavy chain complementarity determining regions of any of those antibodies,
(ii) optionally combining the VH domain thus provided with a VL domain, to provide a VH/VL combination, and
(iii) testing the VH domain or VH/VL domain combination thus provided to identify an antibody with one or more desired characteristics.
Desired characteristics include binding to CSP, for example binding to the four amino acid repeat region NANP of the circumsporozoite protein (CSP) of Plasmodium parasites such as Plasmodium falciparum and optionally other malarial Plasmodium species as mentioned herein. Antibodies with comparable or higher affinity for binding CSP may be identified. Other desired characteristics include inhibiting the pre-erythrocytic stage of infection by Plasmodium, e.g, P. falciparum, which may be determined in an assay as described herein.
When VL domains are included in the method, the VL domain may be a VL domain of any of antibodies 666, 667, 668 or 669, or may be a variant provided by way of addition, deletion, substitution or insertion of one or more amino acids in the amino acid sequence of a parent VL domain, wherein the parent VL domain is the VL domain of any of antibodies 666, 667, 668 and 669 or a VL domain comprising the light chain complementarity determining regions of any of those antibodies.
An amino acid mutation (addition, deletion, substitution or insertion) may be introduced in an antibody variable domain at a position corresponding to a point of sequence variation across multiple antibodies in an antibody lineage. Thus, for example, an amino acid in a variable domain (VH or VL domain) of an antibody in a lineage (e.g., 666 lineage, 667 lineage, 668 lineage or 669 lineage) may be substituted with a different amino acid that is present at the corresponding position in another antibody of the same lineage. For instance, the antibody 666 VH domain comprises a C terminal sequence VTS, whereas certain other antibodies of the same lineage (666 lineage) comprise C terminal sequence VSS. The 666 VH domain may be engineered to have the substitution T>S in this C terminal motif.
Comparison of antibody variable domain sequences with human germline gene segment sequences can also identify amino acid residues (e.g., within framework regions) that differ from the germline sequence and may optionally be reverted. Such "germlining" methods are known in the art and comparison with germline gene segment sequences is discussed elsewhere herein.
Further examples of changes that may be introduced in antibody variable domains can be identified by reference to Figures 23 and 24 in which sequences of multiple antibodies are aligned. When introducing one or more amino acid alterations into an antibody variable domain sequence at a given residue position, the alteration or alterations may optionally be designed by reference to the corresponding residue at that position in another antibody shown in the alignment.
Methods of generating variant antibodies may optionally comprise producing copies of the antibody or VH/VL domain combination. Methods may further comprise expressing the resultant antibody. It is possible to produce nucleotide sequences corresponding to a desired antibody VH and/or VL domain, optionally in one or more expression vectors. Suitable methods of expression, including recombinant expression in host cells, are set out in detail herein.
Encoding nucleic acids and methods of expression Isolated nucleic acid may be provided, encoding antibodies according to the present invention. Nucleic acid may be DNA and/or RNA. Genomic DNA, cDNA, mRNA or other RNA, of synthetic origin, or any combination thereof can encode an antibody.
The present invention provides constructs in the form of plasmids, vectors, transcription or expression cassettes which comprise at least one polynucleotide as above.
Exemplary nucleotide sequences are included in the sequence listing. Reference to a nucleotide sequence as set out herein encompasses a DNA molecule with the specified sequence, and encompasses a RNA molecule with the specified sequence in which U is substituted for T, unless context requires otherwise.
The present invention also provides a recombinant host cell that comprises one or more nucleic acids encoding the antibody. Methods of producing the encoded antibody may comprise expression from the nucleic acid, e.g., by culturing recombinant host cells containing the nucleic acid. The antibody may thus be obtained, and may be isolated and/or purified using any suitable technique, then used as appropriate. A method of production may comprise formulating the product into a composition including at least one additional component, such as a pharmaceutically acceptable excipient.
Systems for cloning and expression of a polypeptide in a variety of different host cells are well known. Suitable host cells include bacteria, mammalian cells, plant cells,
filamentous fungi, yeast and baculovirus systems and transgenic plants and animals.
The expression of antibodies and antibody fragments in prokaryotic cells is well established in the art. A common bacterial host is E. coli. Expression in eukaryotic cells in culture is also available to those skilled in the art as an option for production. Mammalian cell lines available in the art for expression of a heterologous polypeptide include Chinese hamster ovary (CHO) cells, HeLa cells, baby hamster kidney cells, NSO mouse melanoma cells, YB2/0 rat myeloma cells, human embryonic kidney cells, human embryonic retina cells and many others.
Vectors may contain appropriate regulatory sequences, including promoter sequences, terminator sequences, polyadenylation sequences, enhancer sequences, marker genes and other sequences as appropriate. Nucleic acid encoding an antibody can be introduced into a host cell. Nucleic acid can be introduced to eukaryotic cells by various methods, including calcium phosphate transfection, DEAE-Dextran, electroporation, liposome-mediated transfection and transduction using retrovirus or other virus, e.g. vaccinia or, for insect cells, baculovirus. Introducing nucleic acid in the host cell, in particular a eukaryotic cell may use a viral or a plasmid based system. The plasmid system may be maintained episomally or may be incorporated into the host cell or into an artificial chromosome. Incorporation may be either by random or targeted integration of one or more copies at single or multiple loci. For bacterial cells, suitable techniques include calcium chloride transformation, electroporation and transfection using bacteriophage. The introduction may be followed by expressing the nucleic acid, e.g., by culturing host cells under conditions for expression of the gene, then optionally isolating or purifying the antibody. Nucleic acid of the invention may be integrated into the genome (e.g. chromosome) of the host cell. Integration may be promoted by inclusion of sequences that promote recombination with the genome, in accordance with standard techniques.
The present invention also provides a method that comprises using nucleic acid described herein in an expression system in order to express an antibody.
To provide medicines suitable for global treatment, antibodies can be produced on a large scale, for instance in cell culture volumes of at least 100 litres or at least 200 litres, e.g., between 100-250 litres. Batch culture, particularly fed-batch culture, is now commonly used for production of biotherapeutics for clinical and commercial use, and such methods may suitably be used in the present invention to generate the antibodies, followed by purification and formulation steps as noted herein. Bioreactors may be metal (e.g., stainless steel) vessels or may be single-use bioreactors.
Formulations and Therapeutic Use
Antibodies may be monoclonal or polyclonal, but are preferably provided as monoclonal antibodies for therapeutic use. They may be provided as part of a mixture of other antibodies, optionally including antibodies of different binding specificity, such as one or more antibodies that bind to different antigens of a Plasmodium parasite, e.g., P.
falciparum.
Antibodies according to the invention, and encoding nucleic acid, will usually be provided in isolated form. Thus, the antibodies, VH and/or VL domains, and nucleic acids may be provided purified from their natural environment or their production environment. Isolated antibodies and isolated nucleic acid will be free or substantially free of material with which they are naturally associated, such as other polypeptides or nucleic acids with which they are found in vivo, or the environment in which they are prepared (e.g. cell culture) when such preparation is by recombinant DNA technology in vitro. Optionally an isolated antibody or nucleic acid (1) is free of at least some other proteins with which it would normally be found, (2) is essentially free of other proteins from the same source, e.g., from the same species, (3) is expressed by a cell from a different species, (4) has been separated from at least about 50 percent of polynucleotides, lipids, carbohydrates, or other materials with which it is associated in nature, (5) is operably associated (by covalent or noncovalent interaction) with a polypeptide with which it is not associated in nature, or (6) does not occur in nature.
Antibodies or nucleic acids may be formulated with diluents or adjuvants and still for practical purposes be isolated - for example they may be mixed with carriers if used to coat microtitre plates for use in immunoassays, and may be mixed with pharmaceutically acceptable carriers or diluents when used in therapy. As described elsewhere herein, other active ingredients may also be included in therapeutic preparations. Antibodies may be glycosylated, either naturally in vivo or by systems of heterologous eukaryotic cells such as CHO cells, or they may be (for example if produced by expression in a prokaryotic cell) unglycosylated. The invention encompasses antibodies having a modified glycosylation pattern. In some applications, modification to remove undesirable glycosylation sites may be useful, or e.g., removal of a fucose moiety to increase antibody dependent cellular cytotoxicity (ADCC) function (see Shields et al. (2002) JBC 277:26733). In other
applications, modification of galactosylation can be made in order to modify complement dependent cytotoxicity (CDC).
Typically, an isolated product constitutes at least about 5%, at least about 10%, at least about 25%, or at least about 50% of a given sample. An antibody may be substantially free from proteins or polypeptides or other contaminants that are found in its natural or production environment that would interfere with its therapeutic, diagnostic, prophylactic, research or other use.
An antibody may have been identified, separated and/or recovered from a component of its production environment (eg, naturally or recombinantly). The isolated antibody may be free of association with all other components from its production environment, eg, so that the antibody has been isolated to an FDA-approvable or approved standard. Contaminant components of its production environment, such as that resulting from recombinant transfected cells, are materials that would typically interfere with research, diagnostic or therapeutic uses for the antibody, and may include enzymes, hormones, and other proteinaceous or non-proteinaceous solutes. In some embodiments, the antibody will be purified: (1) to greater than 95% by weight of antibody as determined by, for example, the Lowry method, and in some embodiments, to greater than 99% by weight; (2) to a degree sufficient to obtain at least 15 residues of N-terminal or internal amino acid sequence by use of a spinning cup sequenator, or (3) to homogeneity by SDS-PAGE under non-reducing or reducing conditions using Coomassie blue or silver stain. Isolated antibody includes the antibody in situ within recombinant cells since at least one component of the antibody's natural environment will not be present. Ordinarily, however, an isolated antibody or its encoding nucleic acid will be prepared by at least one purification step.
The invention provides therapeutic compositions comprising the antibodies described herein. Therapeutic compositions comprising nucleic acid encoding such antibodies are also provided. Encoding nucleic acids are described in more detail elsewhere herein and include DNA and RNA, e.g., mRNA. Nucleic acid encoding the antibody of the invention may be provided as naked DNA, mRNA, replicon RNA or in a viral vector (e.g., adenoviral vector or lentiviral vector, or retroviral vector or poxvirus vector or herpesvirus vector) for administration in a therapeutic method that allows direct expression of the antibody. The nucleic acid will then be expressed in vivo by the recipient eukaryotic cells, providing an in vivo source of the therapeutic antibody, suitable for provision of long term protection against the malarial parasite. Various methods are known for administering nucleic acid for stable expression in vivo. For example, a nucleic acid composition (optionally naked DNA, mRNA, replicon RNA) may be administered by intramuscular injection, or via a 'gene gun'. For viral delivery, a range of viral vectors are known in the art (including gene therapy vectors) and any suitable vector may be used for transient expression, episomal expression (persistent but not integrated into the host genome) or integration of the encoding nucleic acid into cells of the recipient (e.g., liver cells and/or cells of the haematopoietic system).
Compositions may contain suitable carriers, excipients, and other agents that are incorporated into formulations to provide improved transfer, delivery, tolerance, and the like. A multitude of appropriate formulations can be found in the formulary known to all pharmaceutical chemists: Remington's Pharmaceutical Sciences, Mack Publishing
Company, Easton, Pa. These formulations include, for example, powders, pastes, ointments, jellies, waxes, oils, lipids, lipid (cationic or anionic) containing vesicles (such as
LIPOFECTINT™), DNA conjugates, anhydrous absorption pastes, oil-in-water and water-in- oil emulsions, emulsions carbowax (polyethylene glycols of various molecular weights), semi-solid gels, and semi-solid mixtures containing carbowax. See also Powell et al.
"Compendium of excipients for parenteral formulations" PDA (1998) J Pharm Sci Technol 52:238-311. Compositions may comprise the antibody or nucleic acid in combination with medical injection buffer and/or with adjuvant. A composition may comprise the antibody in an aqueous buffered solution at a pH of between 6 and 8, e.g., 6.0 to 6.6, 6.4 to 7.1 , 6.9 to 7.6 or 7.4 to 8.0. Such compositions can be included in medical containers and/or in kits.
Antibodies, or their encoding nucleic acids, may be formulated for the desired route of administration to a patient, e.g., in liquid (optionally aqueous solution) for injection.
Various delivery systems are known and can be used to administer the pharmaceutical composition of the invention. Methods of introduction include, but are not limited to, intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous, intranasal, epidural, and oral routes. The composition may be administered by any convenient route, for example by infusion or bolus injection, by absorption through epithelial or mucocutaneous linings (e.g., oral mucosa, rectal and intestinal mucosa, etc.) and may be administered together with other biologically active agents. Administration can be systemic or local.
The pharmaceutical composition can be also delivered in a vesicle, in particular a liposome (see Langer (1990) Science 249: 1527-1533 ; Treat et al. (1989) in Liposomes in the Therapy of Infectious Disease and Cancer, Lopez Berestein and Fidler (eds.), Liss, New York, pp. 353-365 ; Lopez-Berestein, ibid., pp. 317-327 ; see generally ibid.). In certain situations, the pharmaceutical composition can be delivered in a controlled release system. In one embodiment, a pump may be used (see Langer, supra; Sefton (1987) CRC Crit. Ref. Biomed. Eng. 14:201 ). In another embodiment, polymeric materials can be used; see, Medical Applications of Controlled Release, Langer and Wise (eds.), CRC Pres., Boca Raton, Fla. (1974 ). In yet another embodiment, a controlled release system can be placed in proximity of the composition's target, thus requiring only a fraction of the systemic dose (see, e.g., Goodson, in Medical Applications of Controlled Release, supra, vol. 2, pp. 115-138, 1984 ).
The injectable preparations may include dosage forms for intravenous,
subcutaneous, intracutaneous and intramuscular injections, drip infusions, etc. These injectable preparations may be prepared by methods publicly known. For example, the injectable preparations may be prepared, e.g., by dissolving, suspending or emulsifying the antibody or its salt described above in a sterile aqueous medium or an oily medium conventionally used for injections. As the aqueous medium for injections, there are, for example, physiological saline, an isotonic solution containing glucose and other auxiliary agents, etc., which may be used in combination with an appropriate solubilizing agent such as an alcohol (e.g., ethanol), a polyalcohol (e.g., propylene glycol, polyethylene glycol), a nonionic surfactant [e.g., polysorbate 80, HCO-50 (polyoxyethylene (50 mol) adduct of hydrogenated castor oil)], etc. As the oily medium, there are employed, e.g., sesame oil, soybean oil, etc., which may be used in combination with a solubilizing agent such as benzyl benzoate, benzyl alcohol, etc. The injection thus prepared can be filled in an appropriate ampoule. A pharmaceutical composition of the present invention can be delivered subcutaneously or intravenously with a standard needle and syringe. It is envisaged that treatment will not be restricted to use in the clinic. Therefore, subcutaneous injection using a needle-free device is also advantageous. With respect to subcutaneous delivery, a pen delivery device readily has applications in delivering a pharmaceutical composition of the present invention. Such a pen delivery device can be reusable or disposable. A reusable pen delivery device generally utilizes a replaceable cartridge that contains a pharmaceutical composition. Once all of the pharmaceutical composition within the cartridge has been administered and the cartridge is empty, the empty cartridge can readily be discarded and replaced with a new cartridge that contains the pharmaceutical composition. The pen delivery device can then be reused. In a disposable pen delivery device, there is no replaceable cartridge. Rather, the disposable pen delivery device comes prefilled with the pharmaceutical composition held in a reservoir within the device. Once the reservoir is emptied of the pharmaceutical composition, the entire device is discarded. Numerous reusable pen and autoinjector delivery devices have applications in the subcutaneous delivery of a pharmaceutical composition of the present invention. Examples include, but certainly are not limited to AUTOPEN™ (Owen Mumford, Inc., Woodstock, UK), DISETRONIC™ pen (Disetronic Medical Systems, Burghdorf, Switzerland), HUMALOG MIX 75/25™ pen, HUMALOG™ pen, HUMALIN 70/30™ pen (Eli Lilly and Co., Indianapolis, Ind.), NOVOPEN™!, II and III (Novo Nordisk, Copenhagen, Denmark), NOVOPEN JUNIOR™ (Novo Nordisk, Copenhagen, Denmark), BD™ pen (Becton Dickinson, Franklin Lakes, N.J.), OPTIPENT™, OPTIPEN PRO™, OPTIPEN STARLET™, and OPTICLIKT™ (Sanofi- Aventis, Frankfurt, Germany), to name only a few. Examples of disposable pen delivery devices having applications in subcutaneous delivery of a pharmaceutical composition of the present invention include, but certainly are not limited to the SOLOSTAR™ pen (Sanofi- Aventis), the FLEXPEN™ (Novo Nordisk), and the KWIKPEN™ (Eli Lilly).
Advantageously, the pharmaceutical compositions for oral or parenteral use described above are prepared into dosage forms in a unit dose suited to fit a dose of the active ingredients. Such dosage forms in a unit dose include, for example, tablets, pills, capsules, injections (ampoules), suppositories, etc. The amount of the aforesaid antibody contained is generally about 5 to about 500 mg per dosage form in a unit dose; especially in the form of injection, the aforesaid antibody may be contained in about 5 to about 100 mg and in about 10 to about 250 mg for the other dosage forms.
The antibody, nucleic acid, or composition comprising it, may be contained in a medical container such as a phial, syringe, IV container or an injection device. In an example, the antibody, nucleic acid or composition is in vitro, and may be in a sterile container. In an example, a kit is provided comprising the antibody, packaging and instructions for use in a therapeutic method as described herein. The kit may comprise an insert (e.g., paper) and/or a label on a container containing the antibody or on the outer packaging of the kit, carrying the instructions for use in the therapeutic method, for example specifying use for prevention or treatment of malaria or of infection by Plasmodium such as P. falciparum. The insert or label may bear a marketing authorisation number, e.g., an FDA or EMA authorisation number. The antibody may be within a medical container comprising plastics material. Alternative medical grade materials include metal or glass. The medical container (e.g., phial, syringe, intravenous container or injection device) may comprise the antibody in a fluid form, optionally aqueous solution or in a composition comprising a pharmaceutically acceptable excipient as described herein.
One aspect of the invention is a composition comprising an antibody or nucleic acid of the invention and one or more pharmaceutically acceptable excipients, examples of which are listed above. "Pharmaceutically acceptable" refers to approved or approvable by a regulatory agency of the USA Federal or a state government or listed in the U.S.
Pharmacopeia or other generally recognized pharmacopeia for use in animals, including humans. A pharmaceutically acceptable carrier, excipient, or adjuvant can be administered to a patient, together with an agent, e.g., any antibody or antibody chain described herein, and does not destroy the pharmacological activity thereof and is nontoxic when administered in doses sufficient to deliver a therapeutic amount of the agent.
Compositions according to the present invention optionally include one or more additional active ingredients. Further therapeutic agents may be anti-malarial agents such as other antibodies that bind antigens of P. falciparum or other malarial Plasmodium species. Optionally, such compositions contain multiple antibodies (or encoding nucleic acids) in a combined preparation, e.g., a single formulation comprising the anti-CSP antibody and one or more other antibodies to the same or different antigens of malarial Plasmodium species such as P. falciparum. For example, a composition may include an antibody to Pfs25, an antigen of P. falciparum. Other example antibodies to Plasmodium antigens are antibodies to MSP-1 , MSP-2, TRAP, CelTOS, AMA1 , Rh5 or LSA1 , e.g., from P. falciparum. Other antimalarial agents include chemoprophylactic drugs such as mefloquinine, doxycycline, atovaquone, proguanil, quinine, artemether, lumefantrine, clindamycin, primaquine, artemisinin, sulphadoxine-pyrimethamine and chloroquine. Atovaquone and proguanil are usually administered in combination. Further anti-malarial drug combinations include artemether with lumefantrine, quinine plus doxycycline, and quinine plus clindamycin. Other therapeutic agents that it may be desirable to administer with antibodies or nucleic acids according to the present invention include antibiotics such as amikacin, and analgaesic agents. Any such agent or combination of agents may be administered in combination with, or provided in compositions with antibodies or nucleic acids according to the present invention, whether as a combined or separate preparation. The antibody or nucleic acid according to the present invention may be administered separately and sequentially, or concurrently and optionally as a combined preparation, with another therapeutic agent or agents such as those mentioned.
Multiple compositions can be administered separately or simultaneously. Separate administration refers to the two compositions being administered at different times, e.g. at least 10, 20, 30, or 10-60 minutes apart, or 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 12 hours apart. One can also administer compositions at 24 hours apart, or even longer apart. Alternatively, two or more compositions can be administered simultaneously, e.g. less than 10 or less than 5 minutes apart. Compositions administered simultaneously can, in some aspects, be administered as a mixture, with or without similar or different time release mechanism for each of the components.
Antibodies, and their encoding nucleic acids, can be used as anti-malarial agents. They may be used for passive immunisation of mammals. An antibody or nucleic acid may be administered to a mammal, e.g., by any route of administration mentioned herein.
Mammals may be humans, including humans at risk of malaria or humans diagnosed with malaria. The human or other mammal to whom the composition is administered may be one who has been, or is suspected of having been, infected with a malarial Plasmodium parasite, and/or who exhibits one or more symptoms of malaria.
An antibody molecule of the present invention, or a composition comprising such an antibody molecule or its encoding nucleic acid, may be provided for use in a method of: treating or preventing malaria in a mammal;
reducing risk of malaria in a mammal;
reducing one or more symptoms of malaria in a mammal;
inhibiting the pre-erythrocytic stage of a Plasmodium infection in a mammal reducing progression of Plasmodium infection in a mammal; and/or
reducing transmission, or reducing risk of transmission, of Plasmodium to and/or from a mammal;
wherein the method comprises administering the antibody or composition to a mammal.
