Clinical Outcomes of First-line Abiraterone Acetate or Enzalutamide for Metastatic Castration-resistant Prostate Cancer After Androgen Deprivation Therapy + Docetaxel or ADT Alone for Metastatic Hormone-sensitive Prostate Cancer

Clin Genitourin Cancer. 2018 Apr;16(2):130-134. doi: 10.1016/j.clgc.2017.12.012. Epub 2017 Dec 27.

Abstract

Background: The CHAARTED (ChemoHormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer) and STAMPEDE (Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy) trials showed that the addition of docetaxel (D) to androgen deprivation therapy (ADT) prolonged longevity of men with metastatic hormone-sensitive prostate cancer (mHSPC). However, the impact of upfront D on subsequent therapies is still unexplored. As abiraterone acetate (AA) and enzalutamide (E) are the most commonly used first-line treatment for metastatic castration-resistant prostate cancer (mCRPC), we aimed to assess whether they maintained their efficacy after ADT+D versus ADT alone.

Patients and methods: A cohort of patients with mCRPC treated between 2014 and 2017 with first-line AA or E for mCRPC was identified from 3 hospitals' institutional review board-approved databases. Patients were classified by use of D for mHSPC. This time frame was chosen as ADT+D became a valid therapeutic option for mHSPC in 2014, and it inherently entailed a short follow-up time on AA/E. The endpoints included overall survival from ADT start, overall survival from AA/E start, and time to AA/E start from ADT start. Differences between groups were assessed using the log-rank test.

Results: Of the 102 patients with mCRPC identified, 50 (49%) had previously received ADT alone, while 52 (51%) had ADT+D. No statistically significant difference in any of the evaluated outcomes was observed between the 2 cohorts. Yet, deaths in the ADT+D group were 12 versus 21 in the ADT alone, after a median follow-up of 24.4 and 29.8 months, respectively.

Conclusion: In a cohort of ADT/ADT+D-treated patients with mCRPC with short times to first-line AA/E and follow-up, the efficacy of AA/E is similar regardless of previous use of D.

Keywords: AR targeting agents; CHAARTED; mCRPC; mCRPC sequencing; mHSPC.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Abiraterone Acetate / administration & dosage*
  • Abiraterone Acetate / therapeutic use
  • Antineoplastic Combined Chemotherapy Protocols / administration & dosage
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Disease-Free Survival
  • Docetaxel / administration & dosage*
  • Docetaxel / therapeutic use
  • Humans
  • Male
  • Phenylthiohydantoin / administration & dosage
  • Phenylthiohydantoin / analogs & derivatives*
  • Phenylthiohydantoin / therapeutic use
  • Prostatic Neoplasms, Castration-Resistant / drug therapy*
  • Retrospective Studies
  • Survival Analysis
  • Treatment Outcome

Substances

  • Docetaxel
  • Phenylthiohydantoin
  • enzalutamide
  • Abiraterone Acetate