WO2020260595A1 - Combination treatment of medulloblastoma using a placental growth factor inhibitor and a chemotherapeutic agent - Google Patents

Abstract

The present invention relates to the use of a PlGF inhibitor for the treatment of medulloblastoma, wherein said treatment further comprises administration of a chemotherapeutic agent.

Description

COMBINATION TREATMENT OF MEDULLOBLASTOMA USING A PLACENTAL GROWTH FACTOR INHIBITOR AND A CHEMOTHERAPEUTIC AGENT

FIELD OF THE INVENTION

The present invention relates to the use of a PIGF inhibitor for the treatment of medulloblastoma, wherein said treatment further comprises administration of a chemotherapeutic agent.

BACKGROUND OF THE INVENTION

Medulloblastoma is the most common malignant brain tumor in children, accounting for 15-20% of all primary central nervous system tumor diagnoses in patients less than 19 years of age. Approximately 80% of medulloblastomas occur in children under the age of 15. Medulloblastoma starts in the cerebellum and can spread through cerebrospinal fluid (CSF) to other areas of the brain and spinal cord. It rarely spreads to other parts of the body. Based on mRNA expression profiles, medulloblastoma has recently been classified into 4 distinct subgroups: wingless (WNT), sonic hedgehog (SHH), Group 3, and Group 4. These categories are associated with different clinical outcomes. Those of the WNT group tend to have the most favorable outcome and patients younger than 16 years with WNT tumors consistently show 5-year survival rates of > 95% (Ramaswamy and Taylore, J Clinic Oncol 2017, 35:2355-2363). Outcomes of SHH tumors are age specific. Infants have an excellent outcome, while TP-53- mutant SHH tumors carry a high risk in childhood (idem). Patients with Group 4 tumors have an intermediate prognosis, while those in Group 3 fare very poorly. The exact cause of medulloblastoma is currently unknown. Treatments of medulloblastoma depend on several factors, including patient age and overall health; tumor size, location, nature, stage and/or progression; and other factors. In almost all cases however, surgery is first used to remove the tumor and relieve the symptoms of hydrocephalus, a build-up of cerebrospinal fluid causing increased pressure in the brain. Following surgery, radiotherapy and chemotherapy are often used, alone or in combination.

Radiotherapy of the brain and spine typically begins approximately two to four weeks after surgery. Radiotherapy is an important adjunct therapy because it can destroy microscopic cancer cells that are too small to be seen and may remain after surgery. These microscopic cells may lead to a recurrence of the tumor.

In advanced and high-risk cases, therapy may also include treatment with certain anticancer drugs (chemotherapy) during or after radiotherapy. Chemotherapeutic agents that have been used to treat medulloblastoma include e.g. vincristine, methotrexate, lomustine, cisplatin, cyclophosphamide, and carboplatin. Chemotherapy is usually given to infants and young children under the age of three to avoid the potential long-term side effects of radiotherapy.

Despite improved survival rates with the current treatments described above, patients often encounter devastating morbidity including decline in cognition and intellect and secondary malignancies. In addition, hormonal alterations due to medulloblastoma and its treatment regimens can strongly impact growth of the patient. There is therefore still an urgent need for new therapies that reduce the significant morbidity and other effects associated with current therapies.

While survival rates for patients with medulloblastoma have improved since the nineties, the prognosis for patients that relapse is extremely poor. Relapses occur in nearly 75 % of pediatric cases within 2 years and most medulloblastomas that recur post-cytotoxic therapies are fatal (Massimo et al., Crit Rev Oncol Hematol 2016, 105:35-51 ). Unfortunately, outcome is invariably poor for those who relapse, with long-term survival of 6% (Bautista et al., Cancer medicine 2017, 1 1 :2606-2624). Patients with medulloblastoma at early relapse have a median survival of 1.4 years and median event-free survival of 1 year (Grill et al., Neuro- Oncology 2013, 15:1236-1243). A Phase II trial of irinotecan in combination with temozolomide in early relapse patients (77% first relapse) showed a median time to progression of 4.3 months (idem). Trials with novel therapies, such as idarubicin, taxol, topotecan, temozolomide and irinotecan, recorded few responses with nearly all patients developing further tumor progression (Massimo et al., 2016).

Placental growth factor (PIGF) is a member of the vascular endothelial growth factor (VEGF) family and is involved in multiple physiological processes including the formation of new blood vessels, a process called angiogenesis. PIGF was found to regulate the angiogenic switch in disease by binding to the VEGFR-1 receptor (also known as Flt-1 ) thereby leading to excessive blood vessel growth. As excessive vessel growth promotes tumor development, intensive efforts have been overtaken to develop therapeutic strategies to inhibit angiogenesis in cancer. In this context, inhibition of PIGF resulted in antitumor effects in different cancer types (see for example W02006/099698). Fisher et al. (Cell 2007, 131 :463-475) explored the therapeutic potential and mechanisms of action of an anti-PIGF antibody in the context of pancreatic cancer and melanoma tumor models. In these models, the anti-PIGF antibody inhibited tumor angiogenesis by preventing intratumoral macrophage infiltration and severe tumor hypoxia. This was contrasted with the mode of action of VEGF inhibitors, which switch on the angiogenic rescue program, thereby leading to potential resistance.

In contrast, in other models, PIGF overexpression was found to inhibit tumor progression (Xu et al. Cancer research 2006, 66:3971 -3977) and blockade of PIGF did not result in antiangiogenic and antitumor effects (Bais et al., Cell 2010, 141 :166-177). The mode of action of PIGF was also specifically investigated in the context of medulloblastoma (Snuderl et al., Cell 2013, 152:1065-1076). In this specific case, blockade of PIGF resulted in only modest effects on angiogenesis and no effect tumor-associated macrophages or hypoxia. Surprisingly, the authors demonstrated that in medulloblastoma, PIGF does not act through VEGFR1 as in other cancer types, but rather through the neuropillin-1 receptor (Nrp-1) to promote tumor cell survival. This demonstrates the different mechanism of medulloblastoma compared to other cancer types regarding the mode of action of PIGF, and furthermore suggests specific responses to medical treatments.

In conclusion, medulloblastoma is a devastating disease that most commonly arises in infants and children. There remains an urgent need for novel and improved treatments of medulloblastoma, in particular treatments that are also effective in patients with a poor prognosis, namely patients with high-risk tumor types and patients that relapsed.

SUMMARY OF THE INVENTION

The inventors have now surprisingly found that a PIGF inhibitor in combination with a chemotherapeutic agent as detailed in the claims fulfils the above- mentioned need. In particular, the inventors have surprisingly found that a PIGF inhibitor and a chemotherapeutic agent exert synergistic effects when combined in a regime for medulloblastoma treatment.

It is thus an object of the present invention to provide PIGF inhibitors and chemotherapeutic agents for use in the treatment of medulloblastoma. Therefore, in a first embodiment, the present invention provides a PIGF inhibitor for use in the treatment of medulloblastoma, wherein said treatment further comprises administration of a chemotherapeutic agent.

Preferably, the PIGF inhibitor is an anti-PIGF antibody or antigen-binding fragment thereof.

In a further embodiment, the PIGF inhibitor is an anti-PIGF antibody or antigen binding fragment thereof that comprises a variable region of a heavy chain corresponding to SEQ ID NO:2 or corresponding to an amino acid sequence of at least 80% sequence identity, preferably of at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% sequence identity to SEQ ID NO:2; and a variable region of a light chain corresponding to SEQ ID NO:4, or corresponding to an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably at least 90% sequence identity, even more preferably at least 95% sequence identity to SEQ ID NO: 4.

In a preferred embodiment of the present invention, the anti-PIGF antibody or antigen-binding fragment thereof comprises a variable region of a heavy chain corresponding to SEQ ID NO: 15 or corresponding to an amino acid sequence of at least 80% sequence identity, preferably of at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% sequence identity to SEQ ID NO: 15; and a variable region of a light chain corresponding to SEQ ID NO: 16, or corresponding to an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably at least 90% sequence identity, even more preferably at least 95% sequence identity to SEQ ID NO: 16.

In another embodiment, the antibody or antigen-binding fragment thereof comprises at least two complementarity-determining regions (CDRs) selected from the group consisting of SEQ ID NO: 5 (GYTFTDYY), SEQ ID NO: 6 (IYPGSGNT), SEQ ID NO: 7 (VRDSPFFDY), SEQ ID NO: 8 (QSLLNSGMRKSF), SEQ ID NO: 9 (WAS), and SEQ ID NO:10 (KQSYHLFT) or at least two amino acid sequences having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably at least 90% sequence identity, even more preferably at least 95% sequence identity to SEQ ID NO: 5-10.

In still another embodiment, the antibody or antigen-binding fragment thereof comprises CDRs of SEQ ID NO: 5-10.

In still another embodiment, said fragment is selected from the group consisting of Fab, Fab’ or F(ab’)2, single domain antibody (sdAb), and a single chain variable fragment (scFv) of said anti-PIGF antibody. For example, SEQ ID NO: 12 represents a scFv with an HA-tag (amino acids 246 to 254) and His-tag (amino acids 256-262). SEQ ID NO: 14 represents a humanized scFv with an HA-tag and His-tag at the same position in the sequence. Therefore, in a particular embodiment, the present invention provides an antigen-binding fragment that has an amino acid sequence of amino acids 1 to 243 of SEQ ID NO: 12 or an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% sequence identity to amino acids 1 to 243 of SEQ ID NO: 12. In another particular embodiment, the present invention provides an antigen-binding fragment that has an amino acid sequence of amino acids 1 to 243 of SEQ ID NO: 14 or an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% sequence identity to amino acids 1 to 243 of SEQ ID NO: 14.