The invention also provides a method of:
treating, or preventing or reducing risk of malaria in a mammal;
reducing one or more symptoms of malaria in a mammal;
reducing risk of malaria in a mammal;
inhibiting the pre-erythrocytic stage of Plasmodium infection in a mammal;
reducing progression of Plasmodium infection in a mammal; and/or
reducing transmission, or reducing risk of transmission, of Plasmodium to and/or from a mammal;
the method comprising administering an antibody of the invention, or a composition comprising the antibody or its encoding nucleic acid, to the mammal
Administration is normally in a "therapeutically effective amount", this being an amount that produces the desired effect for which it is administered, sufficient to show benefit to a patient. The exact amount will depend on the purpose of the treatment, and will be ascertainable by one skilled in the art using known techniques (see, for example, Lloyd (1999) The Art, Science and Technology of Pharmaceutical Compounding). Benefit to the patient may be at least amelioration of at least one symptom of malaria, e.g., reduction in liver-stage parasite load, or protection against malaria or infection by malarial Plasmodium species such as P. falciparum. Prescription of treatment, e.g. decisions on dosage etc, is within the responsibility of general practitioners and other medical doctors and may depend on the severity of the symptoms and/or progression of a disease being treated. A
therapeutically effective amount or suitable dose of antibody or nucleic acid can be determined by comparing its in vitro activity and in vivo activity in an animal model. Methods for extrapolation of effective dosages in mice and other test animals to humans are known. In methods of treatment described herein, one or more doses may be administered. In some cases, a single dose may be effective to achieve a long-term benefit. Thus, the method may comprise administering a single dose of the antibody, its encoding nucleic acid, or the composition. Alternatively, multiple doses may be administered, usually sequentially and separated by a period of days, weeks or months.
As used herein, the terms "treat," "treatment," "treating," or "amelioration" refer to therapeutic treatments, wherein the object is to reverse, alleviate, ameliorate, inhibit, slow down or stop the progression or severity of a condition associated with a disease or disorder. The term "treating" includes reducing or alleviating at least one adverse effect or symptom of a condition, disease or disorder. Treatment is generally "effective" if one or more symptoms or clinical markers are reduced. Alternatively, treatment is "effective" if the progression of a disease is reduced or halted. That is, "treatment" includes not just the improvement of symptoms or markers, but also a cessation of, or at least slowing of, progress or worsening of symptoms compared to what would be expected in the absence of treatment. Beneficial or desired clinical results include, but are not limited to, alleviation of one or more symptom(s), diminishment of extent of disease, stabilised (i.e., not worsening) state of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, remission (whether partial or total), and/or decreased mortality, whether detectable or undetectable. The term "treatment" of a disease also includes providing relief from the symptoms or side- effects of the disease (including palliative treatment). For treatment to be effective a complete cure is not contemplated. The method can in certain aspects include cure as well. In the context of the invention, treatment may be preventative treatment, optionally the prevention or reduction of infection by Plasmodium such as P. falciparum, and/or the prevention of malaria, or reduction of at least one symptom of malaria. Diagnostics
A further aspect of the invention relates to diagnostic uses of the antibodies described herein. The antibodies offer advantages for point of care diagnostics in mammals, and are especially envisaged for use in humans, where rapid diagnosis of malaria and/or Plasmodium infection is of significant clinical benefit. An antibody according to the invention may be used to detect Plasmodium, e.g., Plasmodium falciparum.
For diagnostic purposes, an antibody may comprise or be conjugated to a detectable label, such as a radioisotope or a fluorescent label. An antibody according to the invention may be used for determining the presence or absence of CSP or Plasmodium in a sample.
A method of determining the presence or absence of CSP or Plasmodium in a sample may comprise contacting the sample with the antibody; and
testing for binding between the antibody and CSP or Plasmodium in the sample.
Detection of binding indicates the presence of CSP or Plasmodium in the sample, whereas absence of binding indicates the absence of CSP or Plasmodium in the sample.
Methods may further comprise quantifying the level of binding, for example by comparing the level of binding with a control. Control assays may be run in parallel, or the level of binding may be compared with previously obtained control values. Suitable controls include negative control samples in which no CSP or Plasmodium is present, thus establishing a level of background signal, which can be subtracted from the signal obtained from the test assay. Positive controls may also be conducted, by contacting the antibody with a sample known to contain a pre-determined amount of CSP or Plasmodium.
Determining the level of binding in the test sample compared with the level of binding in one or more positive controls is one method of quantifying the amount of CSP or Plasmodium in the sample.
The sample may be one that has been obtained from a mammal who has been, or is suspected of having been, infected with a malarial Plasmodium parasite, and/or who exhibits one or more symptoms of malaria. It may be a blood sample, e.g., serum or whole blood. Peripheral blood samples are routinely obtainable from mammals, including human patients, in a clinical setting.
Antibodies may be provided in diagnostic kits. A kit may comprise the antibody, or a composition as described herein, and optionally one or more buffering solutions. As noted, the antibody may comprise or be conjugated to a detectable label. Labelled antibodies allow for detection of the antibody, facilitating detection of binding of the antibody to its target. Alternatively, an antibody may be used in combination with a secondary antibody or other labelled agent, the secondary antibody comprising or carrying a detectable label. Thus a kit may comprise a first reagent comprising an antibody according to the present invention, plus a second reagent comprising a detector molecule that binds to the first reagent. The detector molecule may be an antibody that comprises or is conjugated to a detectable label.
Mammals and transgenic animals In the context of the present invention, mammals may be humans or other mammalian subjects such as wild animals, livestock or test (laboratory) animals. The mammal may be one who has been, or is suspected of having been, infected with a malarial Plasmodium parasite, and/or who exhibits one or more symptoms of malaria. Such mammals represent potential subjects for treatment with antibodies and compositions of the invention, and subjects from whom it may be of value to obtain samples for performing the diagnostic methods described herein.
In a research context, laboratory mammals have been engineered to express antibodies comprising human variable regions. A mammal may be a non-human mammal comprising a human immunoglobulin variable region that is capable of generating antibodies comprising human variable regions. The Kymouse™ is a transgenic mouse containing a humanised antibody heavy chain locus and a humanised antibody light chain locus. It is described in Lee et al., Nature Biotechnology 32(4): 356-367 2014 and in WO2011004192.
A number of different Kymice™ have been developed, including mice with humanised kappa light chain variable regions, humanised lambda light chain variable regions, and mice in which the heavy chain variable regions and both lambda and kappa light chain variable regions are fully humanised and comprise the full repertoire of human immunoglobulin gene segments, reflecting the full diversity of the human antibody repertoire.
In addition to the Kymouse™, other transgenic animals have been created for production of antibodies comprising human variable regions. These include other mice, such as Velocimouse® , Omnimouse® , Xenomouse®, HuMab Mouse® and MeMo Mouse®, and rats such as the Omnirat®.
Owing to their ability to mirror aspects of the human antibody immune response, these animals - especially the Kymouse™ - are of particular value in a pre-clinical setting for the development of vaccines and for testing compositions to determine efficacy of immunisation against infection by malarial Plasmodium parasites. They find use in many aspects of the invention, such as in testing anti-malarial vaccines as described in more detail elsewhere herein.
Plasmodium Plasmodium is a genus of parasitic protozoa. Infection with Plasmodium results in the disease malaria, which can be fatal. The malarial Plasmodium parasite has two hosts in its life cycle - a Dipteran insect host and a vertebrate host. The life-cycle is complex, involving a sequence of different stages both in the vector and the vertebrate host. These stages include sporozoites, which are injected by the insect vector into the vertebrate host's blood; latent hypnozoites, which may rest undetected in the liver for up to 30 years; merosomes and merozoites, which infect the red cells (erythrocytes) of the blood; trophozoites, which grow in the red cells, and schizonts, which divide in red blood cells. Schizonts produce merozoites, which leave to infect more red cells. The sexual forms, gametocytes, are taken up by other insect hosts during feeding. Gametocytes develop into gametes in the insect midgut, and then fertilise each other to form motile zygotes, which escape the gut. Zygotes grow into new sporozoites, which move to the insect's salivary glands. Sporozoites are injected into vertebrate hosts during insect feeding, thus completing the cycle of infection. Biting mosquitos are a common route of transmission between mammals, including humans. See Figure 1.
In the present invention, unless the context requires otherwise, Plasmodium may be any Plasmodium species, such as P. falciparum, P. vivax, P. ovale, or P. malariae. It may be a naturally occuring Plasmodium species, or a laboratory-engineered Plasmodium such as P. berghei that has been engineered to express CSP from Plasmodium falciparum. Such engineered protozoa are useful in animal models, especially with mice as described herein.
Antibodies according to the present invention may target or bind Plasmodium sporozoites. Antibodies may inhibit or reduce the risk of Plasmodium infection, specifically the pre-erythrocytic or sporozoite stage of infection. This provides the advantage of targeting the Plasmodium at an early stage of entry to the vertebrate host body, offering the possibility of preventing infection from taking place. Where a body is already infected with Plasmodium, inhibition of sporozoites nevertheless has the advantage of reducing progression of
Plasmodium infection and of inhibiting sporozoites in the blood stream, thereby lessening the risk of transmission of Plasmodium from that individual to another via insect feeding e.g., mosquito bite or via contact with infected blood.
Anti-Malarial Vaccines and Immunisation Efforts to produce effective vaccines against malarial Plasmodium parasites are ongoing. It is desirable to eradicate malaria, or at least to reduce its prevalence, and improving the efficacy of anti-malarial vaccines offers a route to achieving this goal.
CSP, fragments of CSP comprising the NANP repeat region, or synthetic NANP repeat peptide such as (NANP)n, where n = 4 to 40, e.g., (NANP)40, (NANP)10 or (NANP)4, (SEQ ID NO: 44, SEQ ID NO: 45 and SEQ ID NO: 46, respectively) may be used for immunisation of a mammal against infection by a malarial Plasmodium parasite, and represent potential components for vaccine compositions. Fragments of CSP or synthetic peptides comprising other epitopes identified herein, e.g., NPDPNANP, may be used for such immunisations and also represent potential components for vaccine compositions. A synthetic repeat peptide may be generated, comprising repeats of the motif NPDPNANP, optionally including one or more additional amino acids at one or both ends of the repeated motif. A vaccine composition may optionally include part but not all of the NANP repeat region, e.g., may be a fragment or C-terminal truncated CSP, including the sequence NPDPNANP and optionally upstream sequence, but lacking a C-terminal and/or central portion of the NANP repeat region. Such peptide vaccines could be coupled to carrier proteins or virus like nanoparticles to achieve a more optimal and long lived immune response. Advantageously, compositions may further comprise one or more additional antigens or antigen fragments from one or more malarial Plasmodium parasites, optionally P. falciparum.
When developing vaccines, candidate compositions must be tested for efficacy.
Efficacy may be measured in pre-clinical models, such as in mice, and in human clinical trials. One way to measure the ability of a composition to confer protection against a malarial Plasmodium parasite is to administer the composition to a mammal and determine the efficacy of immunisation of that mammal resulting from the administration. Measures of efficacy of immunisation include strength of immune response generated, e.g., antibody titre, and quality of antibodies generated, e.g., in terms of their binding specificity, neutralising ability, or sequence and/or epitope-binding diversity. Efficacy of immunisation can also be determined by subsequently challenging the individual with a malarial Plasmodium parasite and observing the degree to which the individual develops, or is protected from, Plasmodium infection and/or symptoms of malaria. It is useful to measure efficacy of immunisation in populations of individuals, such as cohorts of mice, and to determine protection against challenge in terms of length of survival of the individuals following challenge. It will be appreciated that individuals, or populations of individuals, will usually be compared with control individuals or populations of individuals that receive the same challenge without having previously been immunised with the candidate composition. Control individuals may be placed in the same experimental conditions except that they do not receive the administration of candidate composition. They may for example receive a mock injection - injection of buffer/saline in place of an injection of the test composition. Efficacy of immunisation, and protection from challenge, are thus usually compared with control data.
Antibodies according to the present invention may be used to determine the efficacy of immunisation against a malarial Plasmodium parasite. They may be used as diagnostic reagents for determining the level of CSP or Plasmodium in a sample, this being indicative of the level of P. falciparum (or of other Plasmodium species that express CSP, such as P. berghei engineered to express P. falciparum CSP) in the sample, and thus the level of infection in the mammal from whom the sample is obtained, particularly the pre-erythrocytic or sporozoite stage of the parasite. Methods of detecting CSP or Plasmodium with antibodies are described in detail elsewhere herein.
A method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite may comprise:
administering CSP, a fragment thereof comprising the NANP repeat region, or a synthetic NANP repeat peptide, and optionally one or more other antigens of the Plasmodium parasite, to a mammal, allowing time for development of an immune response in the mammal;
challenging the mammal with a malarial Plasmodium parasite, for example by exposing the mammal to biting by a mosquito infected with the parasite, and allowing time for development of an immune response in the mammal, to provide a challenged mammal; obtaining a sample from the challenged mammal;
contacting the sample with the antibody; and
determining the level of binding between the antibody and CSP or Plasmodium in the sample;
the level of binding being negatively correlated with the efficacy of immunisation.
Alternatively, a method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite may comprise:
providing a sample obtained from a challenged mammal provided as described above;
contacting the sample with the antibody; and
determining the level of binding between the antibody and CSP or Plasmodium in the sample;
the level of binding being negatively correlated with the efficacy of immunisation.
Any suitable diagnostic method, as described elsewhere herein, may be used to determine the level of binding. As noted, binding may be quantified relative to binding in samples obtained from control individuals, or relative to positive and/or negative control samples.
The CSP (or fragment thereof, or NANP repeat peptide) or the Plasmodium may be administered by any method suitable to generate an immune response in the mammal. Common methods of delivering vaccines include by intramuscular, subcutaneous or intravenous injection, and any such method may be used here. Other possible methods of administration are described elsewhere herein, and may be applied to methods of administering the CSP (or fragment thereof, or NANP repeat peptide) or the Plasmodium. Administering the candidate vaccine composition comprising the antigen or antigens may comprise injecting live or killed Plasmodium, or antigen or antigens purified from
Plasmodium or recombinantly expressed, into the mammal. The antigen or antigens may be administered in combination with an adjuvant.
Mice are a suitable test animal for vaccine development. The mammal in these methods may thus be a mouse. In a mouse model, a suitable Plasmodium parasite is P. berghei, which can be engineered to express P. falciparum CSP or a fragment thereof comprising the NANP repeat region, ensuring that the P. berghei is bound by antibodies according to the present invention. Where transgenic mice containing a human antibody repertoire are employed, this provides a model of infection of humans by P. falciparum, the antibody response in the mice representing a model antibody response generated by the human immune system.
The Kymouse™ is especially suitable for use in such models. It is possible to use other transgenic mice or other test animals engineered to express antibodies with human variable regions, and examples of these are mentioned elsewhere herein.
When challenging such mice with malarial Plasmodium parasites (e.g., P. berghei engineered to express P. falciparum CSP or a fragment thereof comprising the NANP region), the generation of antibodies according to the present invention provides an indication that the mouse generates an effective immune response. Equally, in humans, generation of antibodies according to the present invention is an indication that the human generates an effective immune response against P. falciparum. Antibodies according to the invention may thus be used as a measure of vaccine efficacy in anti-malarial vaccine trials, whether pre-clinical (e.g., in transgenic animals expressing antibodies with human variable domains) or clinical (in humans).
A method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite may comprise:
administering CSP, a fragment thereof comprising the NANP repeat region, or a NANP repeat peptide, and optionally one or more other antigens of the Plasmodium parasite, to a mammal, allowing time for development of an immune response in the mammal, and obtaining a sample from the mammal; and
assaying for the presence of an antibody according to the present invention in the sample;
wherein the presence of one or more such antibodies is indicative of effective immunisation.
Alternatively, a method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite may comprise:
providing a sample obtained from a mammal, wherein the mammal has received an administration of CSP, a fragment thereof comprising the NANP repeat region, or a NANP repeat peptide, and optionally one or more other antigens of the Plasmodium parasite, and wherein the sample has been obtained after allowing time for development of an immune response; and
assaying for the presence of an antibody according to the present invention in the sample;
wherein the presence of one or more such antibodies is indicative of effective immunisation. As noted above, fragments of CSP or synthetic peptides comprising epitopes identified herein, e.g., NPDPNANP, may be administered. A synthetic repeat peptide may be generated, comprising repeats of the motif NPDPNANP, optionally including one or more additional amino acids at one or both ends of the repeated motif. A vaccine composition or a composition used for immunisation or administration to a mammal may optionally contain part but not all of the NANP repeat region, e.g., may be a fragment or C-terminal truncated CSP, including the sequence NPDPNANP and optionally upstream sequence, but lacking a C-terminal and/or central portion of the NANP repeat region. Such vaccines could be coupled to carrier proteins or virus like nanoparticles to achieve a more optimal and long lived immune response.
Thus, further methods of the invention include methods of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite, comprising:
administering a composition comprising CSP, or comprising a fragment of CSP or a synthetic peptide comprising NPDPNANP, to a mammal, allowing time for development of an immune response in the mammal, and obtaining a sample from the mammal; and
assaying for the presence of an antibody according to the present invention in the sample;
wherein the presence of one or more such antibodies is indicative of effective immunisation.
A method of determining efficacy of immunisation of a mammal against a malarial
Plasmodium parasite may comprise:
providing a sample obtained from a mammal, wherein the mammal has received an administration of the said composition as defined above, and wherein the sample has been obtained after allowing time for development of an immune response; and
assaying for the presence of an antibody according to the present invention in the sample;
wherein the presence of one or more such antibodies is indicative of effective immunisation.
As noted, the administered compositions may optionally further comprise one or more other antigens of the Plasmodium parasite.
Exemplary antibodies are antibodies comprising the antibody 667 or antibody 668 CDRs, and variants thereof, as described herein.
Methods of determining efficacy of immunisation may comprise assaying for the presence of, or determining enrichment of, antibody comprising the structural motif as defined herein. Thus, the antibody may comprise a VH domain comprising HCDR1 , HCDR2 and HCDR3 in a framework, and a VL domain comprising LCDR1 , LCDR2 and LCDR3 in a framework, wherein LCDR1 , LCDR3, HCDR2 and HCDR3 are as follows: LCDR1 contains an N and a hydrophobic residue. Preferably, the N is at position 31. Preferably, the N is either directly preceded or followed by the hydrophobic residue. The hydrophobic residue is preferably Y.
LCDR3 contains a Y residue and a W residue. Preferably, the Y precedes W (in the N to C direction). Preferably, Y is at position 91. Preferably, W is at position 96.
HCDR2 contains W and N. Preferably, the W precedes N (in the N to C direction). Preferably, W is at position 50. Preferably, N is at at position 52.
HCDR3 contains at least one Y residue. Y may be present at any position in the HCDR3.
Assaying for the presence of an antibody molecule may comprise identifying whether any B cells in the mammal encode antibodies according to the present invention, for example by sequencing nucleic acid from the B cells. Methods may comprise determining whether antibodies (e.g., VH and VL domains comprising the defined structural motif) according to the present invention are enriched in the mammal following administration of the composition. For example, a method may comprise determining whether such antibodies are enriched over background frequencies by at least 0.1 %, at least 1 %, at least 2 %, at least 5 % or at least 10 % in the sample from the mammal, compared with a control sample (e.g., from a mammal who has not received the administered composition, e.g., a sample obtained from the same mammal prior to the administration). As noted previously, a sample may be a blood sample, e.g., serum or whole blood. Peripheral blood samples are routinely obtainable from mammals, including human patients, in a clinical setting. The presence of, and especially the enrichment of, the antibody or antibody sequence according to the invention in the sample provides an indication that the administered composition generates a protective immune response against the malarial Plasmodium parasite (e.g., protecting against infection by P. falciparum).
Suitable methods of administering the composition to a mammal are set out above. The administered composition may be a vaccine or a candidate vaccine, and may comprise one or more adjuvants. The methods described here may be used to determine efficacy of vaccination of a mammal, for example to confirm, predict or test for protection of a vaccinated human individual against infection by a malarial Plasmodium parasite. The methods may also be used in the context of pre-clinical or clinical trials involving a candidate vaccine composition.
The method may further comprise challenging the mammal with a malarial
Plasmodium parasite by exposing the mammal to biting by a Plasmodium-infected mosquito, and determining the degree of protection against challenge, as described.
The following numbered clauses and statements represent features of the invention, and are part of the description. Clause 1. An isolated antibody that binds the circumsporozoite protein (CSP) of Plasmodium falciparum,
wherein the antibody
(i) binds the NANP repeat region of CSP and/or binds a region of 12 amino acids immediately preceding the NANP repeat region; and optionally
(ii) inhibits the pre-erythrocytic stage of Plasmodium infection in a mammal;
(iii) reduces risk of malaria in a mammal;
(iv) reduces one or more symptoms of malaria in a mammal;
(v) reduces progression of Plasmodium infection in a mammal; and/or
(vi) reduces transmission, or reduces risk of transmission, of Plasmodium to and/or from a mammal.
Clause 2. An antibody according to clause 1 , which binds CSP in a region of 12 amino acids KLKQPGDGNPDP immediately preceding the NANP repeat region.
