WO2012121958A2

WO2012121958A2 - Combination

Info

Publication number: WO2012121958A2
Application number: PCT/US2012/027177
Authority: WO
Inventors: Andres BRAINSKY
Original assignee: Glaxosmithkline Llc
Priority date: 2011-03-08
Filing date: 2012-03-01
Publication date: 2012-09-13
Also published as: WO2012121958A3

Abstract

The present invention relates generally to the use of eltrombopag in combination with an anti-CD20 antibody to treat thrombocytopenia, suitably immune thrombocytopenia purpura.

Description

COMBINATION

FIELD OF INVENTION

The present invention relates to a method of treating thrombocytopenia in a mammal and to combinations useful in such treatment. In particular, the method relates to a novel combination comprising an anti-CD20 antibody, and the TPO agonist: 3'-[(2Z)- [1-(3,4-dimethylphenyl)-1 ,5-dihydro-3-methyl-5-oxo-4H-pyrazol-4-ylidene]hydrazino]-2'- hydroxy-[1 , 1 '-biphenyl]-3-carboxylic acid or a pharmaceutically acceptable salt thereof, suitably the bis-monoethanolamine salt, and optional additional antineoplastic agents; pharmaceutical compositions comprising the same; and methods of using such combinations in the treatment of thrombocytopenia.

BACKGROUND OF THE INVENTION Immune thrombocytopenia purpura (ITP) is an autoimmune disorder characterized by autoantibody-induced platelet destruction and impaired platelet production, leading to a chronically low peripheral blood platelet count (<100,000/μΙ_). Symptoms include bruising, gastrointestinal hemorrhage (Gl), mucosal bleeding and intra-cranial haemorrhage and the severity of thrombocytopenia correlates to some extent with the bleeding risk [Provan 2010]. The frequency of death from haemorrhage in patients with platelet counts < 30,000 is estimated to be between 1 .6 and 3.9% per patient-year

[Cohen, 2000]. Anti-platelet antibodies are present in up to 80% percentage of primary ITP patients (He, 1994). First-line treatments for adult ITP such as corticosteroids, intravenous immunoglobulins (IVIg) or anti-D are effective in increasing platelet counts in about 70% of adult ITP patients, approximately 50% of whom will achieve platelet counts in the normal range [Provan 2010]. Many patients, however, suffer relapse when the steroid dose is lowered or regular administration of IVIg is discontinued and suffer side effects of high-dose corticosteroids. Second-line therapy in refractory patients involves immunosuppressive or modulating drugs such as azathioprine, cyclosporin A, cyclophosphamide, dapsone and mycophenolate mofetil and rituximab [Provan 2010]. Since these drugs are non-selectively immunosuppressive (i.e. background immunity is reduced), patients suffer morbidity and mortality through infections secondary to their immunosuppression [Portielje 2001]. Splenectomy results in 80% response rates and sustained responses in two thirds of patients, but complications may include bleeding, infection and thrombosis [Provan 2010]. Following splenectomy patients are less able to clear infections, and thus are more susceptible to infections [Balmer 2004]. More recently, thrombopoietin receptor agonists such as eltrombopag and romiplostim have demonstrated efficacy in primary ITP. These drugs act by inducing platelet production from bone marrow. While these therapies have shown low toxicity and good tolerability thus far, they do not prevent the formation of the pathogenic autoantibodies that induce platelet clearance [Bussel 2009].

Rituximab is a chimeric anti-CD20 antibody that results in the rapid depletion of B cells from the periphery by ADCC, phagocytosis and induction of apoptosis [Sanz 2010]. Rituximab treatment leads to a clinical response in -60% of ITP patients [Stasi, 2001], results in the loss of auto antibodies against platelets [Ahn 2005], and normalisation of the T cell V beta repertoire in long term responding patients, thereby supporting a role for B cells in the maintenance of auto-reactive T cells in this disease [Stasi 2007]. Although rituximab has demonstrated efficacy in ITP patients, a major area of concern is its long term effects and potential long-term hazards, and repeated long-term use could result in hypogammaglobulinemia. Also, while the loss of B cells is limited in time in most patients with autoimmune disease, the reconstitution to normal B cell levels can be delayed in certain diseases and often in elderly patients. Prolonged immunosuppression has been associated with increased incidence of cancer, as well as progressive multifocal leukoencephalopathy (PML), due to the reactivation of the JC virus.

Based on the current treatment paradigm, there is significant unmet need, and the benefit of a therapy that could be given without steroid-like side effects, or that could enable steroid withdrawal and avoidance of splenectomy, would offer a significant increase in therapeutic benefit.

Recently there has been many reports of new generation of anti-CD20 antibodies. One such novel antibody is ofatumumab. Ofatumumab is a new generation, human monoclonal antibody that targets a distinct membrane proximal, small loop epitope

(specific binding site) of the CD20 molecule on the surface of B-cells. This generates a superior induction of tumor cell lysis by CDC (complement dependent cytotoxicity) activity, especially in cells with low CD20 density, as is the case in CLL, with similar ADCC (antibody-dependent cell mediated cytotoxicity) activity, compared to tumor cell lysis capability observed with rituximab. Ofatumumab described as 2F2 antibody in

WO2004/035607 is in clinical development for the treatment of non-Hodgkin's lymphoma (NHL), chronic lymphocytic leukemia (CLL), and rheumatoid arthritis (RA). See also Teeling et al., Blood, 104, pp 1793 (2004); and Teeling et al., J. Immunology, 177, pp 362-371 (2007).

The TPO agonist: 3'-[(2Z)-[1 -(3,4-dimethylphenyl)-1 ,5-dihydro-3-methyl-5-oxo-4H- pyrazol-4-ylidene]hydrazino]-2'-hydroxy-[1 , 1 '-biphenyl]-3-carboxylic acid is known by the generic name eltrombopag. The bis-monoethanolamine salt of eltrombopag is generically known as eltrombopag olamine. Eltrombopag olamine is marketed under the trade name Promacta® in the United States and Revolade® outside the United States. Eltrombopag olamine has the represented by Structure I:

Eltrombopag is a compound which is disclosed and claimed, along with pharmaceutically acceptable salts, hydrates, solvates and esters thereof, as being useful as an agonist of the TPO receptor, particularly in enhancing platelet production and particularly in the treatment of thrombocytopenia, in International Application No.

PCT/US01/16863, having an International filing date of May 24, 2001 ; International Publication Number WO 01/89457 and an International Publication date of November 29, 2001 . Eltrombopag is disclosed and claimed as being useful in the treatment of cancer and pre-cancerous syndromes in International Application No. PCT/US08/054046, having an International filing date of February 15, 2008; International Publication Number WO 08/101 141 and an International Publication date of August 21 , 2008.

SUMMARY OF THE INVENTION

In one embodiment, the present invention relates a method of treating, thrombocytopenia, suitably immune thrombocytopenia purpura, suitably rituximab refractory immune thrombocytopenia purpura, in a human patient, comprising the step of administering to the patient an anti-CD20 antibody in combination with eltrombopag, suitably eltrombopag olamine. In one embodiment, the administration is simultaneous. In another embodiment, the administration is sequential in which eltrombopag, suitably eltrombopag olamine is administered first. Yet in another embodiment, an anti-CD20 antibody is administered first. In yet in another embodiment, administration of an anti- CD20 antibody and eltrombopag, suitably eltrombopag olamine is staggered.

