WO2011064758A2

WO2011064758A2 - Fusion protein

Info

Publication number: WO2011064758A2
Application number: PCT/IB2010/055474
Authority: WO
Inventors: Giuseppe Ciaramella; Maria Victoria Flores; Nigel John Horscroft; Madan Katragadda; Yanli Wu
Original assignee: Pfizer Limited
Priority date: 2009-11-30
Filing date: 2010-11-29
Publication date: 2011-06-03
Also published as: WO2011064758A3

Abstract

The present invention provides an interferon-alpha immunoglobulin Fc fusion protein and use of the fusion protein in the treatment of a condition alleviated by the administration of interferon- alpha, such as a liver disorder, for example hepatitis and in particular hepatitis C.

Description

FUSION PROTEIN

Background to the invention Interferon alpha [IFNA] is secreted by many cell types including lymphocytes, macrophages, dendritic cells, fibroblasts, endothelial cells, osteoblasts and others. The cytokine interferon alpha is produced in vivo and acts locally and transiently to stimulate the immune system, particularly macrophages and natural killer cells, and to elicit anti-viral and anti-tumor responses. Interferon alpha has been tested for therapeutic efficacy against various carcinomas, myelomas, sarcomas, leukemias; also chronic viral infections such as hepatitis B; hepatitis C; herpes, varicella/herpes zoster; as well as mycosis fungoides. Of particualr interest is hepatitis C virus (HCV) which is one of the main known causes of liver diseases such as cirrhosis and hepatocellular carcinoma (HCC). It is estimated that about 3% of the world's population is chronically infected. Current therapy is based on pegylated interferon alpha 2a or 2b, in combination with ribavirin but the therapy has inherent side effects and is not fully effective There are 14 interferon alpha subtypes that are called IFNA1 , IFNA2 (2a, 2b), IFNA4, IFNA5, IFNA6,

IFNA7, IFNA8 (8a, 8b, 8c), IFNA10, IFNA13, IFNA14, IFNA16, IFNA17, IFNA21. The subtypes are coded by a gene cluster on chromosome 9. Interferon alpha subtypes exhibit a very high degree of amino-acid similarity but the reason for the existence of so many distinct proteins is still unknown. Only IFNA2a and IFNA2b subtypes are currently used for the treatment of chronic HCV infection. Interferon-alpha [IFNA] has been shown to bind to a specific cell surface receptor complex known as the Interferon-alpha receptor (IFNAR) that consists of IFNAR1 and IFNAR2 chains. Homologous molecules to type IFNA are found in many species, including all mammals, and some have been identified in birds, reptiles, amphibians and fish species. Recombinant interferon alpha has been produced, for example Roche Labs, ROFERON-A™ [IFNA2a] and Schering INTRON-A™ [IFNA2b]. IFNA has a serum half life of between about two to eight hours. Consequently, its use as a systemically administered therapeutic requires frequent and high dosage. Efforts have been made to extend the half life either by pegylation of the interferon alpha [for example Roche product PEGASYS™ or PEGINTRON ™] or by conjugation of the interferon alpha to carrier molecules such as albumin [for example Novartis product ALBUFERON™].

Although IFNA has a short half life it is a small molecule of around 19 kDal and has the ability to move rapidly from the blood stream into surrounding tissues and to cross the blood brain barrier into the central nervous system, consequently there is the risk of toxicity, particularly if administered at high or frequent dose levels.

The present invention relates to an interferon and antibody Fc fusion protein which is designed to overcome the above stated problems and which extends the half-life of the IFNA, reduces toxicity effects or risks, increases potency of binding and antiviral activity with respect to native or recombinant IFNA. Whereby also the fusion protein of the present invention can be used with equal or greater therapeutic efficacy compared to the native IFNA when provided at a respective lower frequency of dose and/or lower amount of dose concentration of IFNA. Brief description of the invention

The present invention provides a fusion protein comprising in an amino terminal to carboxy terminal direction, (a) an immunoglobulin Fc region and (b) an interferon-alpha region, optionally the

immunoglobulin Fc region is linked to the interferon-alpha region by means of a linker region. The present invention further provides use of the fusion protein in the treatment of a condition alleviated by the administration of interferon- alpha, preferably wherein the condition is a liver disorder such as for example hepatitis and in particular hepatitis C.

Description of the Figures Figure 1 :

Plasmid diagram showing the clone map for an Interferon alpha8 Fc fusion protein where the Interferon alpha8 is fused to the C-terminus of Fc via a GS linker (GGGGSGGGGSGGGSG) linker. The Fc portion comprises CH2 and CH3 sequences of lgG2 and a hinge sequence of lgG1.

Figure 2:

Schematic representation of the Interferon alpha Fc fusion proteins F1 to F9

Definitions

As used herein, the term, "immunoglobulin Fc region" is understood to mean the carboxyl-terminal portion of an immunoglobulin chain constant region, preferably an immunoglobulin heavy chain constant region, or a portion thereof. For example, an immunoglobulin Fc region may comprise 1 ) a CH1 domain, a CH2 domain, and a CH3 domain, 2) a CH 1 domain and a CH2 domain, 3) a CH1 domain and a CH3 domain, 4) a CH2 domain and a CH3 domain, or 5) a combination of two or more CH domains and an immunoglobulin hinge region. In a preferred embodiment the immunoglobulin Fc region comprises at least an immunoglobulin hinge region, a CH2 domain and a CH3 domain, and preferably lacks the CH1 domain. As used herein, the term "interferon-alpha" is understood to mean not only full length mature interferon- alpha, for example, human interferon-alpha 1 , human interferon-alpha 2, human interferon-alpha 4, human interferon-alpha 5, human interferon-alpha 6, human interferon-alpha 7, human interferon-alpha 8, human interferon-alpha 10, human interferon-alpha 14, human interferon-alpha 16, human interferon- alpha 17, human interferon-alpha 21 , interferon delta-1 , interferon omega-1 ; and mouse interferon-alpha 1 , mouse interferon- alpha 2, mouse interferon-alpha 4, mouse interferon-alpha 5) mouse interferon-alpha 6, mouse interferon-alpha 7, mouse interferon-alpha 8, and mouse interferon-alpha 9, also variants and bioactive fragments thereof. Known sequences of interferon-alpha may be found in GenBank.

The term bioactive fragment refers to any interferon-alpha protein fragment that has at least 50%, more preferably at least 70%, and most preferably at least 90%, increasingly preferably 95% , 99% or 100% of the biological activity of the template human interferon-alpha protein of any of SEQ ID NOS: 12, 13, 14, 15, 16 or 17, as determined using the proliferation inhibition assay of the Examples herein.

The term variant(s) includes species and allelic variants, as well as other naturally occurring or non- naturally occurring variants, for example, generated by genetic engineering protocols, and are at least 70% to 60% identical, more preferably at least 75% to 65% identical, more preferably at least 80% to 70% identical, more preferably at least 90% to 85% identical, and most preferably at least 99% to 95% identical in sequence to the mature human interferon-alpha protein disclosed in SEQ ID NOS: 12, 13, 14, 15, 16 or 17, or to the Fc or hinge regions disclosed in SEQ ID NOS: 1 , 2, 3, 4, 5, or 6, or linker regions disclosed in SEQ ID NOS: 7, 8, 9, 10, 1 1 . Preferably the species and allelic variants will have the same biological function or activity as the above mentioned sequences determined using a suitable relevant test such as for example using a proliferation inhibition assay for an interferon variant or an Fc effector function assay for an Fc variant or functional tests mentioned herein with reference to interferon, Fc or linker.

Methods to determine percentage identity of polypeptide sequences are well known in the art. For example using tools commercially available and widely used by those skilled in the art.

Variants may also include other interferon-alpha mutant proteins having interferon-alpha- like activity. Species and allelic variants, include, but are not limited to human and mouse interferon-alpha sequences.

As used herein, the term "multimeric" refers to the stable association of two or more polypeptide chains either covalently, for example, by means of a covalent interaction, for example, a disulfide bond, or non- covalently, for example, by hydrophobic interaction. The term multimer is intended to encompass both homomultimers, wherein the subunits (i.e. polypeptide chains) are the same, as well as, heteromultimers, wherein the subunits are different.

As used herein, the term "dimeric" refers to a specific multimeric molecule where two polypeptide chains are stably associated through covalent or non-covalent interactions. Detailed description of the invention

According to the present invention there is provided a fusion protein comprising an immunoglobulin Fc region and an interferon alpha region, nucleic acids encoding the same. Also provided are host cells comprising the nucleic acids of the invention and expressing the fusion protein, and use of the fusion protein for the treatment of a condition alleviated by administration of interferon alpha.

(1) fusion direction

The fusion protein of the present invention may comprise in an amino terminal to carboxy terminal direction, (a) an immunoglobulin Fc region and (b) an interferon-alpha region. Alternatively the fusion protein of the invention may comprise in an amino terminal to carboxy terminal direction, (a) an interferon- alpha region and (b) an immunoglobulin Fc region . The fusion proteins of the present invention demonstrate advantageous biological properties over native non fusion interferon alpha, and over pegylated or albumin conjugated interferon alpha, such as increased solubility, increased stability of the IFNA and increased serum half life, increased binding affinity to target cells, such as cells of target organs such as the liver, and receptors such as for example IFNAR1 and IFNAR2. Increased solubility is desirable in order that bioavailability of the IFNA is maximized on administration and accurate dosage of the IFNA can be determined and carried out. Also aggregates are undesirable causing pain in delivery in-vivo and leading to potential inflammation and immunogenicity. Increased serum half life and/or increased binding affinity to target cells has the advantage of facilitating reduced levels and/or reduced frequency of dose requirement during use for treatment in order to achieve the equivalent or maintained therapeutic effect of the interferon alpha delivered. In this case the interferon alpha is more potent in its therapeutic effect and/ or more stable in the circulation. The resulting lower and/or less frequent doses are advantageous in minimising any potential toxic effects or side effects potentially associated with interferon alpha administration. The molecular weight of the fusion protein is around 1 10 kDa as opposed to around 19 kDa for native IFNA, this has the advantage that the fusion protein will be well retained in the blood circulation when administered intravenously reducing the risk of penetration to undesired sites for example the central nervous system and making the fusion protein suitable for retention or concentration in organs such as the liver thus enhancing its suitability for the treatment of liver disease such as hepatitis, for example hepatitis B or C. Additionally the Fc region of the fusion protein of the present invention is also available for binding to Fc receptors expressed on cells including among others liver cells resulting in improved direction of the IFNA to the liver.

Preferably the fusion protein of the present invention comprises in an amino terminal to carboxy terminal direction, (a) an immunoglobulin Fc region and (b) an interferon-alpha region. Fusion proteins of this orientation demonstrate a reduced toxicity risk of Fc mediated effector functions such as complement fixation or antibody-dependent cellular cytotoxicity against cells bearing receptors for IFNA or Fc.

Additionally fusion proteins of this orientation demonstrate an improved binding affinity to the IFNAR1 and INFAR2 and improved antiviral activity. Furthermore fusion proteins of this orientation demonstrate an improved solubility and pharmacokinetics. Solubility of the fusion protein is important as aggregates of protein molecules are known to give rise to adverse immunological sensitisation and reaction. The solubility of fusion proteins of the opposite orientation (comprising an amino terminal to carboxy terminal direction, (a) an interferon-alpha region and (b) an immunoglobulin Fc region) were found to demonstrate correspondingly poorer solubility in solution in the pH range 5.5 to 7.5 as evident from the heavy precipitation of the fusion protein obtained in this range. Related to this precipitation the molecule showed poor half life in-vivo presumably because the precipitated protein easily becomes denatured and subject to degradation.

(2) Fc region

The immunoglobulin Fc region of the fusion protein of the present invention preferably comprises or consists of an Fc or a portion of an Fc of an immunoglobulin of isotype selected from IgG, IgM, IgA, IgD, IgE, further preferably, lgG1 , lgG2, lgG3, lgG4, lgA1 , lgA2, slgA, more preferably lgG2 or lgG4, most preferably lgG2. Fc receptor is a found on the surface of various cells - including leukocytes that contribute to the protective functions of the immune system, the receptor is also found on liver cells, hence fusion proteins combining Fc-IFNA are advantageous in directing the IFNA to the liver. The Fc region from lgG1 and 3 demonstrated highest affinity followed by lgG4 (ten times weaker than lgG1 ) with lgG2 showing lowest affinity to Fc receptor. The Fc region of lgG1 and 3 demonstrated high tendency for complement fixation or antibody-dependent cellular cytotoxicity against cells, lgG2 shows a reduced tendency in this regard. Accordingly the Fc region of the fusion protein of the present invention may also comprise amino acid mutations, deletions, substitutions or chemical modifications which serve to minimise complement fixation or antibody-dependent cellular cytotoxicity or which improve affinity of binding to the Fc receptor.

