| Antibodies with immune effector activity and that internalize in folate receptor alpha-positive cells -> Monitor Keywords |
|
|
 
Antibodies with immune effector activity and that internalize in folate receptor alpha-positive cellsRelated Patent Categories: Drug, Bio-affecting And Body Treating Compositions, Radionuclide Or Intended Radionuclide Containing; Adjuvant Or Carrier Compositions; Intermediate Or Preparatory Compositions, Attached To Antibody Or Antibody Fragment Or Immunoglobulin; DerivativeAntibodies with immune effector activity and that internalize in folate receptor alpha-positive cells description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060239910, Antibodies with immune effector activity and that internalize in folate receptor alpha-positive cells. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATION [0001] This claims benefit of U.S. Provisional Application 60/674,185, filed Apr. 22, 2005, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] This invention relates to the use of monoclonal and polyclonal antibodies that specifically bind to and alternatively become internalized by cells expressing or bearing folate receptor alpha (FRA) ("FRA-positive cells") and induce an immune effector activity such as antibody dependent cellular cytotoxicity. The antibodies are useful in specific delivery of pharmacologic agents to FRA-positive cells as well as in eliciting an immune-effector activity particularly on tumor and dysplastic cells. The invention is also related to cells expressing the monoclonal antibodies, polyclonal antibodies, antibody derivatives, such as chimeric and humanized monoclonal antibodies, antibody fragments, methods of detecting FRA-positive cells, and methods of treating cancer using the antibodies of the invention. BACKGROUND OF THE INVENTION [0003] There are three major isoforms of the human membrane folate binding proteins, .alpha., .beta., and .gamma.. The .alpha. and .beta. isoforms have about 70% amino acid sequence homology and differ dramatically in their stereospecificity for some folates. Both isoforms are expressed in both fetal and adult tissue, although normal tissue generally expresses low to moderate amounts of FR-.beta.. FR-.alpha., however, is expressed in a subset of normal epithelial cells, and is frequently strikingly elevated in a variety of carcinomas (Ross et al. (1994) Cancer 73(9):2432-2443; Rettig et al. (1988) Proc. Natl. Acad. Sci. USA 85:3110-3114; Campbell et al. (1991) Cancer Res. 51:5329-5338; Coney et al. (1991) Cancer Res. 51:6125-6132; Weitman et al. (1992) Cancer Res. 52:3396-3401; Garin-Chesa et al. (1993) Am. J. Pathol. 142:557-567; Holm et al. (1994) APMIS 102:413-419; Franklin et al. (1994) Int. J. Cancer 8 (Suppl.):89-95; Miotti et al. (1987) Int. J. Cancer 39:297-303; and Vegglan et al. (1989) Tumori 75:510-513). FR-.alpha. is overexpressed in greater than 90% of ovarian carcinomas (Sudimack and Lee (2000) Adv. Drug Deliv. Rev. 41(2):147-62). In addition, it is also over-expressed in a number of other cancers such as but not limited to breast, colorectal, renal, and lung cancer. [0004] In 1987, Miotti et al. described three new monoclonal antibodies that recognized antigens on human ovarian carcinoma cells (Miotti et al. (1987) Int. J. Cancer 39(3):297-303). One of these was designated MOv18, which recognizes a 38 kDa protein on the surface of choriocarcinoma cells. MOv18 is a murine, IgG1, kappa antibody and mediates specific cell lysis of the ovarian carcinoma cell line, IGROV1. Alberti et al. ((1990) Biochem. Biophys. Res. Commun. 171(3):1051-1055) showed that the antigen recognized by MOv18 was a GPI-linked protein. This was subsequently identified as the human folate binding protein (Coney et al. (1991) Cancer Res. 51(22):6125-6132). Tomassetti et al. showed that MOv18 recognizes a soluble form and a GPI-anchored form of the folate binding protein in IGROV1 cells (Tomassetti et al. (1993) FEBS Lett. 317(1-2):143-146). Subsequent work combined the variable regions of the mouse MOv18 with human IgGI (kappa) constant region to create a chimerized MOv18 antibody. The chimerized antibody mediated higher and more specific lysis of IGROV1 cells at 10-100 fold lower antibody concentrations (Coney et al. (1994) Cancer Res. 54(9):2448-2455). [0005] U.S. Pat. No.5,952,484 describes a humanized antibody that binds to a 38 kDa protein (FR-.alpha.). The antibody was named LK26, after the antigen by the same name. The original mouse monoclonal antibody was described by Rettig in European Patent Application No. 86104170.5 (published as EP0197435 and issued in the U.S. as U.S. Pat. No. 4,851,332). [0006] Ovarian cancer is the major cause of death due to gynecological malignancy. Although chemotherapy is the recommended treatment and has enjoyed some success, the 5-year survival term is still less than 40%. [0007] A difficult problem in treating ovarian cancer as well as other cancers with cytotoxic drugs is that often the cytotoxin causes toxicity to normal tissues as well as cancerous tissues. An approach to get better specificity to treat cancer is the use of antibodies that can