Targeted binding agents directed to the antigen PDGFR-alpha and uses of such agents are disclosed herein. More specifically the invention relates to fully human monoclonal antibodies directed to the antigen PDGFR-alpha and uses of these antibodies. Aspects of the invention also relate to hybridomas or other cell lines expressing such antibodies. The described targeted binding agents and antibodies are useful as diagnostics and for the treatment of diseases associated with the activity and/or overexpression of PDGFR-alpha.

Description of the Invention

Embodiments of the invention described herein relate to targeted binding agents that bind to PDGFR-alpha. In some embodiments, the targeted binding agents are antibodies that bind to PDGFR-alpha and inhibit tumor cell growth. Other embodiments of the invention include fully human anti-PDGFR-alpha antibodies, and antibody preparations that are therapeutically useful. Such anti-PDGFR-alpha antibody preparations preferably have desirable therapeutic properties, including strong binding affinity for PDGFR-alpha, high selectivity for inhibition of PDGFR-alpha signaling, low toxicity, the ability to block PDGF-AA ligands from binding to PDGFR-alpha, the ability to block PDGF-AB ligands from binding to PDGFR-alpha or PDGFR-alpha/beta heterodimers, the ability to block PDGF-BB ligands from binding to PDGFR-alpha or PDGFR-alpha/beta heterodimers, the ability to bock PDGF-CC ligands from binding to PDGFR-alpha or PDGFR-alpha/beta heterodimers, and/or the ability to inhibit tumor cell growth in vitro and in vivo. Some embodiments relate to fully human anti-PDGFR-alpha antibodies that do not cross-react with PDGFR-beta.

Embodiments of the invention also include targeted binding agents which are isolated binding fragments of anti-PDGFR-alpha antibodies. Preferably, the binding fragments are derived from fully human anti-PDGFR-alpha antibodies. Exemplary fragments include Fv, Fab' dAb or other well-known antibody fragments, as described in more detail below. Embodiments of the invention also include cells that express fully human antibodies against PDGFR-alpha. Examples of cells include hybridomas, or recombinantly created cells, such as Chinese hamster ovary (CHO) cells that produce antibodies against PDGFR-alpha.

In addition, embodiments of the invention include methods of using these antibodies for treating diseases. Anti-PDGFR-alpha antibodies are useful for inhibiting tumor growth. The mechanism of action can include, but is not limited to, blocking ligand binding and/or inhibiting cell signaling implicated in cell growth. Diseases that are treatable through this mechanism include, but are not limited to, neoplastic diseases, such as, cancers including, lung cancer, ovarian cancer, prostate cancer, colon cancer, glioblastoma, melanoma and gastrointestinal stromal tumor (GIST).

Other embodiments of the invention include diagnostic assays for specifically determining the presence and/or quantity of PDGFR-alpha in a patient or biological sample. The assay kit can include anti-PDGFR-alpha antibodies along with the necessary labels for detecting such antibodies. These diagnostic assays are useful to screen for PDGFR-alpha-related diseases including, but not limited to, neoplastic diseases, such as cancers including, breast cancer, lung cancer, ovarian cancer, prostate cancer, colon cancer, glioblastoma, melanoma and gastrointestinal stromal tumor (GIST).

Another embodiment is an antibody comprising a heavy chain polypeptide comprising the sequence of SEQ ID NO.:2. In one embodiment, the antibody further comprises a light chain polypeptide comprising the sequence of SEQ ID NO.:4. Another embodiment includes an antibody comprising a heavy chain polypeptide comprising the sequence of SEQ ID NO.:10. In one embodiment, the antibody further comprises a light chain polypeptide comprising the sequence of SEQ ID NO.:12. Still another embodiment is an antibody comprising a heavy chain polypeptide comprising the sequence of SEQ ID NO.:14. In one embodiment, the antibody further comprises a light chain polypeptide comprising the sequence of SEQ ID NO.:16.

Yet another embodiment is a hybridoma that produces the light chain and/or the heavy chain of antibody as described hereinabove. The hybridoma may produce a light chain and/or a heavy chain of a fully human monoclonal antibody. In one embodiment, the hybridoma produces the light chain and/or the heavy chain of the fully human monoclonal antibody 2.175.3, 2.449.1.3, and 2.998.2. Alternatively the hybridoma may produce an antibody that binds to the same epitope or epitopes as fully human monoclonal antibody 2.175.3, 2.449.1.3, and 2.998.2. Alternatively the hybridoma may produce an antibody that competes for binding to PDGFR-alpha with fully human monoclonal antibody 2.175.3, 2.449.1.3, and 2.998.2.

Still another embodiment is a nucleic acid molecule encoding the light chain or the heavy chain of the antibody as described hereinabove. In this embodiment, the nucleic acid molecule may encode the light chain or the heavy chain of a fully human monoclonal antibody. In one embodiment, the nucleic acid molecule encodes the light chain or the heavy chain of one of the fully human monoclonal antibodies 2.175.3, 2.449.1.3, or 2.998.2.

An additional embodiment is a vector comprising a nucleic acid molecule or molecules as described hereinabove, wherein the vector encodes a light chain and/or a heavy chain of an antibody as defined hereinabove.

One embodiment of the invention includes a host cell comprising a vector as described hereinabove. Alternatively the host cell may comprise more than one vector.

In addition, one embodiment of the invention is a method of producing an antibody by culturing host cells under conditions wherein a nucleic acid molecule is expressed to produce the antibody, followed by recovery of the antibody.

In one embodiment the invention includes a method of making a targeted binding agent by transfecting at least one host cell with at least one nucleic acid molecule encoding the targeted binding agent as described hereinabove, expressing the nucleic acid molecule in the host cell and isolating the targeted binding agent. Another embodiment of the invention is a method of making an antibody by transfecting at least one host cell with at least one nucleic acid molecule encoding the antibody as described hereinabove, expressing the nucleic acid molecule in the host cell and isolating the antibody.

Another aspect of the invention is a method of inhibiting the growth of cells that express PDGFR-alpha by administering a targeted binding agent as described hereinabove. The method may include selecting an animal in need of treatment for disease-related to PDGFR-alpha expression, and administering to the animal a therapeutically effective dose of a targeted binding agent that specifically binds to PDGFR-alpha.

Still another aspect is a method of treating a neoplastic disease in a mammal by administering a therapeutically effective amount of a targeted binding agent that specifically binds PDGFR-alpha. The method may include selecting an animal in need of treatment for a neoplastic disease, and administering to the animal a therapeutically effective dose of a targeted binding agent that specifically binds PDGFR-alpha. The agent can be administered alone, or can be administered in combination with a second anti-neoplastic agent selected from an antibody, a chemotherapeutic drug, or a radioactive drug.

One other aspect is a method of treating cancer in a mammal by administering a therapeutically effective amount of a targeted binding agent that specifically binds PDGFR-alpha. The method may include selecting an animal in need of treatment for cancer, and administering to the animal a therapeutically effective dose of a targeted binding agent that specifically binds PDGFR-alpha. The agent can be administered alone, or can be administered in combination with a second anti-neoplastic agent selected from an antibody, a chemotherapeutic drug, or a radioactive drug.

According to another aspect of the invention a targeted binding agent can be used that specifically binds PDGFR-alpha for the manufacture of a medicament for the treatment of a neoplastic disease.

One embodiment the invention is particularly suitable for use in inhibiting tumor growth in patients with a tumor that is dependent alone, or in part, on PDGFR-alpha expression.