Further preferably the fusion protein of present invention may comprise an immunoglobulin Fc region or portion thereof comprising or consisting of any of:

(a) a CH2 domain or portion thereof and a CH3 domain or portion thereof,

(b) a CH2 domain or portion thereof, or

(c) a CH3 domain or portion thereof, wherein the Fc region or portion thereof is of isotype selected from IgG, IgM, IgA, IgD, IgE, further preferably, lgG1 , lgG2, lgG3, lgG4, lgA1 , lgA2, slgA, more preferably lgG2 or lgG4, most preferably lgG2. The immunoglobulin Fc region of the fusion protein of the present invention preferably comprises or consists of the carboxy terminal region of an immunoglobulin heavy chain and may comprise the CH2 and/or CH3 domains, or parts thereof, from IgG, IgA or IgD antibody isotypes, or the CH2 and/or CH3 and/or CH4 domains, or parts thereof from IgM or IgE. A fragment of the Fc, comprising mainly CH3 and a small portion of CH2, is derivable by pepsin digestion of the immunoglobulin. The full Fc region, comprising CH2 and CH3, additionally connected to a hinge region (which is a short segment of heavy chain connecting the CH1 and CH2 regions in the intact immunoglobulin, which may be produced by papain digestion of the immunoglobulin).

Preferably the immunoglobulin Fc region of the fusion protein of the present invention comprises or consists of a human immunoglobulin Fc region of amino acid sequence selected from SEQ ID No. 1 or 2 or a species or allelic variant thereof, or the CH2 and/or CH3 domains, or portions thereof derived from SEQ ID NO. 1 or 2.

The fusion protein of the invention possesses the following advantages with respect to native IFNA, particularly by virtue of comprising the Fc region (a) it can be expressed at high levels from variety of mammalian host cells to provide a single species of IFNA and can be efficiently purified by affinity chromatography by binding to Staphylococcus aureus protein A. It has a prolonged half life of IFNA and higher stability in serum hence permitting a dosage regime of less frequent dosing and/or lower dosing levels hence reducing potential toxicity or side effects in-vivo to achieve the same equivalent therapeutic effect. The fusion protein can dimerise (promoting higher receptor binding affinity) and has increased affinity to IFNA R1 or 2, as IFNA activity is propagated through the binding of the IFNA receptor the tighter binding higher potency of the fusion protein over the native IFNA will result in a higher therapeutic efficacy as judged by the IFNA mediated effects for example as determined by an anti viral activity / anti proliferation / replicon assay such as those described herein. Higher potency has the benefit that the fusion protein can be used at lower dosage amounts and/or lower dosage frequency than native IFNA to achieve the same therapeutic efficacy hence reducing potential toxicity or side effects in-vivo.

Additionally the fusion protein of the invention benefits from minimised CNS penetration and toxicity being 1 10kDa as opposed to 19kD for native IFNA. The Fc region can be glycosylated and highly charged at physiological pH hence helping solubilise the molecule. The Fc region also permits detection of the fusion protein by anti-Fc ELISA for diagnostic purposes According to a preferred embodiment of the present invention the immunoglobulin Fc region of the fusion protein of the present invention preferably comprises or consists of an Fc or a portion of an Fc of an immunoglobulin which comprises one or more amino acid mutations of the wild type sequence in the CH2 region which reduce Fc effector function. Preferably these mutations are selected from, individually or in combination, A330, P331 to S330, S331 (amino acid numbering with reference to the wildtype lgG2 sequence, wherein the CH2 region is in the human heavy chain lgG2 constant region: [Eur. J. Immunol. (1999) 29:2613-2624]).

(3) hinge region

According to a further embodiment of the present invention the immunoglobulin Fc region of the fusion protein may further comprise an immunoglobulin hinge region (hinge region sequence) or a part of an immunoglobulin hinge region (hinge region sequence). Preferably the hinge region comprises or consists of a hinge region (hinge region sequence) or part of a hinge region (hinge region sequence) derived from an IgG preferably human IgG, more preferably selected from lgG1 , lgG2, lgG3, lgG4, most preferably lgG1 or is alternatively a species or allelic variant of the foregoing hinge region embodiments. The hinge region or a part of an immunoglobulin hinge region can be located at the C or N-terminal end of the Fc region, preferably at the N-terminal end.

Preferably the hinge region comprises or consists of a human immunoglobulin hinge region amino acid sequence or an amino acid sequence selected from SEQ ID No. 3, 4, 5 or 6 or a species or allelic variant thereof.

Preferably the hinge region or part of the hinge region provides the benefit of enabling multimerisation of two or more of the fusion protein of the invention. Preferably two fusion proteins of the invention are associated covalently by means of at least one or more preferably two interchain disulfide bonds via cysteine residues, preferably located within immunoglobulin hinge region comprised within the immunoglobulin Fc region of fusion protein of the invention.

Advantageously the hinge region or part of the hinge region provides the benefit of enabling multimerisation, (for example dimerisation), of two or more of the fusion protein of the invention and/or the benefit of reduced cytotoxicity and/or immunogenicity. This has been found to be particularly advantageously achieved by use of an lgG1 hinge region or part of the hinge region.

Alternatively the two fusion proteins may associate, either covalently, for example, by a disulfide bond, a polypeptide bond or a crosslinking agent, or non-covalently, to produce a multimeric, preferably dimeric fusion protein. Hence the invention contemplates that crosslinking at other positions in the fusion protein may be chosen and enabled, by the introduction either by mutation or by chemical modification, of amino acids which facilitate covalent bonding (for example cysteines) or modified amino acids achieving the same result. Also contemplated is the introduction of hydrophobic amino acids permitting non-covalent association, for example, by hydrophobic interaction. In general the multimerisation such as for example dimerisation of a ligand, for example the fusion protein of the invention, increases the apparent binding affinity between the ligand and its receptor.

(4) Interferon-alpha (IFNA) Region

The IFNA region of the fusion protein of the present invention preferably comprises or consists of an IFNA which is selected from IFNA1 , IFNA2 (2a, 2b), IFNA4, IFNA5, IFNA6, IFNA7, IFNA8 (8a, 8b, 8c), IFNA10, IFNA13, IFNA14, IFNA16, IFNA17 or IFNA21 , further preferably, IFNA2 (2a, 2b) or IFNA8 (8a, 8b, 8c), most preferably IFNA8 (8a, 8b, 8c). Preferably the IFNA is a human IFNA. Most preferably the IFNA region of the fusion protein comprises or consists of any one of sequences SEQ ID No 12, 13, 14, 15, 16 or 17 or a species or allelic variant thereof. Alternatively the IFNA region of the fusion protein may further comprise any one of sequences SEQ ID No 18, 19 or 20 or a species or allelic variant thereof.

Interferon alpha subtypes exhibit a very high degree of amino-acid similarity (over 75%) but the reason for the existence of so many distinct proteins is still unknown, only IFN-A2a and IFN-A2b subtypes are currently used for the treatment of chronic HCV infection potency of other subtypes in combating HCV activity is yet to be demonstrated.

The IFNA region of the fusion protein of the present invention preferably comprises or consists of an IFNA8, the mutation K71 R may optionally be present in the IFNA8 sequence, preferably IFNA8a or IFNA8b or IFNA8c, most preferably IFN8a, and which residue is underlined to identify it in the SEQ ID NOs 15, 16, 17. When the IFNA region of the fusion protein is an IFNA8, tighter binding is seen to IFNA receptor 1 and 2 (IFNAR1 and 2) and in comparison to when the IFNA region of the fusion protein is IFNA2. A further advantage is that the fusion protein also demonstrates both antiviral and antiproliferative effect greatly improved in comparison to when the IFNA region of the fusion protein is IFNA2.

(5) linker region

The fusion protein of the present invention may comprise either an immunoglobulin Fc region that is directly linked to an interferon-alpha region, for example by a peptide bond. Alternatively the

immunoglobulin Fc region can be linked to the interferon-alpha region by means of a linker region or linker sequence.

Preferably the linker region or linker sequence is a polypeptide linker which comprises or consists of one or a plurality of amino acids or comprises or consists of a polypeptide sequence of amino acids, preferably about 5, 6, 7, 8, or 9 to about 25 amino acids, further preferably between about 10 to about 1 1 , 12, 13, 14, 15, 16, 17, 18, 19 , 20, 21 22, 23 or 24 amino acids, most preferably 13 or 15 amino acids. Preferably the linker region comprises or consists of a polypeptide sequence of amino acids that lacks any stable secondary structure such as alpha helix, beta strand, 3₁₀ helix and pi helix, polyproline helix, alpha sheet. Preferably the linker region comprises or consists of a polypeptide sequence of amino acids that defines a flexible or dynamic or unstructured polypeptide such as for example a flexible loop, random coil or flexible turn, such unstructured polypeptides are often found connecting regions of secondary structure in larger protein molecules.

Preferably the linker region is a polypeptide sequence of amino acids that comprises greater than or about 50% glycine and/or alanine or serine in composition, further preferably greater than or about 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100% glycine and/or alanine and/or serine in composition. Preferably the linker comprises or consists of a polypeptide sequence of amino acids that comprises both glycine and serine, preferably with a greater proportion of glycine that serine, preferably the linker region comprises or consists of SEQ ID No. 7 or 8 or sequence GGGGSGGGGSGGGGS. Alternatively the linker may comprise or consist of a polypeptide sequence of amino acids that comprises a combination of glutamate, leucine, glutamine, serine, alanine, glycine and aspartate or a combination of glutamine, glutamate, phenylalanine, aspartate, lysine and alanine. Further preferably the linker region comprises or consists of SEQ ID No. 9 or 10. Alternatively the linker may comprise or consist of a polypeptide sequence of amino acids that comprises a combination of alanine, glutamate and lysine, further preferably comprising the repeating sequence "EAAAK", further preferably the linker region comprises or consists of SEQ ID No. 1 1.

Preferably the linker peptide overcomes or prevents steric hindrance from the Fc region which could interfere with the biological activity of the IFNA region when compared to native IFNA. Hence the linker region preferably permits flexibility between the IFNA region and the Fc region and allows retention or improvement of the biological activity of IFNA in the fusion protein in comparison to free native IFNA as determined by binding to IFNA receptor 1 or 2 or in an anti viral activity / anti proliferation / replicon assay such as described herein.

Further preferably the linker region is immunologically inert, such that it does not trigger complement mediated lysis, does not stimulate antibody-dependent cell mediated cytotoxicity (ADCC), does not activate microglia or T-cells. Preferably the linker region is reduced in one or more of these activities. Preferably the linker region comprises or consists of a polypeptide derived from a human IFNA; preferably the IFNA is selected from IFNA1 , IFNA2 (2a, 2b), IFNA4, IFNA5, IFNA6, IFNA7, IFNA8 (8a, 8b, 8c), IFNA10, IFNA13, IFNA14, IFNA16, IFNA17 or IFNA21 , further preferably I FN A2 (2a, 2b) or IFNA8 (8a, 8b, 8c), most preferably IFNA8 (8a, 8b, 8c). Alternatively the linker region is a polypeptide derived from a human immunoglobulin, preferably immunoglobulin of isotype selected from IgG, IgM, IgA, IgD, IgE, further preferably, lgG1 , lgG2, lgG3, lgG4, lgA1 , lgA2, slgA, more preferably lgG2 or lgG4, most preferably lgG2. Most preferably the linker region comprises or consists of a polypeptide derived from a human IFNA or immunoglobulin known or predicted from structural analysis or structural prediction to be a flexible or dynamic or unstructured polypeptide or to lack a stable secondary structure. Most preferably the linker region comprises or consists of a polypeptide loop AB of interferon alpha 8 or a part thereof, preferably wherein the sequence of the polypeptide loop AB of interferon alpha 8 comprises of consists of SEQ ID NO. 10.

The advantage associated with using a linker region that is derived from a human IFNA or

immunoglobulin is that it reduces the possibility of generating a new immunogenic epitope at the fusion point of the Fc region and the IFNA region of the fusion protein, and thereby reduces immunogenicity.

In one embodiment the fusion protein of the invention may also comprise a proteolytic cleavage site, optionally interposed between the immunoglobulin Fc region and the interferon-alpha region. The proteolytic cleavage site may be located in the linker region or at the junction of the linker region with either the Fc region or/and the IFNA region. The IFNA may be cleaved from the fusion protein prior to formulation and or administration for therapeutic purposes.

