Immunomedics Genetics a biopharmaceutical company primarily focused on the development of monoclonal antibody-based products for the targeted treatment of cancer, autoimmune and other serious diseases, today announced the issuance of U.S. patent no. 8,617,558 for additional claims under the patent family.
“Camptothecin-binding moiety conjugates,” and U.S. patent no. 8,617,518 with additional claims for the patent family “Methods and compositions for improved F-18 labeling of proteins, peptides and other molecules.”
Patent 8,617,558 relates to our proprietary linker technology for conjugating SN-38 to the Company’s humanized antibodies for targeted delivery of the potent drug to the tumor. The patent will expire in December 2023. Additional patents covering the Company’s antibody-drug conjugates are being prosecuted in major countries worldwide.
“This is a key patent for the protection of our antibody-drug conjugates patent family, of which IMMU-132, an anti-TROP-2-SN-38 conjugate, and IMMU-130, an anti-CEACAM5-SN-38 conjugate, constitute two of our most exciting new agents for solid cancer therapy,” commented Cynthia L. Sullivan, President and Chief Executive Officer. “Both IMMU-132 and 130 are in Phase II clinical development and we plan to report results from these studies in the second quarter of 2014 at upcoming scientific and medical conferences.”
In early dose-escalation studies, the two antibody-SN-38 conjugates have shown evidence of tumor shrinkage in patients with difficult-to-treat solid tumors who had failed multiple prior therapies, including irinotecan.
SN-38 is the active metabolite of irinotecan, a camptothecin analogue approved for the treatment of metastatic colorectal cancer. While SN-38 is 2 to 3 orders of magnitude more potent than its parent molecule, it does not dissolve in water and cannot be administered directly to patients. Our unique linker allows us to produce antibody-SN-38 conjugates that are soluble in water with excellent yields, as well as preservation of antibody binding and drug activity, even after attaching about 7 drug molecules per antibody.
The second patent, 8,617,518, which will expire in December 2027, concerns the methods and compositions of labeling peptides and other molecules with the diagnostic radioisotope, fluorine-18 (F-18) or the magnetic resonance imaging (MRI) label, fluorine-19 (F-19).
The Company has invented a simple-to-use kit for the rapid labeling of peptides and proteins, including antibodies, to be used as imaging agents for positron-emission tomography (PET) and MRI of diseases. In particular, antibody-based targeting agents, an area of our strength, for immunoPET imaging can become a companion diagnostic to our therapeutic products, including the antibody-drug conjugates currently in clinical trials.
“This is an important technology for us,” Ms. Sullivan stated, “and is of interest to major pharmaceutical companies wanting an imaging companion to their therapeutics.”