Zytiga Receives New Indication, with Prednisone, for Metastatic, High-Risk Castration-Sensitive Prostate Cancer
On February 7, 2018, abiraterone acetate (Zytiga; Janssen Biotech) received FDA approval for use, in combination with prednisone, for the treatment of patients with metastatic, high-risk castration-sensitive prostate cancer (CSPC). The FDA approved this new indication under its priority review program.
The combination of abiraterone acetate plus prednisone was previously approved for the treatment of patients with metastatic, castration-resistant prostate cancer (CRPC), including patients who had received chemotherapy and patients with newly diagnosed metastatic CRPC.
This expanded FDA approval was based on the results of the international, placebo-controlled, LATITUDE clinical trial that included 1199 patients with metastatic, high-risk CSPC. Patients were randomized to abiraterone acetate 1000 mg plus prednisone 5 mg once daily (N = 597) or to placebo (N = 602). All patients received a gonadotropin-releasing hormone or had a bilateral orchiectomy. The primary end point was overall survival (OS). The median OS could not be reached in the abiraterone acetate plus prednisone arm, and was 34.7 months in the placebo arm (hazard ratio [HR], 0.621; 95% confidence interval [CI], 0.509-0.756; P <.0001). Similarly, the median time to chemotherapy initiation was not reached in the combination arm versus 38.9 months in the placebo arm (HR, 0.44; 95% CI, 0.35-0.56; P <.0001).
The most common (≥5%) adverse reactions with abiraterone acetate in the LATITUDE study were hypertension, hot flush, hypokalemia, increased alanine aminotransferase, increased aspartate aminotransferase, headache, urinary tract infection, upper respiratory tract infection, and cough.