Sequential Enzalutamide–Docetaxel Versus Abiraterone–Docetaxel Therapy in Castration‐Resistant Prostate Cancer: A Subanalysis of the
ENABLE
Study
Manabu Kamiyama, Kouji Izumi, Takahiko Mitsui, Takashi Shima, Yuki Kato, Koji Mita, Takehiko Okamura, Shogo Inoue, Seiji Hoshi, Nobumichi Tanaka, Yuko Yoshio, Shuichi Tatarano, Ippei Chikazawa, Noriyasu Kawai, Kohei Hashimoto, Takashi Fukagai, Kazuyoshi Shigehara, Shizuko Takahara, Atsushi Mizokami ABSTRACT
Background
Docetaxel (DTX) is commonly employed in patients with castration‐resistant prostate cancer (CRPC) following failure of androgen receptor signaling inhibitors (ARSIs). However, the impact of prior ARSI treatment on the efficacy of subsequent DTX therapy remains unclear. This study aimed to compare oncological outcomes between enzalutamide (ENZ)–DTX and abiraterone acetate plus prednisolone (ABI)–DTX sequential treatment strategies in patients with CRPC.
Methods
The ENABLE study for PCa was an investigator‐initiated, multicenter, randomized controlled trial conducted in Japan to compare ENZ and ABI. This subanalysis evaluated the efficacy of subsequent DTX therapy in patients who had received either ENZ or ABI.
Results
Between February 2015 and July 2019, 203 patients were enrolled, of whom 184 were randomized to receive ENZ or ABI (92 per arm). Among them, 20 and 21 patients subsequently initiated DTX therapy following ENZ and ABI, respectively. Median prostate cancer‐specific survival (PCSS) in the ENZ–DTX and ABI–DTX groups was 22.7 and 32.1 months, respectively ( p = 0.1724). Median PCSS from the initiation of DTX was 16.1 months in the ENZ–DTX group and 25.3 months in the ABI–DTX group ( p = 0.0966). In the overall cohort ( n = 41), patients who received additional ARSIs after ARSI–DTX therapy had significantly longer PCSS from the initiation of DTX compared with those who did not (median 21.6 vs. 13.8 months, p = 0.0157).
Conclusions
ENZ–DTX and ABI–DTX sequential therapies demonstrated comparable survival outcomes in patients with CRPC. Notably, the administration of additional ARSIs following ARSI–DTX therapy may confer a survival benefit, suggesting a potential role for continued ARSI use in this treatment sequence.
Trial Registration
The trial was registered with the University Hospital Medical Information Network (UMIN) Center under the identifier UMIN000015529 on November 1, 2014