In yet another embodiment, said antigen-binding fragment has an amino acid sequence corresponding to SEQ ID NO: 12 or SEQ ID NO: 14, or an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% sequence identity to SEQ ID NO: 12 or SEQ ID NO: 14.

In another particular embodiment, the anti-PIGF antibody or antigen-binding fragment thereof is a monoclonal antibody or antigen-binding fragment thereof. In another particular embodiment, the anti-PIGF antibody or antigen-binding fragment is a humanized antibody or antigen-binding fragment thereof.

In another particular embodiment, said inhibitor is administered in in a dose of between 75 and 250 mg of the PIGF inhibitor per kg bodyweight of the treated subject. In another embodiment, the chemotherapeutic agent is selected from the group consisting of alkylating agents, anthracyclines, cytoskeletal disruptors, epothilones, histone deacetylase inhibitors, topoisomerase inhibitors, kinase inhibitors, nucleotide analogs, peptide antibiotics, platinum-based agents, retinoids, vinca alkaloids, and derivates thereof. In a preferred embodiment, the chemotherapeutic agent is an alkylating agent or a topoisomerase inhibitor.

Preferably, the chemotherapeutic agent is an alkylating agent. An alkylating agent is a type of anti-neoplastic agent that attaches an alkyl group to DNA, thereby interfering with DNA in a number of ways, mainly linked to inhibition of DNA replication. Preferably, the alkylating agent is selected from the group consisting of alkyl sulfonates, busulfan, ethyleneimines and methylmelamines, hexamethymelamine, thiotepa, nitrogen mustards, cyclophosphamide, mechlorethamine, mustine, uramustine, uracil mustard, melphalan, chlorambucil, ifosfamide, nitrosureas, carmustine, cisplatin, streptozocin, triazenes, decarbazine, imidazotetrazines, and temozolomide. Preferred alkylating agents are selected from the group of cyclophosphamide, mechlorethamine, chlorambucil, melphalan, dacarbazine, nitrosoureas, temozolomide, and a salt, prodrug, or ester thereof.

In yet another embodiment the chemotherapeutic agent is a topoisomerase inhibitor. A topoisomerase inhibitor is a compound which blocks the action of topoisomerase I and/or II thereby blocking proper completion of the cell cycle. Preferably, the topoisomerase inhibitor is selected from the group consisting of: anthracyclines, camptothecin, topotecan, irinotecan, doxorubicin, etoposide, teniposide, tafluposide, mitoxantrone, and a salt, prodrug, or ester thereof. In a particular embodiment, the chemotherapeutic agent is etoposide or a salt or prodrug thereof, including etoposide phosphate, etoposide toniribate, etoposide glucuronide, etoposide sulfate, and esters of etoposide.

In a preferred embodiment, the chemotherapeutic agent is etoposide, temozolomide, or a salt, prodrug or ester thereof.

In another particular embodiment, said chemotherapeutic agent is administered in a dose of between 0.5 and 2,000 mg of the chemotherapeutic agent per square meter of body surface of the treated subject.

Another object of the present invention is to provide a method for the treatment of medulloblastoma in a subject in need thereof, wherein said method comprises administration of a PIGF inhibitor and a chemotherapeutic agent to the subject.

BRIEF DESCRIPTION OF FIGURES

Figure 1 illustrates the total lesion size in mm² as determined by MRI for a patient during treatment with PIGF inhibitor only (I) or with the combination of PIGF inhibitor and chemotherapeutic agent (I + C). DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described in the following with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto.

Unless otherwise defined herein, scientific and technical terms used in connection with the present invention shall have the meanings that are commonly understood by those of ordinary skill in the art. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular. Generally, nomenclature used in connection with, and techniques of, molecular biology, immunology, microbiology, genetics and protein and nucleic acid chemistry described herein are those well-known and commonly used in the art.

As used herein and in the claims, the terms“comprising” and“including” are inclusive or open-ended and do not exclude additional unrecited elements, compositional components, or method steps. Accordingly, the terms“comprising” and“including” encompass the more restrictive terms“consisting essentially of” and“consisting of”.

As described herein, the term“inhibitor” of a specific target denotes a molecule capable of specific binding to the said target, such as a carbohydrate, polynucleotide, lipid, polypeptide, etc., or to its receptor, and thereby inhibiting the activation of said receptor by said target. Specifically, an inhibitor of PIGF as used herein refers to a molecule capable of binding to one or both isoforms PIGF- 1 and PIGF-2 of placental growth factor (PIGF) and thereby inhibiting the activation of fms related tyrosine kinase 1 (Flt-1 ) and neuropilin-1 (Nrp-1 ) by PIGF.

As described herein, the term“antibody” is an immunoglobulin molecule capable of specific binding to a target, such as a carbohydrate, polynucleotide, lipid, polypeptide, etc., through at least one antigen recognition site, located in the variable region of the immunoglobulin molecule. Antibodies may be derived from any species, including but not limited to mouse, rat, rabbit, goat, bovine, non human primate, human, dromedary, camel, llama, alpaca, and shark. As used herein, the term“monoclonal antibody” refers to an antibody composition having a homogeneous antibody population. It is understood that monoclonal antibodies are highly specific, being directed against a single antigenic site. Furthermore, in contrast to conventional antibody (polyclonal) preparations which typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody is directed against a single determinant on the antigen.

As used herein, the term“humanized antibody” refers to an antibody produced by molecular modeling techniques to identify an optimal combination of human and non-human (such as mouse or rabbits) antibody sequences, that is, a combination in which the human content of the antibody is maximized while causing little or no loss of the binding affinity attributable to the variable region of the non-human antibody. For example, a humanized antibody, also known as a chimeric antibody comprises the amino acid sequence of a human framework region and of a constant region from a human antibody to "humanize" or render non-immunogenic the complementarity determining regions (CDRs) from a non human antibody.

As used herein, the term“human antibody” means an antibody having an amino acid sequence corresponding to that of an antibody that can be produced by a human and/or which has been made using any of the techniques for making human antibodies known to a skilled person in the art or disclosed herein. It is also understood that the term “human antibody” encompasses antibodies comprising at least one human heavy chain polypeptide or at least one human light chain polypeptide. One such example is an antibody comprising murine light chain and human heavy chain polypeptides.

As used herein, the term “anti-PIGF antibody” as used herein refers to an antibody capable of binding to placental growth factor (PIGF) with sufficient affinity and specificity. The antibody selected will normally have a binding affinity for PIGF, for example, the antibody may bind huPIGF with a Kd value of between 100 nM and 1 pM. Antibody affinities may be determined by a surface plasmon resonance based assay (such as the BIAcore assay as described in PCT Application Publication No. W02005/012359); enzyme- linked immunoabsorbent assay (ELISA); and competition assays (e.g. RIA's), for example. A preferred method for determining Kd values is by using surface plasmon resonance assays using a BIAcore™-2000 or a BIAcore™-3000 (BIAcore, Inc., Piscataway, NJ) at 25°C with immobilized huPIGF CM5 chips at 10 response units (RU). Anti-PIGF antibodies preferably bind one or more PIGF isoforms, in particular PIGF-1 and PIGF-2, and inhibit the activation of fms related tyrosine kinase 1 (Flt-1 ) and neuropilin-1 (Nrp-1 ) by PIGF. Preferred anti-PIGF antibodies and antigen-binding fragments thereof are anti-PIGF-2 antibodies and antigen-binding fragments.

The term“antigen-binding fragment” is intended to refer to an antigen-binding portion of said intact polyclonal or monoclonal antibodies that retains the ability to specifically bind to a target antigen or a single chain thereof, fusion proteins comprising an antibody, and any other modified configuration of the immunoglobulin molecule that comprises an antigen recognition site. The antigen-binding fragment comprises, but not limited to Fab; Fab'; F(ab')₂; a Fc fragment; a single domain antibody (sdAb or dAb) fragment. These fragments are derived from intact antibodies by using conventional methods in the art, for example by proteolytic cleavage with enzymes such as papain (to produce Fab fragments) or pepsin (to produce F(ab')₂ fragments). As used herein, antigen binding fragment also refers to fusion proteins comprising heavy and/or light chain variable regions, such as single-chain variable fragments (scFv). Thus, the term “antigen-binding fragment thereof” as used herein refers to an antigen binding fragment having the binding specificity to PIGF, and thereby preventing PIGF from binding to its receptor.

As used herein, the term "sequence identity" means that two polynucleotide sequences are identical (i.e., on a nucleotide-by-nucleotide basis) over the window of comparison. The term "percentage of sequence identity" is calculated by comparing two optimally aligned sequences over the window of comparison, determining the number of positions at which the identical nucleic acid base (e.g., A, T, C, G, U, or I) occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison (i.e., the window size), and multiplying the result by 100 to yield the percentage of sequence identity. As used herein, the term "substantial identity" or“substantially identical” as used herein denotes a characteristic of a polynucleotide sequence, wherein the polynucleotide comprises a sequence that has at least 80% sequence identity, preferably at least 85% sequence identity, more preferably 90% sequence identity, still more preferably 95 % sequence identity, yet more preferably at least 99% sequence identity as compared to a reference sequence, wherein the percentage of sequence identity is calculated by aligning the reference sequence to the polynucleotide sequence which may include deletions or additions which in total about 20% or less of the reference sequence over the window of comparison. The reference sequence may be a subset of a larger sequence. Optimal alignment of sequences may be carried out by conventional software or methods known by those of ordinary skill in the art.

