Title: Abiraterone plus Prednisone in Metastatic, Castration-Sensitive Prostate Cancer

Fizazi, K. et al.


What You Need to Know:

Overall survival and radiographic-free survival were significantly increased in men with metastatic, castration-sensitive cancer when abiraterone acetate and prednisone were added to androgen-deprivation therapy.

Trial Design:

  • Double-blind, placebo-controlled phase 3 study evaluated “the clinical benefit of abiraterone acetate plus prednisone with androgen-deprivation therapy in patients with newly diagnosed, metastatic, castration-sensitive prostate cancer”
  • 1199 patients were randomized to the abiraterone group or placebo group
  • Abiraterone group: received androgen-deprivation therapy + 1000mg abiraterone acetate daily (administered 4 times/day) + 5mg prednisone daily
  • Placebo group: received androgen-deprivation therapy + dual placebos
  • Primary endpoints: overall survival, radiographic progression-free survival

Key Outcomes:

  • Median follow-up: 30.4 months (after 406 patients died)
  • Median overall survival at 30.4 months: not reached for patients in the abiraterone group vs 34.7 months for patients in the placebo group (HR for death: 0.62; 95% CI: 0.51, 0.76; P<0.001)
  • Median time of radiographic progression-free survival: 33.0 months for patients in the abiraterone group vs 14.8 months for patients in the placebo group (HR for disease progression or death: 0.47; 95% CI: 0.39, 0.55; P<0.001)
  • Abiraterone group exhibited better outcomes with respect to time to pain progression, subsequent therapy for prostate cancer, chemotherapy initiation, and progression of prostate-specific antigen (P<0.001 for all comparisons), as well as with subsequent symptomatic skeletal events (P=0.009)
  • “These findings led to the unanimous recommendation by the independent data and safety monitoring committee that the trial be unblinded and crossover be allowed for patients in the placebo group to receive abiraterone”
  • Higher rates of grade 3 hypertension and hypokalemia were reported in patients in the abiraterone group