A new multi-center study shows that an experimental drug lowers prostate specific antigen (PSA) levels a marker for tumor growth in men with advanced prostate cancer for whom traditional treatment options have failed. The study, led by researchers at Memorial Sloan-Kettering Cancer Center (MSKCC), is published today in Science Express, the online version of the journal Science.
Most men with metastatic prostate cancer eventually build up resistance to the drugs that lower or block male hormones and develop a more aggressive form of the illness called castration-resistant prostate cancer (CRPC), or hormone-refractory disease. According to the study's findings, investigators studied two novel compounds, RD162 and MDV3100, and not only gained an understanding of their novel mechanism of action, but found that these agents showed activity in CRPC cells in culture and in mice.
The study also reports on a Phase 1/2 trial of MDV3100 in 30 patients with advanced CRPC and found that 22 out of 30 men showed declining PSA levels, and 13 out of 30 men (43 percent) had PSA levels fall by more than half.
Several years ago, the senior author of the study, Charles Sawyers, MD, and his colleagues at the University of California, Los Angeles (UCLA), uncovered a potential reason why metastatic prostate cancer patients eventually relapse with CRPC. This insight was used to discover RD162 and MDV3100.
"It's gratifying to know that our hypotheses about why men develop resistance to currently available treatments are confirmed and, most importantly, that there are already patients who are benefiting from our research," said Dr. Sawyers, Chair of the Human Oncology and Pathogenesis Program at MSKCC and a Howard Hughes Medical Institute investigator.
Current treatments for men who have advanced prostate cancers inhibit the activity of male hormones that help drive tumor growth. Many of these drugs disrupt the androgen (male hormone) receptor,
|Contact: Esther Napolitano|
Memorial Sloan-Kettering Cancer Center