Although the linker region can comprise or consist of a polypeptide derived from a region of a human IFNA of immunoglobulin as herein described it may comprise or consist of a species or allelic variant thereof.

(6) overall structure

According to a preferred embodiment of the present invention the fusion protein of the present invention preferably comprises, preferably in an amino terminal to carboxy terminal direction but alternatively in a carboxy terminal to amino terminal direction: (1 ) an immunoglobulin Fc region comprising or consisting of SEQ ID NO 1 and SEQ ID NO, 3 or 4; alternatively 5 or 6 (2) an IFNA region comprising or consisting of a sequence selected from SEQ ID NO. 15, 16 or 17 and wherein the immunoglobulin Fc region is linked to the interferon-alpha region, either directly by a peptide bond or, preferably by means of a linker region comprising or consisting of a sequence selected from SEQ ID NO. 7, 8, 9, 10 or 1 1 , preferably SEQ ID NO. 10. According to a further preferred embodiment of the present invention the fusion protein of the present invention preferably comprises, preferably in an amino terminal to carboxy terminal direction but alternatively in a carboxy terminal to amino terminal direction: (1 ) an immunoglobulin Fc region comprising or consisting of SEQ ID NO 2 and SEQ ID NO, 3 or 4; alternatively 5 or 6 (2) an IFNA region comprising or consisting of a sequence selected from SEQ ID NO. 15, 16 or 17 and wherein the immunoglobulin Fc region is linked to the interferon-alpha region, either directly by a peptide bond or, preferably by means of a linker region comprising or consisting of a sequence selected from SEQ ID NO. 7, 8, 9, 10 or 1 1 , preferably SEQ ID NO. 10.

According to a further preferred embodiment of the present invention the fusion protein of the present invention preferably comprises, preferably in an amino terminal to carboxy terminal direction but alternatively in a carboxy terminal to amino terminal direction: (1 ) an immunoglobulin Fc region comprising or consisting of SEQ ID NO 1 and SEQ ID NO, 3 or 4; alternatively 5 or 6 (2) an IFNA region comprising or consisting of a sequence selected from SEQ ID NO. 12, 13 or 14 and wherein the immunoglobulin Fc region is linked to the interferon-alpha region, either directly by a peptide bond or, preferably by means of a linker region comprising or consisting of a sequence selected from SEQ ID NO. 7, 8, 9, 10 or 1 1 , preferably SEQ ID NO. 10.

According to a further preferred embodiment of the present invention the fusion protein of the present invention preferably comprises, preferably in an amino terminal to carboxy terminal direction but alternatively in a carboxy terminal to amino terminal direction: (1 ) an immunoglobulin Fc region comprising or consisting of SEQ ID NO 2 and SEQ ID NO, 4; alternatively 5 or 6 (2) an IFNA region comprising or consisting of a sequence selected from SEQ ID NO. 12, 13 or 14 and wherein the immunoglobulin Fc region is linked to the interferon-alpha region, either directly by a peptide bond or, preferably by means of a linker region comprising or consisting of a sequence selected from SEQ ID NO. 7, 8, 9, 10 or 1 1 , preferably SEQ ID NO. 10. According to a further preferred embodiment of the present invention the fusion protein of the present invention preferably comprises or consists of SEQ ID NO. 21 or 23.

According to a further preferred embodiment of the present invention the fusion protein of the present invention may comprise or consist of a multimeric protein comprising at least two fusion proteins of the invention, possibly 3 or 4, preferably linked via a covalent bond, further preferably wherein the covalent bond is a disulfide bond, alternatively the at least two fusion proteins of the invention may be preferably linked by means of a non-covalent interaction, for example by hydrophobic interactions.

(7) qlvcosylation

The fusion protein of the invention is preferably synthesized in a cell which glycosylates the Fc region preferably at normal glycosylation sites.

(8) binding affinity IFNAR1 and IFNAR2

The fusion protein of the present invention preferably binds to IFNA receptor 1 [IFNAR1 ] with a binding affinity (K_d) of between about 1 nM to about 5000 nM. In some preferred embodiments, the binding affinity (Kd) is between about 10 nM and any of about 50 nM, 100 nM, 150 nM, 200 nM, 250 nM, 300 nM, 350 nM, 400 nM, 450 nM, 500 nM, 550 nM, 600 nM, 650 nM, 700 nM, 750 nM, 800 nM, 850 nM, 900 nM, 950 nM, 1000 nM, 2000 nM, 3000 nM, 4000 nM, 5000 nM, 6000 nM, 7000 nM, 8000 nM, 9000 nM, or 10,000 nM as measured in an in vitro binding assay for IFNAR1 such as described herein. In some further preferred embodiments, binding affinity (Kd) is less than any of about 12,000 nM, 10,000 nM, 6000 nM, or 5000 nM, as measured in an in vitro binding assay for IFNAR1 such as described herein. In a further more preferred embodiment the binding affinity (Kd) is about 350 nM.

The fusion protein of the present invention preferably binds to IFNA receptor 2 [I FNAR2] with a binding affinity (K_d) of between about 0.01 nM to about 5 nM. In some preferred embodiments, the binding affinity (Kd) is between about 0.01 nM and any of about 0.05 nM, 0.1 nM, 0.15 nM, 0.2 nM, 0.25 nM, 0.3 nM, 0.35 nM, 0.4 nM, 0.45 nM, 0.5 nM, 0.55 nM, 0.6 nM, 0.65 nM, 0.700 nM, 0.75 nM, 0.8 nM, 0.85 nM, 0.9 nM, 0.95 nM, 1 nM, 1.5 nM, 2 nM, 2.5 nM, 3 nM, 3.5 nM, 4 nM, 4.5 nM or 5 nM as measured in an in vitro binding assay for IFNAR2 such as described herein I n some further preferred embodiments, binding affinity (Kd) is or is less than any of about 10 nM, 9 nM, 8 nM, 7 nM, 6 nM or 5 nM, as measured in an in vitro binding assay for IFNAR2 such as described herein. In a further more preferred embodiment the binding affinity (Kd) is about 1 or about 2 nM.

(9) proliferation inhibition assay

Preferably, the fusion protein of the invention inhibits proliferation of lymphoblastoid B cell line [ATCC CCL 213]. Further preferably the fusion protein of the invention inhibits proliferation of lymphoblastoid B cell line [ATCC CCL 213] with an EC50 of between about 0.1 pM and about 25 pM. In some preferred embodiments, the EC50 is between about 0.1 pM and any of about 10 pM, 9 pM, 8 pM, 7 pM, 6 pM, 5 pM, 4 pM, 3 pM, 2 pM, 1 pM, 0.9 pM, 0.8 pM, 0.7 pM, 0.6 pM, 0.5 pM, 0.4 pM, 0.3 pM, 0.2 pM or 0.15 pM, +/- 5% or 10% error as measured in a proliferation inhibition assay such as described herein. In some further preferred embodiments, EC50 is or is less than any of about 3.65 pM, 1 .89 pM or 1.52 pM, +/- 5% or 10% error as measured in a proliferation inhibition assay such as described herein.

(10) antiviral activity against HCVreplicon

Preferably, the fusion protein of the invention demonstrates antiviral activity preferably including antiviral activity against HCV replicon 1 a and/or 1 b and/or 2a, more preferably 1 b. Antiviral activity against HCV replicon 1 a, 1 b, 2a alone or in any combination is indicative of potency of general antiviral activity.

Further preferably, the fusion protein of the invention demonstrates antiviral activity preferably including antiviral activity against any one of HCV replicon 1 a, 1 b, 2a with an EC50 of between about 0.01 pM and about 2.5 pM. In some preferred embodiments, the EC50 is between about 0.01 pM and any of about 1.0 pM, 0.9 pM, 0.8 pM, 0.7 pM, 0.6 pM, 0.5 pM, 0.4 pM, 0.3 pM, 0.2 pM, 0.1 pM, 0.09 pM, 0.08 pM, 0.07 pM, 0.06 pM, 0.05 pM, 0.04 pM, 0.03 pM, 0.02 pM or 0.015 pM, +/- 5% or 10% error as measured in an HCV replicon 1 a, 1 b or 2a, more preferably 1 b. replicon activity such as described herein. In some further preferred embodiments, EC50 is or is less than any of about 0.07 pM, 0.05 pM, 0.035 pM, 0.030 pM or 0.015 pM, +/- 5% or 10% error as measured in an HCV replicon 1 a, 1 b or 2a more preferably 1 b. replicon activity assay such as described herein.

(11) antiviral activity against ECMV

Preferably, the fusion protein of the invention demonstrates antiviral activity preferably including antiviral activity against ECMV [encephalomyocarditis virus]. Antiviral activity against ECMV is indicative of potency of general antiviral activity. Further preferably, the fusion protein of the invention demonstrates antiviral activity preferably including antiviral activity against ECMV with an EC50 of between about 1 pM and about 25 pM. I n some preferred embodiments, the EC50 is between about 1 pM and any of about 20 pM, 19.5 pm, 19 pM, 18.5 pm, 18 pM, 17.5 pm, 17 pM, 16.5 pm, 16 pM, 15.5 pm, 15 pM, 14.5 pm, 14 pM, 13.5 pm, 13 pM, 12.5 pm, 12 pM, 1 1.5 pM, 1 1.0 pm, 10.5 pm,

10 pM, 9.5 pm, 9 pM, 8.5 pm, 8 pM, 7.5 pm, 7 pM, 6.5 pm, 6 pM, 5.5 pm, 5 pM, 4.5 pm, 4 pM, 3.5 pm, 3 pM, 2.5 pm, 2 pM, 1.5 pM or1.25 pm, +/- 5% or 10% error as measured in an ECMV activity assay such as described herein In some further preferred embodiments, EC50 is or is less than any of about 10.5pM, 9.88 pM, 4.45 pM, 2.8 pM, +/- 5% or 10% error as measured in an ECMV activity assay such as described herein.

(12) half life

According to a preferred embodiment of the present invention the fusion protein of the invention has a half life in-vivo of about or more than any one of 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 1 10, 1 12, 1 14, 1 16, 1 18, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152,154, 156, 158, 160, 62, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208 or 210 hours +/- 1 hour, further preferably the half life is about or more than any one of 20 hours, 20.1 hours, 24.3 hours, 27 hours, 27.1 hours, 27.3 hours. Preferably the fusion protein of the invention has a half life in-vivo of about or more than 20 hours. According to a preferred embodiment of the present invention the fusion protein of the invention has a half life in-vivo of about or more than any one of 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 1 10, 1 12, 1 14, 1 16, 1 18, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152,154, 156, 158, 160, 62, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208 or 210 days +/- 1 day, further preferably the half life is about or more than any one of 5 days, 6 days, 20 days, 26 days, 27 days. Preferably the fusion protein of the invention has a half life in-vivo of about or more than 6 days.

According to the foregoing preferred embodiments, preferably the in-vivo half life is half life in rat or half life in human, more preferably in human. Preferably the half life is determined from serum measurements of the levels of fusion protein of the invention following administration in-vivo for example by intravenous or subcutaneous injection.

(13) whole blood stimulation

(13.1) IP-10 and IL-6 stimulation

According to a preferred embodiment of the present invention, the fusion protein of the invention stimulates release of plasma cytokines in whole blood, preferably the cytokine is either IP-10 (interferon inducible protein 10) or Interleukin 6 (IL-6). According to this preferred embodiment of the invention the whole blood can be either human or cynomolgus, preferably human. According to this preferred embodiment of the invention the EC50 value is calculated after any one of about 1 , 2, 3, 4, 5 or 6 hours incubation of the whole blood with the fusion protein of the invention, preferably about 4 hours. The stimulation of production of either IP-10 (interferon inducible protein 10) or Interleukin 6 (IL-6) is strongly linked to an active defensive response against viral infection.

Further preferably, the fusion protein of the invention stimulates release of plasma cytokines, preferably IP-10 or IL-6, in whole blood with an EC50 of between about 10 pg/ml and about 1000 pg/ml. In some preferred embodiments, the EC50 is between about 10 pg/ml and any of about 50 pg/ml, 100 pg/ml, 150 pg/ml, 200 pg/ml, 250 pg/ml, 300 pg/ml, 350 pg/ml, 400 pg/ml, 450 pg/ml, 500 pg/ml, 550 pg/ml, 600 pg/ml, 650 pg/ml, 700 pg/ml, 750 pg/ml, 800 pg/ml, 850 pg/ml, 900 pg/ml, 950 pg/ml or 1000 pg/ml, +/- 5%, 10% or 15% error as measured in a cytokine activity assay, preferably IP-10 or IL-6, such as described herein In some further preferred embodiments, EC50 is or is less than any of about 330 pg/ml +/- 50 pg/ml error, 430 pg/ml +/- 70 pg/ml error, 240 pg/ml +/- 160 pg/ml error or 160 pg/ml +/- 90 pg/ml error, as measured in a cytokine activity assay, preferably IP-10 or IL-6, such as described herein

(13.2) OAS2 Stimulation

Preferably, the fusion protein of the invention stimulates expression of OAS2 (2', 5', oligoadenylate synthetase ) in whole blood, OAS2 is known to be positively correlated with a drop in viral load in human HCV clinical trials. According to this preferred embodiment of the invention the whole blood can be either human or cynomolgus, preferably human. According to this preferred embodiment of the invention the EC50 value is calculated after any one of about 1 , 2, 3, 4, 5 or 6 hours incubation of the whole blood with the fusion protein of the invention, preferably about 4 hours.