As used herein, the term“corresponds to” or“corresponding to” is intended to mean a polynucleotide sequence is identical or similar to all or a portion of a reference polynucleotide sequence. In contradistinction, the term "complementary to" as used herein is intended to mean that the complementary sequence is homologous to all or a portion of a reference polynucleotide sequence. For illustration, the nucleotide sequence "TATAC" corresponds to a reference sequence "TATAC" and is complementary to a reference sequence "GTATA".

As used herein, the terms“anticancer agent”,“conventional anticancer agent”, or “cancer therapeutic drug” refer to any therapeutic agents (e.g. chemotherapeutic compounds and/or molecular therapeutic compounds), radiation therapies, or surgical interventions, used in the treatment of cancer in mammals. A "chemotherapeutic agent" is a biological (large molecule) or chemical (small molecule) compound exhibiting anticancer activity.Classes of chemotherapeutic agents include, but are not limited to, alkylating agents, anthracyclines, cytoskeletal disruptors, epothilones, histone deacetylase inhibitors, topoisomerase inhibitors, kinase inhibitors, nucleotide analogues, peptide antibiotics, platinum-based agents, retinoids, vinca alkaloids, and derivates thereof. Chemotherapeutic agents include compounds used in "targeted therapy" and "non-targeted", conventional chemotherapy. An “effective amount” is an amount sufficient to effect beneficial or desired results. An effective amount can be administered in one or more administrations.

As used herein, the term “administration” refers to the act of giving a drug, prodrug, antibody, or other agent, or therapeutic treatment to a physiological system (e.g. a subject or in vivo, in vitro, or ex vivo cells, tissues, and organs). Exemplary routes of administration to the human body can be through the mouth (oral), skin (transdermal), oral mucosa (buccal), ear, by injection (e.g. intravenously, subcutaneously, intratumorally, intraperitoneally, etc.) and the like.

“Co-administration” refers to administration of more than one agent or therapeutic treatment (e.g. radiation therapy) to a physiological system (e.g. a subject or in vivo, in vitro, or ex vivo cells, tissues, and organs).“Co-administration” of the respective agents may be concurrent, or in any temporal order or physical combination.

As used herein, the term“regression” refers to the return of a diseased subject, cell, tissue, or organ to a non-pathological, or less pathological state as compared to basal nonpathogenic exemplary subject, cell, tissue, or organ. For example, regression of a tumor includes a reduction of tumor mass as well as complete disappearance of a tumor or tumors.

As used herein, the terms“individual”,“subject” or“patient” refer to organisms to be treated by the methods of the present invention. Such organisms include, but are not limited to, humans and veterinary animals (dogs, cats, horses, pigs, cattle, sheep, goats, and the like). In the context of the invention, the term “individual”,“subject” or“patient” generally refers to an individual who will receive or who has received treatment.“Individual”,“subject” or“patient” preferably refers to a mammal, particularly a human.

The term“diagnosed”, as used herein, refers to the recognition of a disease by its signs and symptoms or genetic analysis, pathological analysis, histological analysis, and the like.

As used herein, the term “pharmaceutically acceptable carrier” or “pharmaceutically acceptable excipient” includes any material which, when combined with an active ingredient, allows the ingredient to retain biological activity. Pharmaceutically acceptable carriers enhance or stabilize the composition or can be used to facilitate preparation of the composition. Pharmaceutically acceptable carriers include solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like that are physiologically compatible, as is known to those skilled in the art (see, for example, Remington's Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, pp. 1289- 1329; Remington: The Science and Practice of Pharmacy, 21 st Ed. Pharmaceutical Press 201 1 ; and subsequent versions thereof). Non-limiting examples of said pharmaceutically acceptable carrier comprise any of the standard pharmaceutical carriers such as a phosphate buffered saline solution, water, emulsions such as oil/water emulsion, and various types of wetting agents.

As used herein,“treating” or“treatment” means to administer a treatment to a subject, preferably a human patient. Treating includes a treatment which acts to reduce an existing clinical symptom (such as the mass of the tumor) of a present, diagnosed medulloblastoma, as well as prevention of deterioration of (or slowing of the rate of deterioration of) the present, diagnosed medulloblastoma. “Therapeutic levels” or“therapeutic amount” means an amount or a concentration of an active agent that has been administered that is appropriate to safely treat the condition to reduce or prevent a symptom of the condition.

As used herein, the term“modulate” refers to the activity of a compound to affect (e.g. to promote or treated) an aspect of the cellular function including, but not limited to, cell growth, proliferation, invasion, angiogenesis, apoptosis, and the like.

PIGF inhibitor

As described herein before, the present invention provides a PIGF inhibitor for use in the treatment of medulloblastoma, wherein the treatment further comprises administration of a chemotherapeutic agent. The PIGF inhibitor can be a chemical (small molecule) or biological inhibitor, such as a peptide, antibody, etcetera. As described herein, the term“inhibitor” of a specific target denotes a molecule capable of specific binding to the said target, such as a carbohydrate, polynucleotide, lipid, polypeptide, etc., or to its receptor, and thereby inhibiting the binding of said target to said receptor. Preferably, the IC50 value of the inhibitor for its target is 1 mM or less, particularly 100 nM or less, more particularly 10 nM or less.

In one embodiment of the present invention, the PIGF inhibitor is an anti-PIGF antibody or antigen-binding fragment thereof. In particular, and anti-human PIGF antibody or antigen-binding fragment thereof. Preferably, the anti-PIGF antibody or antigen-binding fragment thereof has a dissociation constant (K_D) of below 10 ⁷, particularly below 10 ⁸, more particularly below 10 ⁹. Even more preferably below 10 ¹⁰. In one particular embodiment, the PIGF inhibitor is an anti-PIGF antibody or antigen-binding fragment that has a K_D value below 10⁹ for human PIGF, in particular human PIGF-1.

It is another object of the invention to provide a nucleic acid sequence encoding for the anti-PIGF antibody or antigen-binding fragment thereof. Therefore, in one embodiment, the present invention provides a nucleic acid sequence encoding for a PIGF inhibitor comprising a nucleic acid sequence encoding for a variable region of a heavy chain (V_H) and having at least 85%, preferably 90%, more preferably 95% sequence identity to SEQ ID NO:1 , and comprising a nucleic acid sequence encoding for a variable region of a light chain (V_L) and having at least 85%, preferably 90%, more preferably 95% sequence identity to SEQ ID NO:3. Even more preferably, the nucleic acid sequence of said PIGF inhibitor thereof comprises SEQ ID NO:1 , and SEQ ID NO:3.

In another embodiment, the anti-PIGF antibody or antigen-binding fragment thereof of the present invention, comprises a V_H amino acid sequence corresponding to at least 85%, preferably 90%, more preferably 95% sequence identity to SEQ ID NO:2, and a V_L amino acid sequence corresponding to at least 85%, preferably 90%, more preferably 95% sequence identity to SEQ ID NO:4. Even more preferably, the amino acid sequence of PIGF inhibitor comprises a V_H sequence corresponding to SEQ ID NO:2, and a V_L sequence corresponding to SEQ ID NO:4. In yet another embodiment, said anti-PIGF antibody or antigen-binding fragment thereof, comprises one or more CDRs of an anti-PIGF antibody as described herein. It is understood that the CDRs and the location thereof in the sequence of said anti-PIGF antibody can be readily identified by conventional methods known by those of ordinary skill in the art, such as but not limited to, internatonal ImMunoGeneTics information system (IMGT) or KABAT system (KABAT). The preferred method for determining CDR sequences in the context of the invention is the IMGT method (Lefranc, M.-P. et al., 2009, Nucleic Acids Research, 37, D1006-1012, http://www.imgt.org). Accordingly, using the IMGT method, the CDRs as identified within the variable regions of said anti-PIGF antibody, as detailed above, correspond to:

SEQ ID NO: 5 (GYTFTDYY);

SEQ ID NO: 6 (IYPGSGNT);

SEQ ID NO: 7 (VRDSPFFDY); SEQ ID NO: 8 (QSLLNSGMRKSF);

SEQ ID NO: 9 (WAS) and;

SEQ ID NO: 10 (KQSYHLFT).

Thus, the anti-PIGF antibody or the antigen-binding fragment thereof, as detailed above comprises at least one, preferably at least two, still preferably at least three, more preferably at least four, even more preferably at least five CDRs selected from the group consisting of SEQ ID NO:5 to SEQ ID NO:10.

Preferably, said anti-PIGF antibody or the antigen-binding fragment thereof, as detailed above comprises the six CDRs corresponding to SEQ ID NO:5 to SEQ ID NO:10. In one embodiment of the present invention, the antigen-binding fragment is a single-chain variable fragment (scFv) of said anti-PIGF antibody. Preferably, an scFv is a genetically engineered antibody fragment that comprises a V_H and V_L of an antibody joined together by a peptide linker. In a further embodiment, the scFV comprises the CDR regions of said anti-PIGF antibody, as detailed herein. The amino acid sequence of the scFv and/or the CDR regions may be humanized to reduce immunogenicity for humans. Said scFv and the humanized version thereof of the present invention may be obtained or synthesized by conventional methods in the art, which comprise but are not limited to, amplification of the DNA sequences of the variable parts of human V_H and V_L in separated reactions and cloning, followed by insertion of a linker sequence, between the V_H and V_L by polymerase chain reaction (PCR). The resulting fragments can then be inserted into a suitable vector for expression of the scFv as soluble or phase-displayed polypeptide, which can be readily understood and achieved by a skilled person in the art.