In one embodiment, the invention relates to a method of treating

thrombocytopenia, suitably immune thrombocytopenic purpura, suitably rituximab refractory immune thrombocytopenia purpura, in a human patient, comprising the step of administering to the patient an anti-CD20 antibody in combination with eltrombopag, suitably eltrombopag olamine. In one embodiment the administration is simultaneous. In another embodiment, the administration is sequential in which eltrombopag, suitably eltrombopag olamine is administered first. Yet in another embodiment an anti-CD20 antibody is administered first. In yet in another embodiment, administration of an anti- CD20 antibody and eltrombopag, suitably eltrombopag olamine is staggered.

In one embodiment, the invention relates to a pharmaceutical composition comprising eltrombopag, suitably eltrombopag olamine and an anti-CD20 antibody wherein the combination is suitable for separate, sequential and/or simultaneous administration. In another embodiment, the anti-CD20 antibody is ofatumuamb.

In one embodiment, the invention relates to the use of an anti-CD20 antibody (in particular ofatumumab) in the manufacture of a medicament for the treatment of thrombocytopenia, suitably immune thrombocytopenia purpura, wherein the medicament is for administration in combination therapy with eltrombopag, suitably eltrombopag olamine.

In one embodiment, the invention relates to an anti-CD20 antibody (in particular ofatumuamb) for use in the treatment of thrombocytopenia, suitably immune

thrombocytopenia purpura, in combination with eltrombopag, suitably eltrombopag olamine. Detailed Description

Traditional treatment strategies for immune thrombocytopenia purpura focus on diminishing the antibody-mediated increased platelet destruction. Novel therapies such as thrombopoietin receptor agonists have focused on the impaired platelet production of the disease. There is a balance between achieving effective therapy without toxicity. Therefore, there is an unmet need for effective therapies with limited side effects for the treatment of the majority of immune thrombocytopenia purpura patients, especially those who become refractory traditional therapies, splenectomy and rituximab. Ofatumumab has shown activity in rituximab resistant subjects [Hagenbeek, et al. Blood 2008;

1 1 1 :5486-5495], and eltrombopag, suitably eltrombopag olamine has shown activity in several cancer models (WO 08/101 141 ), and to enhance platelet production and in the treatment of thrombocytopenia (WO 01/89457). Combination of ofatumumab and eltrombopag, suitably eltrombopag olamine is expected to combine efficacy with a low toxicity profile for subjects who become refractory to other treatment modalities.

The invention relates to a method of treating thrombocytopenia, suitably immune thrombocytopenia purpura, in a human patient, comprising the step of administering to the patient an anti-CD20 antibody in combination with eltrombopag, suitably eltrombopag olamine. In one embodiment, the administration is simultaneous. In another

embodiment, the administration is sequential in which eltrombopag, suitably eltrombopag olamine is administered first. Yet in another embodiment an anti-CD20 antibody is administered first. In yet in another embodiment, administration of an anti-CD20 antibody and eltrombopag, suitably eltrombopag olamine is staggered.

The invention also relates to a method of treating thrombocytopenia, suitably immune thrombocytopenia purpura, in a human patient, comprising the step of administering to the patient an anti-CD20 antibody in combination with eltrombopag, suitably eltrombopag olamine. In one embodiment, the administration is simultaneous. In another embodiment, the administration is sequential in which eltrombopag, suitably eltrombopag olamine is administered first. Yet in another embodiment, an anti-CD20 antibody is administered first. In yet in another embodiment, administration of an anti- CD20 antibody and eltrombopag, suitably eltrombopag olamine is staggered.

Non-limiting way to dose eltrombopag, suitably eltrombopag olamine and ofatumuamb is exemplified in Example 1.

In one embodiment of the invention, the anti-CD20 antibody is monoclonal.

In one embodiment, the anti-CD20 antibody has Fc mediated effector function. In one embodiment, the anti-CD20 antibody has antibody-dependent-cell- mediated cytoxicity (ADCC) effector function.

In one embodiment, the anti-CD20 antibody has complement-dependent-cytoxicity (CDC) effector function.

In one embodiment of the invention, the anti-CD20 antibody is a chimeric, humanized or human monoclonal antibody.

In one embodiment, the monoclonal antibody against CD20 (anti-CD20 antibody) is a full-length antibody selected from the group consisting of a full- length lgG1 antibody, a full-length lgG2 antibody, a full-length lgG3 antibody, a full-length lgG4 antibody, a full-length IgM antibody, a full-length lgA1 antibody, a full-length lgA2 antibody, a full-length secretory IgA antibody, a full-length IgD antibody, and a full-length IgE antibody, wherein the antibody is glycosylated in a eukaryotic cell.

In one embodiment, the anti-CD20 antibody is a full-length antibody, such as a full-length lgG1 antibody.

In one embodiment, the anti-CD20 antibody is an antibody fragment, such as a scFv or a UniBody™ (a monovalent antibody as disclosed in WO 2007/059782). In one embodiment of the invention, the antibody against CD20 (anti-CD20 antibody) is a binding-domain immunoglobulin fusion protein comprising (i) a binding domain polypeptide in the form of a heavy chain variable region of SEQ ID NO:1 or a light chain variable region of SEQ ID NO:2 that is fused to an immunoglobulin hinge region polypeptide, (ii) an immunoglobulin heavy chain CH2 constant region fused to the hinge region, and (iii) an immunoglobulin heavy chain CH3 constant region fused to the CH2 constant region.

In one embodiment, the antibody against CD20 binds to mutant P172S CD20

(proline at position 172 mutated to serine) with at least the same affinity as to human CD20.

In one embodiment of the invention, the antibody against CD20 binds to an epitope on CD20

(i) which does not comprise or require the amino acid residue proline at position

172;

(ii) which does not comprise or require the amino acid residues alanine at position 170 or proline at position 172;

(iii) which comprises or requires the amino acid residues asparagine at position 163 and asparagine at position 166; (iv) which does not comprise or require the amino acid residue proline at position 172, but which comprises or requires the amino acid residues asparagine at position 163 and asparagine at position 166; or

(v) which does not comprise or require the amino acid residues alanine at position 170 or proline at position 172, but which comprises or requires the amino acid residues asparagine at position 163 and asparagine at position 166.

In one embodiment, the antibody against CD20 binds to an epitope in the small first extracellular loop of human CD20.

In one embodiment, the antibody against CD20 binds to a discontinuous epitope on CD20.

In one embodiment, the antibody against CD20 binds to a discontinuous epitope on CD20, wherein the epitope comprises part of the first small extracellular loop and part of the second extracellular loop.

In one embodiment, the antibody against CD20 binds to a discontinuous epitope on CD20, wherein the epitope has residues AGIYAP of the small first extracellular loop and residues MESLNFIRAHTPYI of the second extracellular loop.

In one embodiment, the antibody against CD20 has one or more of the characteristics selected from the group consisting of:

(i) capable of inducing complement dependent cytotoxicity (CDC) of cells expressing CD20 in the presence of complement;

(ii) capable of inducing complement dependent cytotoxicity (CDC) of cells expressing CD20 and high levels of CD55 and/or CD59 in the presence of complement;

(iii) capable of inducing apoptosis of cells expressing CD20;

(iv) capable of inducing antibody dependent cellular cytotoxicity (ADCC) of cells expressing CD20 in the presence of effector cells;

(v) capable of inducing homotypic adhesion of cells which express CD20;

(vi) capable of translocating into lipid rafts upon binding to CD20;

(vii) capable of depleting cells expressing CD20;

(viii) capable of depleting cells expressing low levels of CD20 (CD20low cells); and

(ix) capable of effectively depleting B cells in situ in human tissues.

In one embodiment of the invention, the antibody against CD20 comprises a VH CDR3 sequence of SEQ ID NO. 5.