Another embodiment of the invention includes an assay kit for detecting PDGFR-alpha in mammalian tissues, cells, or body fluids to screen for neoplastic and/or fibrotic and/or immune system diseases. The kit includes a targeted binding agent that binds to PDGFR-alpha and a means for indicating the reaction of the targeted binding agent with PDGFR-alpha, if present. The targeted binding agent may be a monoclonal antibody. In one embodiment, the antibody that binds PDGFR-alpha is labeled. In another embodiment the antibody is an unlabeled primary antibody and the kit further includes a means for detecting the primary antibody. In one embodiment, the means includes a labeled second antibody that is an anti-immunoglobulin. Preferably the antibody is labeled with a marker selected from the group consisting of a fluorochrome, an enzyme, a radionuclide and a radio-opaque material.

Further embodiments, features, and the like regarding anti-PDGFR-alpha antibodies are provided in additional detail below.

Antibody Structure

The basic antibody structural unit is known to comprise a tetramer. Each tetramer is composed of two identical pairs of polypeptide chains, each pair having one "light" (about 25 kDa) and one "heavy" chain (about 50-70 kDa). The amino-terminal portion of each chain includes a variable region of about 100 to 110 or more amino acids primarily responsible for antigen recognition. The carboxy-terminal portion of each chain defines a constant region primarily responsible for effector function. Human light chains are classified as kappa and lambda light chains. Heavy chains are classified as mu, delta, gamma, alpha, or epsilon, and define the antibody's isotype as IgM, IgD, IgA, and IgE, respectively. Within light and heavy chains, the variable and constant regions are joined by a "J" region of about 12 or more amino acids, with the heavy chain also including a "D" region of about 10 more amino acids. See generally, Fundamental Immunology Ch. 7 (Paul, W., ed., 2nd ed. Raven Press, N.Y. (1989)) (incorporated by reference in its entirety for all purposes). The variable regions of each light/heavy chain pair form the antibody binding site.

Thus, an intact antibody has two binding sites. Except in bifunctional or bispecific antibodies, the two binding sites are the same.

The chains all exhibit the same general structure of relatively conserved framework regions (FR) joined by three hyper variable regions, also called complementarity determining regions or CDRs. The CDRs from the two chains of each pair are aligned by the framework regions, enabling binding to a specific epitope. From N-terminal to C-terminal, both light and heavy chains comprise the domains FR1, CDR1, FR2, CDR2, FR3, CDR3 and FR4. The assignment of amino acids to each domain is in accordance with the definitions of Kabat Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md. (1987 and 1991)), or Chothia & Lesk J. Mol. Biol. 196:901-917 (1987); Chothia et al. Nature 342:878-883 (1989).

A bispecific or bifunctional antibody is an artificial hybrid antibody having two different heavy/light chain pairs and two different binding sites. Bispecific antibodies can be produced by a variety of methods including fusion of hybridomas or linking of Fab' fragments. See, e.g., Songsivilai & Lachmann Clin. Exp. Immunol. 79: 315-321 (1990), Kostelny et al. J. Immunol. 148:1547-1553 (1992). Bispecific antibodies do not exist in the form of fragments having a single binding site (e.g., Fab, Fab', and Fv).

Typically, a VH domain is paired with a VL domain to provide an antibody antigen-binding site, although a VH or VL domain alone may be used to bind antigen. The VH domain (see Table 12 (see Original Patent)) may be paired with the VL domain (see Table 13 (see Original Patent)), so that an antibody antigen-binding site is formed comprising both the VH and VL domains.

Human Antibodies and Humanization of Antibodies

Human antibodies avoid some of the problems associated with antibodies that possess murine or rat variable and/or constant regions. The presence of such murine or rat derived proteins can lead to the rapid clearance of the antibodies or can lead to the generation of an immune response against the antibody by a patient. In order to avoid the utilization of murine or rat derived antibodies, fully human antibodies can be generated through the introduction of functional human antibody loci into a rodent, other mammal or animal so that the rodent, other mammal or animal produces fully human antibodies.

One method for generating fully human antibodies is through the use of XenoMouse.RTM. strains of mice that have been engineered to contain up to but less than 1000 kb-sized germline configured fragments of the human heavy chain locus and kappa light chain locus. See Mendez et al. Nature Genetics 15:146-156 (1997) and Green and Jakobovits J. Exp. Med. 188:483-495 (1998). The XenoMouse.RTM. strains are available from Amgen, Inc. (Fremont, Calif., U.S.A).

Such mice, then, are capable of producing human immunoglobulin molecules and antibodies and are deficient in the production of murine immunoglobulin molecules and antibodies. Technologies utilized for achieving the same are disclosed in U.S. patent application Ser. No. 08/759,620, filed Dec. 3, 1996 and International Patent Application Nos. WO 98/24893, published Jun. 11, 1998 and WO 00/76310, published Dec. 21, 2000, the disclosures of which are hereby incorporated by reference. See also Mendez et al. Nature Genetics 15:146-156 (1997), the disclosure of which is hereby incorporated by reference.

The production of the XenoMouse.RTM. strains of mice is further discussed and delineated in U.S. patent application Ser. Nos. 07/466,008, filed Jan. 12, 1990, 07/610,515, filed Nov. 8, 1990, 07/919,297, filed Jul. 24, 1992, 07/922,649, filed Jul. 30, 1992, 08/031,801, filed Mar. 15, 1993, 08/112,848, filed Aug. 27, 1993, 08/234,145, filed Apr. 28, 1994, 08/376,279, filed Jan. 20, 1995, 08/430,938, filed Apr. 27, 1995, 08/464,584, filed Jun. 5, 1995, 08/464,582, filed Jun. 5, 1995, 08/463,191, filed Jun. 5, 1995, 08/462,837, filed Jun. 5, 1995, 08/486,853, filed Jun. 5, 1995, 08/486,857, filed Jun. 5, 1995, 08/486,859, filed Jun. 5, 1995, 08/462,513, filed Jun. 5, 1995, 08/724,752, filed Oct. 2, 1996, 08/759,620, filed Dec. 3, 1996, U.S. Publication 2003/0093820, filed Nov. 30, 2001 and U.S. Pat. Nos. 6,162,963, 6,150,584, 6,114,598, 6,075,181, and 5,939,598 and Japanese Patent Nos. 3 068 180 B2, 3 068 506 B2, and 3 068 507 B2. See also European Patent No., EP 0 463 151 B1, grant published Jun. 12, 1996, International Patent Application No., WO 94/02602, published Feb. 3, 1994, International Patent Application No., WO 96/34096, published Oct. 31, 1996, WO 98/24893, published Jun. 11, 1998, WO 00/76310, published Dec. 21, 2000. The disclosures of each of the above-cited patents, applications, and references are hereby incorporated by reference in their entirety.