More preferably, said scFv of said anti-PIGF antibody and a humanized version thereof are encoded by a nucleic acid sequence corresponding to SEQ ID NO: 1 1 and SEQ ID NO:13, respectively. In another embodiment, the present invention provides an scFv comprising an amino acid sequence corresponding to SEQ ID NO: 12. In a further embodiment, the present invention provides a humanized scFv comprising an amino acid sequence corresponding to SEQ ID NO: 14.

In another embodiment of the present invention, said anti-PIGF antibody or antigen-binding fragment thereof is a humanized antibody or antigen-binding fragment thereof. Notably, said humanized antibody or antigen-binding fragment thereof retains the binding affinity to PIGF. Said humanized antibody or antigen binding fragment thereof of the present invention can be obtained by replacing one or more amino acids which are not involve in the binding affinity to PIGF in the backbone of said anti-PIGF antibody, so as to resemble closely the backbone of a human antibody. Different types of levels of humanization are envisaged.

In a particular embodiment, the anti-PIGF antibody or antigen-binding fragment thereof comprises a V_H sequence corresponding to SEQ ID NO: 2 and a V_L sequence corresponding to SEQ ID NO: 4, or a variant comprising a V_H and V_L sequence having at least 85% sequence identity to SEQ ID NO: 2 and SEQ ID NO: 4, respectively; wherein said variant comprises SEQ ID NO: 5 to 10. Thus, any variation is to be found outside of the CDR regions, i.e. in the framework regions. In a further embodiment, said variant comprises a V_H and V_L sequence having at least 90%, in particular at least 95%, more in particular at least 97, 98 or 99% sequence identity to SEQ ID NO: 2 and SEQ ID NO: 4, respectively; wherein said variant comprises SEQ ID NO: 5 to 10. In another particular embodiment, the anti-PIGF antibody or antigen-binding fragment thereof comprises a V_H sequence corresponding to SEQ ID NO: 15 and a V_L sequence corresponding to SEQ ID NO: 16, or a variant comprising a V_H and V|_ sequence having at least 85% sequence identity to SEQ ID NO: 15 and SEQ ID NO: 16, respectively; wherein said variant comprises SEQ ID NO: 5 to 10. In a further embodiment, said variant comprises a V_H and V_L sequence having at least 90%, in particular at least 95%, more in particular at least 97, 98 or 99% sequence identity to SEQ ID NO: 15 and SEQ ID NO: 16, respectively; wherein said variant comprises SEQ ID NO: 5 to 10.

In another preferred embodiment of the present invention, a variable region of the anti-PIGF antibodies or antigen-binding fragments described herein is combined with at least one constant region of a human antibody, so as to result in a chimeric antibody or fragment.

According to a particular embodiment of the invention, the antibody is a humanized antibody, more particularly a hybrid antibody, most particularly a mouse/human hybrid antibody. Alternatively, the humanized antibody is one which comprises the CDR regions of the antibody of the present invention capable of binding to PIGF, grafted onto the backbone of a human antibody.

It is understood that methods for associating the binding CDRs from a non human anti-PIGF antibody with human framework regions - in particular the constant C region of human gene - are known to those ordinary skill in the art, such as disclosed by Jones P.T. et al. (Nature 1986, 321 :522) or Riechmann, L, et al. (Nature 1988, 332:323). Alternatively, replacement with a limited number of amino acids of the non-human anti-PIGF antibodies of the invention is also envisaged. In further embodiments of the present invention, the humanized antibodies of said anti-PIGF antibody comprise a V_H and/or V_L having at least 80%, preferably at least 85%, more preferably at least 90%, still more preferably at least 95% sequence identity to SEQ ID NO: 15 and SEQ ID NO: 16, respectively.

In a preferred embodiment, the anti-PIGF antibody comprises the V_H and V_L sequences as described herein, in particular the humanized V_H and V_L sequences described herein, linked to constant domains of an IgG backbone. Preferably a human IgG backbone, such as the constant domains of a human IgG 4 or lgG1 backbone, in particular with a kappa light chain.

In one preferred embodiment of the present invention, said anti-PIGF antibody and said antigen-binding fragments thereof, as detailed herein, comprise a V_H having an amino acid sequence corresponding to SEQ ID NO: 2, wherein one or more of the following amino acids have been changed: I2V, P9A, K40A and/or T1 1 1 L. Additionally or alternatively, said anti-PIGF antibody, said variants thereof, and said antigen-binding fragments comprise the V_L having an amino acid sequence corresponding to SEQ ID NO: 4, wherein one or more of the following amino acids has been changed: S5T, S9D, A15L, K18R, R22N and/or L89V.

In one more preferred embodiment of the present invention, said anti-PIGF antibody, said variants thereof, and said antigen-binding fragments thereof, as detailed above, comprise a V_H having an amino acid sequence corresponding to SEQ ID NO: 2, wherein one or more of the following amino acids has been changed: I2V, P9A, K40A and/or T1 1 1 L, and the V_L having an amino acid sequence corresponding to SEQ ID NO: 4 wherein one or more of the following amino acids has been changed: S5T, S9D, A15L, K18R, R22N and/or L89V.

The anti-PIGF antibody or the antigen-binding fragment thereof, as described herein, binds to human PIGF, such as PIGF-1 , PIGF-2, PIGF-3 and PIGF-4, and thereby inhibits the human PIGF to activate its receptors Flt-1 and Nrp-1. Thus, said PIGF inhibitor can be used for the inhibition of PIGF in a therapeutic or prophylactic context. In a preferred embodiment, the anti-PIGF antibody or antigen-binding fragment thereof binds to the PIGF isoforms PIGF-1 , PIGF-2, PIGF-3, and PIGF-4. Chemotherapeutic agent

As described herein before, the present invention provides PIGF inhibitors for use in the treatment of medulloblastoma, wherein said treatment further comprises administration of a chemotherapeutic agent. A wide range of chemotherapeutic agents find use with the present invention. Any chemotherapeutic agent that can be co-administered with the agents of the present invention, or associated with the agents of the present invention is suitable for use in the methods of the present invention. Preferred chemotherapeutic agents are cytotoxic agents. In a further preferred embodiment, the chemotherapeutic agent is an organic compound, in particular a small molecule. More in particular, a chemotherapeutic agent has a molecular weight below 2000 dalton, in particular below 1500 dalton, more in particular below 900 dalton.

Various classes of chemotherapeutic agents are contemplated for use in certain embodiments of the present invention. Chemotherapeutic agents suitable for use with the present invention include, but are not limited to, agents that induce apoptosis, agents that inhibit adenosine deaminase function, inhibit pyrimidine biosynthesis, inhibit purine ring biosynthesis, inhibit nucleotide interconversions, inhibit ribonucleotide reductase, inhibit thymidine monophosphate (TMP) synthesis, inhibit dihydrofolate reduction, inhibit DNA synthesis, form adducts with DNA, damage DNA, inhibit DNA repair, intercalate with DNA, deaminate asparagines, inhibit RNA synthesis, inhibit protein synthesis or stability, inhibit microtubule synthesis or function, and the like.

In another embodiment, the chemotherapeutic agent is selected from the group consisting of alkylating agents, anthracyclines, cytoskeletal disruptors, epothilones, histone deacetylase inhibitors, topoisomerase inhibitors, kinase inhibitors, nucleotide analogs, peptide antibiotics, platinum-based agents, retinoids, vinca alkaloids, and derivates thereof.

In a particular embodiment, the chemotherapeutic agent is selected from the group consisting of actinomycin, alitretinoin, all-trans retinoic acid, altretamine, amsacrine, asparaginase, azacytidine, azathioprine, bendamustine, bexarotene, bleomycin, bortezomib, busulfan, cabazitaxel, carboplatin, carmustine, capecitabine, cisplatin, chlorambucil, cladribine, clofarabine, cyclophosphamide, cytarabine, dacarbazine, dactinomycin, daunorubicin, dicycloplatin, docetaxel, doxifluridine, doxorubicin, epirubicin, epothilone, eptaplatin, eribulin, erlotinib, etoposide, fludarabine, fluorouracil, gefitinib, gemcitabine, hydroxycarbamide, hydroxyurea, idarubicin, ifosfamide, imatinib, irinotecan, leucovorin, lobaplatin, lomustine, mechlorethamine, mercaptopurine, methotrexate, melphalan, miriplatin, mitomycin, mitotane, mitoxantrone, mitozolomide, nitrosourea, nedaplatin, oxaliplatin, paclitaxel, pemetrexed, pentostatin, picoplatin, pomalidomide, procarbazine, raltitrexed, romidepsin, satraplatin, silmitasertib, sonidegib, tafluposide, temozolomide, teniposide, thiotepa, tioguanine, tipifarnib, topotecan, trabectedin, treosulfan, triplatin tetranitrate, valrubicin, vemurafenib, vinblastine, vincristine, vindesine, vinorelbine, vorinostat, vismodegib, and a salt, prodrug, or ester thereof. In a further embodiment, the chemotherapeutic agent is selected from the group consisting of carboplatin, carmustine, cisplatin, cyclophosphamide, etoposide, irinotecan, lomustine, methotrexate, sonidegib, temozolomide, thiopeta, topotecan, vincristine, vismodegib, and a salt, prodrug, or ester thereof.