In one embodiment, the antibody against CD20 comprises a VH CDR1 of SEQ ID NO:3, a VH CDR2 of SEQ ID NO:4, a VH CDR3 of SEQ ID NO:5, a VL CDR1 of SEQ ID NO:6, a VL CDR2 of SEQ ID NO:7 and a VL CDR3 sequence of SEQ ID NO:8. In one embodiment of the invention, the antibody against CD20 has human heavy chain and human light chain variable regions comprising the amino acid sequences as set forth in SEQ ID NO:1 and SEQ ID NO:2, respectively; or amino acid sequences which are at least 95% identical, and more preferably at least 98%, or at least 99% identical to the amino acid sequences as set forth in SEQ ID NO:1 and SEQ ID NO:2, respectively.

In one embodiment of the invention an anti-CD20 antibody is selected from one of the anti-CD20 antibodies disclosed in WO 2004/035607, such as ofatumumab (2F2), 1 1 B8, or 7D8, one of the antibodies disclosed in WO 2005/103081 , such as 2C6, one of the antibodies disclosed in WO 2004/103404, AME-133 (humanized and optimized anti- CD20 monoclonal antibody, developed by Applied Molecular Evolution), one of the antibodies disclosed in US 2003/01 18592, TRU-015 (CytoxB20G, a small modular immunopharmaceutical fusion protein derived from key domains on an anti-CD20 antibody, developed by Trubion Pharmaceuticals Inc), one of the antibodies disclosed in WO 2003/68821 , IMMU-106 (a humanized anti-CD20 monoclonal antibody), one of the antibodies disclosed in WO 2004/56312, ocrelizumab (2H7.v16, PRO-70769, R-1594), Bexxar® (tositumomab), and Rituxan® / MabThera® (rituximab). The terms "CD20" and "CD20 antigen" are used interchangeably herein, and include any variants, isoforms and species homologs of human CD20, which are naturally expressed by cells or are expressed on cells transfected with the CD20 gene. Synonyms of CD20, as recognized in the art, include B-lymphocyte surface antigen B1 , Leu-16 and Bp35. Human CD20 has UniProtKB/Swiss-Prot entry P1 1836.

The term "immunoglobulin" as used herein refers to a class of structurally related glycoproteins consisting of two pairs of polypeptide chains, one pair of light (L) low molecular weight chains and one pair of heavy (H) chains, all four inter-connected by disulfide bonds. The structure of immunoglobulins has been well characterized. See for instance Fundamental Immunology Ch. 7 (Paul, W., ed., 2nd ed. Raven Press, N.Y.

(1989)). Briefly, each heavy chain typically is comprised of a heavy chain variable region (abbreviated herein as VH) and a heavy chain constant region. The heavy chain constant region, CH, typically is comprised of three domains, CH1 , CH2, and CH3. Each light chain typically is comprised of a light chain variable region (abbreviated herein as VL) and a light chain constant region. The light chain constant region typically is comprised of one domain, CL. The VH and VL regions may be further subdivided into regions of hypervariability (or hypervariable regions which may be hypervariable in sequence and/or form of structurally defined loops), also termed complementarity determining regions (CDRs), interspersed with regions that are more conserved, termed framework regions (FRs). Each VH and VL is typically composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1 , CDR1 , FR2, CDR2, FR3, CDR3, FR4 (see also Chothia and Lesk J. Mol. Biol. 196, 901-917 (1987)).

Typically, the numbering of amino acid residues in this region is performed by the method described in Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD. (1991 ) (phrases, such as variable domain residue numbering as in Kabat or according to Kabat herein refer to this numbering system for heavy chain variable domains or light chain variable domains). Using this numbering system, the actual linear amino acid sequence of a peptide may contain fewer or additional amino acids corresponding to a shortening of, or insertion into, a FR or CDR of the variable domain. For example, a heavy chain variable domain may include a single amino acid insert (for instance residue 52a according to Kabat) after residue 52 of VH CDR2 and inserted residues (for instance residues 82a, 82b, and 82c, etc. according to Kabat) after heavy chain FR residue 82. The Kabat numbering of residues may be determined for a given antibody by alignment at regions of homology of the sequence of the antibody with a "standard" Kabat numbered sequence.

The term "antibody" as used herein refers to an immunoglobulin molecule, a fragment of an immunoglobulin molecule, or a derivative of either thereof, which has the ability to specifically bind to an antigen under typical physiological conditions for a significant period of time, such as at least about 30 minutes, at least about 45 minutes, at least about one hour, at least about two hours, at least about four hours, at least about 8 hours, at least about 12 hours, about 24 hours or more, about 48 hours or more, about 3, 4, 5, 6, 7 or more days, etc., or any other relevant functionally-defined period (such as a time sufficient to induce, promote, enhance, and/or modulate a physiological response associated with antibody binding to the antigen and/or a time sufficient for the antibody to recruit an Fc-mediated effector activity).

The variable regions of the heavy and light chains of the immunoglobulin molecule contain a binding domain that interacts with an antigen. The constant regions of the antibodies may mediate the binding of the immunoglobulin to host tissues or factors, including various cells of the immune system (such as effector cells) and components of the complement system such as C1 q, the first component in the classical pathway of complement activation.

The anti-CD20 antibody may be mono-, bi- or multispecific. Indeed, bispecific antibodies, diabodies, and the like, provided by the present invention may bind any suitable target in addition to a portion of CD20. As indicated above, the term "antibody" as used herein, unless otherwise stated or clearly contradicted by the context, includes fragments of an antibody provided by any known technique, such as enzymatic cleavage, peptide synthesis and recombinant techniques that retain the ability to specifically bind to an antigen. It has been shown that the antigen-binding function of an antibody may be performed by fragments of a full- length (intact) antibody. Examples of antigen-binding fragments encompassed within the term "antibody" include, but are not limited to (i) a Fab fragment, a monovalent fragment consisting of the VL, VH, CL and CH1 domains; (ii) F(ab)2 and F(ab')2 fragments, bivalent fragments comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) a Fd fragment consisting essentially of the VH and CH1 domains; (iv) a Fv fragment consisting essentially of the VL and VH domains of a single arm of an antibody, (v) a dAb fragment (Ward et al., Nature 341 , 544-546 (1989)), which consists essentially of a VH domain and also called domain antibodies (Holt et al. (November 2003) Trends Biotechnol. 21 (1 1 ):484-90); (vi) a camelid antibody or nanobody (Revets et al. (January 2005) Expert Opin Biol Ther. 5(1 ):1 1 1-24), (vii) an isolated complementarity determining region (CDR), such as a VH CDR3, (viii) a UniBody™, a monovalent antibody as disclosed in WO 2007/059782, (ix) a single chain antibody or single chain Fv (scFv), see for instance Bird et al., Science 242, 423-426 (1988) and Huston et al., PNAS USA 85, 5879-5883 (1988)), (x) a diabody (a scFv dimer), which can be monospecific or bispecific (see for instance PNAS USA 90(14), 6444-6448 (1993), EP 404097 or WO 93/1 1 161 for a description of diabodies), a triabody or a tetrabody. Although such fragments are generally included within the definition of an antibody, they collectively and each independently are unique features of the present invention, exhibiting different biological properties and utility. These and other useful antibody fragments in the context of the present invention are discussed further herein.

It should be understood that the term antibody generally includes monoclonal antibodies as well as polyclonal antibodies. The antibodies can be human, humanized, chimeric, murine, etc. An antibody as generated can possess any isotype.

The term "human antibody", as used herein, is intended to include antibodies having variable and constant regions derived from human germline immunoglobulin sequences. The human antibodies of the present invention may include amino acid residues not encoded by human germline immunoglobulin sequences (for instance mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo). However, the term "human antibody", as used herein, is not intended to include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted into human framework sequences.