Further preferably, the fusion protein of the invention stimulates expression of OAS2 in whole blood with an EC50 of between about 10 pg/ml and about 1000 pg/ml. In some preferred embodiments, the EC50 is between about 10 pg/ml and any of about 50 pg/ml, 100 pg/ml, 150 pg/ml, 200 pg/ml, 250 pg/ml, 300 pg/ml, 350 pg/ml, 400 pg/ml, 450 pg/ml, 500 pg/ml, 550 pg/ml, 600 pg/ml, 650 pg/ml, 700 pg/ml, 750 pg/ml, 800 pg/ml, 850 pg/ml, 900 pg/ml, 950 pg/ml or 1000 pg/ml, +/- 5%, 10% or 15% error as measured in an OAS expression assay such as described herein. In some further preferred embodiments, EC50 is or is less than any of about 640 pg/ml +/- 250 pg/ml error, or 630 pg/ml +/- 300 pg/ml error, as measured in an OAS expression assay such as described herein. (13.3) CD69 Stimulation

Preferably, the fusion protein of the invention stimulates expression of CD69 in whole blood, CD69 is known to be positively correlated with immunostimulation and antiviral activity. According to this preferred embodiment of the invention the whole blood can be either human or cynomolgus, preferably human. According to this preferred embodiment of the invention the EC50 value is calculated after any one of about 1 , 2, 3, 4, 5 or 6 hours incubation of the whole blood with the fusion protein of the invention, preferably about 4 hours.

Further preferably, the fusion protein of the invention stimulates expression of CD69 in whole blood with an EC50 of between about 100 pg/ml and about 10000 pg/ml. In some preferred embodiments, the EC50 is between about 100 pg/ml and any of about 200 pg/ml, 300 pg/ml, 400 pg/ml, 500 pg/ml, 600 pg/ml, 700 pg/ml, 800 pg/ml, 900 pg/ml, 1000 pg/ml, 1 100 pg/ml, 1200 pg/ml, 1300 pg/ml, 1400 pg/ml, 1500 pg/ml, 1600 pg/ml, 1700 pg/ml, 1800 pg/ml, 1900 pg/ml, 2000 pg/ml, 2500 pg/ml, 3000 pg/ml, 3500 pg/ml, 4000 pg/ml, 4500 pg/ml, 5000 pg/ml, 5500 pg/ml, 6000 pg/ml, 6500 pg/ml, 7000 pg/ml, 7500 pg/ml, 8000 pg/ml, 850 pg/ml, 9000 pg/ml, 9500 pg/ml or 10000 pg/ml, +/- 5%, 10% or 15% error as measured in a CD69 expression assay such as described herein In some further preferred embodiments, EC50 is or is less than about 1655 pg/ml +/- 5%, 10% or 15% error as measured in a CD69 expression assay such as described herein. (14) Medical Use

The invention further provides a fusion protein according to the present invention for use in the treatment of a condition alleviated by the administration of interferon- alpha, preferably, IFNA2 (2a, 2b) or IFNA8 (8a, 8b, 8c), most preferably IFNA8 (8a, 8b, 8c). Preferably the condition is a liver disorder, further preferably hepatitis A, B or C, more preferably hepatitis C. Alternatively the condition is multiple sclerosis or cancer.

Alternatively the present invention provides a nucleic acid encoding a fusion protein according to the invention or a vector comprising the nucleic acid for use in the treatment of a condition alleviated by the administration of interferon- alpha, preferably, IFNA2 (2a, 2b) or IFNA8 (8a, 8b, 8c), most preferably

IFNA8 (8a, 8b, 8c). Preferably the condition is a liver disorder, further preferably hepatitis A, B or C, more preferably hepatitis C. Alternatively the condition is multiple sclerosis or cancer.

The invention further provides the use of a fusion protein according to the present invention for the manufacture of a medicament for preventing, ameliorating, controlling, reducing incidence of, or delaying the development or progression of a viral infection and/or symptoms of a viral infection, optionally wherein the medicament is prepared for peripheral administration or wherein the medicament is administered peripherally. Preferably the viral infection is hepatitis A, B or C, more preferably hepatitis C.

The invention further provides the use of a fusion protein according to the present invention for the manufacture of a medicament for preventing, ameliorating, controlling, reducing incidence of, or delaying the development or progression of a disease selected from the following diseases: chronic hepatitis B, C and D, condylomata acuminata (genital warts), AIDS-related Kaposi's sarcoma, hairy cell leukemia, malignant melanoma, basal cell carcinoma, multiple myeloma, renai cell carcinoma, herpes ! and H, varicella/herpes zoster, and mycosis fungoides, prostate cancer and chronic myelogenous leukemia. The invention further provides a fusion protein according to the present invention for use in preventing, ameliorating, controlling, reducing incidence of, or delaying the development or progression of any of the foregoing diseases or of a viral infection and/or symptoms of a viral infection, optionally wherein the medicament is prepared for peripheral administration or wherein the medicament is administered peripherally. Preferably the viral infection is hepatitis A, B or C, more preferably hepatitis C.

The invention further provides a method of preventing, ameliorating, controlling, reducing incidence of, or delaying the development or progression of any of the foregoing diseases or of a viral infection and/or symptoms of a viral infection in an individual, comprising administration to the individual of an effective amount of a fusion protein according to the present invention, optionally by peripheral administration.

According to a preferred embodiment of the present invention the individual is preferably a mammal, for example a companion animal such as a horse, cat or dog or a farm animal such as a sheep, cow or pig. Most preferably the mammal is a human. Preferably the viral infection is hepatitis A, B or C, more preferably hepatitis C. According to a preferred embodiment of the present invention the medicament, nucleic acid or fusion protein according to the present invention is prepared for oral, sublingual, buccal, topical, rectal, inhalation, transdermal, subcutaneous, intravenous, intra-arterial, intramuscular, intracardiac, intraosseous, intradermal, intraperitoneal, transmucosal, vaginal, intravitreal, intra-articular, peri-articular, local or epicutaneous administration. In one embodiment, the fusion protein according to the present invention acts peripherally on administration, preferably peripheral administration.

According to a further preferred embodiment the medicament, nucleic acid or fusion protein according to the present invention is prepared for administration prior to and/or during and/or after the viral infection. The viral infection may be selected from chronic hepatitis A, B, C and D, condylomata acuminata (genital warts), AIDS-related Kaposi's sarcoma, hairy cell leukemia, malignant melanoma, basal cell carcinoma, multiple myeloma, renal cell carcinoma, herpes I and II, varicella/herpes zoster, and mycosis fungoides, prostate cancer and chronic myelogenous leukemia. Preferably the viral infection is hepatitis A, B or C, more preferably hepatitis C.

According to a preferred embodiment of the present invention the viral infection comprises one or more, of hepatitis A, B or C, more preferably hepatitis C

According to a further aspect of the present invention there is provided a pharmaceutical composition for preventing, ameliorating, controlling, reducing incidence of, or delaying the development or progression of any of the foregoing diseases or of a viral infection and/or symptoms of a viral infection, comprising a nucleic acid and/or fusion protein according to the present invention and a pharmaceutically acceptable carrier and/or an excipient. Preferably the viral infection is hepatitis A, B or C, more preferably hepatitis C.

According to a further preferred embodiment of the present invention, the pharmaceutical composition, medicament, nucleic acid or fusion protein of the invention does not produce effects on the central nervous system and preferably does not induce any one or more of the following: amnesia, confusion, depersonalization, hypesthesia, abnormal thinking, trismus, vertigo, akathisia, apathy, ataxia, circumoral paresthesia, CNS stimulation, emotional lability, euphoria, hallucinations, hostility, hyperesthesia, hyperkinesia, hypotonia, incoordination, libido increase, manic reaction, myoclonus, neuralgia, neuropathy, psychosis, seizure, abnormal speech, stupor, suicidal ideation; dizziness, somnolence, Insomnia, anxiety, tremor, depression or paresthesia. Further preferably the pharmaceutical composition, medicament, nucleic acid or fusion protein of the invention does not effect respiratory, renal or gastro-intestinal impairment, nor effect physical and/or psychological dependence.

(15) Dosage

According to a further embodiment of the present invention the pharmaceutical composition, medicament, nucleic acid or fusion protein of the invention is prepared for administration between once to 7 times per week, further preferably between once to four times per month, further preferably between once to six times per 6 month period, further preferably once to twelve times per year. Preferably the medicament is prepared to be peripherally administered in a period selected from: once daily, once every two, three, four, five or six days, weekly, once every two weeks, once every three weeks, monthly, once every two months, once every three months, once every four months, once every five months, once every six months, once every seven months, once every eight months, once every nine months, once every ten months, once every eleven months or once yearly.

According to preferred embodiments the pharmaceutical composition, medicament, nucleic acid or fusion protein of the invention is prepared to be peripherally administered via a route selected from one or more of; orally, sublingually, buccally, topically, rectally, via inhalation, transdermally, subcutaneously, intravenously, intra-arterially or intramuscularly, via intracardiac administration, intraosseously, intradermally, intraperitoneally, transmucosally, vaginally, intravitreally ,epicutaneously, intra-articularly, peri-articularly or locally. According to a further embodiment of the present invention the medicament, nucleic acid or fusion protein of the invention is prepared for administration with an fusion protein concentration of between about 0.1 to about 200 mg/ml; preferably at any one of about 0.5, 1 , 5, 10,15 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 1 10, 120, 130, 140, 150, 160, 170, 180, 190 or 200 mg/ml +/- about 10% error, most preferably at about 50 mg/ml.

According to a further embodiment of the present invention the medicament, nucleic acid or fusion protein of the invention is prepared for administration with an fusion protein concentration of between about 0.1 to about 200 mg/kg of body weight; preferably at any one of about 0.5, 1 , 5, 10,15 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 1 10, 120, 130, 140, 150, 160, 170, 180, 190 or about 200 mg/kg of body weight +/- about 10% error, most preferably at about 10 mg/kg.

(16) Combinations

According to a further aspect of the present invention there is provided the use or method according to any aspect of the present invention wherein the medicament, nucleic acid or fusion protein of the invention is administered separately, sequentially or simultaneously in combination with one or more further pharmacologically active compounds or agents, preferably compounds or agents useful for treating viral infection. Preferably the additional agent(s) is/are selected from one or more of: anti- polymerases, anti-proteases, ribavirin, NS5 inhibitors. (17) Kit

According to a further aspect of the present invention there is provided a kit comprising:

(a) a pharmaceutical composition as defined above; and

(b) instructions for the administration of an effective amount of said pharmaceutical composition to an individual for the prevention and/or treatment of viral infection and/or symptoms of viral infection or for ameliorating, controlling, reducing incidence of, or delaying the development or progression of viral infection and/or symptoms of viral infection. The kit may include one or more containers containing an fusion protein described herein and instructions for use in accordance with any of the methods and uses of the invention. The kit may further comprise a description of selecting an individual suitable for treatment based on identifying whether that individual has a viral infection or is at risk of having a viral infection. The instructions for the peripheral administration of the pharmaceutical composition may include information as to dosage, dosing schedule and routes of administration for the intended treatment.

(18) Nucleic acid sequences

According to a further aspect of the present invention there is provided a nucleic acid molecule of the invention encoding a fusion protein according to the invention. According to a preferred embodiment of the present invention the nucleic acid may further comprise a region encoding a signal sequence for example DNA or RNA sequences. Preferably nucleic acid may further comprise a region encoding a signal sequence selected from SEQ ID NO. 18, 19 and 20. According to a further aspect of the present invention there is provided a method of expressing the nucleic acid of the invention to produce or secrete the fusion protein of the invention.