In an alternative approach, others, including GenPharm International, Inc., have utilized a "minilocus" approach. In the minilocus approach, an exogenous Ig locus is mimicked through the inclusion of pieces (individual genes) from the Ig locus. Thus, one or more VH genes, one or more DH genes, one or more JH genes, a mu constant region, and usually a second constant region (preferably a gamma constant region) are formed into a construct for insertion into an animal. This approach is described in U.S. Pat. No. 5,545,807 to Surani et al. and U.S. Pat. Nos. 5,545,806, 5,625,825, 5,625,126, 5,633,425, 5,661,016, 5,770,429, 5,789,650, 5,814,318, 5,877,397, 5,874,299, and 6,255,458 each to Lonberg and Kay, U.S. Pat. Nos. 5,591,669 and 6,023.010 to Krimpenfort and Berns, U.S. Pat. Nos. 5,612,205, 5,721,367, and 5,789,215 to Berns et al., and U.S. Pat. No. 5,643,763 to Choi and Dunn, and GenPharm International U.S. patent application Ser. Nos. 07/574,748, filed Aug. 29, 1990, 07/575,962, filed Aug. 31, 1990, 07/810,279, filed Dec. 17, 1991, 07/853,408, filed Mar. 18, 1992, 07/904,068, filed Jun. 23, 1992, 07/990,860, filed Dec. 16, 1992, 08/053,131, filed Apr. 26, 1993, 08/096,762, filed Jul. 22, 1993, 08/155,301, filed Nov. 18, 1993, 08/161,739, filed Dec. 3, 1993, 08/165,699, filed Dec. 10, 1993, 08/209,741, filed Mar. 9, 1994, the disclosures of which are hereby incorporated by reference. See also European Patent No. 0 546 073 B1, International Patent Application Nos. WO 92/03918, WO 92/22645, WO 92/22647, WO 92/22670, WO 93/12227, WO 94/00569, WO 94/25585, WO 96/14436, WO 97/13852, and WO 98/24884 and U.S. Pat. No. 5,981,175, the disclosures of which are hereby incorporated by reference in their entirety. See further Taylor et al., 1992, Chen et al., 1993, Tuaillon et al., 1993, Choi et al., 1993, Lonberg et al., (1994), Taylor et al., (1994), and Tuaillon et al., (1995), Fishwild et al., (1996), the disclosures of which are hereby incorporated by reference in their entirety.

Kirin has also demonstrated the generation of human antibodies from mice in which, through microcell fusion, large pieces of chromosomes, or entire chromosomes, have been introduced. See European Patent Application Nos. 773 288 and 843 961, the disclosures of which are hereby incorporated by reference. Additionally, KMTM--mice, which are the result of cross-breeding of Kirin's Tc mice with Medarex's minilocus (Humab) mice have been generated. These mice possess the human IgH transchromosome of the Kirin mice and the kappa chain transgene of the Genpharm mice (Ishida et al., Cloning Stem Cells, (2002) 4:91-102).

Human antibodies can also be derived by in vitro methods. Suitable examples include but are not limited to phage display (CAT, Morphosys, Dyax, Biosite/Medarex, Xoma, Symphogen, Alexion (formerly Proliferon), Affimed) ribosome display (CAT), yeast display, and the like.

In another embodiment, the antibodies of the invention the compete with the disclosed antibodies. Competition between antibodies may be assayed easily in vitro, for example using ELISA and/or by tagging a specific reporter molecule to one binding member which can be detected in the presence of one or more other untagged antibodies, to enable identification of antibodies which bind the same epitope or an overlapping epitope. Such methods are readily known to one of ordinary skill in the art, and are described in more detail herein. Thus, a further aspect of the present invention provides an antigen binding site comprising a human antibody antigen-binding site that competes with an antibody molecule, for example especially an antibody molecule comprising a VH and/or VL domain, CDR e.g. HCDR3 or set of CDRs of the parent antibody or any of antibodies disclosed herein that bind to PDGFR-alpha. In one embodiment, the an antibody of the invention competes with 2.175.3, 2.449.1.3 and/or 2.998.2.

Preparation of Antibodies

In general, antibodies produced by the fused hybridomas were human IgG2 or IgG4 heavy chains with fully human kappa or lambda light chains. Antibodies can also be of other human isotypes, including IgG1 heavy chains. The antibodies possessed high affinities, typically possessing a Kd of from about 10-6 through about 10-12 M or below, when measured against cells in FACS-based affinity measurement techniques. The affinity can also be measured by solid phase and solution phase techniques. In one embodiment, the antibodies described herein bind CD PDGFR-alpha 20 with a Kd of less than about 500, 400, 300, 200 or 100 picomolar (pM) and inhibit tumor growth. In some embodiments, the antibodies bind PDGFR-alpha with a Kd of less than about 75, 60, 50, 40, 30, 25, 20, 10, or 5 pM.

As will be appreciated, anti-PDGFR-alpha antibodies can be expressed in cell lines other than hybridoma cell lines. Sequences encoding particular antibodies can be used to transform a suitable mammalian host cell. Transformation can be by any known method for introducing polynucleotides into a host cell, including, for example packaging the polynucleotide in a virus (or into a viral vector) and transducing a host cell with the virus (or vector) or by transfection procedures known in the art, as exemplified by U.S. Pat. Nos. 4,399,216, 4,912,040, 4,740,461, and 4,959,455 (which patents are hereby incorporated herein by reference). The transformation procedure used depends upon the host to be transformed. Methods for introducing heterologous polynucleotides into mammalian cells are well known in the art and include dextran-mediated transfection, calcium phosphate precipitation, polybrene mediated transfection, protoplast fusion, electroporation, encapsulation of the polynucleotide(s) in liposomes, and direct microinjection of the DNA into nuclei.

Mammalian cell lines available as hosts for expression are well known in the art and include many immortalized cell lines available from the American Type Culture Collection (ATCC), including but not limited to Chinese hamster ovary (CHO) cells, HeLa cells, baby hamster kidney (BHK) cells, monkey kidney cells (COS), human hepatocellular carcinoma cells (e.g., Hep G2), human epithelial kidney 293 cells, and a number of other cell lines. Cell lines of particular preference are selected through determining which cell lines have high expression levels and produce antibodies with constitutive PDGFR-alpha binding properties.

Anti-PDGFR-alpha antibodies are useful in the detection of PDGFR-alpha in patient samples and accordingly are useful as diagnostics for disease states as described herein. In addition, based on their ability to inhibit tumor growth, anti-PDGFR-alpha antibodies have therapeutic effects in treating symptoms and conditions resulting from PDGFR-alpha expression. In specific embodiments, the antibodies and methods herein relate to the treatment of symptoms resulting from PDGFR-alpha induced tumor growth. Further embodiments involve using the antibodies and methods described herein to treat neoplastic diseases, such as cancers including, lung cancer, ovarian cancer, prostate cancer, colon cancer, glioblastoma, melanoma and gastrointestinal stromal tumor (GIST).

Antibody Sequences

Embodiments of the invention include the specific anti-PDGFR-alpha antibodies listed below in Table 1 (see Original Patent). This table reports the identification number of each anti-PDGFR-alpha antibody, along with the SEQ ID number of variable regions of the corresponding heavy chain and light chain genes.

Each antibody has been given an identification number that includes either two or three numbers separated by one or two decimal points. In some cases, only two identification numbers separated by one decimal point are listed. However, in some cases, several clones of one antibody were prepared. Although the clones have the identical nucleic acid and amino acid sequences as the parent sequence, they may also be listed separately, with the clone number indicated by the number to the right of a second decimal point. Thus, for example, the nucleic acid and amino acid sequences of antibody 2.84 are identical to the sequences of antibody 2.84.1, 2.84.2, and 2.84.3.