As used herein, a human antibody is "derived from" a particular germline sequence if the antibody is obtained from a system using human immunoglobulin sequences, for instance by immunizing a transgenic mouse carrying human

immunoglobulin genes or by screening a human immunoglobulin gene library, and wherein the selected human antibody is at least 90%, such as at least 95%, for instance at least 96%, such as at least 97%, for instance at least 98%, or such as at least 99% identical in amino acid sequence to the amino acid sequence encoded by the germline immunoglobulin gene. Typically, a human antibody derived from a particular human germline sequence will display no more than 10 amino acid differences, such as no more than 5, for instance no more than 4, 3, 2, or 1 amino acid difference from the amino acid sequence encoded by the germline immunoglobulin gene. For VH antibody sequences the VH CDR3 domain is not included in such comparison.

The term "chimeric antibody" refers to an antibody that contains one or more regions from one antibody and one or more regions from one or more other antibodies. The term "chimeric antibody" includes monovalent, divalent, or polyvalent antibodies. A monovalent chimeric antibody is a dimer (HL)) formed by a chimeric H chain associated through disulfide bridges with a chimeric L chain. A divalent chimeric antibody is a tetramer (H2L2) formed by two HL dimers associated through at least one disulfide bridge. A polyvalent chimeric antibody may also be produced, for example, by employing a CH region that assembles into a molecule with 2+ binding sites (for instance from an IgM H chain, or μ chain). Typically, a chimeric antibody refers to an antibody in which a portion of the heavy and/or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, so long as they exhibit the desired biological activity (see for instance US 4,816,567 and Morrison et al., PNAS USA 81 , 6851 -6855 (1984)). Chimeric antibodies are produced by recombinant processes well known in the art (see for instance Cabilly et al., PNAS USA 81 , 3273-3277 (1984), Morrison et al., PNAS USA 81 , 6851 -6855 (1984), Boulianne et al., Nature 312, 643-646 (1984), EP125023, Neuberger et al., Nature 314, 268-270 (1985), EP171496, EP173494, WO 86/01533, EP184187, Sahagan et al., J. Immunol. 137, 1066-1074 (1986), WO 87/02671 , Liu et al., PNAS USA 84, 3439-3443 (1987), Sun et al., PNAS USA 84, 214-218 (1987), Better et al., Science 240, 1041-1043 (1988) and Harlow et al., Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., (1988)).

The term "humanized antibody" refers to a human antibody which contain minimal sequences derived from a non-human antibody. Typically, humanized antibodies are human immunoglobulins (recipient antibody) in which residues from a hypervariable region of the recipient are replaced by residues from a hypervariable region of a non- human species (donor antibody), such as mouse, rat, rabbit or non-human primate having the desired specificity, affinity, and capacity.

Furthermore, humanized antibodies may comprise residues which are not found in the recipient antibody or in the donor antibody. These modifications are made to further refine antibody performance. In general, a humanized antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the hypervariable loops correspond to those of a non-human immunoglobulin and all or substantially all of the FR regions are those of a human immunoglobulin sequence. A humanized antibody optionally also will comprise at least a portion of a human immunoglobulin constant region. For further details, see Jones et al., Nature 321 , 522-525 (1986), Riechmann et al., Nature 332, 323-329 (1988) and Presta, Curr. Op. Struct. Biol. 2, 593-596 (1992).

The term "patient" refers to a human patient.

The terms "monoclonal antibody" or "monoclonal antibody composition" as used herein refer to a preparation of antibody molecules of single molecular composition. A monoclonal antibody composition displays a single binding specificity and affinity for a particular epitope. Accordingly, the term "human monoclonal antibody" refers to antibodies displaying a single binding specificity which have variable and constant regions derived from human germline immunoglobulin sequences. The human monoclonal antibodies may be generated by a hybridoma which includes a B cell obtained from a transgenic or transchromosomal nonhuman animal, such as a transgenic mouse, having a genome comprising a human heavy chain transgene and a light chain transgene, fused to an immortalized cell.

The term "recombinant human antibody", as used herein, includes all human antibodies that are prepared, expressed, created or isolated by recombinant means, such as (a) antibodies isolated from an animal (such as a mouse) that is transgenic or transchromosomal for human immunoglobulin genes or a hybridoma prepared therefrom (described further elsewhere herein), (b) antibodies isolated from a host cell transformed to express the antibody, such as from a transfectoma, (c) antibodies isolated from a recombinant, combinatorial human antibody library, and (d) antibodies prepared, expressed, created or isolated by any other means that involve splicing of human immunoglobulin gene sequences to other DNA sequences. Such recombinant human antibodies have variable and constant regions derived from human germline

immunoglobulin sequences. In certain embodiments, however, such recombinant human antibodies may be subjected to in vitro mutagenesis (or, when an animal transgenic for human Ig sequences is used, in vivo somatic mutagenesis) and thus the amino acid sequences of the VH and VL regions of the recombinant antibodies are sequences that, while derived from and related to human germline VH and VL sequences, may not naturally exist within the human antibody germline repertoire in vivo.

The terms "transgenic, non-human animal" refers to a non-human animal having a genome comprising one or more human heavy and/or light chain transgenes or transchromosomes (either integrated or non-integrated into the animal's natural genomic DNA) and which is capable of expressing fully human antibodies. For example, a transgenic mouse can have a human light chain transgene and either a human heavy chain transgene or human heavy chain transchromosome, such that the mouse produces human anti-CD20 antibodies when immunized with CD20 antigen and/or cells expressing CD20. The human heavy chain transgene may be integrated into the chromosomal DNA of the mouse, as is the case for transgenic mice, for instance the HuMAb-Mouse®, such as HCo7 or HCo12 mice, or the human heavy chain transgene may be maintained extrachromosomally, as is the case for the transchromosomal KM-Mouse® as described in WO 02/43478. Such transgenic and transchromosomal mice (collectively referred to herein as "transgenic mice") are capable of producing multiple isotypes of human monoclonal antibodies to a given antigen (such as IgG, IgA, IgM, IgD and/or IgE) by undergoing V-D-J recombination and isotype switching. Transgenic, nonhuman animals can also be used for production of antibodies against a specific antigen by introducing genes encoding such specific antibody, for example by operatively linking the genes to a gene which is expressed in the milk of the animal.

For amino acid (polypeptide) sequences, the term "identity" or "homology" indicates the degree of identity between two amino acid sequences when optimally aligned and compared with appropriate insertions or deletions. The percent identity between two sequences is a function of the number of identical positions shared by the sequences (i.e., % identity = number of identical positions/total number of positions times 100), taking into account the number of gaps, and the length of each gap, which need to be introduced for optimal alignment of the two sequences. The comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm, as described below. The percent identity between two polypeptide sequences can be determined using the GAP program in the GCG software package, using a NWSgapdna.CMP matrix and a gap weight of 40, 50, 60, 70, or 80 and a length weight of 1 , 2, 3, 4, 5, or 6. The percent identity between two amino acid sequences can also be determined using the algorithm of E. Meyers and W. Miller (Comput. Appl. Biosci., 4:1 1-17 (1988)) which has been incorporated into the ALIGN program (version 2.0), using a PAM120 weight residue table, a gap length penalty of 12 and a gap penalty of 4. In addition, the percent identity between two amino acid sequences can be determined using the Needleman and Wunsch (J. Mol. Biol. 48:444-453 (1970)) algorithm which has been incorporated into the GAP program in the GCG software package, using either a Blossum 62 matrix or a PAM250 matrix, and a gap weight of 16, 14, 12, 10, 8, 6, or 4 and a length weight of 1 , 2, 3, 4, 5, or 6.

