ANTIBODIES: Patent Awarded for "Abtides" - Cytogen Corp's proprietary human antigen - Product Information

Applied Genetics News, April, 1999

Cytogen Corp. (600 College Rd. East, CN 5308, Princeton, NJ 08540; Tel: 609/750-8200, Fax: 609/452-2975, Website: www.cytogen.com) has been awarded U.S. Patent 5,885,577 titled "Antigen Binding Peptides (abtides) Form Peptide Libraries." The patent covers the compositions of novel abtides that bind to prostate specific membrane antigen (PSMA), Cytogen's proprietary human antigen that is associated with prostate and other cancers.

PSMA is the antigen targeted by trademarked Prostacint, Cytogen's diagnostic imaging agent for patients at high risk for the spread of prostate cancer. The PSMA binding abtides were discovered using the company's genetic diversity library (GDL) technology, now the platform technology of AxCell Biosciences Corp., a wholly-owned subsidiary of Cytogen. Because abtides are much smaller than antibodies but possess the same binding characteristics, they can potentially be used to target tumors faster and more efficiently. Because of their small size, they are less likely to cause immune responses and also clear from the body more rapidly than antibodies. When conjugated to toxins or genes, abtides may be useful alternatives to antibodies for delivery of therapeutic agents to specific sites of disease in the body. "The '577 patent is a very important addition to Cytogen's PSMA patent domain and may allow a new proprietary approach to be realized in therapeutic targeting," says H. Joseph Reiser, CEO and president of Cytogen. "Given this expanded patent position for PSMA, AxCell will initiate a targeted program in its proprietary proteomics data base to identify potential drug targets in the prostate disease area."