Antibodies, as described herein in the Examples, were prepared through the utilization of the XenoMouse.RTM. technology, as described below. Such mice, then, are capable of producing human immunoglobulin molecules and antibodies and are deficient in the production of murine immunoglobulin molecules and antibodies. Technologies utilized for achieving the same are disclosed in the patents, applications, and references disclosed in the background section herein. In particular, however, a preferred embodiment of transgenic production of mice and antibodies therefrom is disclosed in U.S. patent application Ser. No. 08/759,620, filed Dec. 3, 1996 and International Patent Application Nos. WO 98/24893, published Jun. 11, 1998 and WO 00/76310, published Dec. 21, 2000, the disclosures of which are hereby incorporated by reference. See also Mendez et al. Nature Genetics 15:146-156 (1997), the disclosure of which is hereby incorporated by reference.

Through the use of such technology, fully human monoclonal antibodies to a variety of antigens have been produced. Essentially, XenoMouse.RTM. lines of mice are immunized with an antigen of interest (e.g. PDGFR-alpha), lymphatic cells (such as B-cells) are recovered from the hyper-immunized mice, and the recovered lymphocytes are fused with a myeloid-type cell line to prepare immortal hybridoma cell lines. These hybridoma cell lines are screened and selected to identify hybridoma cell lines that produced antibodies specific to the antigen of interest. Provided herein are methods for the production of multiple hybridoma cell lines that produce antibodies specific to PDGFR-alpha. Further, provided herein are characterization of the antibodies produced by such cell lines, including nucleotide and amino acid sequence analyses of the heavy and light chains of such antibodies.

Alternatively, instead of being fused to myeloma cells to generate hybridomas, B cells can be directly assayed. For example, CD19+ B cells can be isolated from hyperimmune XenoMouse.RTM. mice and allowed to proliferate and differentiate into antibody-secreting plasma cells. Antibodies from the cell supernatants are then screened by ELISA for reactivity against the PDGFR-alpha immunogen. The supernatants might also be screened for immunoreactivity against fragments of PDGFR-alpha to further map the different antibodies for binding to domains of functional interest on PDGFR-alpha. The antibodies may also be screened other related human receptors and against the rat, the mouse, and non-human primate, such as Cynomolgus monkey, orthologues of PDGFR-alpha, the last to determine species cross-reactivity. B cells from wells containing antibodies of interest may be immortalized by various methods including fusion to make hybridomas either from individual or from pooled wells, or by infection with EBV or transfection by known immortalizing genes and then plating in suitable medium. Alternatively, single plasma cells secreting antibodies with the desired specificities are then isolated using a PDGFR-alpha-specific hemolytic plaque assay (see for example Babcook et al., Proc. Natl. Acad. Sci. USA 93:7843-48 (1996)). Cells targeted for lysis are preferably sheep red blood cells (SRBCs) coated with the PDGFR-alpha antigen.

In the presence of a B-cell culture containing plasma cells secreting the immunoglobulin of interest and complement, the formation of a plaque indicates specific PDGFR-alpha-mediated lysis of the sheep red blood cells surrounding the plasma cell of interest. The single antigen-specific plasma cell in the center of the plaque can be isolated and the genetic information that encodes the specificity of the antibody is isolated from the single plasma cell. Using reverse-transcription followed by PCR (RT-PCR), the DNA encoding the heavy and light chain variable regions of the antibody can be cloned. Such cloned DNA can then be further inserted into a suitable expression vector, preferably a vector cassette such as a pcDNA, more preferably such a pcDNA vector containing the constant domains of immunoglobulin heavy and light chain. The generated vector can then be transfected into host cells, e.g., HEK293 cells, CHO cells, and cultured in conventional nutrient media modified as appropriate for inducing transcription, selecting transformants, or amplifying the genes encoding the desired sequences.

Anti-PDGFR-alpha antibodies can have therapeutic effects in treating symptoms and conditions related to PDGFR-alpha expression. For example, the antibodies can inhibit growth of cells expressing PDGFR-alpha, thereby inhibiting tumor growth, or the antibodies can be associated with an agent and deliver a lethal toxin to a targeted cell. Anti-PDGFR-alpha antibodies can have therapeutic effects in treating fibrotic diseases, such as cardiac, lung, liver, kidney or skin fibrosis. Anti-PDGFR-alpha antibodies can also have therapeutic effects in the treatment of allograft vasculopathy or restenosis. In addition, the anti-PDGFR-alpha antibodies are useful as diagnostics for the disease states, especially neoplastic, fibrotic and immune system diseases.

If desired, the isotype of an anti-PDGFR-alpha antibody can be switched, for example to take advantage of a biological property of a different isotype. For example, in some circumstances it can be desirable in connection with the generation of antibodies as therapeutic antibodies against PDGFR-alpha that the antibodies be capable of fixing complement and participating in complement-dependent cytotoxicity (CDC). There are a number of isotypes of antibodies that are capable of the same, including, without limitation, the following: murine IgM, murine IgG2a, murine IgG2b, murine IgG3, human IgM, human IgA, human IgG1, and human IgG3. In other embodiments it can be desirable in connection with the generation of antibodies as therapeutic antibodies against PDGFR-alpha that the antibodies be capable of binding Fc receptors on effector cells and participating in antibody-dependent cytotoxicity (ADCC). There are a number of isotypes of antibodies that are capable of the same, including, without limitation, the following: murine IgG2a, murine IgG2b, murine IgG3, human IgG1, and human IgG3. It will be appreciated that antibodies that are generated need not initially possess such an isotype but, rather, the antibody as generated can possess any isotype and the antibody can be isotype switched thereafter using conventional techniques that are well known in the art. Such techniques include the use of direct recombinant techniques (see e.g., U.S. Pat. No. 4,816,397), cell-cell fusion techniques (see e.g., U.S. Pat. Nos. 5,916,771 and 6,207,418), among others.

By way of example, the anti-PDGFR-alpha antibodies discussed herein are fully human antibodies. If an antibody possessed desired binding to PDGFR-alpha, it could be readily isotype switched to generate a human IgM, human IgG1, or human IgG3 isotype, while still possessing the same variable region (which defines the antibody's specificity and some of its affinity). Such molecule would then be capable of fixing complement and participating in CDC and/or be capable of binding to Fc receptors on effector cells and participating in ADCC.

In the cell-cell fusion technique, a myeloma, CHO cell or other cell line is prepared that possesses a heavy chain with any desired isotype and another myeloma, CHO cell or other cell line is prepared that possesses the light chain. Such cells can, thereafter, be fused and a cell line expressing an intact antibody can be isolated.

Accordingly, as antibody candidates are generated that meet desired "structural" attributes as discussed above, they can generally be provided with at least certain of the desired "functional" attributes through isotype switching.

Therapeutic Administration and Formulations

Embodiments of the invention include sterile pharmaceutical formulations of anti-PDGFR-alpha antibodies that are useful as treatments for diseases. Such formulations would inhibit cell growth, thereby effectively treating pathological conditions where, for example, PDGFR-alpha expression is abnormally elevated or PDGFR-alpha expressing cells mediate disease states. Anti-PDGFR-alpha antibodies preferably possess adequate affinity to specifically bind PDGFR-alpha, and preferably have an adequate duration of action to allow for infrequent dosing in humans. A prolonged duration of action will allow for less frequent and more convenient dosing schedules by alternate parenteral routes such as subcutaneous or intramuscular injection.

Sterile formulations can be created, for example, by filtration through sterile filtration membranes, prior to or following lyophilization and reconstitution of the antibody. The antibody ordinarily will be stored in lyophilized form or in solution. Therapeutic antibody compositions generally are placed into a container having a sterile access port, for example, an intravenous solution bag or vial having an adapter that allows retrieval of the formulation, such as a stopper pierceable by a hypodermic injection needle.