According to a further aspect of the present invention there is provided a replicable expression vector for transfecting a mammalian cell for the expression of the fusion protein of the invention, the vector comprising the nucleic acid of the invention, preferably the vector is a viral vector. According to a further aspect of the present invention there is provided a cell harboring the nucleic acid or vector of the invention, preferably the cell is a mammalian cell.

Preferred features of each aspect of the invention apply equally to each other aspect mutatis mutandis.

Accordingly, it is the object of the present invention to provide a fusion protein which would be useful to increase the potency and effective serum half-life in patients being treated with interferon-alpha while at the same time minimizing side effects such as cytotoxicity.

Given the high dosage, low efficacy, short serum half-life, difficulties in purification, and side effects of interferon-alpha, there is a need in the art for methods of enhancing the production and improving the pharmacological properties of this therapeutic agent.

The invention will now be described by reference to the following examples which are provided to illustrate, but not to limit, the invention.

Examples

Cloning human IFNA cDNA and constructing the IFNA-Fc expression vector The clone map for Fc fusion of Interferon alpha8 protein, where the interferon domain is fused to C- terminus of Fc via GGGGSGGGGSGGGSG linker, the Fc portion comprises CH2 and CH3 sequences of lgG2 and a hinge sequence of lgG1 is shown in Figure 1. The gene sequence that codes for IL3 leader- Fc-(GGGGS)3-lfna8 was synthesized and amplified using the primers designed to generate Hind 111 at 5' and EcoRI at 3' ends. The PCR amplified fragment and the pcDNA3.1 (+) vector were digested with Hindi II and ECoRI followed by ligation of vector and the insert. The resulting clone is 6683 bp in size.

Expression and purification of human IFNA cDNA and constructing the IFNA-Fc expression vector HEK293 cells were transfected with the clone using lipofectamine. The transfected cells were grown for five days in wave bioreactors during which the protein was expressed at -30 mg/L as measured on analytical protein A column. All the subsequent purification steps were carried out on AKTA explorer instrument. The culture medium was isolated from cells and passed through a Hitrap protein A column equilibrated with PBS pH 7.2. Following a wash with three column volumes of PBS pH 7.2 and five column volumes of 20mM sodium acetate pH 5.5 buffers, the protein was eluted using ten column volumes of 20mM sodium acetate pH 3.5 buffer. All the fractions containing protein as judged from the absorbance at 280nM were pooled and the pH adjusted to 5.5 using 8%(v/v) of 1 M sodium acetate pH 8.0 solution. The resulting protein was dialyzed into 20mM sodium acetate, 140mM NaCI pH 5.5.

Characterisation of human IFNA cDNA and constructing the IFNA-Fc expression vector Integrity of protein was checked by SDS-PAGE under reducing and non-reducing conditions and size exclusion column (SEC) run using 200 mM sodium phosphate pH 7.4 buffer. SDS-PAGE gel analysis and SEC profile showed that the final product was >95% pure and run as dimer under non-reducing conditions on SDS-PAGE and SEC. Mass spectrum analysis indicated that the protein made has accurate mass when deglycosylated.

Binding affinity assay

Binding of fusion proteins of the invention to the ectodomains of IFNAR1 and IFNAR2 immobilized on solid support was monitored in real time by solid phase detection using Biacore™. Different kinetic and equilibrium assays were applied. The extracellular domains of IFNAR1 and IFNAR2 fused to a C-terminal decahistidine tag and (IFNAR1 -H10 and IFNAR2-H 10, respectively) were immobilized through Ni-NTA interaction. Binding assays were carried out on glass surfaces modified with PEG and tris-NTA chelator groups by reflectance interference detection as published [Lata, S.; Piehler, J., Anal Chem 2005, 77, (4), 1096 -1 105.]. After loading the chelator with Ni(ll) ions, the receptor subunit was immobilized, followed by blocking with 2μΜ MBP-H10. All samples were prepared in 20 mM Hepes pH 7.4 with 150 mM sodium choride (HBS) and measurements were carried out at 25°C. After injection of several IFNs, the surface was regenerated by a pulse of 500 mM imidazole prior to immobilization of fresh IFNAR. Samples of IFNA were always prepared freshly 5 min before the injection in order to minimize loss of sample by adsorption. As a negative control, binding of 100 nM and 1 μΜ of each IFN to surfaces only blocked with 2 μΜ MBP-H10 was measured. Binding assays may also be performed according to the methods described in the following publications: Lata, S.; Piehler, J., Anal Chem 2005, 77, (4), 1096 -1 105; . Kalie, E.; Jaitin, D. A.; Abramovich, R.; Schreiber, G., J Biol Chem 2007, 282, (15), 1 1602-1 1. Table 1. Binding affinity to interferon receptors. IFNR1 = interferon alpha receptor 1 , IFNAR2 = interferon alpha receptor 2. ka = association rate constants, kd = dissociation rate constants, KD = equilibrium dissociation constant. * = Mutation in IFNA8 molecule K71 R (K71 change to R71 )

HCV replicon assay

The HCV replicon system is to determine the antiviral potency of the fusion protein of the invention against HCV replicon 1 b, 1 a and 2a. The HCV replicon system is a surrogate for HCV infection and uses a human hepatoma cell line, Huh7, that contains a functional subgenomic HCV replicon that can autonomously replicate. Different replicons can be constructed, harbouring sequences from genotype 1 b, 1 a or 2a. The replicon also contains a Firefly or Renilla Luciferase reporter gene which allows the determination of replicon levels by measuring the luciferase luminescence signal which in turn is directly proportional to the level of HCV RNA present in the host cells. Compounds that inhibit the replicon replication will show a reduced luminescence signal.

Huh7 cells stably transfected with a sub genomic self replicating HCV RNA, HCV replicon, (reagents from R. Bartenschlager, University of Mainz, Germany) were cultured in a T225 flask (Corning, cat 3001 ) and split periodically before reaching 50 - 80% confluence. For the assay a sub-confluent T225 flask was washed with 10 mL Dulbecco's phosphate buffered saline (DPBS, Gibco, cat14190) followed by a wash with 5 mL Trypsin/EDTA (Gibco, cat 25200), and incubated for 3 - 5 minutes at 37°C, 5% C0₂. The cells were re-suspended in 10 mL media; one milliliter of the suspension was used for cell and viability count using a Cedex Counter (Innovatis, Germany), and the remaining volume centrifuged at 1500 rpm (445xg), 5 minutes at room temperature. The pellet was re-suspended to a cell concentration 1.1 x 105 cell/mL in cell culture media. Replicon assays using genotype 1 a and 2a sequences were performed as described, except that the two Huh7 cell lines harbor an HCV replicon with sequences from genotype 1 a and 2a and a Renilla Luciferase reporter gene, (Promega, cat E2810). All compounds were diluted in DPBS containing 2% heat inactivated fetal bovine serum (PAA cat A15- 151 ) to an initial concentration of 100 ng/mL from which a nine point serial dilution, typically 1 :5, was performed in a 96 well plate (Perkin Elmer, UK part no. 6005680). Ten microliters of the diluted compounds were transferred to the assay plate and 90 μί of the replicon cell suspension containing 1.1 x 105 cell/mL were added. Pegylated interferon A2a (Pegasys, Roche) and Interferon A2a (Roferon-A, Roche) were used as controls.

The plates were centrifuged at 700 rpm for 5 minutes and incubated at 37°C and 5% C0₂ for 48 hours. The firefly luciferase levels were determined by adding 100 μΙ Bright-Glo Luciferase Assay System (Promega, cat E2620) per well and the luminescence signal measured using an Analyst plate reader (Molecular Devices, Canada). The results were expressed in relative luminescent units (RLU). The percentage of inhibition was calculated as described in the data analysis section, using 1000 lU/well of Roferon-A as a positive control and DPBS containing 2% FBS as a negative control.

Replicon cytotoxicity assay

The cytotoxicity assay is based on the reduction of WST-1 substrate (Roche, cat. 1 1 644 807 001 ) by Huh7 cells (from R. Bartenschlager, University of Mainz, Germany). WST-1 measures the metabolic activity of the cells: viable cells produce a soluble formazan salt that can be detected by absorbance at 450 nm.

Assay plates, 96 well black clear bottom (Corning cat 3603) were prepared as described above, with starting concentrations of 600 ng'mL (10 nM) for Pegasys and 400 ng/mL (8.7 nM) for F1 . Following 48 hours incubation the media was removed and replaced with a media containing WST-1 (1 :5 dilution in media, 100 L/well). The plates were incubated for 1 hour and the absorbance at 450 nm was determined using an EnVision reader (Perkin Elmer, UK). The percentage of inhibition was calculated using 40μΜ cyclohexamide solution as a positive control and DPBS containing 2% FBS as a negative control.

Table 2a. Antiviral activity against HCV replicon 1 b. EC₅₀ = Geometric mean. Fold change Pegasys is calculated in molar basis. N = Number of independent experiments. 95%CI = 95% confidence interval of the EC₅₀ Geometric Mean (pM). Peg = Pegylation. Fc = Fragment crystallisable region of an anti-lgG2 antibody. MW = molecular weight. * = Mutation in IFNA8 molecule K71 R (K71 change to R71 ).

Compound Fusion IFN type MW (Da) EC₅₀ (pM) ¹ N Fold change

N to C (95% CI) Pegasys² direction

Pegasys Peg A2a 60 000 0.59 8 1.00

(0.35-1.07) Compound Fusion IFN type MW (Da) EC₅₀ (pM)¹ N Fold change

N to C (95% CI) Pegasys² direction

Roferon None A2a 19 241 0.095 9 6.21

(0.06-0.15)

Albuferon HEK Albumin A2b 85 700 6.12 14 0.10

(4.804- 7.798)

IFNA8 None A8 19 500 0.05 5 13.40

(0.038- 0.068)

F8 Fc A8 89544 0.09 7 6.78

IFNA8-FC

F3 Fc A8 89544 3.38 7 0.17

FC-IFNA8 (2.29-4.98)

F5 Fc A8 93634 0.35 7 1.67

Fc-TM- (0.029-4.28)

IFNA8

F4 Fc A8 93604 0.07 7 8.43

(Fc-mTM- (0.053- IFNA8) 0.093)

F1 Fc A8 91690 0.05 17 12.04

Fc-GS- (0.03-0.08)

IFNA8*

F2 Fc A8 93082 0.03 7 21.85

Fc- (0.02-0.06)

loopAB- IFNA8

F7 Fc A8 92906 0.015 6 39.33

Fc-EK- (0.010- IFNA8* 0.022)

F6 Fc A8 93026 0.035 3 16.86

Fc-GS- (0.017- IFNA8 0.070)

Table 2b. Comparison of IFNA2 and IFNA8 fusion proteins for antiviral activity against HCV replicon 1 b. EC₅₀ = Geometric mean. Fold change Pegasys is calculated in molar basis. N = Number of independent experiments. 95%CI = 95% confidence interval of the EC₅₀ Geometric Mean (pM). Peg = Pegylation. Fc = Fragment crystallisable region of an anti-lgG2 antibody. MW = molecular weight. * = Mutation in IFNA8 molecule K71 R (K71 change to R71 ). Compound Fusion IFN type EC₅₀ (pM)¹ N Fold change

N to C (95% CI) Pegasys²

direction

Pegasys Peg A2a 8.08 6 1.00

Roferon None A2a 0.16 6 49

F1 Fc A8 0.38 7 44

Fc-GS- IFNA8*

F5 Fc A8 0.25 7 33

Fc-TM- IFNA8*

F9 Fc A2 2.75 6 3

Fc-GS- IFNA2

EMCV activity assay

The general antiviral activity was also determined using the EMCV assay where Huh7 cells were challenged with Encephalomyocarditis virus (EMCV). The antiviral potency, expressed as EC₅₀, was calculated by comparing the percentage of protection to cell death of compound treated cells to those of untreated cells. As interferon is also known to inhibit proliferation the antiproliferative activity of those molecules was determined using the Daudi Burkitt's lymphoma cell line, a cell line highly sensitive to interferon. The EMCV, assay was performed as follows: fusion proteins of the invention and controls were diluted in DPBS containing 2% FBS to an initial concentration of 100 ng/mL, and Pegasys and Roferon-A were diluted to a 800 ng/mL solution. For all compounds, an eight point serial dilution, typically 1 :5, was performed in a 96 well plate. Ten microliters of the diluted compounds were transferred to a mixing plate where 90 μί of cell media was added (Note: the media used for the EMCV assay contains 2% FBS instead of 10%).

In the assay plate, 100 μί of a Huh7 cell suspension containing 6 x 105 cells/mL were seeded, and after 3 - 4 hours incubation at 37 °C, 5% C0₂, the media was removed and 100μί of the interferon solutions were added. After incubation for 24 hours, the cells were challenged with 280 plaque-forming units (pfu) of EMCV (ATCC cat VR-129B). To achieve the desired pfu, the virus stock kept at -80°C was thawed and diluted 1 :32000 in cell culture media.