Clause 3. An antibody according to clause 2, which binds CSP in the NPDP motif immediately preceding the NANP repeat region. Clause 4. An antibody according to any preceding clause, which binds the initial sequence NANPNVDPNANP of the NANP repeat region.
Clause 5. An antibody according to any preceding clause, which binds the first NANP motif of the NANP repeat region.
Clause 6. An antibody according to the preceding clauses, which binds CSP within the sequence NPDPNANP.
Clause 7. An antibody according to any preceding clause, comprising
an antibody VH domain comprising complementarity determining regions (CDRs)
HCDR1 , HCDR2 and HCDR3, and
an antibody VL domain comprising complementarity determining regions LCDR1 , LCDR2 and LCDR3,
wherein the HCDR3 is an HCDR3 of antibody 666, antibody 667, antibody 668 or antibody 669, or comprises the antibody 666, 667, 668 or 669 HCDR3 with 1 , 2, 3, 4 or 5 amino acid alterations. Clause 8. An antibody according to clause 7, wherein the HCDR2 is an HCDR2 of antibody 666, 667, 668 or 669, or comprises the antibody 666, 667, 668 or 669 HCDR2 with 1 , 2, 3, 4 or 5 amino acid alterations. Clause 9. An antibody according to clause 7 or clause 8, wherein the HCDR1 is an HCDR1 of antibody 666, 667, 668 or 669, or comprises the antibody 666, 667, 668 or 669 HCDR1 with 1 , 2, 3, 4 or 5 amino acid alterations.
Clause 10. An antibody according to clause 9, wherein the antibody heavy chain CDRs are those of antibody 666, antibody 667, antibody 668 or antibody 669, or comprise the antibody 666, 667, 668 or 669 heavy chain CDRs with 1 , 2, 3, 4 or 5 amino acid alterations.
Clause 1 1. An antibody according to clause 10, wherein the antibody VH domain has the heavy chain CDRs of antibody 667 or antibody 668.
Clause 12. An isolated antibody according to any preceding clause, comprising
an antibody VH domain comprising complementarity determining regions HCDR1 ,
HCDR2 and HCDR3, and
an antibody VL domain comprising complementarity determining regions LCDR1 , LCDR2 and LCDR3,
wherein LCDR3 is a LCDR3 of antibody 666, antibody 667, antibody 668 or antibody
669, or comprises the antibody 666, 667, 668 or 669 LCDR3 with 1 , 2, 3, 4 or 5 amino acid alterations. Clause 13. An antibody according to clause 12, wherein the LCDR2 is an LCDR2 of antibody 666, 667, 668 or 669, or comprises the antibody 666, 667, 668 or 669 LCDR2 with 1 , 2, 3, 4 or 5 amino acid alterations.
Clause 14. An antibody according to clause 12 or clause 13, wherein the LCDR1 is an LCDR1 of antibody 666, 667, 668 or 669, or comprises the antibody 666, 667, 668 or 669 LCDR1 with 1 , 2, 3, 4 or 5 amino acid alterations.
Clause 15. An antibody according to clause 14, wherein the antibody light chain CDRs are those of antibody 666, antibody 667, antibody 668 or antibody 669, or comprise the antibody 666, 667, 668 or 669 light chain CDRs with 1 , 2, 3, 4 or 5 amino acid alterations. Clause 16. An antibody according to clause 15, wherein the antibody VL domain has the light chain CDRs of antibody 667 or antibody 668.
Clause 17. An antibody according to any of the preceding clauses, comprising VH and/or VL domain framework regions of human germline gene segment sequences.
Clause 18. An antibody according to any of the preceding clauses, comprising an antibody VH domain which
(i) is derived from recombination of a human heavy chain V gene segment, a human heavy chain D gene segment and a human heavy chain J gene segment, wherein
the V segment is IGHV1-3;
the D gene segment is IGHD3-10, IGHD3-9, IGHD4-1 1 or IGHD2-2; and/or the J gene segment is IGHJ6, or
(ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein
FR1 aligns with human germline V gene segment IGHV1-3 with up to 1 , 2, 3, 4 or 5 amino acid alterations,
FR2 aligns with human germline V gene segment IGHV1-3 with up to 1 , 2, 3, 4 or 5 amino acid alterations,
FR3 aligns with human germline V gene segment IGHV1-3 with up to 1 , 2, 3, 4 or 5 amino acid alterations, and/or
FR4 aligns with human germline J gene segment IGHJ6 with up to 1 , 2, 3, 4 or 5 amino acid alterations.
Clause 19. An isolated antibody according to any preceding clause, comprising an antibody VH domain which
(i) is derived from recombination of a human heavy chain V gene segment IGHV1-3, a human heavy chain D gene segment and a human heavy chain J gene segment, or
(ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein FR1 , FR2 and FR3 each align with human germline V segment IGHV1-3 with up to 1 , 2, 3, 4 or 5 amino acid alterations,
wherein the antibody inhibits the pre-erythrocytic stage of Plasmodium infection in a mammal, reduces risk of malaria in a mammal, reduces one or more symptoms of malaria in a mammal, reduces progression of Plasmodium infection in a mammal, and/or reduces transmission, or reduces risk of transmission, of Plasmodium between mammals.
Clause 20. An antibody according to clause 19, wherein the D gene segment is IGHD3- 10, IGHD3-9, IGHD4-1 1 or IGHD2-2 and/or the J gene segment is IGHJ6, or wherein the VH domain framework region FR4 aligns with human germline J gene segment IGHJ6 with 1 , 2, 3, 4 or 5 amino acid alterations.
Clause 21. An antibody according to any of the preceding clauses, comprising an antibody VL domain which
(i) is derived from recombination of a human light chain V gene segment and a human light chain J gene segment, wherein
the V segment is IGLV2-23, and/or
the J gene segment is IGLJ3; or
(ii) comprises framework regions FR1 , FR2, FR3 and FR4, wherein
FR1 aligns with human germline V gene segment IGLV2-23 with up to 1 , 2, 3, 4 or 5 amino acid alterations,
FR2 aligns with human germline V gene segment IGLV2-23 with up to 1 , 2, 3, 4 or 5 amino acid alterations,
FR3 aligns with human germline V gene segment IGLV2-23 with up to 1 , 2, 3, 4 or 5 amino acid alterations, and/or
FR4 aligns with human germline J gene segment IGLJ3 with up to 1 , 2, 3, 4 or 5 amino acid alterations. Clause 22. An antibody according to any of the preceding clauses, comprising an antibody VL domain derived from recombination of a human light chain V gene segment and a human light chain J gene segment, wherein
the V segment is IGLV2-23, and optionally
the J gene segment is IGLJ3.
Clause 23. An antibody according to any of the preceding clauses, comprising an antibody VH domain which is the VH domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VH domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669.
Clause 24. An antibody according to any of the preceding clauses, comprising an antibody VL domain which is the VL domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VL domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669.
Clause 25. An antibody according to clause 24, comprising an antibody VH domain which is selected from the VH domain of antibody 666, antibody 667, antibody 668 or antibody 669, or which has an amino acid sequence at least 90 % identical to the antibody VH domain sequence of antibody 666, antibody 667, antibody 668 or antibody 669, and
an antibody VL domain which is the VL domain of said selected antibody, or which has an amino acid sequence at least 90 % identical to the antibody VL domain sequence of said selected antibody.
Clause 26. An antibody according to clause 25, comprising the antibody 667 VH domain and the antibody 667 VL domain.
Clause 27. An antibody according to clause 25, comprising the antibody 668 VH domain and the antibody 668 VL domain. Clause 28. An antibody according to any of the preceding clauses, comprising an antibody constant region.
Clause 29. An antibody according to clause 28, wherein the constant region comprises a human heavy and/or light chain constant region.
Clause 30. An antibody according to clause 28 or clause 29, wherein the antibody is an IgG.
Clause 31. An antibody according to clause 30, wherein the antibody is a human IgGl
Clause 32. An antibody according to clause 30 or clause 31 , wherein the IgG comprises a CH2 domain having "YTE" mutations to extend the in vivo half-life of the antibody, the YTE mutations being tyrosine at residue 252, threonine at residue 254 and glutamic acid at residue 256, numbered according to the EU index of Kabat.
Clause 33. An isolated antibody that competes for binding to CSP of Plasmodium falciparum with a human lgG1 antibody comprising the heavy and light chain
complementarity determining regions of antibody 666, antibody 667, antibody 668 or antibody 669.
Clause 34. A composition comprising an isolated antibody according to any of the preceding clauses and a pharmaceutically acceptable excipient. Clause 35. A composition comprising isolated nucleic acid encoding an antibody according to any of the preceding clauses and a pharmaceutically acceptable excipient. Clause 36. A composition according to clause 34 or clause 35 formulated for intravenous or subcutaneous administration.
Clause 37. A composition according to any of clauses 34 to 36, further comprising one or more additional agents that are anti-malarial agents.
Clause 38. A composition according to any of clauses 34 to 36, further comprising one or more additional antibodies, or nucleic acid encoding one or more additional antibodies.
Clause 39. A composition according to clause 38, wherein the one or more additional antibodies bind one or more antigens of a malarial Plasmodium parasite.
Clause 40. A composition according to clause 39, wherein the malarial Plasmodium parasite is P. falciparum. Clause 41. An antibody according to any of clauses 1 to 33, or a composition according to any of clauses 34 to 40, for use in a method of:
treating or preventing malaria in a mammal;
reducing risk of malaria in a mammal;
reducing one or more symptoms of malaria in a mammal;
inhibiting the pre-erythrocytic stage of Plasmodium infection in a mammal;
reducing progression of Plasmodium infection in a mammal; and/or
reducing transmission, or reducing risk of transmission, of Plasmodium between mammals;
wherein the method comprises administering the antibody or composition to a mammal.
Clause 42. An antibody or composition for use according to clause 41 , wherein the mammal is a human patient aged 50 years or under. Clause 43. An antibody or composition for use according to clause 42, wherein the mammal is a human paediatric patient. Clause 44. An antibody or composition for use according to any of clauses 41 to 43, wherein the method comprises administering a single dose of the antibody or composition.
Clause 45. A method of:
treating, preventing or reducing risk of malaria in a mammal;
reducing one or more symptoms of malaria in a mammal;
reducing risk of malaria in a mammal;
inhibiting the pre-erythrocytic stage of Plasmodium infection in a mammal;
reducing progression of Plasmodium infection in a mammal; and/or
reducing transmission, or reducing risk of transmission, of Plasmodium to and/or from a mammal;
the method comprising administering atherapeutically effective amount of an antibody according to any of clauses 1 to 33 or of a composition according to any of clauses 34 to 40 to the mammal.
Clause 46. An antibody or composition for use according to clause 45, wherein the mammal is a human patient aged 50 years or under.
Clause 47. An antibody or composition for use according to clause 46, wherein the mammal is a human paediatric patient.
Clause 48. A method according to any of clauses 45 to 47, wherein a single dose of the antibody is administered to the mammal. Clause 49. Isolated nucleic acid encoding an antibody, or an isolated VH or VL domain of an antibody according to any of clauses 1 to 33.
Clause 50. A host cell in vitro containing nucleic acid according to clause 49. Clause 51. A method of producing an antibody or an antibody VH or VL domain, comprising culturing host cells according to clause 50 under conditions for expression of the antibody or antibody VH or VL domain, and obtaining the expressed antibody or domain.
Clause 52. A method according to clause 51 , comprising culturing host cells in a culture medium of at least 100 litres (e.g., 100 - 250 litres) in a bioreactor. Clause 53. A method according to clause 52, wherein the culturing comprises fed-batch culture.
Clause 54. A method according to clause 52 or clause 53, wherein the bioreactor comprises a metal (e.g., stainless steel) vessel or is a single-use bioreactor.
Clause 55. A method according to any of clauses 51 to 54, further comprising isolating and/or purifying the antibody or antibody VH or VL domain. Clause 56. A method according to any of clauses 51 to 55, further comprising formulating the antibody, or antibody VH or VL domain into a composition comprising at least one additional component, such as one or more additional antibodies and/or a pharmaceutically acceptable excipient. Clause 57. A method according to clause 56, comprising formulating the antibody, or antibody VH or VL domain, into a composition for subcutaneous or intravenous
administration.
Clause 58. A method for producing an antibody according to any of clauses 1 to 33, the method comprising
(i) providing, by way of addition, deletion, substitution or insertion of one or more amino acids in the amino acid sequence of a parent antibody VH domain, an antibody VH domain that is an amino acid sequence variant of the parent antibody VH domain,
wherein the parent antibody VH domain is the VH domain of any of antibodies 666, 667, 668 and 669 or a VH domain comprising the heavy chain complementarity determining regions of any of those antibodies,
(ii) optionally combining the VH domain thus provided with a VL domain, to provide a VH/VL combination, and
(iii) testing the VH domain or VH/VL domain combination thus provided to identify an antibody according to any of clauses 1 to 33.
Clause 59. A method according to clause 58, wherein the VL domain is provided by way of addition, deletion, substitution or insertion of one or more amino acids in the amino acid sequence of a parent VL domain, wherein the parent VL domain is the VL domain of any of antibodies 666, 667, 668 and 669 or a VL domain comprising the light chain
complementarity determining regions of any of those antibodies. Clause 60. A method according to clause 58 or clause 59, wherein the VH domain is provided by CDR mutagenesis of the parent VH domain.
Clause 61. A method according to any of clauses 58 to 60, further comprising expressing the antibody comprising the identified VH domain or VH/VL domain combination.
Clause 62. Use of an antibody according to any of clauses 1 to 33 for determining the presence or absence of CSP or Plasmodium in a sample. Clause 63. A method of determining the presence or absence of CSP or Plasmodium in a sample, the method comprising
contacting the sample with an antibody according to any of clauses 1 to 64; and testing for binding between the antibody and CSP or Plasmodium in the sample; wherein detection of binding indicates the presence of CSP or Plasmodium in the sample and wherein absence of binding indicates the absence of CSP or Plasmodium in the sample.
Clause 64. A method according to clause 63, wherein the antibody comprises or is conjugated to a detectable label.
Clause 65. Use according to clause 62, or a method according to clause 63 or clause 64, wherein the sample has been obtained from a mammal who has been or is suspected of having been infected with a malarial Plasmodium parasite and/or who exhibits one or more symptoms of malaria.
Clause 66. Use or a method according to any of clauses 62 to 65, wherein the
Plasmodium is P. falciparum.
Clause 67. Use or a method according to any of clauses 62 to 66, wherein the sample is a serum or whole blood sample.
Clause 68. A diagnostic kit for the use or method as set out in any of clauses 62 to 67, comprising an antibody according to any of clauses 1 to 33, and optionally one or more buffering solutions.
Clause 69. A diagnostic kit according to clause 68, wherein the antibody comprises or is conjugated to a detectable label. Clause 70. A diagnostic kit according to clause 69, comprising
a first reagent comprising the antibody according to any of clauses 1 to 33, and a second reagent comprising a detector molecule that binds to the first reagent.
Clause 71. A diagnostic kit according to clause 70, wherein the detector molecule is an antibody that comprises or is conjugated to a detectable label.
Clause 72. Use of an antibody according to any of clauses 1 to 33 or a composition according to any of clauses 34 to 40, for determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite or as a correlate of protection following vaccination to protect from infection by a malarial Plasmodium parasite.
Clause 73. An antibody according to any of clauses 1 to 33 or a composition according to any of clauses 34 to 40, for use in determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite or as a correlate of protection following vaccination to protect from infection by a malarial Plasmodium parasite.
Clause 74. A method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite, the method comprising:
administering CSP, a fragment thereof comprising the NANP repeat region, or a synthetic NANP repeat peptide, and optionally one or more other antigens of the
Plasmodium parasite, to a mammal;
allowing time for development of an immune response in the mammal;
obtaining a sample from the mammal; and
assaying for the presence of an antibody according to any of clauses 1 to 33 in the sample;
wherein the presence of one or more such antibodies is indicative of effective immunisation.
Clause 75. A method of determining efficacy of immunisation of a mammal against a malarial Plasmodium parasite, the method comprising:
providing a sample obtained from a mammal, wherein the mammal has received an administration of CSP, a fragment thereof comprising the NANP repeat region, or a synthetic NANP repeat peptide, and optionally one or more other antigens of the Plasmodium parasite, and wherein the sample has been obtained after allowing time for development of an immune response; and assaying for the presence of an antibody according to any clauses 1 to 33 in the sample;
wherein the presence of one or more such antibodies is indicative of effective immunisation.
Clause 76. A method according to clause 74 or clause 75, wherein administering the antigen or antigens comprises injecting live or killed Plasmodium, or antigen or antigens purified from Plasmodium or recombinantly expressed, into the mammal, optionally together with an adjuvant.
Clause 77. A method according to any of clauses 74 to 76, further comprising challenging the mammal with a malarial Plasmodium parasite by exposing the mammal to biting by a Plasmodium-infected mosquito, and determining the degree of protection against challenge. Clause 78. A method according to clause 77, wherein the mammal is a mouse that expresses antibodies comprising human antibody variable regions.
Clause 79. A method according to clause 78, wherein the Plasmodium parasite is P. berghei expressing P. falciparum CSP or a fragment thereof comprising the NANP repeat region.
Clause 80. A method according to any of clauses 74 to 77, wherein the Plasmodium parasite is P. falciparum. Clause 81. A method according to clause 80, wherein the mammal is a human.
Clause 82. A method according to any of clauses 74 to 81 , for evaluating efficacy of a vaccine or candidate vaccine composition. Statements of invention:
1. A method of producing an antibody that binds circumsporozoite protein (CSP) of Plasmodium falciparum, wherein the antibody binds within the sequence NPDPNANP of CSP, the method comprising
culturing host cells containing nucleic acid encoding the antibody, in vitro in a culture medium of at least 100 litres in a bioreactor under conditions for expression of the antibody, and obtaining the expressed antibody. 2. A method according to statement 1 , wherein the culturing comprises fed-batch culture. 3. A method according to statement 1 or statement 2, wherein the bioreactor comprises a metal (e.g., stainless steel) vessel or is a single-use bioreactor.
4. A method according to any preceding statement, further comprising isolating and/or purifying the antibody.
5. A method according to any preceding statement, further comprising formulating the antibody into a composition comprising at least one additional component, such as one or more additional antibodies and/or a pharmaceutically acceptable excipient. 6. A method according to statement 5, comprising formulating the antibody into a composition for subcutaneous or intravenous administration.
7. A method of preventing malaria or reducing risk of malaria in a mammal, comprising administering a therapeutically effective amount of an antibody to the mammal, wherein the antibody binds circumsporozoite protein (CSP) of Plasmodium falciparum, wherein the antibody binds within the sequence NPDPNANP of CSP, and wherein the mammal is a human patient aged 50 years or under, e.g., a paediatric patient.
8. An isolated antibody that binds circumsporozoite protein (CSP) of Plasmodium falciparum, wherein the antibody binds within the sequence NPDPNANP of CSP, for use in a method of preventing malaria or reducing risk of malaria in a mammal,
wherein the method comprises administering the antibody to the mammal, wherein the mammal is a human patient aged 50 years or under, e.g., a paediatric patient. 9. A method according to any of statements 1 to 7 or an antibody for use according to statement 8, wherein the antibody binds CSP in the NPDP motif immediately preceding the NANP repeat region.
10. A method or an antibody for use according to any preceding statement, wherein the antibody binds the first NANP motif of the NANP repeat region. 11. A method or an antibody for use according to any of the preceding statements, wherein the antibody comprises
an antibody VH domain comprising complementarity determining regions (CDRs) HCDR1 , HCDR2 and HCDR3, and
an antibody VL domain comprising complementarity determining regions LCDR1 ,
LCDR2 and LCDR3, wherein
the antibody VH domain is the VH domain of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab-c1281 , Ab-c1315 or Ab-c1731 , or wherein the VH domain has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab-c1281 , Ab-c1315 or Ab-c1731 , and/or wherein the antibody VL domain is the VL domain of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab- c1281 , Ab-c1315 or Ab-c1731 , or wherein the VL domain has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Abel 94, Ab-c265, Ab-c1281 , Ab-c1315 or Ab-c1731.
12. A method or an an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 666, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 666.
13. A method or an antibody for use according to any preceding statement, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of antibody 666.
14. A method or an antibody for use according to any preceding statement, wherein the antibody comprises the antibody 666 VH domain and the antibody 666 VL domain. 15. A method or an antibody for use according to statement 11 , wherein the antibody comprises an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 667, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 667.
16. A method or an antibody for use according to any of statements 1 to 11 or statement 15, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of antibody 667.
17. A method or an antibody for use according to any of statements 1 to 11 or 15 to 16, wherein the antibody comprises the antibody 667 VH domain and the antibody 667 VL domain.
18. A method or an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 668, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 668. 19. A method or an antibody for use according to any of statements 1 to 11 or statement 18, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of antibody 668.
20. A method or an antibody for use according to any of statements 1 to 11 or 18 to 19, wherein the antibody comprises the antibody 668 VH domain and the antibody 668 VL domain.
21. A method or an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least
95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 669, and an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 669. 22. A method or an antibody for use according to any of statements 1 to 11 or statement 21 , wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of antibody 669.
23. A method or an antibody for use according to any of statements 1 to 11 or 21 to 22, wherein the antibody comprises the antibody 669 VH domain and the antibody 669 VL domain.
24. A method or an an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least
95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab-c82, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c82.
25. A method or an antibody for use according to any of statements 1 to 11 or statement 24, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c82. 26. A method or an antibody for use according to any of statements 1 to 11 or 24 to 25, wherein the antibody comprises the Ab-c82 VH domain and the Ab-c82 VL domain.
