Enzalutamide and Survival in Nonmetastatic, Castration-Resistant Prostate Cancer

N Engl J Med. 2020 Jun 4;382(23):2197-2206. doi: 10.1056/NEJMoa2003892. Epub 2020 May 29.

Abstract

Background: Preliminary trial results showed that enzalutamide significantly improved metastasis-free survival among men who had nonmetastatic, castration-resistant prostate cancer and rapidly increasing prostate-specific antigen (PSA) levels while taking androgen-deprivation therapy. Results from the final analysis of overall survival have not yet been reported.

Methods: In this double-blind, phase 3 trial, men with nonmetastatic, castration-resistant prostate cancer (defined on the basis of conventional imaging and a PSA doubling time of ≤10 months) who were continuing to receive androgen-deprivation therapy were randomly assigned (in a 2:1 ratio) to receive enzalutamide at a dose of 160 mg or placebo once daily. Overall survival was assessed with a group sequential testing procedure and an O'Brien-Fleming-type alpha-spending function.

Results: As of October 15, 2019, a total of 288 of 933 patients (31%) in the enzalutamide group and 178 of 468 (38%) in the placebo group had died. Median overall survival was 67.0 months (95% confidence interval [CI], 64.0 to not reached) in the enzalutamide group and 56.3 months (95% CI, 54.4 to 63.0) in the placebo group (hazard ratio for death, 0.73; 95% CI, 0.61 to 0.89; P = 0.001). The exposure-adjusted rate of adverse events of grade 3 or higher was 17 per 100 patient-years in the enzalutamide group and 20 per 100 patient-years in the placebo group. Adverse events in the enzalutamide group were consistent with those previously reported for enzalutamide; the most frequently reported events were fatigue and musculoskeletal events.

Conclusions: Enzalutamide plus androgen-deprivation therapy resulted in longer median overall survival than placebo plus androgen-deprivation therapy among men with nonmetastatic, castration-resistant prostate cancer and a rapidly rising PSA level. The risk of death associated with enzalutamide was 27% lower than with placebo. Adverse events were consistent with the established safety profile of enzalutamide. (Funded by Pfizer and Astellas Pharma; PROSPER ClinicalTrials.gov number, NCT02003924.).

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / drug therapy*
  • Adenocarcinoma / mortality
  • Aged
  • Androgen Antagonists / therapeutic use*
  • Antineoplastic Combined Chemotherapy Protocols / adverse effects
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Double-Blind Method
  • Humans
  • Kallikreins / blood
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Phenylthiohydantoin / adverse effects
  • Phenylthiohydantoin / analogs & derivatives*
  • Phenylthiohydantoin / therapeutic use
  • Placebos
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms, Castration-Resistant / drug therapy*
  • Prostatic Neoplasms, Castration-Resistant / mortality
  • Survival Analysis

Substances

  • Androgen Antagonists
  • MDV 3100
  • Placebos
  • Phenylthiohydantoin
  • Kallikreins
  • kallikrein-related peptidase 3, human
  • Prostate-Specific Antigen

Associated data

  • ClinicalTrials.gov/NCT02003924