Viable cells were quantified after incubation for 22-24 hours at 37°C, 5%C0₂ by adding 10Ομί. of CellTitre Glo Luminescent Cell Viability Assay (Promega, cat G7570) per well. The luminescent signal produced is proportional to the number of viable cells present and the relative luminescent units obtained were used to calculate the percentage of protection. The antiviral activity was expressed as EC₅₀. IFN concentration required for 50% protection is represented by the EC50. The relative potency of dose molecules against Pegasys correlates fairly well between the two assays replicon 1 b and EMCV, showing that the assays correlate well in antiviral readout. Table 3. Antiviral activity against Encephalomiocarditis virus (EMCV). EC₅₀ = Geometric mean (pM).

EC₅₀ fold change Pegasys is calculated in molar basis. N - Number of independent experiments. 95%CI: 95% confidence interval of the EC₅₀ Geometric Mean (pM). Peg = Pegylation, Fc = Fragment crystallisable region of an anti-lgG2 antibody. MW = molecular weight. ND = no determined. EMCV assay measures the ability of the interferon molecules to protect human hepatocarcinoma cell line (Huh7) against the cytophatic effect of the encephalomiocarditis virus.

Proliferation inhibition activity assay The antiproliferative activity was assessed using the Daudi Burkitt's cell line, human B lymphoblast cell line (ATCC cat CCL 213). Daudi cells (5000 cells/well) were incubated 4 days in the presence of increasing concentrations of Pegasys, Roferon-A and F1 , the starting concentration in the assay was 10 nM (Pegasys) and 4.3 nM for Roferon-A and the fusion protein of the invention; for all compounds, an eight point serial dilution, typically 1 :5, was performed. Cell viability was determined by adding 10 μί of AlamarBlue (Invitrogen, cat DAL 1 100) per 100 μL of media during the last 24 hours of incubation and the fluorescence signal was determined using the EnVision plate reader (Perkin Elmer, UK) with an excitation wavelength of 530 nm and an emission wavelength of 590 nm. Table 4. Anti proliferation assay which determines the inhibition of proliferation of Daudi human lymphoblastoid B cell line.

EC₅₀ = Geometric mean. Fold change Pegasys is calculated in molar basis. N = Number of independent experiments. 95%CI = 95% confidence interval of the EC₅₀ Geometric Mean (pM). Peg = Pegylation. Fc = Fragment crystallisable region of an anti-lgG2 antibody. MW = molecular weight. * = Mutation in IFNA8 molecule K71 R (K71 change to R71 ).

EC50 determination The percentage of inhibition was calculated from the RLU read out (replicon assay and EMCV), absorbance read out (cytotoxicity assay) or fluorescence read out (proliferation assay) using the following equation:

Inhibition(%) =——— · 100 where

(Pc - Nc)

S: Sample read out. Nc: negative control read-out, average of three values, obtained in the presence of DPBS and 2%FBS; Pc: positive controls read-out, average of three values obtained in the presence of 1000 IU Roferon-A well for replicon assays or 10 000 IU Roferon-A well for the EMCV and

antiproliferation assays. The EC₅₀ values (the concentration of compound that results in a 50% reduction of the signal) were calculated by fitting the percentage of inhibition vs. concentration data to an unconstrained sigmoid (LabStats add-in program , MS Excel. The fold change was calculated as the ratio of the EC₅₀s.

IP-10 and IL-6 cytokine immunoassay

The cytokines Interferon Inducible protein 10 (IP-10)and Interleukin 6 (IL-6) are shown here to be reliable biomarkers of modified interferon pharmacology. IP-10 and IL6 levels are associated with antiviral response in clinical studies. An ex-vivo whole blood stimulation approach was used to characterise the pharmacology of the fusion proteins of the invention in comparison to the pegylated IFNA2 product Pegasys™ and the albumin linked IFNA2 product Albuferon™. Samples of the fusion proteins of the invention were tested in either human or Cynomolgus whole blood for their ability to stimulate IP-10 and IL6 levels.

Treatment of human whole blood: Test compounds / samples [fusion proteins of the invention or comparator compounds for example Pegasys™] were diluted in PBS/2% serum to 20X final assay concentration.10μΙ aliquots were transferred to duplicate wells of a 96 well assay plate. Heparinised blood was collected from healthy donors with informed consent .Whole blood, in aliquots of 190μΙ_, was added to each well containing compound. Assay plates were incubated in a humidified atmosphere at 37°C, 5% C0₂ for 1 hour, 2 hours, 3 hours or 4 hours. After the indicated time, each assay plate was centrifuged at 2000rpm for 5 minutes to separate plasma from the blood cells. The plasma layer was transferred to a clean replica plate and stored at -20°C until use.

Treatment of Cynomolgus whole blood: Whole blood from adult male cynomolgus monkeys was collected into sodium heparin. The blood was subjected to ex-vivo treatment within 4 hrs of harvest. Ex-vivo treatment was carried out as described for human whole blood except incubation times were 2 hours, 3 hours and 4 hours. Detection of IP-10 / IL-6 was carried out using a cytokine immunoassay.

Cytokine immunoassay: Mesoscale Discovery (MSD) singleplex immunoassays were used for plasma cytokine quantification, using reagents provided with the MSD Ultra-Sensitive Kit [MSD Cat # K1 1 1 AVC- 4] including the relevant anti-cytokine capture antibodies. The plasma was thawed to room temperature and diluted 1 :2 with MSD human plasma cytokine assay diluent. 25μΙ of the diluted sample was added per sample well of the immunoassay plate and the assay performed as per manufacturers instructions.

Plates were read on a MSD Sector Imager 6000. The standard curve was fitted using a 5-parameter logistic model including a 1/Y² weighting function. Results are presented in Tables 5a to d.

Table 5a

Summary of IP-10 human whole blood EC₅₀ values after 4 hour treatment. The number of donors used to generate these values is as follows : F1 n= 8, Pegasys™ n=7 , Albuferon™ n=7. For several donors the Albuferon™ curve did not reach an upper asymptote, therefore a "greater than" value is given. [* = Mutation in IFNA8 molecule K71 R (K71 change to R71 )]. The term N or n as used herein means the number of experiments done.

Table 5b

Summary of IP-10 Cyno whole blood EC₅₀ values after 4 hour treatment. The number of animals used to generate these values is as follows: F1 n= 6, Pegasys™ n=5, Albuferon™ n=5. [* = Mutation in IFNA8 molecule K71 R (K71 change to R71 )].

Table 5c

Summary of IL-6 human whole blood EC₅₀ values after 4 hour treatment. The number of animals used to generate these values is as follows: F1 n= 2. Albuferon™ and Pegasys™ curves did not reach an upper asymptote, therefore a "greater than" value is given.

[* = Mutation in IFNA8 molecule K71 R (K71 change to R71 )].

EC₅o pg/ml of compound in Cyno whole blood

(Geometric mean +/- SE)

F1 Pegasys "^Vl Albuferon "^Vl (FC-GS4FNA8*)

240 +/- 160 >30000 >30000

Table 5d

Summary of IL-6 cyno whole blood EC₅₀ values after 4 hour treatment. The number of animals used to generate these values is as follows: F1 n= 5, Pegasys™ n=4, Albuferon™ n=5. [* = Mutation in IFNA8 molecule K71 R (K71 change to R71 )].

In summary, plasma IP-10 levels increase in a dose and time dependant manner in response to F1 , Pegasys™ and Albuferon™. The rank order of potency of the compounds in eliciting an IP-10 response are : F1 > Pegasys™ > Albuferon™. Plasma I L-6 levels increase in a dose and time dependant manner in response to F1 , Pegasys™ and Albuferon™. The amplitude of response is low compared to that of IP- 10, rank order of potency of the compounds in eliciting an IP-10 response are : F1 > Pegasys™ >

Albuferon™. The level of IL-6 response in cynomolgus plasma appears to be higher than that seen in human plasma. However the use of a specific anti-cyno IL-6 antibody would be needed to confirm this.

These IP-10 data demonstrate that the potency of F1 is more than 10fold that of Pegasys™. Data for IL6 obtained from both Human and Cynomolgus monkey would suggest that induction of this proinflammatory cytokine is positively linked to the interferon mechanism; since the EC₅₀ for IL6 release is similar to that of IP-10.

Assay for expression of OAS2 from human ex vivo whole blood treated with fusion protein of the invention

Increase in expression levels of the 2'5'oligoadenylate Synthetase (OAS) is shown here to be reliable biomarker of modified interferon pharmacology and has been positively correlated to a drop in viral load in human HCV clinical studies. An ex-vivo whole blood stimulation approach was used to characterise the pharmacology of the fusion proteins of the invention in comparison to the pegylated IFNA2 product Pegasys™ and the albumin linked IFNA2 product Albuferon™. Samples of the fusion proteins of the invention were tested in either human or Cynomolgus whole blood for their ability to stimulate expression levels of the 2'5'oligoadenylate Synthetase (OAS). Assay method: Human and Cynomolgus whole blood were harvested and treated with fusion protein of the invention or comparator compounds for example Pegasys™ or Albuferon™ as described above [see: "Treatment of human whole blood" and "Treatment of Cynomolgus whole blood']. RNA was extracted from whole blood using the MagMAX -96 well whole blood RNA extraction kit (Ambion #AM1837) using the original manufactures protocol and materials. In summary plasma was removed from the whole blood and the plasma "free" blood was re-suspend and 50 pis from was transfered into a well of a fresh 96-well plate containing 10ul Lysis/Binding Enhancer Solution and re-suspended to homogenised completely. A further 65pl/well of Lysis/Binding Solution (without isopropanol) was added, pipette up & down 10 times so that efficient lysis occurs. The microtitreplate was incubated for 5min at room temperature on a shaker. The plate is then sealed and placed at -80°C until sample are ready for RNA extraction ) using the original manufactures protocol.

Post RNA extraction cDNA synthesis was performed using the High Capacity cDNA Reverse Transcription Kit, (High Capacity cDNA Archive Kit; Cat # 4368813 Applied Biosystems). Subsequently the RNA concentration of each sample was determined. A 2ul sample of each RNA was aliquoted in a sterile 96well Greiner polypropylene plates (Sigma L391 1 -100EA). The samples were processed following the manufacturer protocol for RiboGreen^® RNA Quantification Reagent & Kit (Cat # R-1 1490 - Molecular Probes) and read on the FLUOstar Galaxy (BMG Lab Technologies). The transcripts were profiled by qPCR; 2.5ul of cDNA was used in a 25ul qPCR reaction using the TaqMan Universal Master Mix (Cat # 4304437 Applied Biosystems) and Assay On Demand (Target Specific - Applied Biosystems) reagents. Different species specific primers were used for the Human and Cynomologus qPCR studies. Human samples OAS2, Hs00159719_m 1 (FAM) with Human ACTB (beta-Actin) Endogenous Control (VIC/MGB Probe, Non-Primer Limited) (Cat # 4352935E Applied Biosystems) were used. Cynomologus samples OAS2 HS00942650_m1 with 18S RNA endogenous control for eukaryotes, VIC ref 4319413E were used and importantly the cDNA was diluted 1/20 for all samples. The resulting experimental data was analysed using standard methodology. The delta Ct for OAS is calculated by subtracting the OAS2 Ct value from the HKG Ct value. The delta delta Ct for OAS is calculated by subtracting the delta Ct of OAS from the treated group from the delta Ct of OAS from the non-treated control group. Finally fold change (RQ) is calculated by multiplying 2 to the power of minus delta delta Ct of OAS (2^A-delta delta Ct). A dose response graph, for each compound, donor and time point was produced with error bars representing the duplicates values using "labstats" in Excel.

Seven independent experiments have been performed that includes 5 different donors (ID1 141 , ID1 107, ID1 135, ID1250, ID1203) with 2 donors repeated twice over the course of this study (ID1 107 and ID1 135). The results are summarised in Table 6

Table 6

A summary of the human and cyno whole blood EC₅₀ values for production of OAS transcript taken at the time of maximal response, data from 9 independent experiments was used to generate these values. The number of donors used to generate these values is as follows : F1 n=9, Pegasys™ n=5 , Albuferon™ n=5. For most cases the curves rarely reached a plateau, so the EC₅₀ are estimates.

