UroGenesys Researchers Report Antibodies to Prostate Cancer Target Block Tumor Growth, Inhibit Metastases and Prolong Survival in Mice - Studies Published in PNAS underscore Potential of New Therapy Using Antibody to Prostate Cancer Target, PSCA Santa Monica, CA, February 13, 2001 - Researchers at UroGenesys, Inc. today reported significantly blocked tumor growth, inhibition of metastases and prolonged survival in mice treated with monoclonal antibodies directed against a protein found predominantly on human prostate tumors. The studies, published in today's Early Edition of the Proceedings of the National Academy of Sciences USA (PNAS), suggest that the protein, called PSCA, is a highly promising target for antibody therapy. Antibody-based products to PSCA (Prostate Stem Cell Antigen) are under development by Genentech (NYSE: DNA) through a licensing agreement with UroGenesys announced last July. "In previous studies, we demonstrated that PSCA, a predominantly prostate-specific, cell surface antigen, is expressed at significant levels on tumors of most prostate cancer patients," said Aya Jakobovits, Ph.D., the paper's senior author and Chief Scientific Officer of UroGenesys. "In this paper, we have provided preclinical validation for the potential utility of PSCA antibodies in the treatment of local and metastatic disease." "Specifically, these PSCA antibodies retarded the growth of hormone-sensitive and hormone-refractory tumors and significantly reduced the spread of tumors to distant sites, leading to major prolongation of lifespan," she continued. "Many of the deaths due to prostate cancer, the second leading cause of cancer-related death in U.S. males, occur after the development of metastatic disease, for which no current therapy is available." The key preclinical studies reported in the paper utilized a proprietary prostate cancer xenograft mouse model that closely resembles the progression of human disease. This model allowed UroGenesys researchers to evaluate the effect of therapeutics on major clinically relevant end-points - PSA levels (tumor growth), metastatic spread, health and prolongation of survival. For example, in mice bearing human prostate tumors in their prostates, PSCA antibodies were capable of prolonging the lifespan by over 50 percent as compared to the untreated mice. Moreover, the antibodies demonstrated the ability to inhibit the spread of prostate cancer to the lung, even in the presence of high tumor burdens. Many metastases were detected in the lungs of all control mice, while among the treated mice, no micrometastases were detected in most and very few were found in the others. "This research highlights UroGenesys' expanding capability not only to discover but also to carry out preclinical validation of promising targets for cancer indications," said Donald Rice, President and Chief Executive Officer of UroGenesys. "The research also underscores the value of our approach to employing our proprietary disease models as an integral part of our discovery and validation programs." Prostate cancer, which accounts for about 40 percent of all male cancers, is currently the most common type of cancer in American men and the second leading cause of cancer-related death in this population. An estimated 180,000 new cases of prostate cancer are diagnosed each year in the United States, and approximately 40,000 American men die of the disease annually. These numbers are expected to rise as the U.S. population experiences an increasing number of men entering their senior years, when most prostate cancers are diagnosed. UroGenesys, Inc. is a privately held biotechnology company engaged in the development of innovative products for the treatment and diagnosis of cancers, with an initial focus on urological cancers. UroGenesys, which began operations in 1997, was founded by leading cancer researchers and clinicians from the University of California, Los Angeles (UCLA) together with Donald B. Rice, Ph.D., an experienced business executive. The Company has generated a large and diverse portfolio of proprietary antigen targets in cancer with potential for product development in antibody, small molecule, vaccine and other therapeutic approaches. In July 2000, the Company signed a licensing agreement with Genentech to develop antibody-based therapeutics for cancer using Prostate Stem Cell Antigen (PSCA) as a target antigen. The Company's laboratories and offices are located in Santa Monica, CA. A backgrounder with additional information on UroGenesys, Inc. is available upon request. Contacts Donald Rice, Ph.D. Aya Jakobovits, Ph.D. Vice President, Research & CSO UroGenesys, Inc. (310) 820-8029 www.urogenesys.com Robert Gottlieb Sharon Karlsberg Feinstein Kean Healthcare (617) 577-8110 www.fkhealth.com << Back to Press Releases