Prostate Cancer Drug Label Updated with Survival Data

The FDA has updated the label of Janssen’s abiraterone acetate (Zytiga) to reflect its ability to significantly prolong survival in chemotherapy-naïve men with metastatic castration-resistant prostate cancer (mCRPC).

The label update was based on the final analysis of COU-AA-302, a phase 3 study demonstrating a median overall survival of nearly 3 years with Zytiga plus prednisone, versus 30.3 months with placebo plus prednisone.

"The statistically significant improvement in overall survival demonstrated in the final analysis and resulting label update help affirm the established efficacy, safety, and tolerability that physicians treating men with metastatic castration-resistant prostate cancer have seen with Zytiga," said Charles Ryan, lead investigator of the trial, in a press release. "…This analysis adds to the robust body of clinical data supporting Zytiga as an important treatment option for men with metastatic castration-resistant prostate cancer."

After a median follow-up of more than 4 years, no notable changes in Zytiga’s safety profile were seen since the interim analyses of the COU-AA-302 study.

The most common adverse reactions associated with the drug included fatigue, joint swelling, and edema, among others. Patients with a history of cardiovascular disease need to be monitored when taking the drug, which can cause hypertension, hypokalemia, and fluid retention.

The FDA’s original approval of Zytiga plus prednisone for treating men with mCRPC prior to chemotherapy was based on the results of a planned second interim analysis of COU-AA-302.