A multicenter retrospective analysis of sequential treatment of abiraterone acetate followed by docetaxel in Japanese patients with metastatic castration-resistant prostate cancer.

Abstract

OBJECTIVE:

Abiraterone acetate and docetaxel are promising treatment options for metastatic castration-resistant prostate cancer patients. However, the optimal sequencing of these agents is unclear, and no previous reports discuss Japanese metastatic castration-resistant prostate cancer patients. The purpose of this analysis is to reveal the outcomes of Japanese metastatic castration-resistant prostate cancer patients treated with abiraterone acetate followed by docetaxel.

METHODS:

We retrospectively reviewed Japanese Phase 1 and Phase 2 trials of metastatic castration-resistant prostate cancer patients treated with abiraterone acetate until disease progression and subsequently treated with docetaxel. The primary outcome measure was the rates of prostate-specific antigen declines ≧30 and ≧50%, respectively, with docetaxel. Secondary outcome measures included progression-free survival with docetaxel, and overall survival after initiation of abiraterone acetate and docetaxel. We performed correlation analysis between previous prostate-specific antigen response to abiraterone acetate and subsequent prostate-specific antigen response to docetaxel.

RESULTS:

We identified 15 patients had experienced disease progression with abiraterone acetate and subsequently were treated with docetaxel. Prostate-specific antigen declines ≧30 and ≧50% with docetaxel were observed in five patients (33%) and two patients (13%), respectively. The median progression-free survival with docetaxel was 3.7 months (95% confidence interval: 2.9-4.6). The median overall survival from initiation of docetaxel and abiraterone acetate were 14.4 months (95% confidence interval: 6.3-22.4), and 25.7 months (95% confidence interval: 20.1-30.7), respectively. No significant correlation was observed between these prostate-specific antigen responses (Pearson r = 0.206, P = 0.46).

CONCLUSION:

The efficacy of docetaxel in Japanese mCRPC patients that was resistant to abiraterone acetate was modest. The prostate-specific antigen response to previous abiraterone acetate could not predict the efficacy of subsequent docetaxel. Larger prospective trials are needed to validate these findings.

• Authors: Yujiro Ueda, Nobuaki Matsubara, Itsuhiro Takizawa, Tsutomu Nishiyama, Ken-Ichi Tabata, Takefumi Satoh, Naoto Kamiya, Hiroyoshi Suzuki, Takashi Kawahara, Hiroji Uemura
• Journal: Japanese journal of clinical oncology (Jpn J Clin Oncol) Vol. 45 Issue 8 Pg. 774-9 (Aug 2015) ISSN: 1465-3621 [Electronic] England
• PMID: 25981621 (Publication Type: Journal Article, Multicenter Study)
• Copyright: © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: [email protected].

Chemical References

• Androstenes
• Taxoids
• Docetaxel
• Prostate-Specific Antigen
• Abiraterone Acetate

Topics

• Abiraterone Acetate
• Aged
• Androstenes (administration & dosage)
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Disease Progression
• Disease-Free Survival
• Docetaxel
• Humans
• Japan
• Male
• Middle Aged
• Prostate-Specific Antigen (blood)
• Prostatic Neoplasms, Castration-Resistant (blood, drug therapy, pathology)
• Retrospective Studies
• Taxoids (administration & dosage)
• Treatment Outcome