EC₅₀ Geometric mean (pg/ml) of compound ± SEM in whole blood

Albuferon F1 Pegasys

(FC-GS-IFNA8*)

Human whole blood 16300 ± 4800 640 ± 250 4300 ± 1200

Cyno whole blood 32600 ± 24100 630 ± 300 18600 ± 13700

In summary the expression of OAS2 transcript increased in a dose and time dependant manner in response to F1 , Pegasys™ and Albuferon™. The rank order of potency of the compounds in eliciting an OAS2 response are : F1 > Pegasys™ > Albuferon™.

These OAS data demonstrate that the potency of F1 is more than 10fold that of Pegasys™.

Assay for expression of CD69 from human ex vivo whole blood treated with fusion protein of the invention

Increase in expression levels of the CD69 expression is shown here to be reliable biomarker of modified interferon pharmacology and has been positively correlated to a biomarker of lymphocyte activation. An ex-vivo flow cytometry assay is used to detect CD69 expression in response to the fusion proteins of the invention in comparison to the pegylated IFNA2 product Pegasys™ and the albumin linked IFNA2 product Albuferon™

Human blood assay method: Whole human blood was collected from donors into vacutainers containing sodium heparin anti-coagulant. Serial half log dilutions of each compound (fusion proteins of the invention, pegylated IFNA2 product Pegasys™ and the albumin linked IFNA2 product Albuferon™) were prepared in PBS in a 96 well plate at 20 x the desired final concentration. 5μΙ of each concentration was transferred to the appropriate well of a round bottom, 96 shallow well plate. Un-treated control wells received 5μΙ of PBS only. 95μΙ of whole blood was then added to the 5μΙ of interferon solution and the plate mixed by gentle vortexing. A sterile, breathable adhesive plate seal was then placed over the plate before replacing the lid, to prevent evaporation and potential plate effects. The samples were incubated for 24 hours at 37°C in a humidified 5% C0₂ incubator. Following incubation all samples were transferred to a deep well plate (non-sterile) and 75μΙ of Optilyse B was added to each sample and mixed thoroughly by repeat pipetting. Sufficient mixing is vital to ensure full lysis of erythrocytes. Samples were incubated at room temperature for 10 minutes. 1 ml of distilled water was then added and thoroughly mixed before incubating for at least 10 minutes at room temperature - conversion of blood sample from opaque to transparent indicates successful lysis. The deep well plate was then spun in a centrifuge at 400g for 5 minutes to pellet the cells and the resulting supernatant was discarded to Virkon waste. Immediately prior to use a 1/3.3 dilution of anti CD69-PE antibody was prepared in PBS/ 2% BSA and 50μΙ of this added to each well. The cells were incubated with antibody for 30 minutes at room temperature in the dark. Each well was then washed with 1 ml PBS and spun at 400g for 5 minutes before discarding the supernatant to Virkon waste. The remaining cells were resuspended in 200μΙ of PBS and analysed on the Becton Dickinson FACS Array. Lymphocytes were gated on FSC/SSC properties - 5000 events within the lymphocyte gate were recorded. Quadrant gates were set on the PBS only controls and the percentage of CD69+ cells recorded. Data was analysed in FlowJo (Tree Star inc.) and data exported to Microsoft Excel for further analysis with the LabStats add-on. The EC₅₀s and maximum percentage CD69 positive cells are shown below for each of the molecules investigated is shown in Table 7:

Table 7

Table showing Iog10 EC₅₀ values and maximum percentage lymphocytes that were deemed to be CD69+ for the interferon molecules tested F1 (Fc-GS-IFNA8*) and Pegasys™ is included on each plot as a comparator.

In summary data generated from the flow cytometry CD69 assay has demonstrated that F1 is more than 100 fold more potent than Pegasys™.

Assay of fusion protein half life

Fusion proteins of the invention were prepared for both intra-venous infusion and for two site subcutaneous administration to rats. Plasma samples from the administered rats were taken at time points of 0, .1 , 1 , 2, 4, 8, 24, 48, 72 hours, likewise urine samples were also taken over a 0 to 24 hour period. Samples were assayed for levels of the fusion protein using an ELISA based assay comprising a mouse anti human IFNA antibody secured to a solid phase and capable of binding the IFNA fusion protein of the invention. Bound fusion protein was detected using a guinea pig anti human Fc antibody conjugated to a tag comprising a ruthenium emitter, readout of light emission from the conjugated ruthenium tag measured by spectrophotometer is proportional to the amount of fusion protein detected in the sample from this a precise concentration was determined when compared to a predetermined standard curve. Data summarising the half life determinations for the IFNA fusion proteins investigated is shown in Table 8:

Table 8

Rat serum half life comparisons for IFNA fusion protein and recombinant IFNA.

Compound Structure Company T ¹/₂ (hrs) in Rat IntronA¹™ Recombinant Schering 4

IFNA2b Plough, NJ

Pegasys ¹™ Pegylated Hoffman- La- 15

IFNA2a Roche, NJ

Peglntron ¹™ Pegylated Schering 17-25

IFNA2b Plough, NJ

F1 FC-GS-IFNA8 27.1 - 27.3

F2 FC-TM-IFNA8 20.1 - 24.3

In summary the Fc-IFNA fusion proteins of the present invention provide a higher plasma stability than the comparator pegylated and recombinant IFNA compounds, based on this data the projected in human half life is of the order of several days.

Solubility and aggregation analysis:

Comparision of fusion protein solubility can be carried out using a variety of methods including size- exclusion chromatography, analytical ultracentrifugation, dynamic light scattering, SDS-Page, UV spectroscopy and visual inspection of opalescence.

Samples of fusion proteins of the invention were prepared at a concentration of 5 mg/ml in a sample buffer of 20 mM acetate buffer pH5.5. The samples were stored at a temperature of 5, 25 and 40°C for 0, 1 , 2 and 5 weeks.

Each sample was analyzed for aggregation using size exclusion chromatography (SEC). The size exclusion chromatography was carried out using a TSK gel G3000SWXL- G2000SWXL column, mobile phase was sample buffer with a flow rate of 1 ml/min, and UV detection at 214 nm.

Aggregation levels were calculated by integrating the areas under the chromatogram peaks for each sample and reporting the integrated areas under the high molecular weight species peaks as a percentage of total peak area. Aggregation of fusion proteins F1 [Nterminal - lgG2 Fc - GS linker - IFNA8 - Cterminal] and F2 [Nterminal - lgG2 Fc - AB loop linker - IFNA8 - Cterminal] and Albuferon™. Under these conditions F2 [Nterminal - lgG2 Fc - AB loop linker - IFNA8 - Cterminal] presented less aggregates than Albuferon™ and F1 [Nterminal - lgG2 Fc - GS linker - IFNA8 - Cterminal].

Table 9

Notation used for IFNA fusion proteins in this application.

Expr

Structure Mol.wt

Molecule Linker sequence Level

N to C terminal (Da)

(mg/L)

F1 Fc-GS-lfna8 GGGGSGGGGSGGGSG 91690 40

F2 Fc-loopAB- QEEFDDKQFQKAQ 93082 95 lfna8(K71 R)

F3 Fc-lfna8 No linker 89544 18

F4 Fc-mTM-IFNa8 ELQLEESSAEAQDGELDG* 93604 10

(memb bound lgG 1 )

GenBank: BAA1 1363.1

F5 Fc-TM-ifna8 ELQLEESCAEAQDGELDG* 93634 65

F6 Fc-loopAB-ifna8 QEEFDDKQFQKAQ 93026 50

F7 Fc-EK-lfna8 AEAAAKEAAAKEAAAKA 92906 105

(ref)

F8 Ifna8-Fc No linker 89544 20

F9 FC-GS-IFNA2 GGGGSGGGGSGGGSG 91698 Not determin ed

Sequence Listings

Human lgG2 Fc - SEQ ID NO. 1

APPVAGPSVFLFPPKPKDTLMISRTPEVTCVWDVSHEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTF RWSVLTVVHQDWLNGKEYKCKVSNKGLPSSIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVK GFYPSDIAVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQ KSLSLSPGK Human lgG4 Fc - SEQ ID NO. 2

APEFLGGPSV FLFPPKPKDT LMISRTPEVT CWVDVSQED PEVQFNWYVD GVEVHNAKTK PREEQFNSTY RWSVLTVLH QDWLNGKEYKKVSNKGLPS SIEKTISKAK GQPREPQVYT LPPSQEEMTK NQVSLTCLVK GFYPSDIAVE WESNGQPENN YKTTPPVLDS DGSFFLYSRL TVDKSRWQEG NVFSCSVMHE ALHNHYTQKS LSLSLGK

Human lgG1 full hinge sequence - SEQ ID NO. 3

EPKSCDKTHTCPPCPA

Human lgG1 hinge fragment - SEQ ID NO. 4

DKTHTCPPCP

Human lgG2 full hinge sequence - SEQ ID NO. 5

ERKCCVECPPCPAP Human lgG2 hinge fragment - SEQ ID NO. 6

ERKCCVECPPCP

GS Linker A SEQ ID NO: 7 - 15AA

GGGGSGGGGSGGGSG

GS Linker B SEQ ID NO: 8 - 15AA

GGSGGSGGGSGGGGS

TM Linker SEQ ID NO: 9 - 18AA

ELQLEESSAEAQDGELDG

Loop AB from IFNA8 linker SEQ ID NO: 10 - 13AA

QEEFDDKQFQKAQ EK Linker SEQ ID NO: 11 - 17 AA

AEAAAKEAAAKEAAAKA Human I FN A 2a SEQ ID NO. 12

CDLPQTH SLGSRRTLML LAQMRKISLF SCLKDRHDFG FPQEEFGNQF QKAETIPVLH EMIQQIFNLF STKDSSAAWD ETLLDKFYTE LYQQLNDLEA CVIQGVGVTE TPLMKEDSIL AVRKYFQRIT LYLKEKKYSP CAWEWRAEI MRSFSLSTNL QESLRSKE

Human IFNA2b SEQ ID NO. 13

CDLPQTH SLGSRRTLML LAQMRRISLF SCLKDRHDFG FPQEEFGNQF QKAETIPVLH EMIQQIFNLF STKDSSAAWD ETLLDKFYTE LYQQLNDLEA CVIQGVGVTE TPLMKEDSIL AVRKYFQRIT LYLKEKKYSP CAWEWRAEI MRSFSLSTNL QESLRSKE

Human IFNA2c SEQ ID NO. 14

CDLPQTH SLGSRRTLML LAQMRKISLF SCLKDRRDFG FPQEEFGNQF QKAETIPVLH EMIQQIFNLF STKDSSAAWD ETLLDKFYTE LYQQLNDLEA CVIQGVGVTE TPLMKEDSIL AVRKYFQRIT LYLKEKKYSP CAWEWRAEI MRSFSLSTNL QESLRSKE

Human IFNA8a SEQ ID NO. 15

CDLPQTHSLGNRRALILLAQMRRISPFSCLKDRHDFEFPQEEFDDKQFQKAQAISVLHEMIQQTFNLFSTK

DSSAALDETLLDEFYIELDQQLNDLESCVMQEVGVIESPLMYEDSILAVRKYFQRITLYLTEKKYSSCAWE

WRAEIMRSFSLSINLQKRLKSKE

Human IFNA8b SEQ ID NO. 16

CDLPQTHSLGNRRALILLAQMRRISPFSCLKDRHDFEFPQEEFDDKQFQKAQAISVLHEMIQQTFNLFSTK DSSAALDETLLDEFYIELDQQLNDLESCVDQEVGVIESPLMYEDSILAVRKYFQRITLYLTEKKYSSCAWEV VRAEIMRSFSLSINLQKRLKSKE

Human IFNA8c SEQ ID NO. 17

CDLPQTHSLGNRRALILLAQMRRISPFSCLKDRHDFEFPQEEFDDKQFQKAQAISVLHEMIQQTFNLFSTK

DSSAALDETLLDEFYIELDQQLNDLESCVMQEVGVIESPLMYEDSILAVRKYFQRITLYLTEKKYSSCAWE

WRAEIMRSFSLSINLQKD

IL-3 Signal Peptide SEQ ID NO. 18

MSRLPVLLLL QLLVRPGLQA

IFN8 Signal Peptide SEQ ID NO. 19

MALTFYLLVALWLSYKSFSSLG

IFN2 Signal Peptide SEQ ID NO. 20

MALTFALLVALLVLSCKSSCSVG

F1 Protein Sequence SEQ ID NO. 21

DKTHTCPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVWDVSHEDPEVQFNWYVDGVEVHNAKTK PREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPSSIEKTISKTKGQPREPQVYTLPPSREEMT KNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSV MHEALHNHYJQKSLSLSPGKGGGGSGGGGSGGGSGCDLPQTHSLGNRRALILLAQMRRISPFSCLKDR HDFEFPQEEFDDKQFQKAQAISVLHEMIQQTFNLFSTKDSSAALDETLLDEFYIELDQQLNDLESCVMQE VG VIESPLMYEDSILA VRKYFQRITL YL TEKKYSSCA WEVVRAEIMRSFSLSINLQKRLKSKE lgG1 hinge - Uppercase underlined

GS linker - Uppercase bold

IFNA8: Uppercase italic

lgG2 Fc: Uppercase

K71 : Uppercase, bold, italic, underlined.

