A new therapy for metastatic prostate cancer has shown considerable promise in early clinical trials involving patients whose disease has become resistant to current drugs.
Of 30 men who received low doses of one the drugs in a multisite phase I/II trial designed to evaluate safety, 22 showed a sustained decline in the level of prostate specific antigen (PSA) in their blood. Phase III clinical trials are planned to evaluate the drug's effect on survival in a large group of patients with metastatic prostate cancer.
The drugs are second-generation antiandrogen therapies that prevent male hormones from stimulating growth of prostate cancer cells. The new compounds manufactured by the pharmaceutical company Medivation and known as MDV3100 and RD162 appear to work well even in prostate cells that have a heightened sensitivity to hormones. That heightened sensitivity makes prostate cancer cells resistant to existing antiandrogen therapies.
The drugs were discovered in the laboratory of Howard Hughes Medical Institute investigator Charles Sawyers at Memorial Sloan-Kettering Cancer Center in collaboration with chemist Michael Jung at UCLA. He and his colleagues described the development of the drugs and initial testing in an article posted online April 9, 2009, in Science Express, which provides electronic publication of selected Science articles in advance of print. Sawyers's team collaborated on the studies with researchers from the University of California Los Angeles, Oregon Health and Science University, University of Washington and Medivation.
About 186,000 new cases of prostate cancer are diagnosed each year in the United States. The male hormones testosterone and dihydrotestosterone -- also known as androgens -- spur the growth of prostate cells, and drugs that block the receptors for these hormones are the most common treatment for the disease in its advanced, metastatic stage. Antiandrogen drugs, such as bicalutamide, supp
|Contact: Jennifer Michalowski|
Howard Hughes Medical Institute