The route of antibody administration is in accord with known methods, e.g., injection or infusion by intravenous, intraperitoneal, intracerebral, intramuscular, intraocular, intraarterial, intrathecal, inhalation or intralesional routes, or by sustained release systems as noted below. The antibody is preferably administered continuously by infusion or by bolus injection.

An effective amount of antibody to be employed therapeutically will depend, for example, upon the therapeutic objectives, the route of administration, and the condition of the patient. Accordingly, it is preferred that the therapist titer the dosage and modify the route of administration as required to obtain the optimal therapeutic effect. Typically, the clinician will administer antibody until a dosage is reached that achieves the desired effect. The progress of this therapy is easily monitored by conventional assays or by the assays described herein.

Antibodies, as described herein, can be prepared in a mixture with a pharmaceutically acceptable carrier. This therapeutic composition can be administered intravenously or through the nose or lung, preferably as a liquid or powder aerosol (lyophilized). The composition can also be administered parenterally or subcutaneously as desired. When administered systemically, the therapeutic composition should be sterile, pyrogen-free and in a parenterally acceptable solution having due regard for pH, isotonicity, and stability. These conditions are known to those skilled in the art. Briefly, dosage formulations of the compounds described herein are prepared for storage or administration by mixing the compound having the desired degree of purity with physiologically acceptable carriers, excipients, or stabilizers. Such materials are non-toxic to the recipients at the dosages and concentrations employed, and include buffers such as TRIS HCl, phosphate, citrate, acetate and other organic acid salts; antioxidants such as ascorbic acid; low molecular weight (less than about ten residues) peptides such as polyarginine, proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidinone; amino acids such as glycine, glutamic acid, aspartic acid, or arginine; monosaccharides, disaccharides, and other carbohydrates including cellulose or its derivatives, glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; counterions such as sodium and/or nonionic surfactants such as TWEEN, PLURONICS or polyethyleneglycol. To set up animal xenograft studies, mouse cross-reactivity was determined using FACS analysis performed with NIH3T3 cells, a murine fibroblast line which expresses endogenous PDGFRa. NIH3T3 cells were incubated at 0.5.times.106 cells/ml with 10 ug/ml of test antibodies on ice for 1 h, rinsed and then resuspended in PBS with 5 ug/ml of goat-anti-human IgG antibodies labeled with Cy5. Cells were rinsed and analyzed by FACS for the presence of Cy5. Only 3 of the tested monoclonal antibodies exhibited mouse cross-reactivity. Results are summarized in Table 5 (see Original Patent).

Sterile compositions for injection can be formulated according to conventional pharmaceutical practice as described in Remington: The Science and Practice of Pharmacy (20th ed, Lippincott Williams & Wilkens Publishers (2003)). For example, dissolution or suspension of the active compound in a vehicle such as water or naturally occurring vegetable oil like sesame, peanut, or cottonseed oil or a synthetic fatty vehicle like ethyl oleate or the like can be desired. Buffers, preservatives, antioxidants and the like can be incorporated according to accepted pharmaceutical practice.

Suitable examples of sustained-release preparations include semipermeable matrices of solid hydrophobic polymers containing the polypeptide, which matrices are in the form of shaped articles, films or microcapsules. Examples of sustained-release matrices include polyesters, hydrogels (e.g., poly(2-hydroxyethyl-methacrylate) as described by Langer et al., J. Biomed Mater. Res., (1981) 15:167-277 and Langer, Chem. Tech., (1982) 12:98-105, or poly(vinylalcohol)), polylactides (U.S. Pat. No. 3,773,919, EP 58,481), copolymers of L-glutamic acid and gamma ethyl-L-glutamate (Sidman et al., Biopolymers, (1983) 22:547-556), non-degradable ethylene-vinyl acetate (Langer et al., supra), degradable lactic acid-glycolic acid copolymers such as the LUPRON Depot.TM. (injectable microspheres composed of lactic acid-glycolic acid copolymer and leuprolide acetate), and poly-D-(-)-3-hydroxybutyric acid (EP 133,988).

While polymers such as ethylene-vinyl acetate and lactic acid-glycolic acid enable release of molecules for over 100 days, certain hydrogels release proteins for shorter time periods. When encapsulated proteins remain in the body for a long time, they can denature or aggregate as a result of exposure to moisture at 37.degree. C., resulting in a loss of biological activity and possible changes in immunogenicity. Rational strategies can be devised for protein stabilization depending on the mechanism involved. For example, if the aggregation mechanism is discovered to be intermolecular S--S bond formation through disulfide interchange, stabilization can be achieved by modifying sulfhydryl residues, lyophilizing from acidic solutions, controlling moisture content, using appropriate additives, and developing specific polymer matrix compositions.

Sustained-released compositions also include preparations of crystals of the antibody suspended in suitable formulations capable of maintaining crystals in suspension. These preparations when injected subcutaneously or intraperitonealy can produce a sustained release effect. Other compositions also include liposomally entrapped antibodies. Liposomes containing such antibodies are prepared by methods known per se: U.S. Pat. No. DE 3,218,121; Epstein et al., Proc. Natl. Acad. Sci. USA, (1985) 82:3688-3692; Hwang et al., Proc. Natl. Acad. Sci. USA, (1980) 77:4030-4034; EP 52,322; EP 36,676; EP 88,046; EP 143,949; 142,641; Japanese patent application 83-118008; U.S. Pat. Nos. 4,485,045 and 4,544,545; and EP 102,324.

The dosage of the antibody formulation for a given patient will be determined by the attending physician taking into consideration various factors known to modify the action of drugs including severity and type of disease, body weight, sex, diet, time and route of administration, other medications and other relevant clinical factors. Therapeutically effective dosages can be determined by either in vitro or in vivo methods.

An effective amount of the antibodies, described herein, to be employed therapeutically will depend, for example, upon the therapeutic objectives, the route of administration, and the condition of the patient. Accordingly, it is preferred for the therapist to titer the dosage and modify the route of administration as required to obtain the optimal therapeutic effect. A typical daily dosage might range from about 0.001 mg/kg to up to 100 mg/kg or more, depending on the factors mentioned above. Typically, the clinician will administer the therapeutic antibody until a dosage is reached that achieves the desired effect. The progress of this therapy is easily monitored by conventional assays or as described herein.

It will be appreciated that administration of therapeutic entities in accordance with the compositions and methods herein will be administered with suitable carriers, excipients, and other agents that are incorporated into formulations to provide improved transfer, delivery, tolerance, and the like. These formulations include, for example, powders, pastes, ointments, jellies, waxes, oils, lipids, lipid (cationic or anionic) containing vesicles (such as Lipofectin.TM.), 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 mixtures can be appropriate in treatments and therapies in accordance with the present invention, provided that the active ingredient in the formulation is not inactivated by the formulation and the formulation is physiologically compatible and tolerable with the route of administration. See also Baldrick P. "Pharmaceutical excipient development: the need for preclinical guidance." Regul. Toxicol. Pharmacol. 32 (2):210-8 (2000), Wang W. "Lyophilization and development of solid protein pharmaceuticals." Int. J. Pharm. 203 (1-2):1-60 (2000), Charman W N "Lipids, lipophilic drugs, and oral drug delivery-some emerging concepts." J Pharm Sci 0.89 (8):967-78 (2000), Powell et al. "Compendium of excipients for parenteral formulations" PDA J Pharm Sci Technol. 52:238-311 (1998) and the citations therein for additional information related to formulations, excipients and carriers well known to pharmaceutical chemists.

