Prostate Cancer Program Prostate cancer is one of the most common forms of cancer affecting men, with an annual incidence of 220,900 cases in the U.S. as determined by the American Cancer Society. It is estimated that the disease results in over 28,000 U.S. deaths annually. Current treatment options include surgery and radiation for localized tumors and hormone ablation therapy and chemotherapy in cases where the cancer has metastasized. These treatment options carry many potential side effects, including impotence, incontinence and loss of libido. Therion�s PROSTVAC-VF� Vaccines Therion�s PROSTVAC-VF vaccine program uses a recombinant vaccine to target prostate-specific antigen (PSA), a protein produced by prostate tumor cells. Therion�s vaccine candidates use a proprietary, attenuated strain of vaccinia expressing PSA and TRICOM� intended to "prime" or generate an initial immune response against cells displaying PSA; and use a fowl pox virus expressing PSA and TRICOM administered subsequently as a "boost" intended to enhance and sustain the immune response. Main Page Prostate Cancer Vaccine Pancreatic Cancer Vaccine Collaborations PRODUCT CANDIDATES PROSTVAC-VF - Using data generated from multiple clinical trials, Therion is developing PROSTVAC-VF as its next-generation lead prostate cancer vaccine. This candidate builds from the clinical promise demonstrated in Phase II clinical trials of PROSTVAC-VF, and incorporates TRICOM, Therion�s co-stimulatory system for enhancing immune response against tumor cells. The TRICOM component is designed to optimize, through the expression of multiple co-stimulatory molecules, antigen presentation and activation of cytotoxic T-cells critical for tumor destruction. This integrated vaccine is anticipated to further strengthen the immune system's response against PSA-bearing prostate cancers. PROSTVAC-VF entered Phase II clinical trials in fourth quarter 2003. VF DOSING REGIMEN OPTIMIZES PSA STABILIZATION IN PATIENTS: Copyright © Therion Biologics Corporation.