By way of example, a polypeptide sequence may be identical to a polypeptide reference sequence as described herein (for example SEQ ID NO: 1 ) that is be 100% identical, or it may include up to a certain integer number of amino acid alterations as compared to the reference sequence such that the % identity is less than 100%, such as at least 50, 60, 70, 75, 80, 85, 90, 95, 98, or 99% identical. Such alterations are selected from the group consisting of at least one amino acid deletion, substitution, including conservative and non-conservative substitution, or insertion, and wherein said alterations may occur at the amino- or carboxy-terminal positions of the reference polypeptide sequence or anywhere between those terminal positions, interspersed either individually among the amino acids in the reference sequence or in one or more contiguous groups within the reference sequence. The number of amino acid alterations for a given % identity is determined by multiplying the total number of amino acids in the polypeptide sequence encoded by the polypeptide reference sequence as described herein (for example SEQ ID NO: 1 ) by the numerical percent of the respective percent identity (divided by 100) and then subtracting that product from said total number of amino acids in the polypeptide reference sequence as described herein (for example SEQ ID NO: 1 ), or:

n_a < x_a - (x_a · y),

wherein n_a is the number of amino acid alterations, x_a is the total number of amino acids in the polypeptide sequence encoded by SEQ ID NO: 1 , and y is, 0.50 for 50%, 0.60 for 60%, 0.70 for 70%, 0.75 for 75%, 0.80 for 80%, 0.85 for 85%, 0.90 for 90%, 0.95 for 95%, 0.98 for 98%, 0.99 for 99%, or 1 .00 for 100%, · is the symbol for the multiplication operator, and wherein any non-integer product of x_a and y is rounded down to the nearest integer prior to subtracting it from x_a.

The administration of a therapeutically effective amount of the combinations of the invention are advantageous over the individual component compounds in that the combinations will provide one or more of the following improved properties when compared to the individual administration of a therapeutically effective amount of a component compound: i) a greater platelet enhancing effect than the most active single agent, ii) a greater effect on transplant rejection than the most active single agent, iii) a dosing protocol that provides enhanced platelet enhancing activity with reduced side effect profile, iv) a dosing protocol that provides enhanced treatment for transplant rejection with reduced side effect profile, v) a reduction in the toxic effect profile, vi) an increase in the therapeutic window, or vii) an increase in the bioavailability of one or both of the component compounds.

The compounds of the invention may contain one or more chiral atoms, or may otherwise be capable of existing as two enantiomers. Accordingly, the compounds of this invention include mixtures of enantiomers as well as purified enantiomers or enantiomerically enriched mixtures. Also, it is understood that all tautomers and mixtures of tautomers are included within the scope of Compound A, and pharmaceutically acceptable salts or hydrates thereof, and Compound B, and pharmaceutically acceptable salts thereof.

The compounds of the invention may form a solvate which is understood to be a complex of variable stoichiometry formed by a solute (in this invention, Compound A or a salt thereof and/or Compound B or a salt thereof) and a solvent. Such solvents for the purpose of the invention may not interfere with the biological activity of the solute. Examples of suitable solvents include, but are not limited to, water, methanol, dimethyl sulfoxide, ethanol and acetic acid. Suitably the solvent used is a pharmaceutically acceptable solvent. Suitably the solvent used is water.

The pharmaceutically acceptable salts of the compounds of the invention are readily prepared by those of skill in the art.

By the term "thrombocytopenia" and derivatives thereof as used herein is to be broadly interpreted as any decrease in the number of blood platelets below what is considered normal or desired for a healthy individual. Thrombocytopenia is known to have many causative factors, including but not limited to, radiation therapy,

chemotherapy, immune therapy, immune thrombocytopenic purpura (ITP, Bussel J. B., Seminars in Hematology, 2000, 37, Suppl 1 , 1 -49), myelodysplasia syndrome (MDS), aplastic anemia, AML, CML, viral infections (including, but not limited to; HIV, hepatitis C, parvovirus) liver disease, myeloablation, bone marrow transplant, stem cell transplant, peripheral blood stem cell transplant, progenitor cell defect, polymorphisms in stem cells and progenitor cells, defects in Tpo, neutropenia (Sawai, N. J. Leukocyte Biol., 2000, 68, 137-43), dendritic cell mobilization (Kuter D. J. Seminars in Hematology, 2000, 37, Suppl 4, 41 -49), proliferation, activation or differentiation.

The combinations of this invention are advantageous in treating thrombocytopenia as the combination is expected to reduce any adverse immunological effect on platelet production. The combinations of this invention are advantageous in treating transplant rejection as the combination is expected to reduce the adverse side effects, suitably thrombocytopenia, caused by the administration of one component alone.

Prophylactic use of the combinations of this invention is contemplated whenever a decrease in blood or blood platelets is anticipated. Prophylactic use of the combinations of this invention results in a build up of platelets or a commencement of platelet production prior to an anticipated loss of platelets.

Also, contemplated herein is a method of treating thrombocytopenia using a combination of the invention where Compound A, or a pharmaceutically acceptable salt or hydrate thereof, and/or Compound B or a pharmaceutically acceptable salt thereof are administered as pro-drugs. Pharmaceutically acceptable pro-drugs of the compounds of the invention are readily prepared by those of skill in the art.

By the term "treating" and derivatives thereof as used herein, is meant therapeutic therapy. In reference to a particular condition, treating means: (1 ) to ameliorate or prevent the condition of one or more of the biological manifestations of the condition, (2) to interfere with (a) one or more points in the biological cascade that leads to or is responsible for the condition or (b) one or more of the biological manifestations of the condition, (3) to alleviate one or more of the symptoms, effects or side effects associated with the condition or treatment thereof, or (4) to slow the progression of the condition or one or more of the biological manifestations of the condition. Prophylactic therapy is also contemplated thereby. The skilled artisan will appreciate that "prevention" is not an absolute term. In medicine, "prevention" is understood to refer to the prophylactic administration of a drug to substantially diminish the likelihood or severity of a condition or biological manifestation thereof, or to delay the onset of such condition or biological manifestation thereof. Prophylactic therapy is appropriate, for example, when a subject is considered at high risk for developing thrombocytopenia, such as when a subject has a strong family history of thrombocytopenia or when open wounds and cuts can be expected such as when a subject is anticipating surgery.

As used herein, the term "effective amount" means that amount of a drug or pharmaceutical agent that will elicit the biological or medical response of a tissue, system, animal or human that is being sought, for instance, by a researcher or clinician.

Furthermore, the term "therapeutically effective amount" means any amount which, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, prevention, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder. The term also includes within its scope amounts effective to enhance normal physiological function.

By the term "combination" and derivatives thereof, as used herein is meant either, simultaneous administration or any manner of separate sequential administration of a therapeutically effective amount of Compound A, or a pharmaceutically acceptable salt thereof, and Compound B or a pharmaceutically acceptable salt or solvate thereof.

Preferably, if the administration is not simultaneous, the compounds are administered in a close time proximity to each other. Furthermore, it does not matter if the compounds are administered in the same dosage form, e.g. one compound may be administered topically and the other compound may be administered orally. Suitably, Compound A is administered by IV and Compound B is administered orally.

By the term "combination kit" as used herein is meant the pharmaceutical composition or compositions that are used to administer Compound A, or a

pharmaceutically acceptable salt or hydrate thereof, and Compound B, or a

pharmaceutically acceptable salt thereof, according to the invention. When both compounds are administered simultaneously, the combination kit can contain Compound A, or a pharmaceutically acceptable salt or hydrate thereof, and Compound B, or a pharmaceutically acceptable salt thereof, in a single pharmaceutical composition, such as a tablet, or in separate pharmaceutical compositions. When the compounds are not administered simultaneously, the combination kit will contain Compound A, or a pharmaceutically acceptable salt or hydrate thereof, and Compound B, or a

pharmaceutically acceptable salt thereof, in separate pharmaceutical compositions. The combination kit can comprise Compound A, or a pharmaceutically acceptable salt or hydrate thereof, and Compound B, or a pharmaceutically acceptable salt thereof, in separate pharmaceutical compositions in a single package or in separate pharmaceutical compositions in separate packages.