27. A method or an an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least
95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab-c152, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c152. 28. A method or an antibody for use according to any of statements 1 to 11 or statement 27, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c152. 29. A method or an antibody for use according to any of statements 1 to 11 or 27 to 28, wherein the antibody comprises the Ab-c152 VH domain and the Ab-c152 VL domain.
30. A method or an an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least
95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab-c194, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c194.
31. A method or an antibody for use according to any of statements 1 to 11 or statement 30, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c194. 32. A method or an antibody for use according to any of statements 1 to 11 or 30 to 31 , wherein the antibody comprises the Ab-c194 VH domain and the Ab-c194 VL domain.
33. A method or an an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least
95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab-c265, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c265.
34. A method or an antibody for use according to any of statements 1 to 11 or statement 33, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c265. 35. A method or an antibody for use according to any of statements 1 to 11 or 33 to 34, wherein the antibody comprises the Ab-c265 VH domain and the Ab-c265 VL domain. 36. A method or an an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab- c1281 , and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab- C1281. 37. A method or an antibody for use according to any of statements 1 to 11 or statement 36, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c1281.
38. A method or an antibody for use according to any of statements 1 to 11 or 36 to 37, wherein the antibody comprises the Ab-c1281 VH domain and the Ab-c1281 VL domain.
39. A method or an an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab- C1315, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab- C1315.
40. A method or an antibody for use according to any of statements 1 to 11 or statement 39, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c1315. 41. A method or an antibody for use according to any of statements 1 to 11 or 39 to 40, wherein the antibody comprises the Ab-c1315 VH domain and the Ab-c1315 VL domain.
42. A method or an an antibody for use according to statement 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least
95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab- C1731 , and an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab- C1731 . 43. A method or an antibody for use according to any of statements 1 to 11 or statement 42, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c1731.
44. A method or an antibody for use according to any of statements 1 to 11 or 42 to 43, wherein the antibody comprises the Ab-c1731 VH domain and the Ab-c1731 VL domain.
45. A method or an antibody for use according to any of the preceding statements, wherein the antibody comprises an antibody constant region. 46. A method or an antibody for use according to statement 45, wherein the antibody is an IgG.
47. A method or an antibody for use according to statement 46, wherein the antibody is a human lgG1.
48. A method or an antibody for use according to statement 46 or statement 47, wherein the IgG comprises a CH2 domain having "YTE" mutations to extend the in vivo half-life of the antibody, the YTE mutations being tyrosine at residue 252, threonine at residue 254 and glutamic acid at residue 256, numbered according to the EU index of Kabat.
Examples
The following examples report experimental work underlying the present invention and serve to illustrate aspects of various embodiments.
This work was funded in whole or in part by the PATH Malaria Vaccine Initiative, in a collaboration between PATH, the Bill and Melinda Gates Foundation, Kymab Limited and Atreca, Inc.. Kymice™ were used in the United Kingdom.
Example 1 : Generation of antibodies
Kymice™, a transgenic mouse platform capable of generating antibodies with human variable domains, were immunised with CSP to generate anti-CSP antibodies.
The Kymouse™ platform used in this study is composed of two strains of mice,
Kymouse HK and Kymouse HL, both of which carry human variable domains and mouse constant domains. The antibody repertoire of these mice are composed of human V, D and J segments. The endogenous mouse variable genes have been silenced and make up a very small portion of the repertoire (less than 0.5 % of all heavy chain variable regions are of mouse origin). The mice display normal B-cell signalling and development. These mice respond robustly to antigen challenge and produce high affinity antibodies with human-like HCDR3 lengths.
Kymouse HK includes engineered IgH and IgK loci. It includes inserted human VH- gene segments and human V-kappa gene segments. It has normal mouse heavy and light constant regions.
Kymouse HL includes engineered IgH and IgL loci. It includes inserted human VH- gene segments and V-lambda gene segments. It has normal mouse heavy regions and human light constant regions.
CSP used for this experiment was sourced from Gennova through the Malaria Vaccine Initiative (MVI). Protein was provided in lyophilised form. The antigen is a 58 kDa protein from P. falciparum strain 3D7; GenBank accession number AL034558. A synthetic nucleotide sequence encoding the full-length, mature translated protein sequence for PfCSP (3D7 strain; GenBank accession number AL034558) was commercially synthesised with codons optimised for maximizing expression of the heterologous gene in E. coli. This synthetic gene encoded the predicted full-length mature protein with a carboxy-terminal hexa-histidine tag, without the signal sequence and putative GPI anchor sequence.
Expression system: E. coli BL21 (DE3). These host cells contain a chromosomal copy of T7 RNA polymerase gene under the control of lacUV5 promoter which is induced by addition of lactose analogue such as isopropyl^-D-thiogalactopyranoside (IPTG). IPTG induces production of T7 RNA polymerase allowing transcription of the target DNA in the plasmid. BL21 (DE3) strain is deficient in both Ion and ompT proteases, thus improving stability of the recombinant protein expressed in these host cells. The purified antigen has been show to elicit a strong T-cell immune response by Elispot. Nucleotide and amino acid sequences of CSP are shown in Figures 6 and 7. The antigen has also previously been shown to be immunogenic in immunisations in animals (Kastenmuller K, Espinosa DA, Trager L,
Stoyanov C, Salazar AM, Pokalwar S, Singh S, Dutta S, Ockenhouse CF, Zavala F, Seder RA. Infect Immun. 2013 Mar;81 (3):789-800. doi: 10.1 128/IAI.01 108-12. Epub 2012 Dec 28).
Immunisations were carried out according to the schedule in Figure 2 using 20 μg of E. coli expressed full length Pf-CSP and Montanide ISA720 adjuvant 70/30 % v/v. Details of the animals used for immunisation are presented in Table 1.
Table 1 : Animals used for CSP immunisation.
Immunisation progress was monitored via serial bleed titres. Following sacrifice, sera were collected for terminal bleed titre via a CSP-ELISA assay. All mice responded to CSP- antigen challenge with >10M final titre.
Example 2: Expression of selected antibody sequences
Post-immunisation antibody responses in the Kymice™ were identified from blasting B cells using the IRC™ sequencing technology. IRC™ technology has been described by Atreca, Inc. in published patent applications. This platform captures full length sequences, enabling detection of somatic mutations across the entire antibody variable region. Natively paired heavy and light chain IgG variable regions are analysed, and constant region isotype assignments can be made. IRC corrects for sequence errors introduced at all steps of a single-cell analysis process and provides unbiased output by correcting for biases from PCR amplification and other sources. IRC can be applied to any B cell type, other isotypes, and any species for which constant region sequences are known, including blasted B cells (e.g. human plasmablasts, mouse splenocytes, etc.) and antigen sorted B cells (e.g. antigen- binding memory B cells). IRC was used here to provide the signal peptide, full variable region, and a portion of the constant region of natively-paired heavy and light chain sequences from individual B cells of the immunised Kymice.
Candidate antibody lineages for expression and testing were chosen based on sequence-features such as the degree of lineage dominance, somatic hypermutation levels, and apparent convergence of lineages across multiple CSP-immunised Kymice. Forty-eight antibody sequences representing thirty-seven diverse, putative antibody lineages were produced via gene synthesis and recombinant expression as fully human antibodies.
Methods of Vector Construction and Recombinant Antibody Expression
Subcloning of antibody sequences into expression vectors:
DNA sequences for paired heavy chain (HC) and light chain (LC) IgG variable regions were synthesised and subcloned into expression vector pLEV123 (LakePharma, Inc.). Heavy chain variable region sequences were fused to the signal peptide
MDPKGSLSWRILLFLSLAFELSYG (SEQ ID NO: 51) and human lgG1 constant regions. The light chain variable region sequences were fused to the signal peptide
MSVPTQVLGLLLLWLTDARC (SEQ ID NO: 52) for the lambda light chain, or
METDTLLLWVLLLWVPGSTG (SEQ ID NO: 53) for the kappa light chain, followed by the compatible human kappa or lambda light chain constant regions.
Small scale transient transfection:
HEK293 cells were seeded in shake flasks one day before transfection, and were grown using serum-free chemically defined media. The DNA expression plasmids were scaled up and transiently transfected into 10-30 ml of suspension HEK293 cells using LakePharma's standard operating procedure for transient transfection. After 20 hours, cultures were fed and production continued for 5 days. Cells were sampled to obtain the viabilities and viable cell counts, and titers were measured (Octet QKe, ForteBio). On day 5, cells were sampled to obtain the viabilities and viable cell counts, and titers were measured (Octet QKe, ForteBio) before harvesting the cell cultures. Protein A affinity purification:
The conditioned media from HEK293 cells expressing antibody were harvested from the transient transfection production run by centrifugation. The supernatant was run over a Protein A column and eluted with a low pH buffer. Filtration using a 0.2 μηι membrane filter was performed before aliquoting. After purification and filtration, the protein concentration was calculated from the OD280 and the extinction coefficient. Antibodies were formulated in HEPES buffer (200 mM HEPES, 100 mM NaCI, 50 mM NaOac, pH 7.) CE-SDS analysis was performed (LabChip GXII, Perkin Elmer) to ensure antibody quality.
Example 3: CSP-binding characterisation
Nine antibody lineages were found to bind CSP when tested by ELISA. Of these, seven bound to native CSP epitopes presented on the surface of whole sporozoites.
Seven of nine ELISA positive lineages were expressed as full-length antibodies with human lgG1 constant region and further characterised using bio-layer interferometry and competitive binding assays to identify distinct binding sites.
Table 2: Dissociation constants were determined via Octet affinity analysis at LakePharma, Inc.. CSP binding site was determined via ELISA with CSP fragments.
Binding affinities against rCSP were measured via ForteBio Octet Red69 using two different assay formats. By changing the Octet assay antibody-antigen orientation (see methods section below for two formats), the dose-dependent responses of Ab667 and Ab668 toward Streptavidin-sensor captured biotin/rCSP were obtained and the kinetics constants were calculated. The kinetic analysis of Ab667 and Ab668 binding toward biotin/rCSP by Octet was used to generate the kinetic constants shown in Table 3 and illustrate the high affinity of antibodies 667 and 668 to the CSP antigen. Loading Sample ID KD (M) kon(1/Ms) kdis(1/s) Full RA2 Full ΧΛ2
Sample ID
Biotin-rCSP AB-000667 3.41 E-10 1 .66E+05 5.67E-05 0.999447 0.008402
Biotin-rCSP AB-000668 5.70E-10 1 .25E+05 7.10E-05 0.999348 0.084204
Table 3. Kinetic constants of AB-000667 and AB-000668 to biotin/rCSP
A direct binding ELISA of the anti-CSP mAbs to two different peptides and the rPf- CSP control antigen (Gennova) was performed. Anti-CSP mAbs 667 and 668 were shown to bind to rPF-CSP and to the NANP repeat region, while lacking binding capacity to the Pf16 motif at the C-terminus region of CSP. See Figure 8.
Competitive binding assays were performed with the ForteBio Octet™ system, in which anti-human Fc coated sensors were sequentially incubated with first antibody, antigen, then second antibody. Binding of each component was monitored by SPR. Results are illustrated in Figure 3, in which a chord between two mAbs indicates a blocking relationship and no chord indicates no blocking.
In order for two antibodies to belong to the same bin, they must block one another and exhibit similar blocking profiles when each is paired with the other antibodies in the test panel. In this project, both assay formats (see methods below) agree that AB-000649 has a unique epitope than the other antibodies, and AB-000667 and AB-000668 are in the same epitope bin. AB000643 and AB-000646 are in different bins because they do not block each other. Whether AB-00640 is in the same bin as AB-000646 or AB-000662 depends on the blocking relationship of AB-000640 and AB-000643. From the kinetics analysis results, AB- 000640 is a relatively weaker antibody with a slower on-rate and a fast off-rate. This may contribute to the uncertainty into its bin assignment.
Methods:
Epitope binning tests antibodies in a pairwise manner; antibodies competing for the same binding region are grouped together into bins. In this project, epitope binning was performed on Octet QKe system (ForteBio) using two assay formats. The biosensors were hydrated in sample diluent (0.1 % BSA in PBS and 0.02% Tween 20) and preconditioned in pH 1.9 Glycine. The first assay format (Assay Format 1) used Anti-hFc (AHC) kinetic grade biosensors (ForteBio, #18-5060) to capture rCSP/Ab1 mix (rCSP 100nM, Ab1 300nM, 60 seconds); the sensors were then dipped into high concentration of hFc (150 ug/mL) for 300 seconds to saturate the AHC sensor. Ab1 of 300nM was loaded again for 300 seconds to check for unsaturated Ab1 binding epitope. Lastly, the sensors were dipped into Ab2
(100nM, 120 seconds) to capture the association. A second assay format (Assay Format 2) used Streptavidin (SA) kinetic grade biosensors (ForteBio, #18-5021) to immobilize biotinylated rCSP at a concentration of 20 μg/ml for 120 seconds. The antigen-loaded SA biosensors were then dipped into Ab1 ("saturating antibody") at 20 ug/ml for 600 seconds. A short baseline (30 seconds) was observed using dissociation buffer after the Ab1 loading. The sensor was then dipped into Ab2 ("competing antibody") at 5 ug/mL and the association was observed for 120 seconds, followed by 120 seconds of dissociation. Parallel references were set up by repeating all the steps except for the saturating antibody step. Instead, the biosensors were dipped into the dissociation buffer directly. The Ab2 binding sensorgram captured the difference between the SA sensor-antigen-Ab1 and the SA sensor-antigen-buffer.
Methods for Enzyme-Linked Immunosorbent Assays (ELISA)
Ninety-six-well EIA plates were coated with 100 μΙ_Λ/νβΙΙ, 2 μg/mL Pf CSP antigen and incubated at 4 °C overnight. Antigen was diluted in 1x phosphate buffer (PB), pH 6.5.
Coated plates were then blocked with 1x PBS, 2.5% BSA the next morning at room temperature for 2 hrs. Two serial dilutions (1 :10 and 1 : 100) of each conditioned HEK 293 cell culture medium sample was prepared with 1x PBS, 1 % BSA assay diluent. Duplicate 100 μΙ_ samples were added to each well; plates were then incubated at room temperature for 1 hour on a microplate shaker and then washed three times in 1X PBS. Secondary antibody (100 μΙ_ of 1 :5,000 dilution) was added to each well: goat anti-mouse Fc-HRP was used for controls and anti-human Fc-HRP was used for the test sample wells. Plates were shaken at room temperature for 1 hour, followed by three washes with 1x PBS. Plates were then developed using TMB; the OD450 of each well was determined and recorded with a BMG POLARstar Omega Microplate reader.
Methods for Peptide ELISA for Epitope Mapping Studies For determination of the specific Pf CSP epitope these antibodies bind to, ELISAs were performed using two different CSP-specific peptides, Pf 16 (C-terminus) and
EPO70034 (NANP repeat region). Peptide Pf16 was reconstituted with DMSO to 20 mg/mL and then diluted with sterile water to obtain a final concentration of 5 mg/mL. EP070034 was reconstituted with sterile water to obtain a final concentration of 5 mg/mL. 96-well plates were coated overnight with the three antigens (including the full-length Pf CSP antigen) at a final concentration of ^g/mL. The plate was blocked with 1x PBS, 2.5% BSA for 2 hours the next morning at room temperature. Antibody samples were prepared in an 8-point 1 :5 serial dilution series with 1x PBS, 1 % BSA with a starting concentration of 50 μg/mL. The HRP- goat anti-human Fc was diluted 1 :5,000 for detection as described above. Methods for Octet Affinity Analyses
Affinity determination was performed on an Octet QKe system (ForteBio). Anti-hFc (AHC) kinetic grade biosensors (ForteBio, #18-5060) were hydrated in sample diluent (0.1 % BSA in PBS and 0.02% Tween 20) and preconditioned in pH 1.9 Glycine. Antibody was immobilised onto AHC biosensors at a concentration of 20 μg/mL for 60 seconds. The antibody-loaded AHC biosensors were then dipped into an 8-point dilution series of the Pf CSP antigen (starting at 1000 nM, 1 :3 diluted down). Association was observed for 120 seconds, followed by 180 seconds of dissociation. A short baseline (30 seconds) was established using dissociation buffer after AHC loading. Parallel references were set up by using unloaded bare sensor and sensor dipped into an 8-point dilution series of the antigen. During data processing, the parallel reference was used for normalization. The binding affinity of Pf CSP to each antibody was characterized by fitting kinetic sensorgrams to a monovalent binding model (1 :1 binding). This assay set up was used for five related antibodies (AB-000662, AB-000640, AB-000649, AB000646 and AB000643).
However, the binding affinity of AB-000667 and AB-000668 was near the level of detection in this format. To confirm the binding affinity of AB-000667 and AB-000668 to PF CSP, another assay orientation was conducted using Streptavidin kinetic grade biosensors (ForteBio, #18- 5021) to capture biotinylated rCSP. The biotin/Pf CSP loaded SA sensor was then dipped into an 8- point dilution series of the AB-000667 or AB-000668 (starting at 33 nM or 133 nM, 1 :3 diluted down).
Example 4a: In vivo protection studies using mouse malaria challenge model
Candidate antibodies are tested in a mouse malaria challenge model. This in vivo mouse protection assay uses intravenous passive transfer of selected antibodies (300 μg/mouse) followed by challenge with chimeric P. berghei encoding full-length P.
falciparum CSP.
In an initial experiment, antibodies are injected intravenously. Sporozoites are injected 30 minutes later by intravenous challenge. Parasite liver burden (measured by PCR) is used as a readout. Antibodies that show protection in this IV challenge are then further tested in a second experiment, using mosquito bite challenge. Parasitaemia can be used as a readout to assess sterile protection.
Figure 5 illustrates principles of the challenge model.
40 h after challenge with chimeric sporozoites, livers are extracted and RNA is isolated from liver homogenates. Real-time PCR, targeting the parasite 18S rRNA sequence, is used to measure the relative level of liver-stage parasites. Liver-stage parasite load can be quantified in terms of the number of P. berghei 18S rRNA copies in liver. % reduction of parasite load can be determined relative to control mice who do not receive the candidate antibody or who receive a control antibody (naive mice).
Another measure of protection is the % of challenged mice remaining free of blood- stage parasites for a period following challenge. Mice may be monitored for a period of, e.g., 7 or 14 days, and % mice remaining free of blood-stage parasites is determined for challenged mice and control mice.
Example 4b
The mouse challenge described in Example 4a was performed to assess the ability of passively-transferred anti-CSP mAbs to protect mice from sporozoite challenge. As noted, these in vivo protection studies involving transgenic sporozoites comprised initial screening by IV injection of 300 ug of Ab per animal followed by measurement of liver stage burden.
Aspects of the methodology have been previously described in Bruna-Romero et al 2001 Int.
J. Parasitol. 31 : 1499-1502. The anti-CSP mAb 2A10 (Anker, Zavala & Pollok, Eur J
Immunol. 20:2757-2761 1990) was used as a positive control.
Results are shown in Figure 9 and Figure 10. The data indicate that antibodies 667 and 668 confer significant and very strong protection relative to the 2A10 positive control.
To confirm that mAbs 667 and 668 confer protection from transgenic sporozoite challenge and evaluate whether such protection could be sterilising, a second challenge was performed using three different concentrations of antibody. The outcome was evaluated by determination of parasitemia at various time points post-challenge.
Table 4.
Results shown in Figure 11 and in Table 4 demonstrate that
parasitemia data confirm the previously observed protection seen in the liver, protection is fully sterilising in a significant fraction of the animals, and iii) protection is dose-dependent but is still higher at the lower dose of antibodies 667 and 668 than for 2A10 at the highest dose.
For assays culminating in a parasitemia endpoint, challenge is administered by 5 infected mosquito bites. In order to determine how many mosquitoes are needed to challenge mice with 5 infected mosquito bites, 17 days after blood feeding on mice infected with chimeric P. berghei parasites encoding full-length P. falciparum CSP, the proportion of infected mosquitoes was calculated, in this case, -85% (26 out of 30 infected salivary glands). Based on this calculation, it was determined that 6 mosquitoes were needed to challenge mice with 5 infected mosquito bites. Cohorts of seven mice per group underwent treatment, either passive transfer of experimental mAbs or positive control mAb, or in the case of the negative control, were not treated and merely challenged. Upon passive transfer of monoclonal antibodies, mice were anesthetized with 2% Avertin and mosquitoes allowed to feed on mice for -10 minutes. After feeding, the number of mosquitoes positive for a blood meal was determined. On days 4 - 11 after challenge, blood smears were taken from mice to determine parasitemia. % sterile protection was determined by dividing the number of uninfected mice by the total number of mice challenged. Pre-patent period, the number of days prior to detection of parasites in the blood, was also recorded.
Example 5: Inhibition of gliding motility
Plasmodium sporozoites move by gliding motility, a unique form of locomotion, which is required for tissue migration and host cell invasion. The impact of anti-CSP antibodies on sporozoites' gliding motility was assessed using methods previously described by Ejigiri et al. (Ejigiri et al., Shedding of TRAP by a Rhomboid Protease from the Malaria Sporozoite Surface is Essential for Gliding Motility and Sporozoite Infectivity, PLoS Pathog 8(7), 2012). Briefly, P. falciparum sporozoites were pre-incubated with the indicated antibodies (100 ug/ml) for 30 min and then added to wells in the presence of bovine serum albumin and incubated at 37°C for 1 hr. They were then fixed and trails were stained with anti-CSP antibody and counted using a fluorescence microscope.
