Zytiga Approved to Treat Earlier Form of Metastatic Prostate Cancer

New FDA indication comes in combination with prednisone

Abiraterone acetate (Zytiga, Janssen Pharmaceutical) in combination with prednisone has received FDA approval for the treatment of patients with metastatic high-risk castration-sensitive prostate cancer (CSPC). Approval of the new indication is based on phase 3 data from the pivotal LATITUDE clinical trial, which found that in patients with metastatic high-risk CSPC, abiraterone with prednisone reduced the risk of death by 38% compared with placebos.

"LATITUDE was a large global trial which produced impressive and clinically significant results in overall survival," said Karim Fizazi, MD, PhD, Principal Investigator and Head of the Medical Oncology Department at Institute Gustave Roussy in Villejuif, France. "With today's approval, abiraterone acetate plus prednisone could become a standard of care for patients with metastatic high-risk castration-sensitive prostate cancer."

LATITUDE was a multinational, multicenter, randomized, double-blind, placebo-controlled trial that examined the use of abiraterone 1,000 mg once daily in combination with prednisone 5 mg once daily compared with placebos (N = 1,199) in patients with newly diagnosed, metastatic high-risk CSPC who had not received prior cytotoxic chemotherapy.  All the patients received a gonadotropin-releasing hormone (GnRH) analog or had prior bilateral orchiectomy.

The study data were presented at the plenary session of the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, and simultaneously published in The New England Journal of Medicine. The study showed abiraterone in combination with prednisone reduced the risk of death by 38% compared with placebos (median OS not estimable versus 34.7 months, respectively; hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.51–0.76; P < 0.0001). Additional data demonstrated statistically significant delay in time to initiation of chemotherapy for patients in the abiraterone arm compared with those in the placebo arm (median time to initiation of chemotherapy not reached versus 38.9 months, respectively; HR, 0.44; 95% CI, 0.35–0.56; P < 0.0001).

The most common adverse reactions (10% or more) that occurred more commonly (more than 2%) in the abiraterone arm from an analysis of pooled safety data were fatigue, arthralgia, hypertension, nausea, edema, hypokalemia, hot flush, diarrhea, vomiting, upper respiratory infection, cough, and headache.

Metastatic prostate cancer is cancer that has spread to another part of the body. Metastatic castration-sensitive prostate cancer (CSPC), also referred to as metastatic hormone-sensitive prostate cancer (HSPC) in literature, refers to prostate cancer that still responds to testosterone suppression therapy. Patients with newly-diagnosed metastatic disease and high-risk disease characteristics tend to have a poorer prognosis.

Source: Janssen; February 8, 2018.