In one aspect there is provided a combination kit comprising the components: Compound A, or a pharmaceutically acceptable salt or hydrate thereof, in association with a pharmaceutically acceptable carrier; and

Compound B, or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier. In one embodiment of the invention the combination kit comprises the following components:

Compound A, or a pharmaceutically acceptable salt or hydrate thereof, in association with a pharmaceutically acceptable carrier; and

Compound B, or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier,

wherein the components are provided in a form which is suitable for sequential, separate and/or simultaneous administration.

In one embodiment the combination kit comprises:

a first container comprising Compound A, or a pharmaceutically acceptable salt or hydrate thereof, in association with a pharmaceutically acceptable carrier; and

a second container comprising Compound B, or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier, and a container means for containing said first and second containers.

The "combination kit" can also be provided by instruction, such as dosage and administration instructions. Such dosage and administration instructions can be of the kind that is provided to a doctor, for example by a drug product label, or they can be of the kind that is provided by a doctor, such as instructions to a patient. The present invention also provides pharmaceutical compositions (formulations) comprising eltrombopag, suitably eltrombopag olamine. Such compositions comprise a therapeutically effective amount of eltrombopag, suitably eltrombopag olamine, and may further comprise a pharmaceutically acceptable carrier, diluent, or excipient. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil, etc. Water can be used as a carrier when the pharmaceutical

composition is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, for example, for injectable solutions. Compositions can take the form of solutions, suspensions, emulsion, tablets, pills, capsules, powders, sustained-release formulations, and the like. Such compositions will contain a therapeutically effective amount of the compound, often in purified form, together with a suitable amount of carrier so as to provide the form for proper

administration to the patient. The formulation should suit the mode of administration. Suitably, eltrombopag olamine is formulated into a tablet according to International Application No. PCT/US07/074918, having an International filing date of August 1 , 2007; International Publication Number WO 08/136843 and an International Publication date of November 13, 2008. In part, WO 08/136843 describes the production of tablets containing about 15.95mg, 31 .9mg, 63.8mg, 95.7mg and 127.6mg of eltrombopag olamine.

For eltrombopag olamine, the dosage administered to a patient is suitably selected from: 12.5mg, 25mg, 50mg, 75mg and 100mg, based on the weight of eltrombopag as the free or unsalted compound.

The invention also provides a pharmaceutical pack or kit comprising one or more containers filled with one or more of the ingredients of the pharmaceutical compositions of eltrombopag, suitably eltrombopag olamine. Optionally associated with such container(s) can be a notice in the form prescribed by a governmental agency regulating the manufacture, use or sale of pharmaceuticals or biological products, which notice reflects approval by the agency of manufacture, use or sale for human administration. In another embodiment of the invention, a kit can be provided with the appropriate number of containers required to fulfill the dosage requirements for treatment of a particular indication.

Eltrombopag, suitably eltrombopag olamine may be administered by any appropriate internal route, and may be repeated as needed. The dose and duration of treatment relates to the relative duration of the molecules of the present invention in the human circulation, and can be adjusted by one of skill in the art, depending upon the condition being treated and the general health of the patient.

As indicated, therapeutically effective amounts of the combinations of the invention are administered to a human. Typically, the therapeutically effective amount of the administered agents of the present invention will depend upon a number of factors including, for example, the age and weight of the subject, the precise condition requiring treatment, the severity of the condition, the nature of the formulation, and the route of administration. Ultimately, the therapeutically effective amount will be at the discretion of the attending physician. The combinations of the invention are tested for efficacy, advantageous and synergistic properties generally according to known procedures. Anti-CD20 antibodies

A physician or veterinarian having ordinary skill in the art can readily determine and prescribe the effective amount of the pharmaceutical composition comprising anti- CD20 antibody. For example, the physician or veterinarian could start doses of the compounds of the invention employed in the pharmaceutical composition at levels lower than that required in order to achieve the desired therapeutic effect and gradually increase the dosage until the desired effect is achieved. In general, a suitable daily dose of a composition of the invention will be that amount of the compound which is the lowest dose effective to produce a therapeutic effect. It is preferred that administration be intravenous, intramuscular, intraperitoneal, or subcutaneous. If desired, the effective daily dose of a therapeutic composition may be administered as two, three, four, five, six or more sub-doses administered separately at appropriate intervals throughout the day, optionally, in unit dosage forms. While it is possible for anti-CD20 antibody to be administered alone, it is preferable to administer the compound as a pharmaceutical formulation (composition).

In one embodiment, the human monoclonal antibodies according to the invention may be administered by infusion in a weekly dosage of 10 to 2000 mg/m², normally 10 to 500 mg/m², such as 200 to 400 mg/m², such as 375 mg/m². Such administration may be repeated, e.g., 1 to 8 times, such as 3 to 5 times. The administration may be performed by continuous infusion over a period of from 2 to 24 hours, such as of from 2 to 12 hours.

In another embodiment, the antibodies are administered by slow continuous infusion over a long period, such as more than 24 hours, in order to reduce toxic side effects.

In still another embodiment the antibodies are administered in a weekly dosage of from 250 mg to 2000 mg, such as for example 300 mg, 500 mg, 700 mg, 1000 mg, 1500 mg or 2000 mg, for up to 8 times, such as from 4 to 6 times. The administration may be performed by continuous infusion over a period of from 2 to 24 hours, such as of from 2 to 12 hours. Such regimen may be repeated one or more times as necessary, for example, after 6 months or 12 months. The dosage can be determined or adjusted by measuring the amount of circulating anti-CD20 antibodies upon administration in a biological sample by using anti-idiotypic antibodies which target the anti-CD20 antibodies.

In yet another embodiment, the antibodies are administered by maintenance therapy, such as, e.g., once a week for a period of 6 months or more. In one embodiment, the present invention provides a pharmaceutical composition comprising a therapeutically effective amount of an anti-CD20 antibody. The pharmaceutical compositions may be formulated with pharmaceutically acceptable carriers or diluents as well as any other known adjuvants and excipients in accordance with conventional techniques, such as those disclosed in Remington: The Science and Practice of Pharmacy, 19th Edition, Gennaro, Ed., Mack Publishing Co., Easton, PA, 1995. A pharmaceutical composition may include diluents, fillers, salts, buffers, detergents (e. g., a nonionic detergent, such as Tween-80), stabilizers, stabilizers (e. g., sugars or protein-free amino acids), preservatives, tissue fixatives, solubilizers, and/or other materials suitable for inclusion in a pharmaceutical composition. The actual dosage levels of the active ingredients in the pharmaceutical compositions may be varied so as to obtain an amount of the active ingredient which is effective to achieve the desired therapeutic response for a particular patient, composition, and mode of administration, without being toxic to the patient. The selected dosage level will depend upon a variety of pharmacokinetic factors including the activity of the particular compositions employed, the route of administration, the time of administration, the rate of excretion of the particular compound being employed, the duration of the treatment, other drugs, compounds and/or materials used in combination with the particular compositions employed, the age, sex, weight, condition, general health and prior medical history of the patient being treated, and like factors well known in the medical arts.

An anti-CD20 antibody of the present invention may be administered via any suitable route, such as an oral, nasal, inhalable, intrabronchial, intraalveolar, topical (including buccal, transdermal and sublingual), rectal, vaginal and/or parenteral route In one embodiment, a pharmaceutical composition of the present invention is administered parenterally.