Design and Generation of Other Therapeutics

In accordance with the present invention and based on the activity of the antibodies that are produced and characterized herein with respect to PDGFR-alpha, the design of other therapeutic modalities is facilitated and disclosed to one of skill in the art. Such modalities include, without limitation, advanced antibody therapeutics, such as bispecific antibodies, immunotoxins, radiolabeled therapeutics, and single antibody V domains, antibody-like binding agent based on other than V region scaffolds, generation of peptide therapeutics, gene therapies, particularly intrabodies, antisense therapeutics, and small molecules.

An antigen binding site may be provided by means of arrangement of CDRs on non-antibody protein scaffolds, such as fibronectin or cytochrome B etc. (Haan & Maggos (2004) BioCentury, 12 (5): A1-A6; Koide et al. (1998) Journal of Molecular Biology, 284: 1141-1151; Nygren et al. (1997) Current Opinion in Structural Biology, 7: 463-469) or by randomising or mutating amino acid residues of a loop within a protein scaffold to confer binding specificity for a desired target. Scaffolds for engineering novel binding sites in proteins have been reviewed in detail by Nygren et al. (Nygren et al. (1997) Current Opinion in Structural Biology, 7: 463-469). Protein scaffolds for antibody mimics are disclosed in WO/0034784, which is herein incorporated by reference in its entirety, in which the inventors describe proteins (antibody mimics) that include a fibronectin type III domain having at least one randomised loop. A suitable scaffold into which to graft one or more CDRs, e.g. a set of HCDRs, may be provided by any domain member of the immunoglobulin gene superfamily. The scaffold may be a human or non-human protein. An advantage of a non-antibody protein scaffold is that it may provide an antigen-binding site in a scaffold molecule that is smaller and/or easier to manufacture than at least some antibody molecules. Small size of a binding member may confer useful physiological properties, such as an ability to enter cells, penetrate deep into tissues or reach targets within other structures, or to bind within protein cavities of the target antigen. Use of antigen binding sites in non-antibody protein scaffolds is reviewed in Wess, 2004 (Wess, L. In: BioCentury, The Bernstein Report on BioBusiness, 12 (42), A1-A7, 2004). Typical are proteins having a stable backbone and one or more variable loops, in which the amino acid sequence of the loop or loops is specifically or randomly mutated to create an antigen-binding site that binds the target antigen. Such proteins include the IgG-binding domains of protein A from S. aureus, transferrin, albumin, tetranectin, fibronectin (e.g. 10th fibronectin type III domain), lipocalins as well as gamma-crystalline and other Affilin.TM. scaffolds (Scil Proteins). Examples of other approaches include synthetic "Microbodies" based on cyclotides--small proteins having intra-molecular disulphide bonds, Microproteins (Versabodies.TM., Amunix) and ankyrin repeat proteins (DARPins, Molecular Partners).

In addition to antibody sequences and/or an antigen-binding site, a targeted binding agent according to the present invention may comprise other amino acids, e.g. forming a peptide or polypeptide, such as a folded domain, or to impart to the molecule another functional characteristic in addition to ability to bind antigen. Targeted binding agents of the invention may carry a detectable label, or may be conjugated to a toxin or a targeting moiety or enzyme (e.g. via a peptidyl bond or linker). For example, a targeted binding agent may comprise a catalytic site (e.g. in an enzyme domain) as well as an antigen binding site, wherein the antigen binding site binds to the antigen and thus targets the catalytic site to the antigen. The catalytic site may inhibit biological function of the antigen, e.g. by cleavage.

In connection with the generation of advanced antibody therapeutics, where complement fixation is a desirable attribute, it can be possible to sidestep the dependence on complement for cell killing through the use of bispecifics, immunotoxins, or radiolabels, for example.

For example, bispecific antibodies can be generated that comprise (i) two antibodies, one with a specificity to PDGFR-alpha and another to a second molecule, that are conjugated together, (ii) a single antibody that has one chain specific to PDGFR-alpha and a second chain specific to a second molecule, or (iii) a single chain antibody that has specificity to both PDGFR-alpha and the other molecule. Such bispecific antibodies can be generated using techniques that are well known; for example, in connection with (i) and (ii) see e.g., Fanger et al. Immunol Methods 4:72-81 (1994) and Wright and Harris, supra. and in connection with (iii) see e.g., Traunecker et al. Int. J. Cancer (Suppl.) 7:51-52 (1992). In each case, the second specificity can be made as desired. For example, the second specificity can be made to the heavy chain activation receptors, including, without limitation, CD16 or CD64 (see e.g., Deo et al. 18:127 (1997)) or CD89 (see e.g., Valerius et al. Blood 90:4485-4492 (1997)).

Antibodies can also be modified to act as immunotoxins utilizing techniques that are well known in the art. See e.g., Vitetta Immunol Today 14:252 (1993). See also U.S. Pat. No. 5,194,594. In connection with the preparation of radiolabeled antibodies, such modified antibodies can also be readily prepared utilizing techniques that are well known in the art. See e.g., Junghans et al. in Cancer Chemotherapy and Biotherapy 655-686 (2d edition, Chafner and Longo, eds., Lippincott Raven (1996)). See also U.S. Pat. Nos. 4,681,581, 4,735,210, 5,101,827, 5,102,990 (RE 35,500), 5,648,471, and 5,697,902. Each of immunotoxins and radiolabeled molecules would be likely to kill cells expressing the desired multimeric enzyme subunit oligomerization domain. In some embodiments, a pharmaceutical composition comprising an effective amount of the antibody in association with a pharmaceutically acceptable carrier or diluent is provided.

In some embodiments, an anti-PDGFR-alpha antibody is linked to an agent (e.g., radioisotope, pharmaceutical composition, or a toxin). Preferably, such antibodies can be used for the treatment of diseases, such diseases can relate cells expressing PDGFR-alpha or cells overexpressing PDGFR-alpha. For example, it is contemplated that the drug possesses the pharmaceutical property selected from the group of antimitotic, alkylating, antimetabolite, antiangiogenic, apoptotic, alkaloid, COX-2, and antibiotic agents and combinations thereof. The drug can be selected from the group of nitrogen mustards, ethylenimine derivatives, alkyl sulfonates, nitrosoureas, triazenes, folic acid analogs, anthracyclines, taxanes, COX-2 inhibitors, pyrimidine analogs, purine analogs, antimetabolites, antibiotics, enzymes, epipodophyllotoxins, platinum coordination complexes, vinca alkaloids, substituted ureas, methyl hydrazine derivatives, adrenocortical suppressants, antagonists, endostatin, taxols, camptothecins, oxaliplatin, doxorubicins and their analogs, and a combination thereof.

Examples of toxins further include gelonin, Pseudomonas exotoxin (PE), PE40, PE38, diphtheria toxin, ricin, ricin, abrin, alpha toxin, saporin, ribonuclease (RNase), DNase I, Staphylococcal enterotoxin-A, pokeweed antiviral protein, gelonin, Pseudomonas endotoxin, as well as derivatives, combinations and modifications thereof.

