TARRYTOWN, N.Y., Sept. 28, 2012 (GLOBE NEWSWIRE) -- Progenics Pharmaceuticals, Inc. (Nasdaq:PGNX) has opened enrollment in a phase 2 study in prostate cancer patients of its PSMA ADC compound. PSMA ADC is a targeted anti-cancer therapeutic that uses a monoclonal antibody to deliver a cell-killing drug to malignant cells. "New prostate cancer therapies are in high demand. Patients with advanced, hormone-refractory prostate cancer typically do not survive more than 12 to 18 months," said Daniel Petrylak, M.D., Director of the Prostate Cancer Program/Genitourinary Cancer Program and Co-Director of the Signal Transduction Program at Yale University Medical Center. "The hope for PSMA ADC is that its targeted therapeutic approach could be more effective and cause fewer toxic side-effects in treating cancer." Dr. Petrylak participated as an Investigator in the phase 1 trial of PSMA ADC and is continuing his evaluation of PSMA ADC in this phase 2 study. The phase 2 trial is an open-label, multicenter study to assess the anti-tumor activity and tolerability of PSMA ADC in up to 75 subjects with metastatic castration-resistant prostate cancer. Patients will receive a total of eight doses of drug at 2.5 mg/kg. The study endpoints evaluate responses in prostate specific antigen (PSA); circulating tumor cells (CTC); bone, visceral and nodal metastases; and pain. Safety also will be assessed. "This is an exciting moment – for Progenics and for the patients we seek to serve – as we move PSMA ADC into its next phase of clinical testing," said Robert J. Israel, M.D., Progenics' Senior Vice President, Medical Affairs & Clinical Research. "This type of cancer therapy is unique and we believe that PSMA ADC is the most advanced clinical-stage candidate antibody-drug conjugate in development to treat prostate cancer." PSMA ADC is a novel compound designed to deliver a cell-killing drug selectively to prostate cancer cells by targeting prostate specific membrane antigen (PSMA), a validated biomarker of prostate cancer that is expressed on the surface of those cells (as well as on blood vessels supplying other solid tumors). PSMA ADC consists of a fully human monoclonal antibody, which binds PSMA, linked to a cytotoxic drug, monomethyl auristatin E (MMAE), which inhibits cell proliferation by disrupting the cellular "backbone" required for replication. The antibody-drug conjugate is designed to be absorbed by the cell and release active anti-cancer drug, thereby destroying the malignant cell.