The phrases "parenteral administration" and "administered parenterally" as used herein means modes of administration other than enteral and topical administration, usually by injection, and include epidermal, intravenous, intramuscular, intraarterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, intratendinous, transtracheal, subcutaneous, subcuticular, intraarticular, subcapsular, subarachnoid, intraspinal, intracranial, intrathoracic, epidural and intrasternal injection and infusion. In one embodiment an anti-CD20 antibody pharmaceutical composition is administered by intravenous or subcutaneous injection or infusion. For example the pharmaceutical composition may be administered over 2-8 hours, such as 4 hours, in order to reduce side effects.

In one embodiment an anti-CD antibody pharmaceutical composition is administered by inhalation. Fab fragments of an anti-CD20 antibodies may be suitable for such administration route, cf. Crowe et al. (February 15, 1994) Proc Natl Acad Sci USA, 91 (4):1386-1390.

In one embodiment an anti-CD20 antibody pharmaceutical composition is administered in crystalline form by subcutaneous injection, cf. Yang et al., PNAS USA 100(12). 6934-6939 (2003).

Pharmaceutically acceptable carriers include any and all suitable solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonicity agents, antioxidants and absorption delaying agents, and the like that are physiologically compatible with a compound of the present invention.

Examples of suitable aqueous and nonaqueous carriers which may be employed in the pharmaceutical compositions of the present invention include water, saline, phosphate buffered saline, ethanol, dextrose, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils, such as olive oil, corn oil, peanut oil, cottonseed oil, and sesame oil, carboxymethyl cellulose colloidal solutions, tragacanth gum and injectable organic esters, such as ethyl oleate, and/or various buffers. Other carriers are well known in the pharmaceutical arts.

Pharmaceutically acceptable carriers include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. The use of such media and agents for pharmaceutically active substances is known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the pharmaceutical compositions of the present invention is contemplated.

Proper fluidity may be maintained, for example, by the use of coating materials, such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants. Pharmaceutical compositions containing an anti-CD20 antibody may also comprise pharmaceutically acceptable antioxidants for instance (1 ) water soluble antioxidants, such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite and the like; (2) oil-soluble antioxidants, such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, alpha-tocopherol, and the like; and (3) metal chelating agents, such as citric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, and the like.

Pharmaceutical compositions containing an anti-CD20 antibody may also comprise isotonicity agents, such as sugars, polyalcohols such as mannitol, sorbitol, glycerol or sodium chloride in the compositions.

Pharmaceutically acceptable diluents include saline and aqueous buffer solutions.

The pharmaceutical compositions containing an anti-CD20 antibody may also contain one or more adjuvants appropriate for the chosen route of administration, such as preservatives, wetting agents, emulsifying agents, dispersing agents, preservatives or buffers, which may enhance the shelf life or effectiveness of the pharmaceutical composition. An anti-CD20 antibody the present invention may for instance be admixed with lactose, sucrose, powders (e.g., starch powder), cellulose esters of alkanoic acids, stearic acid, talc, magnesium stearate, magnesium oxide, sodium and calcium salts of phosphoric and sulphuric acids, acacia, gelatin, sodium alginate, polyvinyl pyrrolidine, and/or polyvinyl alcohol. Other examples of adjuvants are QS21 , GM-CSF, SRL-172, histamine dihydrochloride, thymocartin, Tio-TEPA, monophosphoryl-lipid

A/microbacteria compositions, alum, incomplete Freund's adjuvant, montanide ISA, ribi adjuvant system, TiterMax adjuvant, syntex adjuvant formulations, immune-stimulating complexes (ISCOMs), gerbu adjuvant, CpG oligodeoxynucleotides, lipopolysaccharide, and polyinosinic:polycytidylic acid.

Prevention of presence of microorganisms may be ensured both by sterilization procedures and by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol, sorbic acid, and the like. In addition, prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption, such as aluminum monostearate and gelatin. The pharmaceutical compositions containing an anti-CD20 antibody may be in a variety of suitable forms. Such forms include, for example, liquid, semi-solid and solid dosage forms, such as liquid solutions (e.g., injectable and infusible solutions), dispersions or suspensions, emulsions, microemulsions, gels, creams, granules, powders, tablets, pills, powders, liposomes, dendrimers and other nanoparticles (see for instance Baek et al., Methods Enzymol. 362, 240-9 (2003), Nigavekar et al., Pharm Res. 21(3), 476-83 (2004), microparticles, and suppositories.

The optimal form depends on the mode of administration chosen and the nature of the composition. Formulations may include, for instance, powders, pastes, ointments, jellies, waxes, oils, lipids, lipid (cationic or anionic) containing vesicles, DNA conjugates, anhydrous absorption pastes, oil-in-water and water-in-oil emulsions, emulsions carbowax (polyethylene glycols of various molecular weights), semi-solid gels, and semi-solid mixtures containing carbowax. Any of the foregoing may be appropriate in treatments and therapies in accordance with the present invention, provided that the anti-CD20 antibody in the pharmaceutical composition is not inactivated by the formulation and the formulation is physiologically compatible and tolerable with the route of administration. See also for instance Powell et al., "Compendium of excipients for parenteral formulations" PDA J Pharm Sci Technol. 52, 238-31 1 (1998) and the citations therein for additional information related to excipients and carriers well known to pharmaceutical chemists.

An anti-CD20 antibody may be prepared with carriers that will protect the compound against rapid release, such as a controlled release formulation, including implants, transdermal patches, and microencapsulated delivery systems. Such carriers may include gelatin, glyceryl monostearate, glyceryl distearate, biodegradable, biocompatible polymers, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid alone or with a wax, or other materials well known in the art. Methods for the preparation of such formulations are generally known to those skilled in the art. See e.g., Sustained and Controlled Release Drug Delivery Systems, J.R. Robinson, ed., Marcel Dekker, Inc., New York, 1978. To administer the pharmaceutical compositions containing an anti-CD20 antibody by certain routes of administration according to the invention, it may be necessary to coat the anti-CD20 antibody with, or co-administer the antibody with, a material to prevent its inactivation. For example, the anti-CD20 antobody may be administered to a subject in an appropriate carrier, for example, liposomes, or a diluent. Liposomes include water-in-oil-in-water CGF emulsions as well as conventional liposomes (Strejan et al., J. Neuroimmunol. 7, 27 (1984)).

Depending on the route of administration, an anti-CD20 antibody may be coated in a material to protect the antibody from the action of acids and other natural conditions that may inactivate the compound. For example, the anti-CD20 antibody may be administered to a subject in an appropriate carrier, for example, liposomes. Liposomes include water-in-oil-in-water CGF emulsions as well as conventional liposomes (Strejan et al., J. Neuroimmunol. 7, 27 (1984)).

Pharmaceutically acceptable carriers for parenteral administration include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. The use of such media and agents for pharmaceutically active substances is known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the pharmaceutical compositions of the present invention is contemplated.

Supplementary active compounds may also be incorporated into the compositions.

Pharmaceutical compositions for injection must typically be sterile and stable under the conditions of manufacture and storage. The composition may be formulated as a solution, microemulsion, liposome, or other ordered structure suitable to high drug concentration. The carrier may be a aqueous or nonaqueous solvent or dispersion medium containing for instance water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils, such as olive oil, and injectable organic esters, such as ethyl oleate. The proper fluidity may be maintained, for example, by the use of a coating, such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols, such as glycerol, mannitol, sorbitol, or sodium chloride in the composition. Prolonged absorption of the injectable compositions may be brought about by including in the composition an agent that delays absorption, for example,

monostearate salts and gelatin. Sterile injectable solutions may be prepared by incorporating the active compound in the required amount in an appropriate solvent with one or a combination of ingredients e.g. as enumerated above, as required, followed by sterilization microfiltration.

Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle that contains a basic dispersion medium and the required other ingredients e.g. from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, examples of methods of preparation are vacuum drying and freeze-drying (lyophilization) that yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.

Sterile injectable solutions may be prepared by incorporating the active compound in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by sterilization microfiltration. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle that contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, examples of methods of preparation are vacuum drying and freeze-drying (lyophilization) that yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof. The present invention may be embodied in other specific forms, without departing from the spirit or essential attributes thereof, and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification or following examples, as indicating the scope of the invention.

As used herein, the term, "carrier", refers to a diluent, adjuvant, excipient, or vehicle with which the therapeutic is administered.

"Isolated" means altered "by the hand of man" from its natural state, i.e., if it occurs in nature, it has been changed or removed from its original environment, or both. For example, a polynucleotide or a polypeptide naturally present in a living organism is not "isolated," but the same polynucleotide or polypeptide separated from at least one of its coexisting cellular materials of its natural state is "isolated", as the term is employed herein. Moreover, a polynucleotide or polypeptide that is introduced into an organism by transformation, genetic manipulation or by any other recombinant method is "isolated" even if it is still present in said organism, which organism may be living or non-living.

As used herein, the term, "pharmaceutical", includes veterinary applications of the invention. The term, "therapeutically effective amount", refers to that amount of therapeutic agent, which is useful for alleviating a selected condition.

As used herein, the term, "pharmaceutically acceptable", means approved by a regulatory agency of the Federal or a state government or listed in the U.S.

Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans. For avoidance of doubt, in one embodiment of administering eltrombopag, suitably eltrombopag olamine with an anti-CD20 antibody is a staggered administration, whereby eltrombopag, suitably eltrombopag olamine and anti-CD20 antibody is given on alternating basis. For avoidance of doubt, either eltrombopag, suitably eltrombopag olamine or an anti-CD20 antibody may be administered first for in a staggered administration.

Example 1 . Non-limiting Example of oftatumumab/eltrombopag olamine combination administration

In order to treat thrombocytopenia, suitably immune thrombocytopenia purpura, in one embodiment, ofatumumab is administered i.v. day 1 : 300mg, day 8: 1000mg in cycle 1 , followed by 1000mg on day 1 of cycles 2 through 6; and eltrombopag olamine is administered once a day in an amount selected from: 12.5mg, 25mg, 50mg, 75mg and 100mg, (based on the weight of the fee or unsalted compound) (each cycle is every 28 days);.

In another embodiment, ofatumumab is administered i.v. day 1 : 300mg, day 8: l OOOmg in cycle 1 , followed by l OOOmg on day 1 of cycles 2 through 6 (each cycle is every 28 days for ofatumuamb); and eltrombopag olamine is administered once a day for 21 days in an amount selected from: 12.5mg, 25mg, 50mg, 75mg and 100mg, (based on the weight of the fee or unsalted compound) followed by 7 days without the administration of eltrombopag olamine (each cycle is every 28 days for eltrombopag olamine).

In further embodiment, ofatumumab may be further administered l OOOmg every 2 months for 2 years after the completion of the 6 cycles of ofatumumab (each cycle is every 28 days). In further embodiment, ofatumumab may be further administered 2000 mg every 2 months after completion of the 6 cycles of ofatumumab (each cycle is every 28 days).

In further embodiment, ofatumumab may be further administered 500 mg every 2 months after completion of the 6 cycles of ofatumumab (each cycles is 28 days).

In further embodiment, ofatumumab may be further administered 500mg, 1000 mg or 2000 mg every month or every three months after completion of the 6 cycles of ofatumumab (each cycles is 28 days). In further embodiment, ofatumumab is further administered 300-2000mg every 2 months for 2 years after the completion the 6 cycles of ofatumumab (each cycles is 28 days).

In further embodiment, ofatumumab may be further administered 300-2000mg every 2 months for 2 years after the completion of the 6 cycles of ofatumumab (each cycles is 28 days) to those subjects achieving a complete remission (CR), partial remission (PR), or stable disease (SD).

In further embodiment, eltrombopag olamine may be further administered in an amount selected from: 12.5mg, 25mg, 50mg, 75mg and 10Omg, (based on the weight of the fee or unsalted compound) every day for 2 years after the completion of the 6 cycles of ofatumumab (each cycle is every 28 days). While the preferred embodiments of the invention are illustrated by the above, it to be understood that the invention is not limited to the precise instructions herein disclosed and that the right to all modifications coming within the scope of the following claims is reserved.

Claims

What is claimed is:

1. A method of treating thrombocytopenia in a human, comprising the step of administering to such human eltrombopag or a pharmaceutically acceptable salt thereof, and an anti-CD20 antibody.

2. The method as claimed in Claim 1 , wherein the thrombocytopenia is immune thrombocytopenia purpura.

3. The method of claim 2 wherein the immune thrombocytopenia purpura is rituximab-refractory.

4. The method as claimed in Claim 3 wherein the administration of eltrombopag olamine and the anti-CD20 is simultaneous.

5. The method as claimed in Claim 1 wherein the administration of eltrombopag olamine and the anti-CD20 antibody is sequential, wherein eltrombopag olamine is administered first.

6. The method as claimed in Claim 1 wherein the administration of eltrombopag olamine and the anti-CD20 antibody is sequential, wherein the antibody is administered first.

7. The method as claimed in Claim 1 wherein the administration of eltrombopag olamine and the anti-CD20 antibody is staggered.

8. The method of Claim 3 in which an anti-CD20 antibody is ofatumumab.

9. The method of claim 8 in which ofatumumab is administered i.v. day 1 : 300mg, day 8: 1000mg in cycle 1 , followed by 1000mg on day 1 of cycles 2 through 6; and eltrombopag is administered every day of cycles 1 through 6 in an amount selected from: 12.5mg, 25mg, 50mg, 75mg and 100mg, (based on the weight of the fee or unsalted compound) (each cycle is every 28 days).

10. The method of claim 9 in which ofatumumab is further administered 10OOmg every 2 months for 2 years after the completion of the 6 cycles.

1 1 . The method of claim 9 in which ofatumumab is further administered 2000 mg every 2 months after completion of the 6 cycles.

12. The method of claim 9 in which ofatumumab is further administered 500 mg every 2 months after completion of the 6 cycles.

13. The method of claim 9 in which ofatumumab is further administered 500mg, 1000 mg or 2000 mg every month or every three months after completion of the 6 cycles.

14. The method of claim 9 in which ofatumumab is further administered 300-2000mg every 2 months for 2 years after the completion the 6 cycles.

15. The method of claim 3 in which ofatumuamb is administered iv and eltrombopag, or a pharmaceutically acceptable salt thereof, is administered orally.

16. A pharmaceutical composition comprising eltrombopag olamine and an anti-CD20 antibody wherein the combination is suitable for separate, sequential and/or simultaneous administration.

17. The pharmaceutical composition according to claim 16, wherein the anti-CD20 antibody is ofatumumab.

18. Use of an anti-CD20 antibody in the manufacture of a medicament for the treatment of immune thrombocytopenia purpura, wherein the medicament is for administration in combination therapy with eltrombopag olamine.

19. Use according to claim 18, wherein the use comprises the features of any one or more of the claims 2 to 15.

20. An anti-CD20 antibody for use in the treatment of immune thrombocytopenia purpura in combination with eltrombopag olamine.

21 . The anti-CD20 antibody for use according to claim 20, wherein the use comprises the features of any one or more of the claims 2 to 15.