Examples of radioisotopes include gamma-emitters, positron-emitters, and x-ray emitters that can be used for localization and/or therapy, and beta-emitters and alpha-emitters that can be used for therapy. The radioisotopes described previously as useful for diagnostics, prognostics and staging are also useful for therapeutics. Non-limiting examples of anti-cancer or anti-leukemia agents include anthracyclines such as doxorubicin (adriamycin), daunorubicin (daunomycin), idarubicin, detorubicin, caminomycin, epirubicin, esorubicin, and morpholino and substituted derivatives, combinations and modifications thereof. Exemplary pharmaceutical agents include cis-platinum, taxol, calicheamicin, vincristine, cytarabine (Ara-C), cyclophosphamide, prednisone, daunorubicin, idarubicin, fludarabine, chlorambucil, interferon alpha, hydroxyurea, temozolomide, thalidomide, and bleomycin, and derivatives, combinations and modifications thereof. Preferably, the anti-cancer or anti-leukemia is doxorubicin, morpholinodoxorubicin, or morpholinodaunorubicin.

The antibodies of the invention also encompass antibodies that have half-lives (e.g., serum half-lives) in a mammal, preferably a human, of greater than that of an unmodified antibody. In one embodiment, said antibody half life is greater than about 15 days, greater than about 20 days, greater than about 25 days, greater than about 30 days, greater than about 35 days, greater than about 40 days, greater than about 45 days, greater than about 2 months, greater than about 3 months, greater than about 4 months, or greater than about 5 months. The increased half-lives of the antibodies of the present invention or fragments thereof in a mammal, preferably a human, result in a higher serum titer of said antibodies or antibody fragments in the mammal, and thus, reduce the frequency of the administration of said antibodies or antibody fragments and/or reduces the concentration of said antibodies or antibody fragments to be administered. Antibodies or fragments thereof having increased in vivo half-lives can be generated by techniques known to those of skill in the art. For example, antibodies or fragments thereof with increased in vivo half-lives can be generated by modifying (e.g., substituting, deleting or adding) amino acid residues identified as involved in the interaction between the Fc domain and the FcRn receptor (see, e.g., International Publication Nos. WO 97/34631 and WO 02/060919, which are incorporated herein by reference in their entireties). Antibodies or fragments thereof with increased in vivo half-lives can be generated by attaching to said antibodies or antibody fragments polymer molecules such as high molecular weight polyethyleneglycol (PEG). PEG can be attached to said antibodies or antibody fragments with or without a multifunctional linker either through site-specific conjugation of the PEG to the N- or C-terminus of said antibodies or antibody fragments or via epsilon-amino groups present on lysine residues. Linear or branched polymer derivatization that results in minimal loss of biological activity will be used. The degree of conjugation will be closely monitored by SDS-PAGE and mass spectrometry to ensure proper conjugation of PEG molecules to the antibodies. Unreacted PEG can be separated from antibody-PEG conjugates by, e.g., size exclusion or ion-exchange chromatography.

As will be appreciated by one of skill in the art, in the above embodiments, while affinity values can be important, other factors can be as important or more so, depending upon the particular function of the antibody. For example, for an immunotoxin (toxin associated with an antibody), the act of binding of the antibody to the target can be useful; however, in some embodiments, it is the internalization of the toxin into the cell that is the desired end result. As such, antibodies with a high percent internalization can be desirable in these situations. Thus, in one embodiment, antibodies with a high efficiency in internalization are contemplated. A high efficiency of internalization can be measured as a percent internalized antibody, and can be from a low value to 100%. For example, in varying embodiments, 0.1-5, 5-10, 10-20, 20-30, 30-40, 40-45, 45-50, 50-60, 60-70, 70-80, 80-90, 90-99, and 99-100% can be a high efficiency. As will be appreciated by one of skill in the art, the desirable efficiency can be different in different embodiments, depending upon, for example, the associated agent, the amount of antibody that can be administered to an area, the side effects of the antibody-agent complex, the type (e.g., cancer type) and severity of the problem to be treated.

In other embodiments, the antibodies disclosed herein provide an assay kit for the detection of PDGFR-alpha expression in mammalian tissues or cells in order to screen for a disease or disorder associated with changes in expression of PDGFR-alpha. The kit comprises an antibody that binds PDGFR-alpha and means for indicating the reaction of the antibody with the antigen, if present.

In some embodiments, an article of manufacture is provided comprising a container, comprising a composition containing an anti-PDGFR-alpha antibody, and a package insert or label indicating that the composition can be used to treat disease mediated by PDGFR-alpha expression. Preferably a mammal and, more preferably, a human, receives the anti-PDGFR-alpha antibody.