F1 DNA Sequence SEQ ID NO. 22

GACAAAACTCACACATGCCCACCGTGCCCAGCACCACCTGTGGCAGGACCGTCAGTCTTCCTCTTC CCCCCAAAACCCAAGGACACCCTCATGATCTCCCGGACCCCTGAGGTCACGTGCGTGGTGGTGGAC GTGAGCCACGAAGACCCCGAGGTCCAGTTCAACTGGTACGTGGACGGCGTGGAGGTGCATAATGC CAAGACAAAGCCACGGGAGGAGCAGTTCAACAGCACGTTCCGTGTGGTCAGCGTCCTCACCGTCGT GCACCAGGACTGGCTGAACGGCAAGGAGTACAAGTGCAAGGTCTCCAACAAAGGCCTCCCATCCAG CATCGAGAAAACCATCTCCAAAACCAAAGGGCAGCCCCGAGAACCACAGGTGTACACCCTGCCCCC ATCCCGGGAGGAGATGACCAAGAACCAGGTCAGCCTGACCTGCCTGGTCAAAGGCTTCTACCCCAG CGACATCGCCGTGGAGTGGGAGAGCAATGGGCAGCCGGAGAACAACTACAAGACCACACCTCCCA TGCTGGACTCCGACGGCTCCTTCTTCCTCTACAGCAAGCTCACCGTGGACAAGAGCAGGTGGCAGC AG GG G AACG TCTTCTC ATG CTCCG TG ATG C ATG AG G CTCTG CACAACC ACTAC AC AC AG AAG AG CC TCTCCCTGTCTCCGGGTAAAGGAGGCGGAGGGTCTGGCGGAGGCGGATCAGGCGGAGGGTCTGG ATGTGATCTGCCTCAGACTCACAGCCTGGGTAACAGGAGGGCCTTGATACTCCTGGCACAAATGCG AA GAA TCTCTCCTTTCTCCTGCCTGAA GGA CA GACA TGACTTTGA G TTCCCCCAGGA GGAG TTTGA T GATAAACAGTTCCAGAAGGCTCAAGCCATCTCTGTCCTCCATGAGATGATCCAGCAGACCTTCAACC TCTTCAGCACAAAGGACTCATCTGCTGCTTTGGA TGAGACCCTTCTAGATGAGTTCTACATCGAACTT GACCAGCAGCTGAA TGACCTGGAGTCCTGTGTGA TGCAGGAAGTGGGGGTGATAGAGTCTCCCCTG ATGTACGAGGACTCCATCCTGGCTGTGAGGAAATACTTCCAAAGAATCACTCTATATCTGACAGAGA AGAAATACAGCTCTTGTGCCTGGGAGGTTGTCAGAGCAGAAATCA TGAGATCCTTCTCTTTATCAATC AACTTGCAAAAAAGATTGAAGAGTAAGGAA lgG1 hinge - Uppercase underlined

GS linker - Uppercase bold

IFNA8: Uppercase italic

lgG2 Fc: Uppercase

F2 Protein Sequence SEQ ID NO. 23

DKTHTCPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVWDVSHEDPEVQFNWYVDGVEVHNAKTK PREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPSSIEKTISKTKGQPREPQVYTLPPSREEMT KNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSV MHEALHNHYJQKSLSLSPGKQEEFDDKQFQKAQCDLPQTHSLGNRRALILLAQMRRISPFSCLKDRHDF EFPQEEFDDKQFQKAQAISVLHEMIQQTFNLFSTRDSSAALDETLLDEFYIELDQQLNDLESCVMQEVGVI ESPLMYEDSILA VRKYFQRITL YL TEKKYSSCA WEVVRAEIMRSFSLSINLQKRLKSKE lgG1 hinge - Uppercase underlined

GS linker - Uppercase bold

IFNA8: Uppercase italic

lgG2 Fc: Uppercase

K71 R mutation: Uppercase, bold, italic, underlined.

F2 DNA Sequence SEQ ID NO. 24

GACAAAACTCACACATGCCCACCGTGCCCAGCACCACCTGTGGCAGGACCGTCAGTCTTCCTCTTC

CCCCCAAAACCCAAGGACACCCTCATGATCTCCCGGACCCCTGAGGTCACGTGCGTGGTGGTGGAC

GTGAGCCACGAAGACCCCGAGGTCCAGTTCAACTGGTACGTGGACGGCGTGGAGGTGCATAATGC CAAGACAAAGCCACGGGAGGAGCAGTTCAACAGCACGTTCCGTGTGGTCAGCGTCCTCACCGTCGT GCACCAGGACTGGCTGAACGGCAAGGAGTACAAGTGCAAGGTCTCCAACAAAGGCCTCCCATCCAG CATCGAGAAAACCATCTCCAAAACCAAAGGGCAGCCCCGAGAACCACAGGTGTACACCCTGCCCCC ATCCCGGGAGGAGATGACCAAGAACCAGGTCAGCCTGACCTGCCTGGTCAAAGGCTTCTACCCCAG CGACATCGCCGTGGAGTGGGAGAGCAATGGGCAGCCGGAGAACAACTACAAGACCACACCTCCCA TGCTGGACTCCGACGGCTCCTTCTTCCTCTACAGCAAGCTCACCGTGGACAAGAGCAGGTGGCAGC AGGGGAACGTCTTCTCATGCTCCGTGATGCATGAGGCTCTGCACAACCACTACACACAGAAGAGCC TCTCCCTGTCTCCGGGTAAACAGGAAGAATTTGATGATAAACAGTTTCAGAAAGCGCAG 7G7G/A7C TGCCTCAGACTCACAGCCTGGGTAACAGGAGGGCCTTGATACTCCTGGCACAAATGCGAAGAATCT CTCCTTTCTCCTGCCTGAAGGACAGACATGACTTTGAGTTCCCCCAGGAGGAGTTTGATGATAAACA GTTCCAGAAGGCTCAAGCCATCTCTGTCCTCCATGAGATGATCCAGCAGACCTTCAACCTCTTCAGC ACACGCGACTCATCTGCTGCTTTGGATGAGACCCTTCTAGATGAGTTCTACATCGAACTTGACCAGC AGCTGAATGACCTGGAGTCCTGTGTGATGCAGGAAGTGGGGGTGATAGAGTCTCCCCTGATGTACG AGGACTCCATCCTGGCTGTGAGGAAATACTTCCAAAGAATCACTCTATATCTGACAGAGAAGAAATA CAGCTC TTG TGCCTGGGAGG TTG TCA GAGCAGAAA TCA TGA GA TCC TTC TC TTTA TCAA TCAA C TTG C AAAAAAGATTGAAGAGTAAGGAA lgG1 hinge - Uppercase underlined

GS linker - Uppercase bold

IFNA8: Uppercase italic

lgG2 Fc: Uppercase

Claims

1. A fusion protein comprising in an amino terminal to carboxy terminal direction,

(a) an immunoglobulin Fc region,

(b) an interferon-alpha region.

2. A fusion protein according to claim 1 wherein the immunoglobulin Fc region is linked to the interferon- alpha region by means of a linker region.

3. A fusion protein according to either of claims 1 or 2, wherein the immunoglobulin Fc region comprises an IgG Fc sequence or portion thereof.

4. A fusion protein according to claim 3, wherein the IgG Fc or portion thereof is a human IgG Fc sequence or portion thereof.

5. A fusion protein according to any of claims 1 to 4, wherein the immunoglobulin Fc region comprises,

(a) a CH2 domain or portion thereof and a CH3 domain or portion thereof,

(b) a CH2 domain or portion thereof, or

(c) a CH3 domain or portion thereof.

6. A fusion protein according to any of claims 1 to 4, wherein the immunoglobulin Fc region, is derived from either lgG2 or lgG4.

7. A fusion protein according to claim 6 in which the Fc region possesses mutations which reduce Fc effector function.

8. A fusion protein according to any of claims 1 to 7, wherein the immunoglobulin Fc region further comprises an immunoglobulin hinge region or a part of an immunoglobulin hinge region.

9. A fusion protein according to claim 6 wherein the immunoglobulin hinge region or part of the immunoglobulin hinge region comprises an IgG hinge region sequence or part thereof.

10. A fusion protein according to claim 9 wherein the IgG hinge region sequence or part thereof is a human IgG hinge region sequence or part thereof.

1 1. A fusion protein according to either of claims 9 or 10, wherein the immunoglobulin hinge region or part of the immunoglobulin hinge region is derived from lgG1.

12. A fusion protein according to any of claims 1 to 1 1 , wherein the immunoglobulin Fc region comprises an amino acid sequence set forth in SEQ. ID 1 or 2.

13. A fusion protein according to any one of claims 1 to 12, wherein the interferon-alpha region comprises an interferon selected from the group; interferon alpha 8a, interferon alpha 8b, interferon alpha 8c, interferon alpha 2a, interferon alpha 2b or interferon alpha 2c. 14. The fusion protein according to claim 13 wherein the interferon-alpha comprises an amino acid sequence set forth in any one of sequences SEQ. ID. NO. 12, 13,

14, 15, 16, 17 or a species or allelic variant thereof.

15. A fusion protein according to any one of claims 1 to 14, wherein the linker region comprises a polypeptide linker.

16. A fusion protein according to claim 12 wherein the polypeptide linker is selected from;

(a) a GS linker,

(b) an EK linker ,

(c)an TM linker ,

(d) a portion of an interferon molecule.

17. A fusion protein according to claim 16 wherein the portion of an interferon molecule comprises the loop AB of interferon alpha 8.

18. A fusion protein according to claim 17 wherein the portion of an interferon molecule comprises the sequence QEEFDDKQFQKAQ (SEQ ID NO. 10) or a part thereof

19. A fusion protein according to claim 16 wherein the polypeptide linker comprises a sequence selected from;

(a) GGGGSGGGGSGGGSG (SEQ ID NO. 7)

(b) GGSGGSGGGSGGGGS (SEQ ID NO. 8)

(c) ELQLEESSAEAQDGELDG (SEQ ID NO. 9)

(d) QEEFDDKQFQKAQ (SEQ ID NO. 10)

(e) AEAAAKEAAAKEAAAKA (SEQ ID NO. 1 1 )

(f) GGGGSGGGGSGGGGS

20. A fusion protein according to claim 1 or 2 comprising SEQ ID NO. 21.

21. A fusion protein according to claim 1 or 2 comprising SEQ ID NO. 23.

22. A fusion protein which is multimeric protein comprising at least two fusion proteins according to any one of claims 1 to 21 wherein the at least two fusion proteins are linked to each other by non covalent or covalent interactions.

23. The fusion protein of claim 22 which is a dimer consisting of two fusion proteins according to to any one of claims 1 to 21 wherein the two fusion proteins are linked to each other by non covalent or covalent interactions

24. The fusion protein of either of claims 22 or 23 wherein the fusion proteins are linked to each other by one or more disulfide bonds.

25. A nucleic acid molecule encoding a fusion protein according to any one of claims 1 to 24.

26. A nucleic acid molecule encoding a fusion protein according to any one of claims 1 to 24 additionally encoding a signal sequence.

27. A replicable expression vector for transfecting a mammalian cell, the vector comprising the nucleic acid of claim 25 or 26

28. The replicable expression vector of claim 27 wherein the vector is a viral vector.

29. A host cell harboring the nucleic acid of claim 25 or 26.

30. The fusion protein according to any one of claims 1 to 24 for use in the treatment of a condition alleviated by the administration of interferon- alpha.

31. The nucleic acid according claim 25 or 26 or the vector according to claim 27 or 28 for use in the treatment of a condition alleviated by the administration of interferon- alpha.

32. The fusion protein for use according to claim 30 or the nucleic acid or vector for use according to claim 31 wherein the condition is a liver disorder.

33. The fusion protein, the nucleic acid or the vector for use according to claim 32 wherein the liver disorder is hepatitis, optionally hepatitis C. 34 A fusion protein comprising,

(a) an immunoglobulin Fc region,

(b) an interferon-alpha region,

wherein the immunoglobulin Fc region is linked to the interferon-alpha region by means of an intervening linker region comprising a portion of an interferon alpha molecule sequence.