Medivation, the pharmaceutical company that owns Xtandi (formerly known as MDV-3100), the new androgen receptor antagonist to treat castrate resistant advanced prostate cancer has a number of active clinical trials, despite the fact that it has already been approved for use. The current FDA approval is specific; it has been approved for men who are castrate resistant after they failed chemotherapy.

Xtandi works as a blockade inhibiting the cancer cell’s ability to absorb and use androgens. Androgens function as a “sort of food” for prostate cancer. Currently, hormone deprivation therapy (ADT) includes Casodex (Bicalutamide) a drug that serves as a blockade, but it is a blockade that leaks.

Medivation is evaluating Xtandi in the pre-chemo setting (phase III PREVAIL study) which could offer the company a significant commercial opportunity as well as offering men with advanced prostate cancer an opportunity to use Xtandi earlier in the disease progression. Xtandi is also in a new phase II study (TERRAIN), which will compare Xtandi with bicalutamide.

Another study (STRIVE) is being conducted in men with either metastatic or non-metastatic disease. A third study (ASPIRE) is being conducted in chemo-naïve patients or at the earliest stage of prostate cancer. Medivation is also enrolling patients in an open-label clinical trial which will study Xtandi as a adjuvant therapy prior to prostatectomy. Medivation is also exploring Xtandi for breast cancer (phase I).

Even without these additional successful trials Xtandi is a major breakthrough drug for men with advanced prostate cancer. Hopefully, we will see the expansion of Xtandi to earlier stages of prostate cancer as well as to additional cancers.

Joel T. Nowak, M.A., M.S.W.