Combinations

The anti-neoplastic treatment defined herein may be applied as a sole therapy or may involve, in addition to the compounds of the invention, conventional surgery, bone marrow and peripheral stem cell transplantations or radiotherapy or chemotherapy. Such chemotherapy may include one or more of the following categories of anti tumor agents: (i) other antiproliferative/antineoplastic drugs and combinations thereof, as used in medical oncology, such as alkylating agents (for example cis-platin, oxaliplatin, carboplatin, cyclophosphamide, nitrogen mustard, melphalan, chlorambucil, busulphan, temozolamide and nitrosoureas); antimetabolites (for example gemcitabine and antifolates such as fluoropyrimidines like 5-fluorouracil and tegafur, raltitrexed, methotrexate, cytosine arabinoside, and hydroxyurea); antitumor antibiotics (for example anthracyclines like adriamycin, bleomycin, doxorubicin, daunomycin, epirubicin, idarubicin, mitomycin-C, dactinomycin and mithramycin); antimitotic agents (for example vinca alkaloids like vincristine, vinblastine, vindesine and vinorelbine and taxoids like taxol and taxotere and polokinase inhibitors); and topoisomerase inhibitors (for example epipodophyllotoxins like etoposide and teniposide, amsacrine, topotecan and camptothecin); (ii) cytostatic agents such as antioestrogens (for example tamoxifen, fulvestrant, toremifene, raloxifene, droloxifene and iodoxyfene), antiandrogens (for example bicalutamide, flutamide, nilutamide and cyproterone acetate), LHRH antagonists or LHRH agonists (for example goserelin, leuprorelin and buserelin), progestogens (for example megestrol acetate), aromatase inhibitors (for example as anastrozole, letrozole, vorazole and exemestane) and inhibitors of 5.alpha.-reductase such as finasteride; (iii) anti-invasion agents (for example c-Src kinase family inhibitors like 4-(6-chloro-2,3-methylenedioxyanilino)-7-[2-(4-methylpiperazin-1-yl)- ethoxy]-5-tetrahydropyran-4-yloxyquinazoline (AZD0530; International Patent Application WO 01/94341) and N-(2-chloro-6-methylphenyl)-2-{6-[4-(2-hydroxyethyl)piperazin-1-yl]-2-met- hylpyrimidin-4-ylamino}thiazole-5-carboxamide (dasatinib, BMS-354825; J. Med. Chem., 2004, 47, 6658-6661), and metalloproteinase inhibitors like marimastat, inhibitors of urokinase plasminogen activator receptor function or, inhibitors of cathepsins, inhibitors of serine proteases for example matriptase, hepsin, urokinase, inhibitors of heparanase); (iv) cytotoxic agents such as fludarabine, 2-chlorodeoxyadenosine, chlorambucil or doxorubicin and combination thereof such as Fludarabine+cyclophosphamide, CVP: cyclophosphamide+vincristine+prednisone, ACVBP: doxorubicin+cyclophosphamide+vindesine+bleomycin+prednisone, CHOP: cyclophosphamide+doxorubicin+vincristine+prednisone, CNOP: cyclophosphamide+mitoxantrone+vincristine+prednisone, m-BACOD: methotrexate+bleomycin+doxorubicin+cyclophosphamide+vincristine+dexametha- sone+leucovorin, MACOP-B: methotrexate+doxorubicin+cyclophosphamide+vincristine+prednisone fixed dose+bleomycin+leucovorin, or ProMACE CytaBOM: prednisone+doxorubicin+cyclophosphamide+etoposide+cytarabine+bleomycin+vi- ncristine+methotrexate+leucovorin. (v) inhibitors of growth factor function, for example such inhibitors include growth factor antibodies and growth factor receptor antibodies (for example the anti-erbB2 antibody trastuzumab [Herceptin.TM.], the anti-EGFR antibody panitumumab, the anti-erbB1 antibody cetuximab [Erbitux, C225] and any growth factor or growth factor receptor antibodies disclosed by Stern et al. Critical reviews in oncology/haematology, 2005, Vol. 54, pp 11-29); such inhibitors also include tyrosine kinase inhibitors, for example inhibitors of the epidermal growth factor family (for example EGFR family tyrosine kinase inhibitors such as N-(3-chloro-4-fluorophenyl)-7-methoxy-6-(3-morpholinopropoxy)quinazolin-4- -amine (gefitinib, ZD1839), N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy)quinazolin-4-amine (erlotinib, OSI-774) and 6-acrylamido-N-(3-chloro-4-fluorophenyl)-7-(3-morpholinopropoxy)-quinazol- in-4-amine (CI 1033), erbB2 tyrosine kinase inhibitors such as lapatinib, inhibitors of the hepatocyte growth factor family, inhibitors of the platelet-derived growth factor family such as imatinib, inhibitors of serine/threonine kinases (for example Ras/Raf signalling inhibitors such as farnesyl transferase inhibitors, for example sorafenib (BAY 43-9006)), inhibitors of cell signalling through MEK and/or AKT kinases, inhibitors of the hepatocyte growth factor family, c-kit inhibitors, abl kinase inhibitors, IGF receptor (insulin-like growth factor) kinase inhibitors, aurora kinase inhibitors (for example AZD1152, PH739358, VX-680, MLN8054, R763, MP235, MP529, VX-528 and AX39459), cyclin dependent kinase inhibitors such as CDK2 and/or CDK4 inhibitors, and inhibitors of survival signaling proteins such as Bcl-2, Bcl-XL for example ABT-737; (vi) antiangiogenic agents such as those which inhibit the effects of vascular endothelial growth factor, [for example the anti-vascular endothelial cell growth factor antibody bevacizumab (Avastin.TM.) and VEGF receptor tyrosine kinase inhibitors such as 4-(4-bromo-2-fluoroanilino)-6-methoxy-7-(1-methylpiperidin-4-ylmethoxy)qu- inazoline (ZD6474; Example 2 within WO 01/32651), 4-(4-fluoro-2-methylindol-5-yloxy)-6-methoxy-7-(3-pyrrolidin-1-ylpropoxy)- quinazoline (AZD2171; Example 240 within WO 00/47212), vatalanib (PTK787; WO 98/35985) and SU11248 (sunitinib; WO 01/60814), compounds such as those disclosed in International Patent Applications WO97/22596, WO 97/30035, WO 97/32856, WO 98/13354, WO00/47212 and WO01/32651 and compounds that work by other mechanisms (for example linomide, inhibitors of integrin .alpha.v.beta.3 function and angiostatin)] or colony stimulating factor 1 (CSF1) or CSF1 receptor; (vii) vascular damaging agents such as Combretastatin A4 and compounds disclosed in International Patent Applications WO 99/02166, WO 00/40529, WO 00/41669, WO 01/92224, WO 02/04434 and WO 02/08213; (viii) antisense therapies, for example those which are directed to the targets listed above, such as G-3139 (Genasense), an anti bcl2 antisense; (ix) gene therapy approaches, including for example approaches to replace aberrant genes such as aberrant p53 or aberrant BRCA1 or BRCA2, GDEPT (gene directed enzyme pro drug therapy) approaches such as those using cytosine deaminase, thymidine kinase or a bacterial nitroreductase enzyme and approaches to increase patient tolerance to chemotherapy or radiotherapy such as multi drug resistance gene therapy; and (x) immunotherapy approaches, including for example treatment with Alemtuzumab (campath-1H.TM.), a monoclonal antibody directed at CD52, or treatment with antibodies directed at CD22, ex vivo and in vivo approaches to increase the immunogenicity of patient tumour cells, transfection with cytokines such as interleukin 2, interleukin 4 or granulocyte macrophage colony stimulating factor, approaches to decrease T cell anergy such as treatment with monoclonal antibodies inhibiting CTLA-4 function, approaches using transfected immune cells such as cytokine transfected dendritic cells, approaches using cytokine transfected tumour cell lines and approaches using anti idiotypic antibodies. (xi) inhibitors of protein degradation such as proteasome inhibitor such as Velcade (bortezomid). (xii) biotherapeutic therapeutic approaches for example those which use peptides or proteins (such as antibodies or soluble external receptor domain constructions) which either sequester receptor ligands, block ligand binding to receptor or decrease receptor signalling (e.g. due to enhanced receptor degradation or lowered expression levels).

Such conjoint treatment may be achieved by way of the simultaneous, sequential or separate dosing of the individual components of the treatment. Such combination products employ the compounds of this invention, or pharmaceutically acceptable salts thereof, within the dosage range described hereinbefore and the other pharmaceutically active agent within its approved dosage range.

In one embodiment of the invention the anti-neoplastic treatments of the invention are combined with agents which inhibit the effects of vascular endothelial growth factor (VEGF), (for example the anti-vascular endothelial cell growth factor antibody bevacizumab (Avastin.RTM.), anti-vascular endothelial growth factor receptor antibodies such anti-KDR antibodies and anti-flt1 antibodies, compounds such as those disclosed in International Patent Applications WO 97/22596, WO 97/30035, WO 97/3285, WO 98/13354, WO00/47212 and WO01/32651) and compounds that work by other mechanisms (for example linomide, inhibitors of integrin avb3 function and angiostatin); In another embodiment of the invention the anti-angiogenic treatments of the invention are combined agents which inhibit the tyrosine kinase activity of the vascular endothelial growth factor receptor, KDR (for example AZD2171 or AZD6474). Additional details on AZD2171 may be found in Wedge et al (2005) Cancer Research. 65 (10):4389-400. Additional details on AZD6474 may be found in Ryan & Wedge (2005) British Journal of Cancer. 92 Suppl 1:S6-13. Both publications are herein incorporated by reference in their entireties. In another embodiment of the invention, the fully human antibodies 1.1.2, 1.5.3, 2.1.2 are combined alone or in combination with Avastin.TM., AZD2171 or AZD6474.

Such conjoint treatment may be achieved by way of the simultaneous, sequential or separate dosing of the individual components of the treatment. Such combination products employ the compounds of this invention, or pharmaceutically acceptable salts thereof, within the dosage range described hereinbefore and the other pharmaceutically active agent within its approved dosage range.
 

Claim 1 of 18 Claims

1. An isolated antibody, or binding fragment thereof, that specifically binds to PDGFR-alpha and inhibits the growth of cells that express PDGFR-alpha, wherein said antibody comprises a heavy chain polypeptide comprising the sequence of SEQ ID NO.: 10, or SEQ ID NO.:10 comprising any one of the combinations of residues indicated by each row of table 8.

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