Any oncolytic agent that can be routinely used in a cancer therapy context can be used in the composition and methods of the present invention. For example, the U.S. Food and Drug Administration maintains a formulary of oncolytic agents approved for used in the United States. International counterpart agencies to the U.S.F.D.A. maintain similar formularies. In a preferred embodiment, the chemotherapeutic agent is an alkylating agent or a topoisomerase inhibitor, particularly a topoisomerase II inhibitor, a salt, prodrug, or ester thereof. In a particular embodiment, the alkylating agent is selected from the group consisting of altretamine, alkyl sulfonates, busulfan, ethyleneimines and methylmelamines, hexamethymelamine, thiotepa, nitrogen mustards, cyclophosphamide, mechlorethamine, mustine, lomustine, uramustine, uracil mustard, melphalan, chlorambucil, ifosfamide, nitrosureas, carmustine, carboplatin, cisplatin, oxaliplatin, streptozocin, triazenes, dacarbazine, imidazotetrazines, and temozolomide. Preferred alkylating agents are selected from the group of cyclophosphamide, mechlorethamine, chlorambucil, melphalan, dacarbazine, nitrosoureas, temozolomide, and a salt, prodrug, or ester thereof.

In a particular embodiment, the topoisomerase inhibitor is selected from the group consisting of: anthracyclines, camptothecin, topotecan, irinotecan, doxorubicin, etoposide, epirubicin, teniposide, tafluposide, mitoxantrone, and a salt, prodrug, or ester thereof. In a particular embodiment, the chemotherapeutic agent is etoposide or a salt or prodrug thereof, including etoposide phosphate, etoposide toniribate, etoposide glucuronide, etoposide sulfate, and esters of etoposide. In a preferred embodiment, the chemotherapeutic agent is temozolomide, etoposide, or a salt, prodrug or ester thereof. In one preferred embodiment, the chemotherapeutic agent is temolozomide or a salt, prodrug or ester thereof. In another preferred embodiment, the chemotherapeutic agent is etoposide or a salt, prodrug or ester thereof.

Combination

As will be understood by the skilled person from the disclosures herein, the present invention relates to a treatment regime comprising administration of a PIGF inhibitor and a chemotherapeutic agent. The present invention expressly foresees any combination of the specific, preferred PIGF inhibitors described above with the specific, preferred chemotherapeutic agents described above. In particular, the humanized anti-PIGF antibodies comprising the CDR and/or heavy and light chain sequences disclosed above in combination with the preferred chemotherapeutic agents. In one embodiment, the treatment regime comprises administration of an anti- PIGF antibody or antigen-binding fragment thereof and a chemotherapeutic agent selected from the group consisting of alkylating agents, anthracyclines, cytoskeletal disruptors, epothilones, histone deacetylase inhibitors, topoisomerase inhibitors, kinase inhibitors, nucleotide analogs, peptide antibiotics, platinum-based agents, retinoids, vinca alkaloids, and derivates thereof.

In another embodiment, the treatment regime comprises administration of an anti-PIGF antibody or antigen-binding fragment thereof that comprises a variable region of a heavy chain corresponding to SEQ ID NO:2 or corresponding to an amino acid sequence of at least 80% sequence identity, preferably of at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% or 100% sequence identity to SEQ ID NO:2; and a variable region of a light chain corresponding to SEQ ID NO:4, or corresponding to an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably at least 90% sequence identity, even more preferably at least 95% or 100% sequence identity to SEQ ID NO: 4 and an alkylating agent or a topoisomerase inhibitor.

In further embodiment, the treatment regime comprises administration of an anti- PIGF antibody or antigen-binding fragment thereof comprising a variable region of a heavy chain corresponding to SEQ ID NO: 15 or corresponding to an amino acid sequence of at least 80% sequence identity, preferably of at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% or 100% sequence identity to SEQ ID NO: 15; and a variable region of a light chain corresponding to SEQ ID NO: 16, or corresponding to an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably at least 90% sequence identity, even more preferably at least 95% or 100% sequence identity to SEQ ID NO: 16 and an alkylating agent or a topoisomerase inhibitor. In one other embodiment, the treatment regime comprises administration of an anti-PIGF antibody or antigen-binding fragment thereof comprising at least two complementarity-determining regions (CDRs) selected from the group consisting of SEQ ID NO: 5 (GYTFTDYY), SEQ ID NO: 6 (IYPGSGNT), SEQ ID NO: 7 (VRDSPFFDY), SEQ ID NO: 8 (QSLLNSGMRKSF), SEQ ID NO: 9 (WAS), and SEQ ID NO:10 (KQSYHLFT) or at least two amino acid sequences having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably at least 90% sequence identity, even more preferably at least 95% sequence identity to SEQ ID NO: 5-10 and an alkylating agent or a topoisomerase inhibitor.

In still another embodiment, the treatment regime comprises administration of an antibody or antigen-binding fragment thereof comprises CDRs of SEQ ID NO: 5- 10 and an alkylating agent or a topoisomerase inhibitor.

In yet another embodiment, the treatment regime comprises administration of an antigen-binding fragment selected from the group consisting of Fab, Fab’ or F(ab’)2, single domain antibody (sdAb), and a single chain variable fragment (scFv) of said anti-PIGF antibody. For example, SEQ ID NO: 12 represents a scFv with an FIA-tag (amino acids 246 to 254) and His-tag (amino acids 256- 262). SEQ ID NO: 14 represents a humanized scFv with an FIA-tag and His-tag at the same position in the sequence. Therefore, in a particular embodiment, the present invention provides an antigen-binding fragment that has an amino acid sequence of amino acids 1 to 243 of SEQ ID NO: 12 or an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% or 100% sequence identity to amino acids 1 to 243 of SEQ ID NO: 12. In another particular embodiment, the present invention provides an antigen-binding fragment that has an amino acid sequence of amino acids 1 to 243 of SEQ ID NO: 14 or an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% or 100% sequence identity to amino acids 1 to 243 of SEQ ID NO: 14 and an alkylating agent or a topoisomerase inhibitor.

In a further embodiment, the treatment regime comprises administration of an antigen-binding fragment having an amino acid sequence corresponding to SEQ ID NO: 12 or SEQ ID NO: 14, or an amino acid sequence having at least 80% sequence identity, preferably at least 85% sequence identity, more preferably 90% sequence identity, or even more preferably 95% or 100% sequence identity to SEQ ID NO: 12 or SEQ ID NO: 14 and an alkylating agent or a topoisomerase inhibitor.

In a still further embodiment, the treatment regime comprises administration of a monoclonal antibody or antigen-binding fragment thereof and an alkylating agent or a topoisomerase inhibitor. In an even more preferred embodiment, the treatment regime comprises administration of a humanized antibody or antigen binding fragment thereof and an alkylating agent or a topoisomerase inhibitor. In a yet preferred embodiment, the treatment regime comprises administration of humanized antibodies of an anti-PIGF antibody as described above comprising a V_H and/or V_L having at least 80%, preferably at least 85%, more preferably at least 90%, still more preferably at least 95% or 100% sequence identity to SEQ ID NO: 15 and SEQ ID NO: 16, respectively and an alkylating agent or a topoisomerase inhibitor. In an additional embodiment, the treatment regime comprises administration of humanized antibodies of an anti-PIGF antibody as described above comprising a V_H and/or V_L having at least 80%, preferably at least 85%, more preferably at least 90%, still more preferably at least 95% or 100% sequence identity to SEQ ID NO: 15 and SEQ ID NO: 16, respectively and etoposide, temozolomide, or a salt, prodrug or ester thereof.

In a preferred embodiment, the treatment regime comprises administration of a monoclonal anti-PIGF antibody comprising a V_H sequence comprising a sequence of SEQ ID NO: 15 and a V_L sequence comprising a sequence of SEQ ID NO: 16 and etoposide, temozolomide, or a salt, prodrug or ester thereof. In a further preferred embodiment, the treatment regime comprises administration of a monoclonal anti-PIGF antibody comprising a V_H sequence comprising a sequence of SEQ ID NO: 15 and a V_L sequence comprising a sequence of SEQ ID NO: 16 and etoposide, or a salt, prodrug or ester thereof.

In yet another preferred embodiment, the treatment regime comprises administration of a monoclonal anti-PIGF antibody comprising a V_H sequence comprising a sequence of SEQ ID NO: 15 and a V_L sequence comprising a sequence of SEQ ID NO: 16 and temozolomide, or a salt, prodrug or ester thereof.

It has furthermore been found useful to complement the PIGF inhibitor and the chemotherapeutic agent with a further chemotherapeutic agent that is a topoisomerase inhibitor. Therefore, in a particular embodiment, the present invention provides a PIGF inhibitor for use in the treatment of medulloblastoma, wherein said treatment further comprises administration of two chemotherapeutic agents, wherein at least one of the chemotherapeutic agents is a topoisomerase inhibitor, particularly a topoisomerase I inhibitor. Preferably, the topoisomerase I inhibitor is selected from irinotecan and topotecan. In a further embodiment, the treatment regime comprises administration of (a) a PIGF inhibitor, (b) etoposide, temozolomide, or a salt, prodrug, or ester thereof, and (c) a topoisomerase I inhibitor.

In a further more preferred embodiment, the treatment regime comprises administration of a (a) PIGF inhibitor, (b) etoposide, or a salt, prodrug, or ester thereof, and (c) a topoisomerase I inhibitor.

In an alternative more preferred embodiment, the treatment regime comprises administration of (a) a PIGF inhibitor, (b) temozolomide, or a salt, prodrug, or ester thereof, and (c) a topoisomerase I inhibitor. In a further more preferred embodiment, the treatment regime comprises administration of (a) a PIGF inhibitor, (b) etoposide, temozolomide, or a salt, prodrug, or ester thereof, and (c) irinotecan, topotecan, or a salt, prodrug, or ester thereof.

