Clinical activity of abiraterone acetate in patients with metastatic castration-resistant prostate cancer progressing after enzalutamide.

Published

Journal Article

BACKGROUND: Abiraterone acetate and enzalutamide both improve outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC). Optimal sequencing for these agents and whether cross-resistance occurs is unknown. METHODS: Multicentre review of patients with mCRPC treated with abiraterone acetate and prednisone after progressing on enzalutamide. Primary objective was to determine abiraterone acetate response. RESULTS: Thirty patients identified from four North American centres. At abiraterone initiation, median age was 70 years (56-84 years); 70% had ECOG performance status of 0-1; all had prior docetaxel. Median prior enzalutamide treatment duration was 41 weeks (6-95 weeks), with 70% (21 of 30) having a ≥30% prostate-specific antigen (PSA) decline. Median abiraterone acetate treatment duration was 13 weeks (1-52). No objective radiographic responses were observed. Median abiraterone time to progression (PSA, objective or symptomatic) was 15.4 weeks [95% confidence interval (CI) 10.7-20.2]. Median overall survival was 50.1 weeks (95% CI 28.3-72.0). Three patients had a ≥30% PSA decline with abiraterone. Two of these patients had PSA progression as best response with prior enzalutamide. CONCLUSIONS: In this study of patients progressing after enzalutamide, treatment with abiraterone was associated with a modest response rate and brief duration of effect. Primary progression on enzalutamide may not preclude a response to abiraterone.

Full Text

Duke Authors

Cited Authors

  • Noonan, KL; North, S; Bitting, RL; Armstrong, AJ; Ellard, SL; Chi, KN

Published Date

  • July 2013

Published In

Volume / Issue

  • 24 / 7

Start / End Page

  • 1802 - 1807

PubMed ID

  • 23585511

Pubmed Central ID

  • 23585511

Electronic International Standard Serial Number (EISSN)

  • 1569-8041

Digital Object Identifier (DOI)

  • 10.1093/annonc/mdt138

Language

  • eng

Conference Location

  • England