Anti-CSP antibodies mAb667 and mAb668 abolished gliding motility of the sporozoites in this assay. Data are shown in Figure 12.
Example 6: Inhibition of liver stage development
The inhibition of liver stage development assay (ILSDA) tests antibodies for the ability to block sporozoite development in hepatocytes. As such the ILSDA is an excellent candidate assay to identify correlates of humoral protection, particularly against the liver stage of malaria infection. The Inhibition of Liver Stage Development Assay (ILSDA) was performed as previously described by Zou et al. (Zou et al, Towards an optimized inhibition of liver stage development assay (ILDSA) for Plasmodium falciparum, Malaria Journal 12:394, 2013). In brief, the NF54 strain of Plasmodium falciparum (Pf) sporozoites (obtained from salivary gland dissections) were mixed with monoclonal antibodies (mAbs) and incubated at room temperature for 20 minutes. The sporozoites-mAbs mixtures were then introduced into the wells containing cryopreserved human hepatocytes (CPHH; BioReclamation IVT, Baltimore MD) and incubated at 37°C for 3 hours to allow sporozoites to infect hepatocytes. The anti- CSP mAb 2A10 was used as a positive control. After the 3 hour incubation period, CPHH were washed with fresh hepatocyte culture media to remove non-invaded sporozoites and incubated at 37°C for 96 hours. The RNA from the cells was then harvested for downstream quantitative real-time PCR (qRT-PCR) analysis. Pf 18s rRNA level were quantified to determine the inhibitive ability of the tested mAbs.
mAb 667 and mAb668 effectively blocked sporozoite development in hepatocytes in this assay (Figure 13).
Example 7: Inhibition of sporozoite traversal and invasion (ISTI)
Monoclonal antibodies were tested for their ability to inhibit invasion and traversal using the ISTI assay as previously published (A. N. Douglass, P. G. Metzger, S. H. Kappe, A. Kaushansky, Flow Cytometry- Based Assessment of Antibody Function Against Malaria Pre-erythrocytic Infection. Methods Mol Biol 1325, 49-58 (2015), and J. G. Kublin et al., Complete attenuation of genetically engineered Plasmodium falciparum sporozoites in human subjects. Sci TransI Med 9, (2017).). Briefly, freshly-dissected PfNF54 salivary gland sporozoites were pre-incubated with 10 μg/mL of mAb or non-specific murine IgG (mock) in complete DMEM containing FITC-dextran for 15 minutes. Sporozoites were then directly added to 100,000 HC04 cells in a 96 well plate at an MOI of 1 :3 (sporozoites: HC04 cells) in triplicate, centrifuged at 500xg for 5 minutes and returned to 37 degrees C. After 90 minutes, cells were fixed and stained for presence of CSP with AlexaFluor-647-conjugated mAb clone 2A10. Cells were then analyzed for invasion (CSP+) or traversal (FITC-dextran+) via flow cytometry. Both invasion and traversal for each well was normalized to the average of mock- treated wells and expressed as "% of mock".
Anti-CSP antibodies mAb667 and mAb668 dramatically reduced both hepatocyte traversal (Figure 14) and hepatocyte invasion (Figure 15) in this assay.
Antibody 666 and antibody 669 were also tested and were confirmed to be functional hits in the ISTI assay. Example 8: Sporozoite challenge into FRG Hu-Hep mice
In addition to the challenge model described in Example 4, a human liver (Hu-Hep) mouse challenge model was used to assess the ability of passively-transferred anti-CSP mAbs to protect mice from sporozoite challenge.
FRG Hu-Hep mice were purchased from Yecuris, Inc. and used in passive transfer experiments as previously described (K. Sack et al., Model for in vivo assessment of humoral protection against malaria sporozoite challenge by passive transfer of monoclonal antibodies and immune serum. Infect Immun 82, 808-817 (2014), and Sack et al., submitted). Briefly, mice were intravenously injected with 150 μg of mAb or non-specific murine IgG (mock) 16-24 hours prior to infection by bite of 50 mosquitos infected with Pf GFP-luciferase parasites (Vaughan et al. 2012) for 10 minutes. Six days after infection, parasite liver burden was assessed by bioluminescent imaging. Percent of mock liver burden was calculated by normalizing all liver burdens to the average of the mock-injected group within each independent experiment. The 3C1 anti-CSP mAb (Zavala et al., J Exp Med 157: 1947-1957 1983) had previously been shown in this model to mediate higher inhibition of infection than the 2A10 positive control and was therefore used as the positive control in the present experiment.
Data from this experiment confirmed the observations made in the transgenic sporozoite model (Example 4), that the two anti-CSP antibodies tested provide robust and dose-dependent protection from liver-stage infection. See Figure 16.
Example 9: Informatics
In view of the encouraging performance of the anti-CSP antibodies 666, 667, 668 and 669 as described herein, informatics analysis was undertaken to identify related antibodies generated by the immunised mice, as structurally-related antibodies derived from the same lymphocyte lineage would be expected to share specificity for the same epitope and to display similar functional properties.
Bioinformatics indicated that the antibodies 667 and 668 belonged to families of phylogenetically similar antibodies, antibodies within each family being recombined from the same heavy chain v and j gene segments and the same or similar light chain germline genes. There is a high probability that other members of those families are functionally active and may demonstrate in vivo activity comparable to that of Ab667 and Ab668.
The phylogenetic family of Ab667 contains Ab666 and a number of further antibodies, as shown in Table 5. h_cdr3 h_cxlr2 h_cdr1 I_cdr3 I_cdr2 I_cdr1
DNFFESSGYYSYYFYGMDV WINAGNGYTKYSQRFQG GYTFTSYAMH CSYVGSSTWI DVSKRPS TGTSSDVGSYNHVS
666 DEYYASGSYYDYYYYGMDV WINAGNGNTKYSQNFQG GYTFTNYAMH CSYAGSSTWV NVSKRPS TGTSSDVGVYNYVS
DEYYASGSYYDYYYYGMDV WINAGNGNTKYSQNFQG GYTFTNYAMH CSYAGSSTWV NVSKRPS TGTSSDVGVYNYVS
DEYYASGSYYDYYYYGMDV WINAGNGNTKYSQNFQG GYTFTNYAMH CSYAGSSTWV NVSKRPS TGTSSDVGVYNYVS
DNFYGSGTYFSYFFYHMDV WINAGNGNTKYSQKFQG GYTFTNYAIH CSYAGSSTWV DVSKRPS TGTSSDVGSYNHVS
DNYYDSGSYYDYYYYGMDV WINAGNGNTKYSQKFQG GYTFTSYAMH CSYAGSSTWV DVSKRPS TGTSSDVGSYNHVS
DNYYDSGSYYEYCYYGMDV WINAGNGYTKYSQKFQG GYTFTNYAMH CSYVGSSTWV DVSKRPS TGTSSDVGSYNHVS
DNYYDSNVYNSYYFYGMDV WINAGNGYTKYSQKFQG GYTFTNYAMH CSYAGSSTWV DVNKRPS TGTSSDVGNYNHVS
DQYYDILTPYYYYYYGMDV WINAGNGNTKYSQKFQG GYTFTSYAMH CSYAGSSTWV VVSKRPS TGTSSDVGGYNYVS
667 DSFYDILSGPVYHYYGMDV WINAGNGYTKYSQKFQD GYTFTNYAMH CSYAGSSAWV DVNKRPS TGTSNDVGIYNHVS
DSFYDILTGPVYHYYGMDV WINAGNGYTKYSQKFQD GYTFTNYAMH CSYAGSSTWV DVSKRPS TGTSNDVGVYNHVS
DSFYDILTGPVYHYYGMDV WINAGNGYTKYSQKFQD GYTFSNYAMH CSYVGNSAWV DVSKRPS TGTSNDVGVYNHVS
DSFYDILTGPVYHYYGMDV WINAGNGYTKYSQKFQD GYTFTNYAMH CSYVGSSAWV DVSKRPS TGTSNDVGVYNHVS
Table 5. Atreca identification of CDRs of antibodies related to Ab666 and Ab667.
The phylogenetic family of Ab668 contains Ab669 and a number of further 5 antibodies, as shown in Table 6.
669
Table 6. Atreca identification of CDRs of antibodies related to Ab668 and Ab669.
In addition, bioinformatics analysis indicated that the phylogenetic branch containing the family of antibody 667 and antibody 668 also contained other individual antibody VH-VL pairs that use the same v gene segments and have light chains with high identity to those of Ab667 and Ab668 respectively. Antibody heavy chains having the following sets of CDRs were identified:
HC CDR3 HC CDR2 HC CDR1
AB-000666 DEYYASGSYYDYYYYGMDV WINAGNGNTKYSQNFQG GYTFTNYAMH AB-000667 DSFYDILSGPVYHYYGMDV WINAGNGYTKYSQKFQD GYTFTNYAMH AB-000668 DGFCPSNTCSGYYGMDV WINAGNGYTKYSQKFQD GFTFTDYAMH AB-000669 DGFCTSTTCSDHYGMDV WINAGNGHTKYSQKFQD GFTFTSYAMH
DQYYD I LKGYYN VDYYYG M D V WINAGNGYTKYSQKFQG GYTFTNYAMH
DNYFDSSVYDSSYYFYYGMDV Wl N AG NGYTKYSQN FQG GYTFTSYAMH
DEYYESGSSNYYYYGMDV Wl N AG NGYTKYSQTFQG GYTFTNYAMH
DQFYETLTGYYNVYYYYGMDV WINAGNGYTKYSQMFQD GYTFTNYAIH
DEYYDSGSSNYYYYGMDV WINAGNGYTKYSQKFQG GYTFTNYAIH
Table 7. Atreca identification of HCDRs of additional antibodies in the phylogenetic branch.
These antibodies have the same germline gene usage, high identity light chains and high identity in the HCDR1 and HCDR2. It is believed that antibodies comprising VH domains having these CDRs may be functionally active in a similar way to Ab666, 667, 668 and 669. This may be confirmed through assays as described in the above Examples.
Separately, further bioinformatic analysis was undertaken to infer lineage trees for antibodies Ab666, Ab667, Ab668 and Ab669. Each tree connects antibody clones predicted to have been derived from the same naive B cell clonal expansion lineage, and shows how they relate to each other, and to the germline sequence. The identified antibody families were as follows:
Ab666 lineage: Ab666, Ab666-1 , Ab666-2, Ab666-3, Ab666-4.
Ab667 lineage: Ab667, Ab667-1 , Ab667-2, Ab667-3.
Ab668 lineage: Ab668, Ab668-1.
Ab669 lineage: Ab669, Ab669-1 , Ab669-2, Ab669-3, Ab669-4, Ab669-5, Ab669-6.
Lineage trees are shown in Figure 18 (Ab666 lineage), Figure 19 (Ab667 lineage), Figure 20 (Ab668 lineage) and Figure 21 (Ab669 lineage).
The antibodies in each given lineage were inferred to have been derived from recombination of the same v, d and j gene segment sequences (heavy chain) and the same v and j gene segments (light chain). See Figure 4 for gene segment identification of antibodies in these lineages. Example 10: Further characterisation of anti-CSP antibodies by surface plasmon resonance
In Example 3 we reported measurements of the affinity of binding between anti-CSP antibodies and the CSP antigen, and showed that binding sites for antibody 667 and antibody 668 were found in the NANP repeat region of the CSP antigen. Here, we further characterise the interaction of the antibodies (666, 667, 668 and 669) with CSP, including measuring the kinetics of binding using SPR and determining binding to an array of CSP peptides to provide additional information on epitope recognition by these antibodies.
Materials & Methods - Expression and SPR
Amino acid sequences of antibodies 666, 667, 668 and 669 are shown in the appended sequence listing. For expression, silent mutations were introduced in certain VH domain nucleotide sequences to remove an AaR1 restriction site.
Antibodies 667, 668 and 669 were expressed as human lgG1 in HEK cells
(Expi293F, Gibco Life Technologies), and antibody 666 was expressed as human lgG1 in CHO cells (ExpiCHO, Gibco Life Technologies). The lgG1 were purified by Protein A and desalting and formulated at a concentration of 1 mg/mL in PBS at pH 7.4. Purity from size exclusion chromatography (SEC) was 92-95 %.
Antibodies 666, 667, 668 and 669 were expressed as Fabs in CHO cells (CHO-3E7, National Research Council Canada), purified on HiTrap nickel columns (GE Healthcare) eluted using 250 nM imidazole in PBS, and formulated at a concentration of 1 mg/mL in PBS at pH 7.4. Purity from SEC was >95 %.
Recombinant CSP (Figure 22) was provided by the Wellcome Trust Sanger Institute. P. falciparum strain 3D7 (GenBank accession number: CAB38998.2), molecular weight 45 kDa. The gene construct encoded CSP without the final 21 amino acids (GPI-anchor) to allow for soluble expression. A biotinylation site (BirA enzyme substrate peptide BSP) and histidine tag was also added.
Recombinant CSP was expressed in HEK293 cells using a mouse variable κ light chain peptide signal sequence for secretion into the culture medium, nickel-affinity purified and dialyzed into DPBS.
SPR experiments were performed as follows:
(i) Binding of antibody 666, 667, 668 and 669 Fabs to CSP, 25 degrees C, 900s dissociation time. The biotinylated recombinant CSP was diluted to 5 μg/mL in running buffer (1X HBS-EP+ Buffer Technova, cat. No. H8022) and captured on an NLC sensor chip (Bio- Rad, cat No 1765021). The surface was then blocked using biocytin (Sigma Aldrich, cat No B1758) at 1 mg/mL to prevent non-specific interaction with the chip surface. The
recombinant human Fabs were used as analyte at 1024 nM, 256 nM, 64 nM, 16 nM and 0 nM and injected over recombinant CSP. The assay was carried out at 25°C, with an association step of 240 sec and a dissociation step of 900 sec. Buffer injection (0 nM) was used to double reference the sensorgrams. The analysis was carried out using the 1 :1 binding model inherent to the Bio-Rad ProteOn's analysis software.
(ii) Binding of antibody 666, 667, 668 and 669 IgG to CSP, 40 degrees C. Five concentrations of CSP (64, 16, 4, 1 and 0.25 nM) were used as analyte over each human lgG1 construct captured at 0.3 μg/mL.
(iii) Binding of reference antibody 2A10 to CSP. Mouse monoclonal antibody 2A10 recognises the minimal epitope (NANP)3 of the Plasmodium falciparum (P. falciparum) circumsporozoite protein (CSP) repeat. It cross-reacts with the variant repeat sequence (NANPNVDPNANP) contained in the 5' repeat region of CSPs of all P. falciparum isolates. Monoclonal antibody 2A10 (lgG2aK) was obtained through BEI Resources, NIAID, NIH (MRA-183A, contributed by E. Nardin). 2A10 was diluted to 5μg/mL in running buffer (1X HBS-EP+ Buffer: Technova, cat. No. H8022) and captured on the anti-mouse capture surface. Recombinant CSP was used as analyte at 64 nM, 16 nM, 4 nM, 1 nM, 0.25 nM and 0 nM, and injected over the monoclonal mouse lgG2a construct. The assay was carried out at 25°C, with an association step of 240 sec and a dissociation step of 600 sec. Buffer injection (0 nM) was used to double reference the sensorgrams. The analysis was carried out using the 1 :1 binding model inherent to the Bio-Rad ProteOn's analysis software.
(iv) Anti-CSP reference antibody 2A10, mouse lgG2aK, 40 degrees C, with recombinant CSP. The concentration of antibody captured on the anti-mouse surface was varied from 5 ug/mL - 0.3125 ug/mL. Varying concentrations of recombinant CSP (64 nM - 0 nM) were passed over the captured antibody.
SPR Results
(i)
Table 8. SPR determination of CSP binding by antibody 666, 667, 668 and 669 Fabs, 25 degrees C (ϋ)
ka (1/Ms) kd (1/s) KD (nM)
666 human lgG1 9.70E+04 1.70E-05 0.18
667 human lgG1 2.15E+05 6.46E-05 0.31
668 human lgG1 5.40E+05 2.47E-05 0.05
669 human lgG1 2.65E+05 1.25E-04 0.47
Table 9. SPR determination of CSP binding by antibody 666, 667, 668 and 669 lgG1 , 40 degrees C. Here a higher temperature (40°C) was used to increase dissociation and lower capture. Considering the difference of affinities between human Fab and lgG1 , results suggest that the binding of the human lgG1 constructs to recombinant CSP is driven by avidity. This correlates with the apparent recognition by these antibodies of sequence NPDPNANP, which is heavily repeated in CSP. The KD values generated for the human lgG1 constructs are therefore considered as apparent affinities for CSP.
(iii)
Table 10. SPR determination of CSP binding by antibody 2A10 IgG, 25 degrees C (iv) The on-rate/off-rate could not be resolved for any of the 2A10 samples at 40 °C and hence no KD values could be generated. Increasing the temperature to 40°C for this analysis did not have an effect on the off-rate.
Materials & Methods - Peptide binding assay with antibody 666, 667, 668 and 669 lgG1
A biolayer interferometry assay was performed to analyse binding of monoclonal human lgG1 antibodies to CSP peptides.
Sensors coated with a commercial streptavidin ligand (Pall ForteBio, cat No 18-5019) were hydrated for 10 min in running buffer (1X HBS-EP+ Buffer: Technova, cat. No. H8022).
The monoclonal human lgG1 Abs were diluted to 30 μg/mL in running buffer.
Commercial CSP peptides and biotinylated recombinant CSP were diluted to 20μg/mL in running buffer. A first set of peptides (#1 to #4) was designed to cover 22 amino acids around the first occurrence of the epitope NPDPNANP, and a second set of peptides (#5 to #17) was designed as an alanine scan replacing one by one all amino acids in the
DGNPDPNANPNV sequence by an alanine (or a lysine if the amino acid is already an alanine). No in Assay Sequence Purity
Peptide #1 Biotin -SGSGKPKHKKLKQPGDGNPDPNANP 97.66%
Peptide #2 Biotin -SGSGKH KKLKQPG 99.50%
Peptide #3 Biotin -SGSGHKKLKQPGDGNPDPNANPN 98.62%
Peptide #4 Biotin -SGSGNPDPNANP 99.25%
Peptide #5 Biotin -SGSGDGNPDPNANPNV 98.07% Original
Peptide #6 Biotin -SGSGAGNPDPNANPNV 98.79%
Peptide #7 Biotin -SGSGDANPDPNANPNV 96.86%
Peptide #8 Biotin -SGSGDGAPDPNANPNV 96.76%
Peptide #9 Biotin -SGSGDGNADPNANPNV 97.93%
Peptide #10 Biotin -SGSGDGNPAPNANPNV 98.87%
Peptide #11 Biotin -SGSGDGNPDANANPNV 98.08% Alanine
Peptide #12 Biotin -SGSGDGNPDPAANPNV 98.13% Scan
Peptide #13 Biotin -SGSGDGNPDPNKNPNV 98.83%
Peptide #14 Biotin -SGSGDGNPDPNAAPNV 97.20%
Peptide #15 Biotin -SGSGDGNPDPNANANV 95.57%
Peptide #16 Biotin -SGSGDGNPDPNANPAV 98.81 %
Peptide #17 Biotin -SGSGDGNPDPNANPNA 97.79%
Table 1 1. Biotinylated CSP peptides.
The biotinylated peptides and recombinant CSP were captured at 20 μg/mL on the streptavidin sensors and then the sensors were dipped into the antibody solutions at 30 μg/mL. Fresh streptavidin sensors were used for each peptide-antibody interaction. The assay was carried out at 25°C. Binding signals were double referenced using a well reference and a sensor reference.
For the analysis, the limit of detection of a binding event (LOD) was defined as: LOD = Average of Buffer Signals + (3 x Standard Deviation of Buffer Signals) Any interaction with a response signal below the LOD was considered as non-binding.
