Medivation develops promising treatment MDV3100 for drug-resistant prostate cancer

A promising new treatment for drug-resistant prostate cancer is currently under development by Medivation. The drug which is yet to be named is currently given a title MDV3100.

MDV3100 is considered radically different approach of attacking prostate cancer. MDV3100 has done well in an early clinical trials. Now Medivation Inc., a California-based biopharmaceutical company that has licensed the drug, is planning for larger-scale testing.

The standard treatment for prostate cancer is to inhibit the activity of androgens, male hormones such as testosterone that help drive tumour growth.

Medivation began clinical studies using MDV3100 in 2007. In those initial studies, 30 men with antiandrogen-resistant prostate cancer received low doses of MDV3100. Twenty-two of those men showed a sustained decline in their blood levels of prostate specific antigen (PSA), an indication that their cancer was responding favorably to the drug. This trial is still under way, and results from a total of 140 patients receiving higher doses of the drug will be reported within the next year, said Sawyers.

MDV3100 was 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.

Prostate cancer becomes resistant to antiandrogen drugs when cancer cells begin to increase production of the androgen receptor, said Sawyers. When the level of androgen receptors on the cells’ surface reaches a certain level, the drugs that originally suppressed the cancer actually begin to stimulate cancer growth.

The researchers tested the new drugs’ effectiveness in mice with tumours derived from drug-resistant prostate cancer cells. “To our delight, we found that these compounds caused very dramatic shrinkage of tumors in the mice,” said Sawyers.

Medivation has received permission from the Food and Drug Administration for a large clinical trial of MDV3100 on about 1,200 patients with antiandrogen-resistant disease. This study will assess MDV3100′s effect on cancer survival and will take several years.

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, suppress the growth of cancer cells temporarily, but in most patients the prostate cancer ultimately develops resistance to drugs. About 29,000 men in the United States die each year from prostate cancer.