In another more preferred embodiment, the treatment regime comprises administration of (a) a PIGF inhibitor, (b) etoposide, or a salt, prodrug, or ester thereof, and (c) irinotecan, topotecan, or a salt, prodrug, or ester thereof.

In yet another more preferred embodiment, the treatment regime comprises administration of (a) a PIGF inhibitor, (b) temozolomide, or a salt, prodrug, or ester thereof, and (c) irinotecan, topotecan or a salt, prodrug, or ester thereof. In still another more preferred embodiment, the treatment regime comprises administration of (a) a PIGF inhibitor, (b) etoposide, or a salt, prodrug, or ester thereof, and (c) irinotecan, or a salt, prodrug, or ester thereof.

In an additional more preferred embodiment, the treatment regime comprises administration of (a) a PIGF inhibitor, (b) etoposide, or a salt, prodrug, or ester thereof, and (c) topotecan, or a salt, prodrug, or ester thereof. In a still additional more preferred embodiment, the treatment regime comprises administration of (a) a PIGF inhibitor, (b) temozolomide, or a salt, prodrug, or ester thereof, and (c) irinotecan, or a salt, prodrug, or ester thereof.

In yet another more preferred embodiment, the treatment regime comprises administration of (a) a PIGF inhibitor, (b) temozolomide, or a salt, prodrug, or ester thereof, and (c) topotecan, or a salt, prodrug, or ester thereof.

Kit

In another embodiment, the invention provides a kit comprising any of the combinations of a PIGF inhibitor and a chemotherapeutic agent as described above. In some embodiments, the kit further contains a pharmaceutically acceptable carrier or excipient of it. In other related embodiments, any of the components of the above combinations in the kit are present in a unit dose, in particular the dosages as described herein. In a yet further embodiment, the kit includes instructions for use in administering any of the components of the above combinations to a subject.

In one particular embodiment, the present invention provides a package comprising a PIGF inhibitor, wherein the package further comprises a leaflet with instructions to administer the PIGF inhibitor to a medulloblastoma patient that also receives treatment with a chemotherapeutic agent.

Patient population

As will be understood by the skilled person from the disclosures herein, the present invention relates to the treatment of patients having medulloblastoma. In a preferred embodiment, the present invention relates to the treatment patients having relapsed, recurrent or refractory medulloblastoma. Refractory refers to medulloblastoma that has not responded to an earlier treatment and is getting worse or staying the same. Relapse refers to a medulloblastoma that responded to an earlier treatment, but then gets worse, generally due to treatment resistance. Recurrent medulloblastoma is part of relapsed medulloblastoma and refers to medulloblastoma that returned after a patient has been diagnosed as being in remission.

In a preferred embodiment, the age of the patients to be treated using the combination of the invention is less than 25 years, such as less than 21 years, in particular less than 18 years, more in particular between 6 months and 18 years old. In one particular embodiment, the subject has been diagnosed with medulloblastoma before the age of 18 years, in particular between 6 months and 18 years, and is treated using the combination of the invention before the age of 28 years, in particular 25 years. In another preferred embodiment, the patients to be treated using the combination of the invention have been diagnosed with medulloblastoma before treatment.

Administration A combination containing a PIGF inhibitor and a chemotherapeutic agent according to the present invention can be administered by any effective method. The elements of the combination can be administered in any sterile, biocompatible pharmaceutical carrier, including, but not limited to, saline, buffered saline, dextrose, and water. Furthermore, the combination according to the present invention contains at least two agents that are administered to a patient under one or more of the following conditions: at different periodicities, at different durations, at different concentrations, by different administration routes, etc. In some embodiments, the PIGF inhibitor is administered prior to the chemotherapeutic agent, e.g. 0.5, 1 , 2, 3, 4, 5, 10, 12 or 18 hours, 1 , 2, 3, 4, 5, or 6 days, 1 , 2, 3, or 4 weeks prior to the administration of the chemotherapeutic agent. In some embodiments, the PIGF inhibitor is administered after the chemotherapeutic agent, e.g. 0.5, 1 , 2, 3, 4, 5, 10, 12 or 18 hours, 1 , 2, 3, 4, 5, or 6 days, 1 , 2, 3, or 4 weeks after the administration of the chemotherapeutic agent. In some embodiments, the PIGF inhibitor and the chemotherapeutic agent are administered concurrently but on different schedules, e.g., the PIGF inhibitor is administered once every two weeks while the chemotherapeutic agent is administered once a week, once every two weeks, once every three weeks, or once every four weeks. In other embodiments, the PIGF inhibitor is administered once every two weeks while the chemotherapeutic agent is administered daily, once a week, once every two weeks, once every three weeks, or once every four weeks. In a preferred embodiment, the PIGF inhibitor is administered once every two weeks, in particular once every two weeks in the preferred doses as described herein below. In another preferred embodiment, the chemotherapeutic agent is administered once every two weeks, in particular once every two weeks in the preferred doses as described herein below. In a further preferred embodiment, PIGF inhibitor and the chemotherapeutic agent are administered once every two weeks. In another preferred embodiment, the PIGF inhibitor and the chemotherapeutic agent are administered on the same day. In a further preferred embodiment, the PIGF inhibitor and the chemotherapeutic agent are administered on the same day and administration is performed once every two weeks.

Depending on the patient age and overall health; tumor size, location, nature, stage and/or progression; and other factors, preferred embodiments of the present combination are formulated and administered systematically or locally. Techniques for formulation and administration can be found in the latest edition of “Remington’s Pharmaceutical Sciences” (Mack Publishing Co, Easton Pa.). Suitable routes may, for example, include oral or transmucosal administration as well as parenteral delivery (e.g. intramuscular, subcutaneous, intramedullary, intrathecal, intraventricular, intravenous, intraperitoneal, or intranasal administration). Preferred routes of administration are by intravenous or oral administration. In a preferred embodiment, the PIGF inhibitor is administered intravenously. In another embodiment, the chemotherapeutic agent is administered orally or intravenously. In one particular embodiment, the PIGF inhibitor and the chemotherapeutic agent are administered intravenously.

The PIGF inhibitor and the chemotherapeutic agent as described in the present invention may be formulated in any form, such as solutions, suspensions, aerosols, viscous or semi-viscous gels, and other types of solid or semi-solid dosage forms for topical administration, ophthalmic administration and/or spray administration. In one embodiment, the present invention provides a composition comprising the PIGF inhibitor and a pharmaceutically acceptable carrier for use in the treatment of medulloblastoma, wherein the treatment further comprises administration of a chemotherapeutic agent. In some embodiments of the present invention, the PIGF inhibitor (and the chemotherapeutic agent) are administered in pharmaceutical compositions where the components are optionally mixed with excipient(s) or other pharmaceutically acceptable carriers. In preferred embodiments of the invention, pharmaceutically acceptable carriers are biologically inert. In preferred embodiments, the PIGF inhibitor and the chemotherapeutic agent are formulated using pharmaceutically acceptable carriers well known in the art in dosages suitable for oral or intravenous administration. Such carriers enable the PIGF inhibitor and the chemotherapeutic agent to be formulated as tablets, pills, capsules, dragees, liquids, gels, syrups, slurries, solutions, suspensions and the like, for respective oral or intravenous administration to a subject.

In preferred embodiments, dosing and administration regimes are tailored by the clinician, or others skilled in the pharmacological arts, based upon well-known pharmacological and therapeutic considerations including, but not limited to, the desired level of therapeutic effect, and the practical level of therapeutic effect obtainable. Generally, it is advisable to follow well-known pharmacological principles for administrating chemotherapeutic agents (e.g. it is generally advisable not to change dosages by more than 50% at time and no more than every 3-4 agent half-lives). For chemotherapeutic agents that have relatively little or no dose-related toxicity considerations, and where maximum efficacy (e.g. destruction of cancer cells) is desired, doses in excess of the average required dose are not uncommon. This approach to dosing is referred to as the“maximal dose” strategy.

The PIGF inhibitor will thus be formulated, dosed, and administered in a fashion consistent with good medical practice. Factors for consideration in this context include the particular disorder being treated, the particular subject being treated, the clinical condition of the individual patient, the cause of the disorder, the site of delivery of the agent, the method of administration, the scheduling of administration, and other factors known to medical practitioners. The "therapeutically effective amount" of the PIGF inhibitor to be administered will be governed by such considerations, and is the minimum amount necessary to prevent, ameliorate, or treat, or stabilize, the cancer; to increase the time until progression (duration of progression free survival) or to treat or prevent the occurrence or recurrence of a tumor, a dormant tumor, or a micrometastases. In certain embodiments, the treatment comprises administration of between 75 and 250 mg of the PIGF inhibitor, such as the anti-PIGF antibody or antigen-binding fragment, per kg bodyweight of the treated subject. Preferably from about 100 to about 200 mg per kg bodyweight, more preferably from about 100 to about 175 mg per kg bodyweight. In one particular embodiment, the PIGF inhibitor is a PIGF antibody or antigen-binding fragment and is administered at a dose of 100 mg per kg bodyweight. In another embodiment, the PIGF inhibitor is a PIGF antibody or antigen-binding fragment thereof that is administered at a dose of 175 mg per kg bodyweight.

In certain embodiments, the chemotherapeutic agent is administered to a subject at a dose between 0.5 and 2000 mg per square meter of body surface area of the treated subject.

Preferably, when the chemotherapeutic agent is temozolomide, or a salt, prodrug, or ester thereof, it is administered to a subject at a dose between 20 and 1000 mg per square meter of body surface area, preferably from about 50 to about 500 mg per square meter of body surface area, more preferably from about 75 to about 200 mg per square meter of body surface area.

