Progenics and Cytogen Report New Findings on Prostate Cancer Therapies
Monday November 10, 5:00 am ET
[Their mAb technology comes from Abgenix. MLNM and MEDX have projects aiming for "the same" target (MLNM2704 and MDX-070)]
TARRYTOWN, N.Y. & PRINCETON, N.J.--(BUSINESS WIRE)--Nov. 10, 2003--
Insights into Antibody and Vaccine Therapies against
Prostate-Specific Membrane Antigen Presented at the Prostate Cancer
Foundation Scientific Retreat and Published in PNAS
The PSMA Development Company LLC (PDC), a joint venture of Progenics Pharmaceuticals, Inc. (Nasdaq: PGNX - News) and Cytogen Corporation (Nasdaq: CYTO - News), today announced publication of new findings on antibody and vaccine therapies that target prostate-specific membrane antigen (PSMA). The findings were published in the current issue of the Proceedings of the National Academy of Sciences USA (PNAS, volume 100, issue 22). PSMA serves as a target for cancer therapy by virtue of its expression on the surface of prostate cancer cells and the new blood vessels that supply most other solid tumors. PDC researchers found that PSMA exists on human cancer cells as a homodimer, a protein complex consisting of two identical PSMA chains. Importantly, researchers also found that when recombinant soluble PSMA (rsPSMA) was used as a cancer vaccine in an animal model, dimer but not monomer efficiently elicited antibodies that recognized PSMA-expressing tumor cells. In addition, PDC researchers reported the discovery of fully human monoclonal antibodies that specifically recognize dimeric but not monomeric rsPSMA. Such antibodies represent candidates for therapy by virtue of their specificity for dimeric PSMA as found on tumor cells. PDC is currently conducting a phase 1 clinical study of a therapeutic prostate cancer vaccine based on a novel proprietary form of dimeric rsPSMA.
"The PNAS publication demonstrates how scientific discoveries on PSMA structure and function can translate into potential therapies for prostate cancer," said William C. Olson, Ph.D., Progenics' Vice President of Research and Development and senior author of the PNAS paper. "In further preclinical studies, our lead PSMA antibody was shown to bind human prostate cancer cells and target their destruction by activating natural immune system functions, including antibody-dependent cellular cytotoxicity (ADCC)." ADCC is a process whereby certain antibodies can trigger specific components of the body's immune system to kill targeted cells rather than relying on a cytotoxin or radioisotope that has been attached to the antibody. The latter findings were presented by William Goeckeler, Ph.D., Cytogen's Vice President of Operations, during an oral presentation at the Tenth Annual Prostate Cancer Foundation Scientific Retreat that is currently being held in New York City.
PSMA is a cell-surface protein that is expressed on prostate cancer cells at all stages of disease, including advanced or metastatic disease. The PSMA gene was first discovered by scientists at Memorial Sloan-Kettering Cancer Center and is exclusively licensed to Cytogen Corporation, which has sublicensed it to the PSMA Development Company for in vivo immunotherapy. PSMA is also present at high levels on the newly formed blood vessels (neovasculature) needed for the growth and survival of many types of solid tumors. If PSMA-targeted therapies can destroy or prevent formation of these new blood vessels, the therapies may prove valuable in treating a broad range of cancers. |