Peptide binding results
Peptide #4 44285 0.1631 Yes
Peptide #5 44289 0.6346 Yes
Peptide #6 44290 0.9073 Yes
Peptide #7 44291 0.951 Yes
Peptide #8 44292 0.6919 Yes
Peptide #9 44293 0.6956 Yes
Peptide #10 44294 3.2183 Yes
Peptide #11 44295 0.0953 Yes
Peptide #12 44296 0.0529 Yes
Peptide #13 44297 -0.0102 No
Peptide #14 44298 -0.0141 No
Peptide #15 44299 0.2132 Yes
Peptide #16 44300 0.6506 Yes
Peptide #17 44301 1.086 Yes
Recombinant CSP 0.5284 Yes
Running Buffer 0.0209
Running Buffer Sensor Error
Running Buffer 0.0169
Buffer Average 0.0189
Buffer St.Dev 0.0028
LOD 0.027
Table 12. Summary of 667 human lgG1 interactions with peptides
Sample ID Loading Sample ID Response (nm) Binding
Peptide #1 44286 6.4733 Yes
Peptide #2 44287 -0.0533 No
Peptide #3 44288 6.341 Yes
Peptide #4 44285 4.6934 Yes
Peptide #5 44289 4.7146 Yes
668 human
Peptide #6 44290 4.8958 Yes lgG1
Peptide #7 44291 4.8788 Yes
Peptide #8 44292 4.8627 Yes
Peptide #9 44293 4.7189 Yes
Peptide #10 44294 5.8228 Yes
Peptide #11 44295 6.006 Yes Peptide #12 44296 4.7362 Yes
Peptide #13 44297 0.0033 No
Peptide #14 44298 0.5966 Yes
Peptide #15 44299 5.6891 Yes
Peptide #16 44300 4.7153 Yes
Peptide #17 44301 4.86 Yes
Recombinant CSP 0.6534 Yes
Running Buffer 0.1213
Running Buffer 0.1003
Running Buffer 0.0739
Buffer Average
Buffer St.Dev 0.024
LOD 0.170
Table 13. Summary of 668 human lgG1 interactions with peptides
Sample ID Loading Sample ID Response (nm) Binding
Peptide #1 44286 5.8313 Yes
Peptide #2 44287 -0.0428 No
Peptide #3 44288 5.0648 Yes
Peptide #4 44285 5.2674 Yes
Peptide #5 44289 3.7565 Yes
Peptide #6 44290 3.8156 Yes
Peptide #7 44291 3.8607 Yes
Peptide #8 44292 3.7931 Yes
Peptide #9 44293 3.6832 Yes
669 human
Peptide #10 44294 4.4782 Yes lgG1
Peptide #11 44295 2.1841 Yes
Peptide #12 44296 2.8081 Yes
Peptide #13 44297 -0.0024 No
Peptide #14 44298 0.0239 No
Peptide #15 44299 2.8174 Yes
Peptide #16 44300 3.6625 Yes
Peptide #17 44301 3.8523 Yes
Recombinant CSP 0.5456 Yes
Running Buffer 0.0674 Running Buffer 0.0879
Running Buffer 0.0507
Buffer Average 0.069
Buffer St.Dev 0.0186
LOD 0.125
Table 14. Summary of 669 human lgG1 interactions with peptides
Table 15. Summary of 666 human lgG1 interactions with peptides Considering the first set of peptides, all four monoclonal human IgGIs bind the peptide #4 (NPDPNANP) and the longest peptides (#1 and #3) that are including this sequence. 667, 668 and 669 do not bind the peptide #2 which covers the same sequence except for the NPDPNANP sequence. The four tested monoclonal human IgGIs show the same results that correlate with an epitope involving the NPDPNANP sequence. However, 666 lgG1 did show weak binding to peptide #2 which suggests the epitope for this antibody extends into the region further upstream, binding an epitope comprising one or more residues of the sequence KHKKLKQPG.
Considering the second set of peptides, the binding of the four monoclonal human IgGIs is disrupted on peptide #13 (DGNPDPNKNPNV) and the binding of 666, 667 and 669 human IgGIs is disrupted on the following peptide as well (DGNPDPNAAPNV). This suggests a refined epitope where the alanine in the NPDPNANP sequence has a role in the binding of the four monoclonal human IgGI s, and the following asparagine is involved in the binding of 666, 667 and 669 human IgGI s.
Example 1 1 : Additional anti-CSP antibody sequences
Further computational analysis of the antibody lineages identified in Example 2 was performed to group antibodies into evolutionarily-related lineages from their nucleotide sequences. Bioinformatics analysis was used to infer phylogenetic trees of antibodies derived from the same B cell clonal lineage.
Antibodies 666, 667, 668 and 669 are derived from IGLV2-23 and IGLJ3 germline genes. An additional 33 antibody sequences were identified which contain the common IGLV2-23 IGLJ3 genotype. These antibodies may therefore also be active against CSP. Alignments of the light and heavy chains of these antibodies are shown in Figures 23 and 24. An additional six antibodies were also selected as they were identified as members of the largest lineages. A large lineage is suggestive of a favoured evolutionary trajectory against an antigen and therefore of greater potential to contain strong antigen binding antibodies. Sequence information for these antibodies is provided in Table 16 and Table 17.
Example 12: SPR characterisaton of additional antibodies
The antibodies identified in Example 11 were expressed as human lgG1 in HEK cells (Expi293F, Gibco Life Technologies) having the VH and VL domains shown in Table 16 and cell culture supernatants were tested for binding to CSP by SPR at 25 degrees C. Antibody 666 was included as a positive control. Positive binding data were obtained for antibody 666 and for 21 of the Table 16 antibodies. Off-rates could not be resolved so kd (1/s) and KD (nM) values were not calculated. On-rates as represented by ka (1/Ms) were as follows:
Table 18. On-rates of antibodies identified in Example 11.
Kinetic Assay Method:
The human IgGls were transiently expressed in HEK293 cells over a week. The
supernatants containing the human IgGls were diluted 1/100 in running buffer (1X HBS-EP+ Buffer Technova, cat. No. H8022) and captured on an anti-human IgG capture surface. The full CSP protein was used as analyte at 64nM, 16nM, 4nM, 1 nM, 0.25nM and OnM, and injected over the captured human IgGls. Finally, the surface was regenerated between each human lgG1 construct using 100mM P04. The assay was carried out at 25°C, with an association step of 210sec and a dissociation step of 600sec. The buffer injection (i.e. OnM) was used to double reference the sensorgrams. The analysis was carried out using the 1 : 1 binding model inherent to the Bio-Rad ProteOn's analysis software.
Example 13: Selection of further protective anti-CSP antibodies with structural motif for NPDPNANP binding
Through sequence analysis of antibodies that showed strong binding to CSP and effective inhibition in biological assays described herein, and considering their structural interface with the NPDPNANP epitope identified herein, we uncovered a structural pattern that may be considered a structural "signature" or motif indicative of a class of antibodies that confer protection against sporozoite infection. Such antibodies are strong candidates for preventing malaria and may thus be administered to a mammal (e.g., human) to reduce risk of malaria in that mammal, methods for which are described in more detail elsewhere herein.
In particular, with reference to the structure of antibody AB-00068, we identified residues that contribute hydrophobic or electrostatic interactions with the CSP epitope.
Furthermore, we ran simulated molecular dynamics to model each of these structures dynamically, to further identify the electrostatically-important residues. This led to the identification of the following structural motif (all numbers are from the Kabat numbering scheme):
LCDR1 containing an N and a hydrophobic residue. Preferably, the N is at position 31. Preferably, the N is either directly preceded or followed by the hydrophobic residue. The hydrophobic residue is preferably Y.
LCDR3 containing a Y residue and a W residue. Preferably, the Y precedes W (in the N to C direction). Preferably, Y is at position 91. Preferably, W is at position 96.
HCDR2 containing W and N. Preferably, the W precedes N (in the N to C direction). Preferably, W is at position 50. Preferably, N is at at position 52.
HCDR3 containing at least one Y residue. Y may be present at any position in the HCDR3.
Antibodies comprising this structural motif represent preferred embodiments of the present invention.
Having identified this structural motif with reference to Ab-000668, we confirmed presence of this motif in numerous other antibodies described in the preceding Examples, and through analysis of other antibody sequences from the immunised mice we were able to further select the additional antibodies presented in Table 18, which contain this structural motif and are thus believed to represent candidate therapeutics according to the present invention. Antibody sequences
Antibody 666:
SEQ ID NO: 1 Ab666 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAAGGCTTCTGGATACACCTTCACAAACTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTAATACAA AATATTCACAAAATTTCCAGGGCAGAGTCACCATTACCAGGGACACATCCGCGAGCACA GCCTACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACTGTGCGA GAGATGAATACTATGCTTCGGGGAGTTATTATGACTACTACTACTACGGTATGGACGTC TGGGGCCAAGGGACCACGGTCACCGTCACCTCAGC
SEQ ID NO: 2 Ab666 H contig amino acid sequence
VH domain sequence encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCKASGYTFTNYAMHWVRQAPGQRLEWMGWINAGNGNT KYSQNFQGRVTITRDTSASTAYMELSSLRSEDTAVYYCARDEYYASGSYYDYYYYGMDVW GQGTTVTVTS
SEQ ID NO: 3 Ab666 HCDR1
GYTFTNYAMH
SEQ ID NO: 4 Ab666 HCDR2
WINAGNGNTKYSQNFQG SEQ ID NO: 5 Ab666 HCDR3
DEYYASGSYYDYYYYGM DV
SEQ ID NO: 6 Ab666 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTGTTTATAACTATGTCTCCTGGTTCCAAC AGCACCCAGGCAAAGCCCCCAAACTCATGATTTATAATGTCAGTAAGCGGCCCTCAGG GGTTTCTAATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAACCTGACCGTCCTAGG SEQ ID NO: 7 Ab666 L contig amino acid sequence
VL domain sequence encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGVYNYVSWFQQHPGKAPKLMIYNVSKRPSGVS NRFSGSKSGNTASLTISGLQAEDEADYYCCSYAGSSTWVFGGGTNLTVL
SEQ ID NO: 8 Ab666 LCDR1
TGTSSDVGVYNYVS
SEQ ID NO: 9 Ab666 LCDR2
NVSKRPS
SEQ ID NO: 10 Ab666 LCDR3
CSYAGSSTWV
Antibody 667:
SEQ ID NO: 11 Ab667 H contig nucleotide sequence
ATGGACTGGACCTGGAGGGTCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAGGGCTTCTGGATACACCTTCACTAACTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTTACACAA AATATTCACAGAAGTTCCAGGACAGAGTCACCATTACCAGGGACACATCCGCGACCAC AGCCTACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTATGTATTACTGTGCG AGAGATTCTTTTTACGATATTTTGAGTGGGCCAGTCTATCACTACTACGGTATGGACGTC TGGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC SEQ ID NO: 12 Ab667 H contig amino acid sequence
VH domain sequence encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCRASGYTFTNYAMHWVRQAPGQRLEWMGWINAGNGYT
KYSQKFQDRVTITRDTSATTAYMELSSLRSEDTAMYYCARDSFYDILSGPVYHYYGMDVW
GQGTTVTVSS
SEQ ID NO: 13 Ab667 HCDR1
GYTFTNYAMH
SEQ ID NO: 14 Ab667 HCDR2
Wl NAG N G YTKYSQ KFQ D SEQ ID NO: 15 Ab667 HCDR3
DSFYDILSGPVYHYYGMDV
SEQ ID NO: 16 Ab667 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGCCACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGACTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAATGATGTTGGTATTTATAACCATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAACTCATGATTTATGATGTCAATAAGCGGCCCTCAGG GATTTCTAATCGCTTCTCTGGCTCCAAGTCTGGCGACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTAGTAGCGC TTGGGTGTTCGGCGGAGGGACCAAATTGACCGTCCTTGG
SEQ ID NO: 17 Ab667 L contig amino acid sequence
VL domain sequence encoded by the nucleotide sequence above:
QSALTQPDSVSGSPGQSITISCTGTSNDVGIYNHVSWYQQHPGKAPKLMIYDVNKRPSGIS NRFSGSKSGDTASLTISGLQAEDEADYYCCSYAGSSAWVFGGGTKLTVL
SEQ ID NO: 18 Ab667 LCDR1
TGTSNDVGIYNHVS
SEQ ID NO: 19 Ab667 LCDR2
DVNKRPS
SEQ ID NO: 20 Ab667 LCDR3
CSYAGSSAWV
Antibody 668:
SEQ ID NO: 21 Ab668 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCGCAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAAGGCTTCTGGATTCACCTTCACTGACTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGCTGGATCAACGCTGGCAATGGTTACACAA AATATTCACAGAAGTTCCAGGACAGACTCACCATTACCAGGGACACATTCGCGAGCACA GTCTACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGACTGTGTATTACTGTGCGA GAGATGGGTTTTGTCCTAGTAACACTTGTTCTGGTTACTACGGTATGGACGTCTGGGGC CAAGGGACCACGGTCACCGTCTCCTCAGC SEQ ID NO: 22 Ab668 H contig amino acid sequence
VH domain sequence encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCKASGFTFTDYAMHWVRQAPGQRLEWMGWINAGNGYT KYSQKFQDRLTITRDTFASTVYMELSSLRSEDTTVYYCARDGFCPSNTCSGYYGMDVWGQ GTTVTVSS
SEQ ID NO: 23 Ab 668 HCDR1
GFTFTDYAMH SEQ ID NO: 24 Ab668 HCDR2
Wl NAGNGYTKYSQKFQD
SEQ ID NO: 25 Ab668 HCDR3
DGFCPSNTCSGYYGMDV
SEQ ID NO: 26 Ab668 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTTCTTATAACTATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAACTCATGATTTATGATGTCAATACGCGGCCCTCAGG GGTTTCTATTCGCTTCTCTGCCTCCAAGTCTGGCAACACGGCCTCCCTGACAGTCTCTG GGCTCCAGGCTGAGGACGAGGCTGTTTATTACTGCTCCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG SEQ ID NO: 27 Ab668 L contig amino acid sequence
VL domain sequence encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGSYNYVSWYQQHPGKAPKLMIYDVNTRPSGV SIRFSASKSGNTASLTVSGLQAEDEAVYYCSSYAGSSTWVFGGGTKLTVL SEQ ID NO: 28 Ab668 LCDR1
TGTSSDVGSYNYVS
SEQ ID NO: 29 Ab668 LCDR2
DVNTRPS
SEQ ID NO: 30 Ab668 LCDR3
SSYAGSSTWV Antibody 669:
SEQ ID NO: 31 Ab669 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAGGG TTTCCTGCAAGGCTTCTGGATTCACCTTCACTAGTTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTCACACA AAATATTCACAGAAGTTCCAGGACAGAGTCGCCATTACCAGGGACACATCCGCGACCA CAGTCTACATGGACCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACTGTAC GAGAGATGGATTTTGTACTAGTACCACCTGCTCCGACCACTACGGTATGGACGTCTGG GGCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 32 Ab669 H contig amino acid sequence
VH domain sequence encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVRVSCKASGFTFTSYAMHWVRQAPGQRLEWMGWINAGNGHT KYSQKFQDRVAITRDTSATTVYMDLSSLRSEDTAVYYCTRDGFCTSTTCSDHYGMDVWGQ GTTVTVSS
SEQ ID NO: 33 Ab669 HCDR1
GFTFTSYAMH
SEQ ID NO: 34 Ab669 HCDR2
WINAGNGHTKYSQKFQD SEQ ID NO: 35 Ab669 HCDR3
DGFCTSTTCSDHYGMDV
SEQ ID NO: 36 Ab669 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTAGTTATAACTATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAATTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTAATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTTGG SEQ ID NO: 37 Ab669 L contig amino acid sequence
VL domain sequence encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGSYNYVSWYQQHPGKAPKFMIYDVSKRPSGV SNRFSGSKSGNTASLTISGLQAEDEADYYCCSYAGSSTWVFGGGTKLTVL
SEQ ID NO: 38 Ab669 LCDR1
TGTSSDVGSYNYVS
SEQ ID NO: 39 Ab669 LCDR2
DVSKRPS
SEQ ID NO: 40 Ab669 LCDR3
CSYAGSSTWV
Antibody 666-3
SEQ ID NO: 64 Ab666-3 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAAGGCTTCTGGATACACCTTCACTAGTTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTAACACAA AATATTCACAGAAGTTCCAGGGCGGAGTCACCATTACCAGGGACACATCCGCGAGCAC AGCCTACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTGTATATTACTGTGCG AGAGACAATTACTATGATTCGGGGAGTTATTATGACTACTACTACTACGGTATGGACGT CTGGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 65 Ab666-3 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCKASGYTFTSYAMHWVRQAPGQRLEWMGWINAGNGNT KYSQKFQGGVTITRDTSASTAYMELSSLRSEDTAVYYCARDNYYDSGSYYDYYYYGMDVW GQGTTVTVSS
SEQ ID NO: 66 Ab666-3 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCTT CTCCTGCACTGGAACCAGCAGTGATGTTGGTAGTTATAATCATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAACTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTAATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
SEQ ID NO: 67 Ab666-3 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITFSCTGTSSDVGSYNHVSWYQQHPGKAPKLMIYDVSKRPSGV SNRFSGSKSGNTASLTISGLQAEDEADYYCCSYAGSSTWVFGGGTKLTVL Antibody 666-4
SEQ ID NO: 71 Ab666-4 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAAGGCGTCTGGATACACCTTCACGAACTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTTACACAA AATATTCACAGAAGTTCCAGGGCAGAGTCACCATTATCAGGGACACATCTGCGACCACA GCCTATATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACTGTGCGA GAGATAATTATTATGATTCGGGGAGTTATTATGAATACTGCTACTACGGTATGGACGTCT GGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 72 Ab666-4 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCKASGYTFTNYAMHWVRQAPGQRLEWMGWINAGNGYT KYSQKFQGRVTIIRDTSATTAYMELSSLRSEDTAVYYCARDNYYDSGSYYEYCYYGMDVW GQGTTVTVSS
SEQ ID NO: 73 Ab666-4 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTAGTTATAACCATGTCTCCTGGTACCAAC AATACCCAGGCAAAGCCCCCAAACTCCTGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTAATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTATG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGTAGGTAGCAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
SEQ ID NO: 74 Ab666-4 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGSYNHVSWYQQYPGKAPKLLIYDVSKRPSGVS NRFSGSKSGNTASLTIYGLQAEDEADYYCCSYVGSSTWVFGGGTKLTVL Antibody 667-1