In another preferred embodiment, when the chemotherapeutic agent is etoposide, or a salt, prodrug, or ester thereof, it is administered to a subject at a dose between 10 and 2000 mg per square meter of body surface area, preferably from about 20 to about 1000 mg per square meter of body surface area, more preferably from about 50 to about 200 mg per square meter of body surface area.

In yet another preferred embodiment, when the treatment comprises irinotecan, or a salt, prodrug, or ester thereof, it is administered to a subject at a dose between 20 and 500 mg per square meter of body surface area, preferably from about 40 to about 200 mg per square meter of body surface area, more preferably from about 80 to about 120 mg per square meter of body surface area.

In yet another preferred embodiment, when the treatment comprises topotecan, or a salt, prodrug, or ester thereof, it is administered to a subject at a dose between 0.2 and 5 mg per square meter of body surface area, preferably from about 0.5 to about 2.5 mg per square meter of body surface area, more preferably from about 0.75 to about 1.5 mg per square meter of body surface area.

Additional dosing considerations relate to calculating proper target levels for the agents being administered, agent’s accumulation and potential toxicity, stimulation of resistance, lack of efficacy, and describing the range of the agent’s therapeutic index.

In certain embodiments, the present invention contemplates using routine methods of titrating the agent’s administration. One common strategy for the administration is to set a reasonable target for the agents in the subject. In some preferred embodiments, agent levels are measured in the subject’s plasma. Proper dose levels and frequencies are then designed to achieve the desired steady-state target level for the agents. Actual, or average, levels of the agents in the subject are monitored (e.g. hourly, daily, weekly, etc.) such that the dosing levels or frequencies can be adjusted to maintain target levels. Of course, the pharmacokinetics and pharmacodynamics (e.g. bioavailability, clearance or bioaccumulation, biodistribution, drug interactions, etc.) of the particular agents being administered can potentially impact what are considered reasonable target levels and thus impact dosing levels or frequencies. Target-level dosing methods typically rely upon establishing a reasonable therapeutic objective defined in terms of a desirable range (or therapeutic range) for the agent in a subject. In general, the lower limit of the therapeutic range is roughly equal to the concentration of the agent that provides about 50% of the maximum possible therapeutic effect. The upper limit of the therapeutic range is usually established by the agent’s toxicity and not by its efficacy. The present invention contemplates that the upper limit of the therapeutic range for a particular agent will be the concentration at which less than 5 or 10% of subjects exhibit toxic side effects. In some embodiments, the upper limit of the therapeutic range is about two times, or less, than the lower limit. Those skilled in the art will understand that these dosing considerations are highly variable and to some extent individualistic (e.g. based on genetic predispositions, immunological considerations, tolerances, resistances, and the like).

In preferred embodiments, the clinician rationally designs an individualized dosing regimen based on known pharmacological principles and equations. In general, the clinician designs an individualized dosing regimen based on knowledge of various pharmacological and pharmacological properties of the agents, including, but not limited to, F (fractional bioavailability of the dose), Cp (concentration in the plasma), CL (clearance/clearance rate), Vss (volume of drug distribution at steady state), Css (concentration at steady state), and t1/2 (drug half-life), as well as information about the agent’s rate of absorption and distribution. Those skilled in the art are referred to any number of well-known pharmacological texts (e.g. Goodman and Gilman’s, Pharmacological Basis of Therapeutics, 10^th ed., Hardman et al., eds., 2001 ) for further explanation of these variables and the complete equation illustration the calculation individualized dosage regimes. Those skilled in the art will be able to anticipate potential fluctuations in these variables in individual subjects. For example, the standard deviation in the values observed for F, CL, and Vss is typically about 20%, 50% and 30%, respectively. The practical effect of potentially widely varying parameters in individual subjects is 95% of the time the Css achieved in a subject is between 35 and 270% that of the target level. For drugs with low therapeutic indices, that is an undesirably wide range. Those skilled in the art wil appreciate, however, that once the agent’s Cp (concentration in the plasma) is measured, it is possible to estimate the values of F, CL, and Vss directly. This allows the clinician to effectively fine tune a particular subject’s dosing regimen.

In still other embodiments, the present invention contemplates that continuing therapeutic drug monitoring techniques be used to further adjust an individual’s dosing methods and regimens. For example, in one embodiment, Css data is used to further refine the estimates of CL/F and subsequently adjust the individual’s maintenance dosing to achieve desired agent target levels using known pharmacological principles and equations. Therapeutic drug monitoring can be conducted at practically any time during the dosing schedule. In preferred embodiments, monitoring is carried out at multiple time points during dosing and especially when administering intermittent doses. For example, drug monitoring can be conducted concomitantly, within fractions of seconds, seconds, minutes, hours, days, weeks, months, etc., of administration of the agents regardless of the dosing methodology employed (e.g. intermittent dosing, loading doses, maintenance dosing, random dosing, or any other dosing method). However, those skilled in the art will appreciate that when sampling rapidly follows administration of the agent(s), the changes in agent(s) effects and dynamics may not be readily observable because changes in plasma concentration of the agent may be delayed (e.g. due to a slow rate of distribution or other pharmacodynamics factors). Accordingly, subject samples obtained shortly after agent administration may have limited or decreased value.

Method for treating medulloblastoma

One aspect of the present invention relates to a method for treating medulloblastoma in a subject in need thereof, wherein said PIGF inhibitor and said chemotherapeutic agent, as detailed above, are administered to the subject. It is also understood that said composition can be administered in accordance with the gender, age, race, body condition of the subject in need thereof, which can be easily modified by those if ordinary skill in the art without undue burden. Optionally, said PIGF inhibitor is administered to a subject at a dose of 75-250 mg per day per kg bodyweight of the treated subject (e.g. for 5-25 weeks). Optionally, the chemotherapeutic agent is administered to a subject at a dose of 0.5-2000 mg per day per square meter of body surface of the treated subject (e.g. for 1 -25 weeks).

In one preferred embodiment of the present invention, said PIGF inhibitor, as detailed above, is administered in a dosage regime, such as but not limited to, between 75 and 250 mg per kg bodyweight of the treated subject per day. More preferably, the dosage regime is between 100 and 200 mg per kg bodyweight per day, more preferably between 100 and 175 mg per per kg bodyweight per day, or any equivalent amounts. In another preferred embodiment of the present invention, said chemotherapeutic agent, as detailed above, is administered in a dosage regime, such as but not limited to, between 0.5 and 2000 mg per square meter of body surface of the treated subject per day or any equivalent thereof.

The dosage regimes or the amounts of said PIGF inhibitor and said chemotherapeutic agent, as described above, are believed to be suitable for human patients and are based on the known and presently understood pharmacology of the compounds, and the action of other similar entities in the human body. It is understood that said PIGF inhibitor, said chemotherapeutic agent, and said dosage regimes, as detailed above, are variable and can be individualized on the basis of the disease and the response of the subject in need thereof, based on the knowledge of those of ordinary skill in the art.

EXAMPLES

The following examples are provided in order to demonstrate and further illustrate certain preferred embodiments and aspects of the present invention and are not construed as limiting the scope thereof.

Example 1. Study of a PIGF inhibitor in combination with chemotherapy in pediatric subjects with relapsed or refractory Medulloblastoma

Subjects between 6 months and 18 years of age and having a historically- confirmed diagnosis of medulloblastoma were selected. Written consent was obtained from the subjects or their legal representative before the study procedure. Subjects further had documented relapse or refractoriness after at least 1 line of standard-of-care therapy, including each of the following:

- Surgery, unless documented contraindication

Radiotherapy, unless documented contraindication

Chemotherapy, unless documented contraindication Subjects have had undergone magnetic resonance imaging (MRI) for medulloblastoma within 1 month prior to first dose of study treatment and had a Lansky score > 40 for subjects up to 16 years of age or a Karnofsky score > 40 for subjects 16 years of age to < 18 years. Additionally, subjects displayed adequate organ function, defined by:

Peripheral absolute neutrophil count ³ 1 .5 10⁹/L Platelet count > 100 10⁹/L

Hemoglobin ³ 8mg/dL (transfusion to reach this level is permitted)

International normalized ratio (INR) < 1.5; partial thromboplastin time (PTT) < 1.5 upper limit of normal (ULN); d-dimer < 250ng/mL

Serum creatinine < specified maximum values based on age as described below:

6 months to 3 years of age: serum creatinine < 0.4mg/dL 3 to 13 years of age: serum creatinine < 0.7mg/dL > 13 years of age: serum creatinine < 1 mg/dL Creatinine clearance > 50mL/min

Serum aspartate aminotransferase (AST) and serum alanine aminotransferase (ALT) < 2.5 ULN; serum bilirubin < 1.5 ULN

Selected subjects had no symptoms of cranial hypertension or convulsions within 14 days prior to first dose of study treatment (anti-epileptic drugs and corticoids are allowed to control any preexisting symptoms). Subjects on corticosteroids for endocrine deficiencies or tumor-associated symptoms, were required to be on a stable (or decreasing) dose for at least 7 days before first dose of study treatment.

Exclusion criteria included have any clinically significant disease considered by the investigator to interfere with study participation, not having fully recovered from the acute toxic effects of prior anticancer therapy (e.g., chemotherapy, immunotherapy, radiation therapy) or are currently receiving cytotoxic chemotherapy, immunotherapy or radiation therapy. A minimum period of 4 weeks / 28 days is required between the end of prior anticancer therapy and the initiation of study treatment, having had cancer other than medulloblastoma in the previous 5 year, having participated in another therapeutic clinical trial with an investigational drug within 1 month, having any known active uncontrolled infection, having had major surgery or bone fracture within 28 days before first dose of study treatment, having have previously received the PIGF inhibitor of the study treatment, having a history of severe allergic or anaphylactic reactions or hypersensitivity to recombinant proteins or excipients in the investigational drug, receiving increasing doses of corticosteroids, being eligible for a curative treatment option, and having had a prior thrombotic event (e.g., pulmonary embolism, deep vein thrombosis) or being currently receiving therapeutic or prophylactic doses of anticoagulants.

