Final Phase III data shows significant improvements with Zytiga in mCRPC - Janssen

A final analysis of the Phase III COU-AA-302 trial showed that Zytiga (abiraterone acetate), from Janssen Research & Development, plus prednisone significantly prolonged overall survival (OS), compared to an active control of placebo plus prednisone, in 1088 men with chemotherapy-naive metastatic castration-resistant Prostate Cancer (mCRPC). The study demonstrated a 19 percent reduction in risk of death in this study population (median OS, 34.7 vs 30.3 months, respectively), after a median follow-up of more than four years (49.2 months). In addition, the final analysis demonstrated a significant improvement in median time to opiate use for cancer-related pain compared to placebo plus prednisone (median 33.4 vs. 23.4 months, respectively).

With two additional years (a total of four years) of follow-up since the last clinical cutoff (median 49.2 months), the safety profile of Zytiga remained unchanged compared to previous reports. The final analysis is the first to demonstrate a statistically significant improvement in OS in this study. The FDA based its 2012 approval of Zytiga plus prednisone for treating men with mCRPC prior to chemotherapy on a planned second interim analysis of COU-AA-302, which met the co-primary endpoint of radiographic progression-free survival (rPFS). Based on results from the final analysis, Janssen has initiated regulatory submissions to relevant health authorities for a revision to the Zytiga label. Data were presented at the European Society for Medical Oncology 2014 Congress.