target specific antigens expressed in cancer cells that are not expressed or are expressed at a lower level on normal cells. These targets can be exploited using antibodies to kill antigen-bearing tumors by inhibiting the biological activity of the antigen, eliciting an immune effector function by complement dependent cytotoxicity (CDC) and/or antibody dependent cellular cytotoxicity (ADCC); or by delivering immuno- or radio-conjugates that when delivered to the antigen-bearing cells, specifically kill the target cell. Finding antibodies that can specifically bind to and effectively kill antigen-bearing tumor cells has proven difficult for many cancers. This has been due in part to the inability to obtain robust killing due to lack of immune-effector function or to lack of efficient internalization of antibodies carrying immunotoxins. FRA offers an opportunity to get tumor-specific targeting for several cancer types including ovarian, renal, colorectal and lung cancer. [0008] Provided herein are in-out anti-FRA antibodies that can in the alternative (i.e., have the ability to do both but only one at a time) elicit a robust immune-effector function on and internalize in FRA-positive cells, for example, for delivering toxic conjugates to FRA-positive cells. The antibodies of the invention are effective therapies for cancers that bear FRA such as but not limited to ovarian, renal, colorectal, breast and lung cancers. SUMMARY OF THE INVENTION [0009] Provided herein are FRA-specific antibodies that alternatively elicit a robust immune-effector function yet are able to internalize in FRA-positive cells, referred to here as in-out anti-FRA antibodies. As used herein, "in-out antibodies" ("in-out Abs") refer to antibodies that can alternatively elicit an immune effector activity and internalize within an antigen-presenting cell by binding to target antigen. Without wishing to be bound by any particular theory, it is believed that in-out Abs bind to the cell surface of an antigen-bearing cell and internalize after a period of time unless engaged by immune-effector cells or biochemicals that are recruited to the antigen-antibody-bearing cell. Antibodies that are able to elicit an immune effector effect such ADCC or CDC and internalize have been previously described (Wolff et al. Monoclonal antibody homodimers: enhanced antitumor activity in nude mice. Cancer Res. Jun. 1, 1993;53:2560-5), however, it is not obvious that in-out antibodies can be developed against any antigen or epitope (Kusano et al. Immunocytochemical study on internalization of anti-carbohydrate monoclonal antibodies. Anticancer Res. November-December 1993;13(6A):2207-12). In-out antibodies that can target FRA have not been described previously. FRA-specific antibodies have been previously described but such antibodies are not known to internalize upon binding to the antigen (Cogliati et al. Preparation and biological characterization of conjugates consisting of ricin and a tumor-specific non-internalizing MAb. Anticancer Res. 11:417-21, 1991). Antibodies that can target cell surface antigens do not always elicit an immune effector function upon binding to the cell surface antigen (Niwa et al. Defucosylated chimeric anti-CC chemokine receptor 4 IgG1 with enhanced antibody-dependent cellular cytotoxicity shows potent therapeutic activity to T-cell leukemia and lymphoma. Cancer Res. 64:2127-33, 2004; Kikuchi et al. Apoptosis inducing bivalent single-chain antibody fragments against CD47 showed antitumor potency for multiple myeloma. Leuk Res. 29:445-50, 2005; Scott et al. Immunological effects of chimeric anti-GD3 monoclonal antibody KM871 in patients with metastatic melanoma. Cancer Immun. February 22;5:3, 2005). Provided herein are antibodies that bind to the cell surface antigen FRA and, in the alternative, elicit an immune effector activity (such as ADCC or CDC) and internalize within antigen-positive cells. These antibodies and derivatives thereof are useful for cancer therapy. [0010] The invention provides in-out antibodies that specifically bind to FRA. In some embodiments, the antibodies bind antigen with greater affinity and/or avidity than LK26 and MOv18. In some embodiments the in-out antibodies of the invention bind the same epitope, for example a conformational epitope, as that bound by LK26 or MOv18. In other embodiments, the in-out antibodies of the invention bind a different epitope as that bound by LK26 or MOv18. [0011] The antibodies of the invention may be chimeric, including, but not limited to a human-mouse chimeric antibodies. The antibodies of the invention may also be humanized. The antibodies of the invention may also be fully human. The invention also provides: hybridoma cells that express the antibodies of the invention; polynucleotides that encode the antibodies of the invention; vectors comprising the polynucleotides that encode the antibodies of the invention; and expression cells comprising the polynucleotides of the invention, referred to as transfectomas. [0012] The invention also provides methods of producing in-out antibodies of the invention. Some methods comprise the