Example 2. Effect of a PIGF inhibitor in combination with chemotherapy on pediatric subjects with relapsed Medulloblastoma

The PIGF inhibitor of the invention was administered to two pediatric subjects (Subject 1 and Subject 2) complying with the requirements set forth above in combination with temozolomide (Subject 1 ) or etoposide (Subject 2). The anti- PIGF inhibitor of the invention used in the study treatment was a humanized anti human PIGF antibody comprising the V_H sequence of SEQ ID NO: 15 and the V_L sequence of SEQ ID NO: 16 linked to the constant regions of a human IgG backbone. The antibody can be produced in accordance with the common general knowledge or the methods described in W02006099698 A2, the content of said patent application is herein incorporated by reference.

Subject 1

Subject 1 is an 18-year old male of 71.7 kg with documented relapse of eight lines of therapy, including earlier chemotherapeutic treatment lines with etoposide and temozolomide, and two brain tumor restrictions. At baseline, the sum of the size of the subject’s two target lesions (TL) was 714.9 mm². In addition, four non target lesions (NTL) were identified upon onset of the treatment. The study treatment consisted in nine cycles of treatment with a duration of one month each. During each cycle, bi-weekly injections were performed, on day 1 and on day 15. During the first cycle, the subject received bi-weekly injections of 100 mg of PIGF inhibitor per kg of body weight. At onset of the second cycle this dose was reduced to about 71 mg of PIGF inhibitor per kg of subject body weight. From the third cycle and until day 1 of cycle 8, the subject received during each cycle bi-weekly injections of 71 mg of PIGF inhibitor per kg of subject body weight in combination with 180 mg of temozolomide. On day 15 of cycle 8 and day 1 of cycle 9, the subject received a dose of 71 mg of PIGF inhibitor per kg of subject body weight without the additional supply of a chemotherapeutic agent.

Disease progression was monitored by performing regular MRI scans to assess the size of the existing tumors (target lesions (TL) and non-target lesions (NTL)), as well as the emergence of new lesions. MRI scans were reviewed by a central reading center. Measurable lesions were defined as contrast enhancing lesions (T1 with contrast) with bi-dimensional measurements (long axis / short axis) with clearly defined margins by MRI scans. They could be entitled either as Target or Non-targets lesions. (> 10mm is a requirement only for the target lesions). Non measurable lesions were defined as lesions that are too small (lesions with maximal perpendicular diameters less than 10mm e.g. 12 X 8 mm), masses with margins not clearly defined or lesions that do not enhance (seen only on T2/FLAIR).

Target (Enhancing) lesions: Contrast-enhancing lesions with two perpendicular diameters > 10mm. Maximum 5 target lesions should be defined (Largest lesions suitable for reproducible measurement). Non-Target Enhancing lesions: Contrast enhancing lesions with at least one diameter < 10mm. In case 5 target lesions have been selected the other enhancing lesions remaining are considered as non-target. Non-target non-enhancing lesions: T2/FLAIR weighted scans are used for evaluation.

Target lesions were considered as stable disease throughout the treatment period (714.9 mm² at baseline vs 688.3 mm² at the end of treatment). No new lesions were identified during treatment. Non-target enhancing lesion sizes were considered as stable disease until MRI measurements around day 1 of cycle 7, where it was evaluated as progressive disease. At day 15 of cycle 9, MRI measurements again indicated progressive disease and treatment with the PIGF inhibitor was stopped. Despite earlier relapse from temozolomide, the current results show that the patient responded well and that the combination of PIGF inhibitor and temozolomide led to disease stabilization for at least 6 months.

Subject 2

Subject 2 is a 17-year old female of 28 kg with documented relapse of three lines of standard-of-care therapy, including earlier chemotherapeutic treatment lines with etoposide and temozolomide, and two cerebellum resections. At baseline, the surface of the subject’s two non-target enhancing lesions, NTL1 and NTL2, was 100.2 mm² and 37.9 mm², respectively. No target lesions as defined for subject 1 above, were identified. The study treatment lasted for 18 cycles of treatment with a duration of one month each. During each cycle, bi-weekly injections were performed, on day 1 and on day 15. From day 1 of cycle 1 until day 1 of cycle 2, the subject received bi-weekly injections of 100 mg of PIGF inhibitor per kg of body weight. In addition, as of day 15 of cycle 2 and until day 15 of cycle 15, the subject received 50 mg of etoposide, still on a bi-weekly basis. As of day 1 of cycle 16, and until the end of the treatment, the subject again received only the bi-weekly injections of 100 mg of PIGF inhibitor per kg of body weight without the additional supply of a chemotherapeutic agent.

Around day 1 of cycle 4, i.e. after treatment with PIGF inhibitor monotherapy, the non-target enhancing lesions were considered to be progressive disease. However, during treatment with the PIGF inhibitor in combination with etoposide, non-target lesions were considered stable disease up and to the MRI scan around day 1 of cycle 19, when it was evaluated as progressive disease and treatment with the PIGF inhibitor was stopped. These results indicate that on PIGF monotherapy, the disease did not fully stabilize. However, upon administration of a combination of PIGF inhibitor and chemotherapy, stable disease was observed for a long period of time (see also Fig. 1 ). No new lesions were identified during the full treatment period. However, after stopping chemotherapy co-administration, the medulloblastoma progressed again. These results support the synergistic effects of PIGF inhibition and chemotherapy for the treatment of medulloblastoma.

Claims

1. A PIGF inhibitor for use in the treatment of medulloblastoma, wherein said treatment further comprises administration of a chemotherapeutic agent.

2. The PIGF inhibitor for use according to claim 1 , wherein said PIGF inhibitor is an anti-PIGF antibody or antigen-binding fragment thereof.

3. The PIGF inhibitor for use according to claim 2, wherein said anti-PIGF antibody or antigen-binding fragment thereof comprises six complementary-determining regions (CDRs) comprising the sequences of SEQ ID NO: 5 to 10.

4. The PIGF inhibitor for use according to claim 2 or 3, wherein said anti-

PIGF antibody or antigen-binding fragment thereof comprises a variable region of a heavy chain (V_H) and a variable region of a light chain (V_L) sequence having at least 85% sequence identity to SEQ ID NO: 15 and SEQ ID NO: 16, respectively, and comprises six CDRs comprising the sequences of SEQ ID NO: 5 to 10.

5. The PIGF inhibitor for use according to claim 2 or 3, comprising an amino acid sequence having at least 85% sequence identity to amino acids 1 to 243 of SEQ ID NO: 14, and comprising the six CDRs having the sequences of SEQ ID NO: 5 to 10.

6. The PIGF inhibitor for use according to any one of the previous claims, wherein the chemotherapeutic agent is selected from the group consisting of carboplatin, carmustine, cisplatin, cyclophosphamide, etoposide, irinotecan, lomustine, methotrexate, sonidegib, temozolomide, thiopeta, topotecan, vincristine, vismodegib, and a salt, prodrug, or ester thereof.

7. The PIGF inhibitor for use according to any one of the previous claims, wherein the chemotherapeutic agent is an alkylating agent or a topoisomerase inhibitor.

8. The PIGF inhibitor for use according to claim 7, wherein said chemotherapeutic agent is selected from the group consisting of cyclophosphamide, mechlorethamine, chlorambucil, melphalan, dacarbazine, nitrosoureas, temozolomide, irinotecan, topotecan, etoposide, teniposide, tafluposide, or a salt, prodrug, or ester thereof.

9. The PIGF inhibitor for use according to any one of the previous claims, wherein said chemotherapeutic agent is temozolomide, etoposide, or a salt, prodrug, or ester thereof.

10. The PIGF inhibitor for use according to any one of the previous claims, wherein said treatment comprises administration of between 75 and 250 mg of the PIGF inhibitor per kg bodyweight of the treated subject.

1 1. The PIGF inhibitor for use according to any one of the previous claims, wherein said treatment comprises administration of between 0.5 and 2000 mg of the chemotherapeutic agent per square meter of body surface of the treated subject.

12. The PIGF inhibitor for use according to claim 1 , wherein the PIGF inhibitor is a monoclonal anti-PIGF antibody comprising a V_H sequence comprising a sequence of SEQ ID NO: 15 and a V_L sequence comprising a sequence of SEQ ID NO: 16; and wherein the chemotherapeutic agent is etoposide, or a salt, prodrug, or ester thereof.

13. A combination comprising a PIGF inhibitor as defined in any one of claims 1 to 5 and a chemotherapeutic agent as defined in any one of claims 1 and 6 to 8 for simultaneous, separate or sequential use in the treatment of medulloblastoma.

14. A combination comprising a) a monoclonal anti-PIGF antibody comprising a V_H sequence comprising a sequence of SEQ ID NO: 15 and a V_L sequence comprising a sequence of SEQ ID NO: 16, and b) etoposide, or a salt, prodrug, or ester thereof.

15. A method for the treatment of medulloblastoma in a subject in need thereof, said method comprising administration of a PIGF inhibitor as defined in any one of claims 1 to 5 and a chemotherapeutic agent as defined in any one of claims 1 and 6 to 9 to said subject.