SEQ ID NO: 79 Ab667-1 H contig nucleotide sequence
ATGGACTGGACCTGGAGGGTCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAGGGCTTCTGGATACACCTTCAGTAATTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTTACACAA AATATTCACAGAAGTTCCAGGACAGAGTCACCATTACCAGGGACACATCCGCGACCAC AGCCTACATGGAACTGAGCAGCCTGAGATCTGAAGACACGGCTATGTATTACTGTTCGA GAGATTCTTTTTACGATATTTTGACTGGGCCAGTCTATCACTACTACGGTATGGACGTCT GGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 80 Ab667-1 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCRASGYTFSNYAMHWVRQAPGQRLEWMGWINAGNGYT KYSQKFQDRVTITRDTSATTAYMELSSLRSEDTAMYYCSRDSFYDILTGPVYHYYGMDVW GQGTTVTVSS
SEQ ID NO: 81 Ab667-1 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGACTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAATGATGTTGGTGTTTATAACCATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAACTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTAATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGTAGGTAATAGCGC TTGGGTGTTCGGCGGAGGGACCAAACTGACCGTCCTAGG
SEQ ID NO: 82 Ab667-1 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPDSVSGSPGQSITISCTGTSNDVGVYNHVSWYQQHPGKAPKLMIYDVSKRPSGV SNRFSGSKSGNTASLTISGLQAEDEADYYCCSYVGNSAWVFGGGTKLTVL Antibody 667-2
SEQ ID NO: 84 Ab667-2 H contig nucleotide sequence
ATGGACTGGACCTGGAGGGTCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAGGGCTTCTGGATACACCTTCACTAACTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTTACACAA AGTATTCACAGAAGTTCCAGGACAGAGTCACCATTACCAGGGACACATCCGCGACCAC AGCCCACATGGAACTGAGCAGCCTGAGATCTGAAGACACGGCTATGTATTACTGTGCG AGAGATTCTTTTTACGATATTTTGACTGGGCCAGTCTATCACTACTACGGTATGGACGTC TGGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 85 Ab667-2 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCRASGYTFTNYAMHWVRQAPGQRLEWMGWINAGNGYT KYSQKFQDRVTITRDTSATTAHMELSSLRSEDTAMYYCARDSFYDILTGPVYHYYGMDVW GQGTTVTVSS
SEQ ID NO: 86 Ab667-2 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGACTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAATGATGTTGGTGTTTATAACCATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAACTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTAATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGTAGGTAGTAGCGC TTGGGTGTTCGGCGGAGGGACCAATCTGACCGTCCTAGG
SEQ ID NO: 87 Ab667-2 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPDSVSGSPGQSITISCTGTSNDVGVYNHVSWYQQHPGKAPKLMIYDVSKRPSGV SNRFSGSKSGNTASLTISGLQAEDEADYYCCSYVGSSAWVFGGGTNLTVL Antibody 667-3
SEQ ID NO: 88 Ab667-3 H contig nucleotide sequence
ATGGACTGGACCTGGAGGGTCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAGGGCTTCTGGATACACCTTCACTAACTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTTACACAA AATATTCACAGAAGTTCCAGGACAGATTCACCATTACCAGGGACACATCCGCGACCACA GCCTACATGGAACTGAGCAGCCTGAGATCTGAAGACACGGCTGTATATTACTGTGCGA GAGATTCTTTTTACGATATTTTGACTGGGCCAGTCTATCACTACTACGGTATGGACGTCT GGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 89 Ab667-3 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCRASGYTFTNYAMHWVRQAPGQRLEWMGWINAGNGYT KYSQKFQDRFTITRDTSATTAYMELSSLRSEDTAVYYCARDSFYDILTGPVYHYYGMDVWG QGTTVTVSS
SEQ ID NO: 90 Ab667-3 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGACTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAATGATGTTGGTGTTTATAACCATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAACTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTAATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGAGTGATTATTACTGCTGCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
SEQ ID NO: 91 Ab667-3 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPDSVSGSPGQSITISCTGTSNDVGVYNHVSWYQQHPGKAPKLMIYDVSKRPSGV SNRFSGSKSGNTASLTISGLQAEDESDYYCCSYAGSSTWVFGGGTKLTVL Antibody 668-1
SEQ ID NO: 93 Ab668-1 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCGCAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAAGGCTTCTGGATTCACCTTCACTGACTACGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGTTGGATCAACGCTGGCAATGGTTACACAA AATATTCACAGAAGTTCCAGGACAGACTCACCATTACCAGGGACACATTCGCGAGCACA GTCTACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGACTGTGTATTACTGTGCGA GAGATGGGTTTTGTCCTAGTAACACTTGTTCTGGTTACTACGGTATGGACGTCTGGGGC CAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 94 Ab668-1 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCKASGFTFTDYAMHWVRQAPGQRLEWMGWINAGNGYT KYSQKFQDRLTITRDTFASTVYMELSSLRSEDTTVYYCARDGFCPSNTCSGYYGMDVWGQ GTTVTVSS
SEQ ID NO: 95 Ab668-1 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTGCTTATAAGTATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAACTCATGATTTATGATGTCAATACGCGGCCCTCAGG GGTTTCTACTCGCTTCTCTGCCTCCAAGTCTGGCAACACGGCCTCCCTGACAGTCTCTG GGCTCCAGGCTGAGGACGAGGCTGTTTATTACTGCTCCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
SEQ ID NO: 96 Ab668-1 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGAYKYVSWYQQHPGKAPKLMIYDVNTRPSGVS TRFSASKSGNTASLTVSGLQAEDEAVYYCSSYAGSSTWVFGGGTKLTVL Antibody 669-1
SEQ ID NO: 100 Ab669-1 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAGGG TTTCCTGCAAGGCTTCTGGATTCACCTTCATTAGTTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAGGGCTTGAGTGGATGGGATGGATCAACGCTGGCGATGGTCACACA AAATATTCACAGAAGTTCCAGGACAGAGTCGCCATTACCAGGGACACATCCGCGACCA CAGTCTACATGGACCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACTGTTC GAGAGATGGATTTTGTACTACTACCACCTGTTCCGACCACTACGGTATGGACGTCTGGG GCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 101 Ab669-1 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVRVSCKASGFTFISYAMHWVRQAPGQGLEWMGWINAGDGHT KYSQKFQDRVAITRDTSATTVYMDLSSLRSEDTAVYYCSRDGFCTTTTCSDHYGMDVWGQ GTTVTVSS
SEQ ID NO: 102 Ab669-1 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTAGTTATAACTATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAATTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTGATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTTGG
SEQ ID NO: 103 Ab669-1 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGSYNYVSWYQQHPGKAPKFMIYDVSKRPSGV SDRFSGSKSGNTASLTISGLQAEDEADYYCCSYAGSSTWVFGGGTKLTVL Antibody 669-2
SEQ ID NO: 106 Ab669-2 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAGGG TTTCCTGCAAGACTTCTGGATTCACCTTCACTAGTTATGCTATACAGTGGGTGCGCCAG GCCCCCGGACAAGGGCTTGAGTGGATGGGATGGATCAACGCTGGCGATGGTCACACG AAATATTCACAGAAGTTCCAGGACAGAGTCGTCATTACCAGGGACACATCCGCGACCA CAGTCTACATGGACCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACTGTAC GAGAGATGGATTTTGTACTACGACCACCTGCTCCGACCACTACGGTATGGACGTCTGG GGCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 107 Ab669-2 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVRVSCKTSGFTFTSYAIQWVRQAPGQGLEWMGWINAGDGHTK YSQKFQDRVVITRDTSATTVYMDLSSLRSEDTAVYYCTRDGFCTTTTCSDHYGMDVWGQG TTVTVSS
SEQ ID NO: 108 Ab669-2 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTAGTTATAACTATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGTCCCCAAATTCATGATTTCTGATGTCAGTAAGCGGCCCTCAGG AATTTCTGATCGCTTCTCTGGCTCCAAGTCTGGCAATACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTGGTAGTAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTTGG
SEQ ID NO: 109 Ab669-2 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGSYNYVSWYQQHPGKVPKFMISDVSKRPSGIS DRFSGSKSGNTASLTISGLQAEDEADYYCCSYAGGSTWVFGGGTKLTVL Antibody 669-3
SEQ ID NO: 113 Ab669-3 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAACCCTGGGGCCTCAGTGAAGG TTTCCTGCAAGGCTTCTGGATTCACCTTCACTAACTATGCTATGCATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTCACACA AAATATTCACAGAAGTTCCAGGACAGAGTCGCCATTACCAGGGACACATCCGCGACCA CAGCCTACATGGAACTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACTGTTC GAGAGATGGATTTTGTAGTACTACCACCTGCTCCGACCACTACGGTATGGACGTCTGG GGCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 114 Ab669-3 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKNPGASVKVSCKASGFTFTNYAMHWVRQAPGQRLEWMGWINAGNGHT KYSQKFQDRVAITRDTSATTAYMELSSLRSEDTAVYYCSRDGFCSTTTCSDHYGMDVWGQ GTTVTVSS
SEQ ID NO: 115 Ab669-3 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTGGTTATAACTATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAATTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCCAATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
SEQ ID NO: 116 Ab669-3 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKFMIYDVSKRPSGV SNRFSGSKSGNTASLTISGLQAEDEADYYCCSYAGSSTWVFGGGTKLTVL Antibody 669-4
SEQ ID NO: 118 Ab669-4 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAAGGCTTCTGGATTCACCTTCACTAGCCATGCTATACATTGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAATGGTTACACAA AATATTCACAGAAGTTCCAGGACAGAGTCGCCATTACCAGGGACACATCCGCGAGCAC AGCCTACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACTGTACG AGAGATGGATTTTGTAGTACTACCACCTGCTCCGACCACTACGGTATGGACGTCTGGG GCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 119 Ab669-4 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCKASGFTFTSHAIHWVRQAPGQRLEWMGWINAGNGYTK YSQKFQDRVAITRDTSASTAYMELSSLRSEDTAVYYCTRDGFCSTTTCSDHYGMDVWGQG TTVTVSS
SEQ ID NO: 120 Ab669-4 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGCGGTTATAACTATGTCTCCTGGTACCAAC AGCACCCAGGCAAAGCCCCCAAATTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTAATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
SEQ ID NO: 121 Ab669-4 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKFMIYDVSKRPSGV SNRFSGSKSGNTASLTISGLQAEDEADYYCCSYAGSSTWVFGGGTKLTVL Antibody 669-5
SEQ ID NO: 124 Ab669-5 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGCCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGTAAGGCTTCTGGATACATCTTTATTAACTATGCTATGCAATGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAACGGTTACACA AAATATTCACAGAAGTTCCAGGGCAGAGTCACCATCACCAGGGACATATCCGCGAGCA CAGTCTACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACTGTGC GAGAGATGGATTTTGTAGGACAACCAGCTGCTCCGACCACTACGGTATGGACGTCTGG GGCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 125 Ab669-5 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCKASGYI Fl NYAMQWVRQAPGQRLEWMGWI NAGNGYTK YSQKFQGRVTITRDISASTVYMELSSLRSEDTAVYYCARDGFCRTTSCSDHYGMDVWGQG TTVTVSS
SEQ ID NO: 126 Ab669-5 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTGGTTATAACTATGTCTCCTGGTACCAAC AACACCCAGGCAAAGCCCCCAAACTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTGATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGACTGAGGACGAGGCTGATTTTTACTGCTGCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
SEQ ID NO: 127 Ab669-5 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSKRPSGV SDRFSGSKSGNTASLTISGLQTEDEADFYCCSYAGSSTWVFGGGTKLTVL Antibody 669-6
SEQ ID NO: 130 Ab669-6 H contig nucleotide sequence
ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTGTCCACTCCC AGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGGCCTCAGTGAAGG TTTCCTGCAAGGCTTCTGGATTCATCTTTATTAACTATGCTATGCAATGGGTGCGCCAG GCCCCCGGACAAAGGCTTGAGTGGATGGGATGGATCAACGCTGGCAACGGTTACACA AAATATTCACAGAAATTCCAGGGCAGAGTCACCATCACCAGGGACATATCCGCGAACAC AGTCTACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACTGTGCG AGAGATGGATTTTGTAGTACAACCACCTGCTCCGACCACTACGGTATGGACGTCTGGG GCCAAGGGACCACGGTCACCGTCTCCTCAGC
SEQ ID NO: 131 Ab669-6 H contig amino acid sequence
VH domain encoded by the nucleotide sequence above:
QVQLVQSGAEVKKPGASVKVSCKASGFIFINYAMQWVRQAPGQRLEWMGWINAGNGYTK YSQKFQGRVTITRDISANTVYMELSSLRSEDTAVYYCARDGFCSTTTCSDHYGMDVWGQG TTVTVSS
SEQ ID NO: 132 Ab669-6 L contig nucleotide sequence
ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGTCCTGGGCCC AGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCCTGGACAGTCGATCACCAT CTCCTGCACTGGAACCAGCAGTGATGTTGGTGGTTATAACTATGTCTCCTGGTACCAAC AACACCCAGGCAAAGCCCCCAAACTCATGATTTATGATGTCAGTAAGCGGCCCTCAGG GGTTTCTGATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTG GGCTCCAGACTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTAGTAGCAC TTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
SEQ ID NO: 133 Ab669-6 L contig amino acid sequence
VL domain encoded by the nucleotide sequence above:
QSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSKRPSGV SDRFSGSKSGNTASLTISGLQTEDEADYYCCSYAGSSTWVFGGGTKLTVL Antibody CDR sequence tables
Ab666-4 Atreca Kabat Chothia
HCDR1 GYTFTNYAMH NYAMH GYTFTNY
SEQ ID NO: 3 SEQ ID NO: 54 SEQ ID NO: 55
HCDR2 WINAGNGYTKYSQKFQG NAGNGY
SEQ ID NO: 68 SEQ ID NO: 68 SEQ ID NO: 138
HCDR3 DNYYDSGSYYEYCYYGMDV
SEQ ID NO: 69 SEQ ID NO: 69 SEQ ID NO: 69
LCDR1 TGTSSDVGSYNHVS
SEQ ID NO: 63 SEQ ID NO: 63 SEQ ID NO: 63
LCDR2 DVSKRPS
SEQ ID NO: 39 SEQ ID NO: 39 SEQ ID NO: 39
LCDR3 CSYVGSSTWV
SEQ ID NO: 70 SEQ ID NO: 70 SEQ ID NO: 70
Ab667-1 Atreca Kabat Chothia
HCDR1 GYTFSNYAMH NYAMH GYTFSNY
SEQ ID NO: 75 SEQ ID NO: 54 SEQ ID NO: 139
HCDR2 WINAGNGYTKYSQKFQD NAGNGY
SEQ ID NO: 14 SEQ ID NO: 14 SEQ ID NO: 138
HCDR3 DSFYDILTGPVYHYYGMDV
SEQ ID NO: 76 SEQ ID NO: 76 SEQ ID NO: 76
LCDR1 TGTSNDVGVYNHVS
SEQ ID NO: 77 SEQ ID NO: 77 SEQ ID NO: 77
LCDR2 DVSKRPS
SEQ ID NO: 39 SEQ ID NO: 39 SEQ ID NO: 39
LCDR3 CSYVGNSAWV
SEQ ID NO: 78 SEQ ID NO: 78 SEQ ID NO: 78
Ab667-3 Atreca Kabat Chothia
HCDR1 GYTFTNYAMH NYAMH GYTFTNY
SEQ ID NO: 13 SEQ ID NO: 54 SEQ ID NO: 55
HCDR2 WINAGNGYTKYSQKFQD NAGNGY
SEQ ID NO: 14 SEQ ID NO: 14 SEQ ID NO: 138
HCDR3 DSFYDILTGPVYHYYGMDV
SEQ ID NO: 76 SEQ ID NO: 76 SEQ ID NO: 76
LCDR1 TGTSNDVGVYNHVS
SEQ ID NO: 77 SEQ ID NO: 77 SEQ ID NO: 77
LCDR2 DVSKRPS
SEQ ID NO: 39 SEQ ID NO: 39 SEQ ID NO: 39
LCDR3 CSYAGSSTWV
SEQ ID NO: 10 SEQ ID NO: 10 SEQ ID NO: 10
Ab668-1 Atreca Kabat Chothia
HCDR1 GFTFTDYAMH DYAMH GFTFTDY
SEQ ID NO: 23 SEQ ID NO: 57 SEQ ID NO: 140
HCDR2 WINAGNGYTKYSQKFQD NAGNGY
SEQ ID NO: 24 SEQ ID NO: 24 SEQ ID NO: 138
HCDR3 DGFCPSNTCSGYYGMDV
SEQ ID NO: 25 SEQ ID NO: 25 SEQ ID NO: 25
LCDR1 TGTSSDVGAYKYVS
SEQ ID NO: 92 SEQ ID NO: 92 SEQ ID NO: 92
LCDR2 DVNTRPS
SEQ ID NO: 29 SEQ ID NO: 29 SEQ ID NO: 29
LCDR3 SSYAGSSTWV
SEQ ID NO: 30 SEQ ID NO: 30 SEQ ID NO: 30
Ab669-1 Atreca Kabat Chothia
HCDR1 GFTFISYAMH SYAMH GFTFISY
SEQ ID NO: 97 SEQ ID NO: 59 SEQ ID NO: 143
HCDR2 WINAGDGHTKYSQKFQD NAGDGH
SEQ ID NO: 98 SEQ ID NO: 98 SEQ ID NO: 144
HCDR3 DGFCTTTTCSDHYGMDV
SEQ ID NO: 99 SEQ ID NO: 99 SEQ ID NO: 99
LCDR1 TGTSSDVGSYNYVS
SEQ ID NO: 38 SEQ ID NO: 38 SEQ ID NO: 38
LCDR2 DVSKRPS
SEQ ID NO: 39 SEQ ID NO: 39 SEQ ID NO: 39
LCDR3 CSYAGSSTWV
SEQ ID NO: 40 SEQ ID NO: 40 SEQ ID NO: 40
Ab669-3 Atreca Kabat Chothia
HCDR1 GFTFTNYAMH NYAMH GFTFTNY
SEQ ID NO: 110 SEQ ID NO: 54 SEQ ID NO: 146
HCDR2 WINAGNGHTKYSQKFQD NAGNGH
SEQ ID NO: 34 SEQ ID NO: 34 SEQ ID NO: 142
HCDR3 DGFCSTTTCSDHYGMDV
SEQ ID NO: 111 SEQ ID NO: 111 SEQ ID NO: 111
LCDR1 TGTSSDVGGYNYVS
SEQ ID NO: 112 SEQ ID NO: 112 SEQ ID NO: 112
LCDR2 DVSKRPS
SEQ ID NO: 39 SEQ ID NO: 39 SEQ ID NO: 39
LCDR3 CSYAGSSTWV
SEQ ID NO: 40 SEQ ID NO: 40 SEQ ID NO: 40
Ab669-5 Atreca Kabat Chothia
HCDR1 GYIFINYAMQ NYAMQ GYIFINY
SEQ ID NO: 122 SEQ ID NO: 149 SEQ ID NO: 150
HCDR2 WINAGNGYTKYSQKFQG NAGNGY
SEQ ID NO: 68 SEQ ID NO: 68 SEQ ID NO: 138
HCDR3 DGFCRTTSCSDHYGMDV
SEQ ID NO: 123 SEQ ID NO: 123 SEQ ID NO: 123
LCDR1 TGTSSDVGGYNYVS
SEQ ID NO: 112 SEQ ID NO: 112 SEQ ID NO: 112
LCDR2 DVSKRPS
SEQ ID NO: 39 SEQ ID NO: 39 SEQ ID NO: 39
LCDR3 CSYAGSSTWV
SEQ ID NO: 40 SEQ ID NO: 40 SEQ ID NO: 40
Table 16: Variable region sequences of further antibodies. CDRs are as identified by IMGT.
Table 17: Closest germline gene segment sequences
Antibody H chain v H chain d H chain j L chain v L chain j name segment segment segment segment segment
CL-141789 IGHVl-3 IGHD2-2 IGHJ6 IGLV2-23 IGU3
CL-141790 IGHV1-3 IGHD3-10 IGHJ6 IGLV2-23 IGU3
CL-141791 IGHVl-3 IGHD3-9 IGHJ6 IGLV2-23 IGU3
CL-141778 IGHV3-15 IGHD6-19 IGHJ4 IGLV3-19 IGU3
CL-141780 IGHV3-15 IGHD6-19 IGHJ4 IGLV3-19 IGU3
CL-141771 IGHV3-15 IGHD6-19 IGHJ4 IGLV3-19 IGU3
CL-141814 IGHV3-15 IGHD3-10 IGHJ4 IGKV1-16 IGKJ3
CL-141813 IGHV3-15 IGHD3-10 IGHJ4 IGKV1-16 IGKJ3
CL-141812 IGHV3-15 IGHD3-10 IGHJ4 IGKV1-16 IGKJ3
Ab-C82 IGHV1-3 IGHD3-10 IGHJ6 IGLV2-23 IGLJ3
Ab-c152 IGHV1-3 IGHD3-10 IGHJ4 IGLV2-23 IGLJ3
Ab-c194 IGHV1-3 IGHD6-19 IGHJ6 IGLV2-14 IGLJ3
Ab-c265 IGHV1-2 IGHD6-19 IGHJ6 IGKV4-1 IGKJ1
Ab-c1281 IGHV1-3 IGHD2-2 IGHJ6 IGLV2-23 IGLJ3
Ab-c1315 IGHV1-3 IGHD2-2 IGHJ6 IGLV2-23 IGLJ3
Ab-c1731 IGHV1-3 IGHD2-2 IGHJ6 IGLV2-23 IGLJ3
Table 18: Variable region sequences of additionally selected anti-CSP antibodies
This table identifies the VH, VL and CDR sequences of the antibodies described in Example 18: Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab-c1281 , Ab-c1315 and Ab-c1731. These antibodies all represent antibodies of the present invention, as do antibodies comprising the CDRs (HCDRs and/or LCDRs), the VH domain and/or the VL domain of any of these antibodies.