step of culturing the transfectoma or hybridoma cell that expresses an antibody of the invention. The antibody-producing cells of the invention may be bacterial, yeast, insect cells, and animal cells, preferably, mammalian cells. [0013] The invention further provides methods of inhibiting the growth of FRA-positive cells such as dysplastic or tumor cells associated with increased expression of FRA. In some embodiments, such methods comprise administering to a patient with FRA-positive cells a composition comprising an in-out antibody of the invention. The methods may be used for the treatment of various dysplastic conditions, such as, but not limited to ovarian, breast, colorectal, renal and lung cancer. In preferred embodiments, the patients are human patients. In some embodiments, the antibodies are conjugated to one or more chemotherapeutic agents such as, but not limited to radionuclides, toxins, and cytotoxic or cytostatic agents. In other embodiments the antibodies are used in combination with one or more chemotherapeutic agents or biomolecules. Yet in other embodiments the antibodies are used in combination with an antifolate compound. In-out antibodies can be administered as a single agent, as a conjugated or unconjugated antibody, or in combination with the conjugated or unconjugated forms or another therapeutic agent. [0014] Previous attempts to develop therapeutic antibodies that specifically target FRA have been performed with little success due to poor internalization and/or affinity such as the MOv 18 antibody (Cogliati et al. Preparation and biological characterization of conjugates consisting of ricin and a tumor-specific non-internalizing MAb. Anticancer Res. 11:417-21, 1991). This lack of internalization could be due to low affinity or poor internalization due to antibody composition and/or epitope binding. In addition, the MOv18 antibody was attempted as an immunoconjugate because the unconjugated form was not cytotoxic itself. Provided herein are in-out antibodies that alternatively internalize in FRA-positive cells and elicit a cytotoxic effect via an immune effector activity. [0015] Other features and advantages of the invention will be apparent from the detailed description and examples that follow. BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 shows a FRA-specific binding antibody ML-1 by ELISA and FACS. FIG. 1A demonstrates FRA-specific antibodies that have in-out activity (ML-1). Shown is an ELISA identifying antibody that can specifically bind to various amounts of recombinant FRA antigen. ELISAs also can be formatted using purified, semi-purified, membrane preps or whole cells expressing FRA. FIG. 1B shows the results of FACS analysis of ML-1 binding to FRA-expressing cells (IGROV-1) while no binding is observed on FRA-null H226 cells. These data were confirmed by western blot analysis. [0017] FIG. 2 demonstrates that ML-1 elicits a robust antibody-dependent cellular cytotoxicity (ADCC) activity. Tumor cell line OVCAR3 (referred to as target) which expresses FRA was incubated with human peripheral blood mononuclear cells (PBMCs) alone (no Ab lane); with ML-1; or control Ig (normal IgG). Cell cultures were assayed for killing by monitoring for lactate dehydrogenase (LDH) release that occurs upon cell lysis. ML-1 has ADCC activity on FRA-expressing cells. [0018] FIG. 3 demonstrates that ML-1 internalizes in FRA-expressing cells. FIG. 3 shows the ability of ML-1 linked to saporin (diamond) to kill cells in contrast to ML-1 unconjugated (square) while an isotype control antibody MORAb-A92 did not kill cells in conjugated or unconjugated toxin form (triangle and X, respectively). As control, cells not expressing FRA were used and found that ML-1 has no toxic effect in toxin-conjugated or unconjugated form (not shown). These data support the finding that ML-1 internalizes in FRA-bearing cells. Data is evaluated by comparing treated and untreated wells and results are expressed as percent of control. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Continue reading about Antibodies with immune effector activity and that internalize in folate receptor alpha-positive cells... Full patent description for Antibodies with immune effector activity and that internalize in folate receptor alpha-positive cells Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Antibodies with immune effector activity and that internalize in folate receptor alpha-positive cells patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Antibodies with immune effector activity and that internalize in folate receptor alpha-positive cells or other areas of interest. ### Previous Patent Application: Antibodies with immune effector activity and that internalize in endosialin-positive cells Next Patent Application: Carrier molecules Industry Class: Drug, bio-affecting and body treating compositions ### FreshPatents.com Support Thank you for viewing the Antibodies with immune effector activity and that internalize in folate receptor alpha-positive cells patent info. IP-related news and info Results in 0.13967 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
