Astellas Pharma Inc. and Medivation Inc. announced in a press release that they submitted a Supplemental New Drug Application (sNDA) to the Food and Drug Administration (FDA). The two companies are seeking approval for Xtandi (enzalutamide) for men with metastatic castration-resistant prostate cancer (mCRPC) who have not received chemotherapy. The drug was approved for the same patient population in 2012, but only for those cancer patients who had been previously treated with docetaxel chemotherapy.
Metastatic Castration-Resistant Prostate Cancer
mCRPC is a progression of prostate cancer. mCRPC is cancer that has become resistant to treatment and has spread to other parts of the body. Deaths in prostate cancer usually result from mCRPC and are the second leading cause of cancer deaths for U.S. men. Men live an average of two years after diagnosis. Recent drug developments have given patients and doctors new hope, but the disease is still incurable.
Xtandi acts on the androgen receptor signaling pathway by inhibiting androgen receptors. The drug also inhibits interaction with DNA and inhibits androgen receptor nuclear translocation. The FDA approved Xtandi in August of 2012 for patients with mCRPC. These patients were previously treated with docetaxel chemotherapy. The new indication sought by the pharmaceutical companies is for patients who have not received chemotherapy. The drug’s sponsors based the application on results of a Phase III trial.
The PREVAIL Trial
The PREVAIL Phase III clinical trial compared Xtandi to a placebo. 1,700 patients took part in the trial. The multi-national study included participants from the U.S., Europe, Canada, Japan and others. Patients were chemotherapy-naïve, not exposed to chemotherapeutic drugs. Patients took a placebo or 160 mg of enzalutamide. Investigators had co-primary endpoints instead of primary and secondary. The endpoints were radiographic progression-free survival and overall survival.
Astellas and Medivation
Astellas is a drug development company focused on oncology and urology. In addition to enzalutamide, it has other compounds in development. Medivation, Inc. focuses on small molecule drugs for rare or serious diseases. The two companies formed a partnership in 2009 to develop and market enzalutamide. They seek to develop the drug for different kinds of cancer. They are marketing enzalutamide together in the U.S. while Astellas takes responsibility for the global market.