Antibody Sequence
VL amino acid MAWALLLLNLLTQDTGSWAQSALTQPASVSGSPGQSITISCTGTSSDVG
VYNYVSWFQQHPGKAPKLMIYNVSKRPSGVSNRFSGSKSGNTASLTISG LQAEDEADYYCCSYAGSSTWVFGGGTNLTVL
LCDR1 SSDVGVYNY
IMGT
LCDR2 NVS
IMGT
LCDR3 CSYAGSSTWV
IMGT
LCDR1 TGTSSDVGVYNYVS
Kabat
LCDR2 NVSKRPS
Kabat
LCDR3 CSYAGSSTWV
Kabat
Ab-cl52 VH nucleotide ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTG
CCCACTCCCAGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCC TGGGGCCTCAGTGAAGGTTTCGTGCAAGGCTTCTGGATACACCTTCACT AGCTATGCTATGCATTGGGTGCGCCAGGCCCCCGGACAAAGGCTTGAGT GGATGGGATGGATCAACGCTGGCAATGGTAACACAAAATATTCACAGAA GTTCCAGGGCAGAGTCACCATTACCAGGGACACATCCGCGAGCACAGCC TACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACT GTGCGAGAGGGGGATCGAGGGACTACTGGGGCCAGGGAACCCTGGTCAC CGTCTCCTCAGC
VH amino acid MDWTWRILFLVAAATGAHSQVQLVQSGAEVKKPGASVKVSCKASGYTFT
SYAMHWVRQAPGQRLEWMGWINAGNGNTKYSQKFQGRVTITRDTSASTA YMELSSLRSEDTAVYYCARGGSRDYWGQGTLVTVSS
HCDR1 GYTFTSYA
IMGT
HCDR2 INAGNGNT
IMGT
HCDR3 ARGGSRDY
IMGT
HCDR1 SYAMH
Kabat
HCDR2 WINAGNGNTKYSQKFQG
Kabat
HCDR3 GGSRDY
Kabat Antibody Sequence
VL nucleotide ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGT
CCTGGGCCCAGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCC TGGACAGTCGATCACCATCTCCTGCACTGGAACCAGCAGTGATGTTGGT GGTTATAACTATGTCTCCTGGTACCAACAGCACCCAGGCAAAGCCCCCA AACTCATGATTTATGATGTCAGTAAGCGGCCCTCAGGGGTTTCTAATCG CTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTGGG CTCCAGGCTGAGGACGAGGCTGATTATTACTGCTGCTCATATGCAGGTA GTAGCACTTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
VL amino acid MAWALLLLNLLTQDTGSWAQSALTQPASVSGSPGQSITISCTGTSSDVG
GYNYVSWYQQHPGKAPKLMIYDVSKRPSGVSNRFSGSKSGNTASLTISG LQAEDEADYYCCSYAGSSTWVFGGGTKLTVL
LCDR1 SSDVGGYNY
IMGT
LCDR2 DVS
IMGT
LCDR3 CSYAGSSTWV
IMGT
LCDR1 TGTSSDVGGYNYVS
Kabat
LCDR2 DVSKRPS
Kabat
LCDR3 CSYAGSSTWV
Kabat
Ab-cl94 VH nucleotide ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTG
CCCACTCCCAGGTCCAACTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCC TGGGGCCTCAGTGAAGGTTTCCTGCAAGGCTTCTGGATACACCTTCATT AGATATACTTTGCATTGGGTGTGCCAGGCCCCCGGACAAAGGCTTGAGT GGATGGGATGGATCAATGTTGGCAATGGTGACACAAAATATTCACAGAA GTTCCAGGGCAGAGTCACCCTTACCAGGGACACATCCGCGAGTACAGCC TACATGGAGGTGAGCAGTTTGAGATCTGAAGACACGGCTGTGTATTACT GTGCGAGAGAGGGTATAGCAGTGGCCGGAACGGGAAAGTACTACAACTT CTACGGGATGGACGTCTGGGGCCAAGGGACCACGGTCACCGTCTCCTCA GC
VH amino acid MDWTWRILFLVAAATGAHSQVQLVQSGAEVKKPGASVKVSCKASGYTFI
RYTLHWVCQAPGQRLEWMGWINVGNGDTKYSQKFQGRVTLTRDTSASTA YMEVSSLRSEDTAVYYCAREGIAVAGTGKYYNFYGMDVWGQGTTVTVSS
HCDR1 GYTFIRYT
IMGT
HCDR2 INVGNGDT
IMGT
HCDR3 AREGIAVAGTGKYYNFYGMDV
IMGT Antibody Sequence
HCDR1 RYTLH
Kabat
HCDR2 WINVGNGDTKYSQKFQG
Kabat
HCDR3 EGIAVAGTGKYYNFYGMDV
Kabat
VL nucleotide ATGGCCTGGGCTCTGCTGCTCCTCACCCTCCTCACTCAGGGCACAGGGT
CCTGGGCCCAGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCC TGGACAGTCGATCACCATCTCCTGCACTGGAACCAGCAGTGACGTTGGT GGTTTTAACTATGTCTCCTGGTACCAACAGCACCCAGGCAAAGCCCCCA CACTCATGATTTATGAGGTCACTTTTCGGCCCTCAGGGGTTTCTAATCG CTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACCATCTCTGGG CTCCAGGCTGAGGACGAGGCTGATTATTACTGCAGCTCATATATAAGCG GCAACACTTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
VL amino acid MAWALLLLTLLTQGTGSWAQSALTQPASVSGSPGQSITISCTGTSSDVG
GFNYVSWYQQHPGKAPTLMIYEVTFRPSGVSNRFSGSKSGNTASLTISG LQAEDEADYYCSSYISGNTWVFGGGTKLTVL
LCDR1 SSDVGGFNY
IMGT
LCDR2 EVT
IMGT
LCDR3 SSYISGNTWV
IMGT
LCDR1 TGTSSDVGGFNYVS
Kabat
LCDR2 EVTFRPS
Kabat
LCDR3 SSYISGNTWV
Kabat
Ab-c265 VH nucleotide ATGGACTGGACCTGGAGGATCCTCTTCTTGGTGGCAGCAGCCACAGGAG
CCCACTCCCAGGTGCAGCTGGTGCAGTCTGGGGCTGAGGTGAAGAAGCC TGGGGCCTCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACACCTTCACC GCCTACTATATACACTGGGTGCGACAGGCCCCTGGACAAGGGCTTGAGT GGATGGGATGGATCAACCCTAACAGTGGTGGCACAAACTATGCACAGAA GTTTCAGGACTGGGTCACCATGACCAGGGACACGTCCATCACCACAGCC TACATGGAGCTGAGTAGACTGAAATCTGACGACACGGCCATATATTACT GTGCGAGAGACGGGGAGGCTGGTACGAACTACTACTACGGTATGGACGT CTGGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC
VH amino acid MDWTWRILFLVAAATGAHSQVQLVQSGAEVKKPGASVKVSCKASGYTFT
AYYIHWVRQAPGQGLEWMGWINPNSGGTNYAQKFQDWVTMTRDTSITTA YMELSRLKSDDTAIYYCARDGEAGTNYYYGMDVWGQGTTVTVSS Antibody Sequence
HCDR1 GYTFTAYY
IMGT
HCDR2 INPNSGGT
IMGT
HCDR3 ARDGEAGTNYYYGMDV
IMGT
HCDR1 AYYIH
Kabat
HCDR2 WINPNSGGTNYAQKFQD
Kabat
HCDR3 DGEAGTNYYYGMDV
Kabat
VL nucleotide ATGGTGTTGCAGACCCAGGTCTTCATTTCTCTGTTGCTCTGGATCTCTG
GTGCCTACGGGGACATCGTGATGACCCAGTCTCCAGACTCCCTGGCTGT GTCTCTGGGCGAGAGGGCCACCATCAACTGCAAGTCCAGTCAGAGTGTT TTATACAGCTCCAACAATAAGAACTACTTGGCTTGGTACCAGCAGAAAC CAGGACAGCCTCCTAAGCTGCTCATTTACTGGGCATCTACCCGGGAATC CGGGGTCCCTGACCGATTCAGTGGCAGCGGGTCTGGGACAGATTTCGCT CTCACCATCAGCAGCCTGCAGGCTGAAGATGTGGCAGTTTATTACTGTC AGCAATATTATAGTACTCCGTGGACGTTCGGCCAAGGGACCAAGGTGGA AATCAAACG
VL amino acid MVLQTQVFISLLLWISGAYGDIVMTQSPDSLAVSLGERATINCKSSQSV
LYSSNNKNYLAWYQQKPGQPPKLLIYWASTRESGVPDRFSGSGSGTDFA LTISSLQAEDVAVYYCQQYYSTPWTFGQGTKVEIK
LCDR1 QSVLYSSNNKNY
IMGT
LCDR2 WAS
IMGT
LCDR3 QQYYSTPWT
IMGT
LCDR1 KSSQSVLYSSNNKNYLA
Kabat
LCDR2 WASTRES
Kabat
LCDR3 QQYYSTPWT
Kabat Antibody Sequence
Ab-cl281 VH nucleotide ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCGCAGGTG
CCCACTCCCAGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCC TGGGGCCTCAGTGAAGGTTTCCTGCAAGGCTTCTGGATTCACCTTCACT GACTATGCTATGCATTGGGTGCGCCAGGCCCCCGGACAAAGGCTTGAGT GGATGGGTTGGATCAACGCTGGCAATGGTTACACAAAATATTCACAGAA GTTCCAGGTCAGACTCACCATTACCAGGGACACATTCGCGAGCACAGTC TACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACT GTGCGAGAGATGGGTTTTGTCCTAGTACCACTTGCTCTGGTTACTACGG TATGGACGTCTGGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC
VH amino acid MDWTWRILFLVAAAAGAHSQVQLVQSGAEVKKPGASVKVSCKASGFTFT
DYAMHWVRQAPGQRLEWMGWINAGNGYTKYSQKFQVRLTITRDTFASTV YMELSSLRSEDTAVYYCARDGFCPSTTCSGYYGMDVWGQGTTVTVSS
HCDR1 GFTFTDYA
IMGT
HCDR2 INAGNGYT
IMGT
HCDR3 ARDGFCPSTTCSGYYGMDV
IMGT
HCDR1 DYAMH
Kabat
HCDR2 WINAGNGYTKYSQKFQV
Kabat
HCDR3 DGFCPSTTCSGYYGMDV
Kabat
VL nucleotide ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGT
CCTGGGCCCAGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCC TGGACAGTCGATCACCATCTCCTGCACTGGAACCAGCAGTGATGTTGGT GCTTATAACTATGTCTCCTGGTACCAACAGCACCCAGGCAAAGCCCCCA AACTCATGATTTATGATGTCAATACGCGGCCCTCAGGGGTTTCTACTCG CTTCTCTGCCTCCAAGTCTGGCAACACGGCCTCCCTGACAGTCTCTGGG CTCCAGGCTGAGGACGAGGCTGTTTATTACTGCTCCTCATATGCAGGTA GTAGCACTTGGATTTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
VL amino acid MAWALLLLNLLTQDTGSWAQSALTQPASVSGSPGQSITISCTGTSSDVG
AYNYVSWYQQHPGKAPKLMIYD TRPSGVSTRFSASKSGNTASLTVSG LQAEDEAVYYCSSYAGSSTWIFGGGTKLTVL
LCDR1 SSDVGAYNY
IMGT
LCDR2 D
IMGT
LCDR3 SSYAGSSTWI
IMGT Antibody Sequence
LCDR1 TGTSSDVGAYNYVS
Kabat
LCDR2 DVNTRPS
Kabat
LCDR3 SSYAGSSTWI
Kabat
Ab-cl315 VH nucleotide ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCGCAGGTG
CCCACTCCCAGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCC TGGGGCCTCAGTGAAGGTTTCCTGCAAGGCTTCTGGATTCACCTTCACT GACTATGCTATGCATTGGGTGCGCCAGGCCCCCGGACAAAGGCTTGAGT GGATGGGTTGGATCAACGCTGGCAATGGTTACACAAAATATTCACAGCA GTTCCAGGTCAGACTCACCATTACCAGGGACACATTCGCGAGCACAGTC TACATGGAGCTGAGCAGCCTGACATCTGAAGACACGGCTGTGTATTACT GTGCGAGAGATGGGTTTTGTCCTAGTACCACTTGCTCTGGTTACTACGG TATGGACGTCTGGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC
VH amino acid MDWTWRILFLVAAAAGAHSQVQLVQSGAEVKKPGASVKVSCKASGFTFT
DYAMHWVRQAPGQRLEWMGWINAGNGYTKYSQQFQVRLTITRDTFASTV YMELSSLTSEDTAVYYCARDGFCPSTTCSGYYGMDVWGQGTTVTVSS
HCDR1 GFTFTDYA
IMGT
HCDR2 INAGNGYT
IMGT
HCDR3 ARDGFCPSTTCSGYYGMDV
IMGT
HCDR1 DYAMH
Kabat
HCDR2 WINAGNGYTKYSQQFQV
Kabat
HCDR3 DGFCPSTTCSGYYGMDV
Kabat
VL nucleotide ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGT
CCTGGGCCCAGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCC TGGACAGTCGATCACCATCTCCTGCACTGGAACCAGCAGTGATGTTGGT GCTTATAACTATGTCTCCTGGTACCAACAGCACCCAGGCAAAGCCCCCA AACTCATGATTTATGATGTCAATACGCGGCCCTCAGGGGTTTCTACTCG CTTCTCTGCCTCCAAGTCTGGCAACACGGCCTCCCTGACAGTCTCTGGG CTCCAGGCTGAGGACGAGGCTGTTTATTACTGCTCCTCATATGCAGGTA GTAGCACTTGGATTTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
VL amino acid MAWALLLLNLLTQDTGSWAQSALTQPASVSGSPGQSITISCTGTSSDVG
AYNYVSWYQQHPGKAPKLMIYD TRPSGVSTRFSASKSGNTASLTVSG LQAEDEAVYYCSSYAGSSTWIFGGGTKLTVL Antibody Sequence
LCDR1 SSDVGAYNY
IMGT
LCDR2 D
IMGT
LCDR3 SSYAGSSTWI
IMGT
LCDR1 TGTSSDVGAYNYVS
Kabat
LCDR2 DVNTRPS
Kabat
LCDR3 SSYAGSSTWI
Kabat
Ab-cl731 VH nucleotide ATGGACTGGACCTGGAGGATCCTCTTTTTGGTGGCAGCAGCCACAGGTG
CCCACTCCCAGGTCCAGCTTGTGCAGTCTGGGGCTGAGGTGAAGAAGCC TGGGGCCTCAGTGAAGGTTTCCTGTAAGGCTTCTGGATACATCTTTATT AACTATGCTATGCAATGGGTGCGCCAGGCCCCCGGACAAAGGCTTGAGT GGATGGGATGGATCAACGCTGGCAACGGTTACACAAAATATTCACAGAA GTTCCAGGGCAGAGTCACCATCACCAGGGACATATCCGCGAGCACAGTC TACATGGAGCTGAGCAGCCTGAGATCTGAAGACACGGCTGTGTATTACT GTGCGAGAGATGGATTTTGTAGGACAACCAGCTGCTCCGACCACTACGG TATGGACGTCTGGGGCCAAGGGACCACGGTCACCGTCTCCTCAGC
VH amino acid MDWTWRILFLVAAATGAHSQVQLVQSGAEVKKPGASVKVSCKASGYIFI
NYAMQWVRQAPGQRLEWMGWINAGNGYTKYSQKFQGRVTITRDISASTV YMELSSLRSEDTAVYYCARDGFCRTTSCSDHYGMDVWGQGTTVTVSS
HCDR1 GYIFINYA
IMGT
HCDR2 INAGNGYT
IMGT
HCDR3 ARDGFCRTTSCSDHYGMDV
IMGT
HCDR1 NYAMQ
Kabat
HCDR2 WINAGNGYTKYSQKFQG
Kabat
HCDR3 DGFCRTTSCSDHYGMDV
Kabat Antibody Sequence
VL nucleotide ATGGCCTGGGCTCTGCTGCTCCTCAACCTCCTCACTCAGGACACAGGGT
CCTGGGCCCAGTCTGCCCTGACTCAGCCTGCCTCCGTGTCTGGGTCTCC TGGACAGTCGATCACCATCTCCTGCACTGGAACCAGCAGTGATGTTGGT GGTTATAACTATGTCTCCTGGTACCAACAACACCCAGGCAAAGCCCCCA AACTCATGATTTATGATGTCAGTAAGCGGCCCTCAGGGGTTTCTGATCG CTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACAATCTCTGGG CTCCAGACTGAGGACGAGGCTGATTTTTACTGCTGCTCATATGCAGGTA GTAGCACTTGGGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTAGG
VL amino acid MAWALLLLNLLTQDTGSWAQSALTQPASVSGSPGQSITISCTGTSSDVG
GYNYVSWYQQHPGKAPKLMIYDVSKRPSGVSDRFSGSKSGNTASLTISG LQTEDEADFYCCSYAGSSTWVFGGGTKLTVL
LCDR1 SSDVGGYNY
IMGT
LCDR2 DVS
IMGT
LCDR3 CSYAGSSTWV
IMG
LCDR1 TGTSSDVGGYNYVS
Kabat
LCDR2 DVSKRPS
Kabat
LCDR3 CSYAGSSTWV
Kabat

Claims

What is claimed is:
1. A method of producing an antibody that binds circumsporozoite protein (CSP) of Plasmodium falciparum, wherein the antibody binds within the sequence NPDPNANP of CSP, the method comprising
culturing host cells containing nucleic acid encoding the antibody, in vitro in a culture medium of at least 100 litres in a bioreactor under conditions for expression of the antibody, and obtaining the expressed antibody.
2. A method according to claim 1 , wherein the culturing comprises fed-batch culture.
3. A method according to claim 1 or claim 2, wherein the bioreactor comprises a metal (e.g., stainless steel) vessel or is a single-use bioreactor.
4. A method according to any preceding claim, further comprising isolating and/or purifying the antibody.
5. A method according to any preceding claim, further comprising formulating the antibody into a composition comprising at least one additional component, such as one or more additional antibodies and/or a pharmaceutically acceptable excipient.
6. A method according to claim 5, comprising formulating the antibody into a composition for subcutaneous or intravenous administration.
7. A method of preventing malaria or reducing risk of malaria in a mammal, comprising administering a therapeutically effective amount of an antibody to the mammal, wherein the antibody binds circumsporozoite protein (CSP) of Plasmodium falciparum, wherein the antibody binds within the sequence NPDPNANP of CSP, and wherein the mammal is a human patient aged 50 years or under, e.g., a paediatric patient.
8. An isolated antibody that binds circumsporozoite protein (CSP) of Plasmodium falciparum, wherein the antibody binds within the sequence NPDPNANP of CSP, for use in a method of preventing malaria or reducing risk of malaria in a mammal,
wherein the method comprises administering the antibody to the mammal, wherein the mammal is a human patient aged 50 years or under, e.g., a paediatric patient.
9. A method according to any of claims 1 to 7 or an antibody for use according to claim 8, wherein the antibody binds CSP in the NPDP motif immediately preceding the NANP repeat region.
10. A method or an antibody for use according to any preceding claim, wherein the antibody binds the first NANP motif of the NANP repeat region.
11. A method or an antibody for use according to any of the preceding claims, wherein the antibody comprises
an antibody VH domain comprising complementarity determining regions (CDRs) HCDR1 , HCDR2 and HCDR3, and
an antibody VL domain comprising complementarity determining regions LCDR1 , LCDR2 and LCDR3, wherein
the antibody VH domain is the VH domain of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab-c1281 , Ab-c1315 or Ab-c1731 , or wherein the VH domain has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab-c1281 , Ab-c1315 or Ab-c1731 , and/or wherein the antibody VL domain is the VL domain of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Ab-c194, Ab-c265, Ab- c1281 , Ab-c1315 or Ab-c1731 , or wherein the VL domain has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 666, antibody 667, antibody 668, antibody 669, Ab-c82, Ab-c152, Abel 94, Ab-c265, Ab-c1281 , Ab-c1315 or Ab-c1731.
12. A method or an antibody for use according to claim 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 666, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 666.
13. A method or an antibody for use according to any preceding claim, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of antibody 666.
14. A method or an antibody for use according to any preceding claim, wherein the antibody comprises the antibody 666 VH domain and the antibody 666 VL domain.
15. A method or an antibody for use according to claim 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody
667, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 667.
16. A method or an antibody for use according to any of claims 1 to 1 1 or claim 15, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of antibody 667.
17. A method or an antibody for use according to any of claims 1 to 1 1 or 15 to 16, wherein the antibody comprises the antibody 667 VH domain and the antibody 667 VL domain.
18. A method or an antibody for use according to claim 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody
668, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 668.
19. A method or an antibody for use according to any of claims 1 to 1 1 or claim 18, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of antibody 668.
20. A method or an antibody for use according to any of claims 1 to 1 1 or 18 to 19, wherein the antibody comprises the antibody 668 VH domain and the antibody 668 VL domain.
21. A method or an antibody for use according to claim 11 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of antibody 669, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of antibody 669.
22. A method or an antibody for use according to any of claims 1 to 1 1 or claim 21 , wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of antibody 669.
23. A method or an antibody for use according to any of claims 1 to 1 1 or 21 to 22, wherein the antibody comprises the antibody 669 VH domain and the antibody 669 VL domain.
24. A method or an an antibody for use according to claim 1 1 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab-c82, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c82.
25. A method or an antibody for use according to any of claims 1 to 1 1 or claim 24, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c82.
26. A method or an antibody for use according to any of claims 1 to 1 1 or 24 to 25, wherein the antibody comprises the Ab-c82 VH domain and the Ab-c82 VL domain.
27. A method or an an antibody for use according to claim 1 1 , wherein the antibody comprises an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab-c152, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c152.
28. A method or an antibody for use according to any of claims 1 to 1 1 or claim 27, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c152.
29. A method or an antibody for use according to any of claims 1 to 1 1 or 27 to 28, wherein the antibody comprises the Ab-c152 VH domain and the Ab-c152 VL domain.
30. A method or an an antibody for use according to claim 1 1 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab-c194, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c194.
31. A method or an antibody for use according to any of claims 1 to 1 1 or claim 30, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c194.
32. A method or an antibody for use according to any of claims 1 to 1 1 or 30 to 31 , wherein the antibody comprises the Ab-c194 VH domain and the Ab-c194 VL domain.
33. A method or an an antibody for use according to claim 1 1 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab-c265, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab-c265.
34. A method or an antibody for use according to any of claims 1 to 1 1 or claim 33, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c265.
35. A method or an antibody for use according to any of claims 1 to 1 1 or 33 to 34, wherein the antibody comprises the Ab-c265 VH domain and the Ab-c265 VL domain.
36. A method or an an antibody for use according to claim 1 1 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab- C1281 , and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab- C1281 .
37. A method or an antibody for use according to any of claims 1 to 1 1 or claim 36, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c1281.
38. A method or an antibody for use according to any of claims 1 to 1 1 or 36 to 37, wherein the antibody comprises the Ab-c1281 VH domain and the Ab-c1281 VL domain.
39. A method or an an antibody for use according to claim 1 1 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab- C1315, and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab- C1315.
40. A method or an antibody for use according to any of claims 1 to 1 1 or claim 39, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c1315.
41. A method or an antibody for use according to any of claims 1 to 1 1 or 39 to 40, wherein the antibody comprises the Ab-c1315 VH domain and the Ab-c1315 VL domain.
42. A method or an an antibody for use according to claim 1 1 , wherein the antibody comprises
an antibody VH domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VH domain sequence of Ab- C1731 , and
an antibody VL domain which has an amino acid sequence at least 90 %, at least 95%, at least 98% or at least 99% identical to the antibody VL domain sequence of Ab- C1731.
43. A method or an antibody for use according to any of claims 1 to 1 1 or claim 42, wherein the antibody comprises the HCDR1 , HCDR2, HCDR3, LCDR1 , LCDR2 and LCDR3 of Ab-c1731.
44. A method or an antibody for use according to any of claims 1 to 1 1 or 42 to 43, wherein the antibody comprises the Ab-c1731 VH domain and the Ab-c1731 VL domain.
45. A method or an antibody for use according to any of the preceding claims, wherein the antibody comprises an antibody constant region.
46. A method or an antibody for use according to claim 45, wherein the antibody is an IgG.
47. A method or an antibody for use according to claim 46, wherein the antibody is a human lgG1.
48. A method or an antibody for use according to claim 46 or claim 47, wherein the IgG comprises a CH2 domain having ΎΤΕ" mutations to extend the in vivo half-life of the antibody, the YTE mutations being tyrosine at residue 252, threonine at residue 254 and glutamic acid at residue 256, numbered according to the EU index of Kabat.
EP18798204.6A 2017-05-11 2018-05-11 Anti-malarial antibodies that bind circumsporozoite protein Pending EP3621643A4 (en)

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WO2020227228A2 (en) * 2019-05-03 2020-11-12 The United States Of America, As Represented By The Secretary, Department Of Health And Human Services Neutralizing antibodies to plasmodium falciparum circumsporozoite protein and their use
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