Premium
Exploring the optimal sequence of abiraterone and enzalutamide in patients with chemotherapy‐naïve castration‐resistant prostate cancer: The Kyoto‐Baltimore collaboration
Author(s) -
Terada Naoki,
Maughan Benjamin L,
Akamatsu Shusuke,
Kobayashi Takashi,
Yamasaki Toshinari,
Inoue Takahiro,
Kamba Tomomi,
Ogawa Osamu,
Antonarakis Emmanuel S
Publication year - 2017
Publication title -
international journal of urology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 67
eISSN - 1442-2042
pISSN - 0919-8172
DOI - 10.1111/iju.13346
Subject(s) - enzalutamide , medicine , hazard ratio , prostate cancer , confidence interval , oncology , abiraterone , urology , cancer , androgen receptor
Objectives To evaluate and compare the efficacy of sequential treatment with abiraterone followed by enzalutamide or vice versa for castration‐resistant prostate cancer. Methods We retrospectively evaluated data on 198 consecutive chemotherapy‐naïve patients who had received both abiraterone and enzalutamide for castration‐resistant prostate cancer at Kyoto University Hospital (including satellite hospitals) and at Johns Hopkins Cancer Center. Prostate‐specific antigen progression‐free survival and overall survival in patients treated with sequential abiraterone ‐to‐ enzalutamide versus enzalutamide ‐to‐ abiraterone without intervening therapies were compared. Results Overall, 113 patients were treated with the abiraterone ‐to‐ enzalutamide sequence and 85 with the enzalutamide ‐to‐ abiraterone sequence. Median prostate‐specific antigen progression‐free survival was not significantly different between abiraterone and enzalutamide in the first‐line setting ( hazard ratio 0.88, 95% confidence interval 0.66–1.19, P = 0.412), but there was an advantage favoring enzalutamide compared with abiraterone in the second‐line setting ( hazard ratio 0.67, 95% confidence interval 0.49–0.91, P = 0.009). Furthermore, the combined prostate‐specific antigen progression‐free survival was significantly longer in the abiraterone ‐to‐ enzalutamide sequence than in the enzalutamide ‐to‐ abiraterone sequence ( hazard ratio 0.56, 95% confidence interval 0.41–0.76, P < 0.001). The difference was significant even in multivariate analyses ( hazard ratio 0.65, 95% confidence interval 0.42–0.99, P = 0.044). There was no statistical difference in overall survival between the two sequences in univariate ( hazard ratio 0.88, 95% confidence interval 0.53–1.43, P = 0.599) and multivariate analyses ( hazard ratio 0.81, 95% confidence interval 0.49–1.35, P = 0.427). Conclusions The abiraterone ‐to‐ enzalutamide sequence might have more favorable efficacy in terms of combined prostate‐specific antigen progression‐free survival than the enzalutamide ‐to‐ abiraterone sequence, although no differences in overall survival were observed. This could possibly be attributable to longer prostate‐specific antigen progression‐free survival with second‐line enzalutamide compared with abiraterone .