Clinical Outcomes of Patients with High-risk Metastatic Hormone-naïve Prostate Cancer: A 3-year Interim Analysis of the Observational J-ROCK Study.

Androgen deprivation therapy (ADT), administered alone, as combined androgen blockade (CAB) or as ADT plus androgen receptor signalling inhibitors (ARSIs) or ADT plus docetaxel, is the standard treatment for metastatic hormone-naïve prostate cancer (mHNPC) in Japanese real-world practice.

To investigate treatment patterns and clinical outcomes in LATITUDE criteria high-risk mHNPC.

The longitudinal, multicentre, J-ROCK registry study enrolled patients initiating ADT in Japan after May 2019, and categorised them as cohort 1 (ADT or CAB) or cohort 2 (ADT plus ARSIs or docetaxel).

Prostate-specific antigen (PSA) response, progression-free survival (PFS), time to castrate-resistant prostate cancer (CRPC), overall survival (OS), and safety were evaluated. PFS, time to CRPC, and OS were estimated via the Kaplan-Meier method and between-cohort comparisons via multivariate Cox regression models.

In total, 974 patients were included (cohort 1: 38.1%, cohort 2: 61.9%). CAB was preferred (67.4%) to ADT alone in cohort 1, and abiraterone acetate plus prednisolone was used most frequently in cohort 2 (59.4%). The proportion of patients with ≥50%/≥90% PSA decline or who achieved PSA ≤0.2/≤0.1 ng/ml tended to be higher in cohort 2. PFS (adjusted hazard ratio 0.42; 95% confidence interval [CI] 0.31-0.55), time to CRPC (0.28; 95% CI 0.23-0.36), and OS (0.54; 95% CI 0.35-0.82) were longer in cohort 2. In cohorts 1 and 2, adverse drug reactions of special interest (ADRSIs) occurred in 1.3% and 15.1%, and fatal adverse events occurred in 1.9% and 1.7%, respectively. Limitations included nonrandomised design, varying time since marketing authorisation for ARSIs, and limited safety assessments.

ADT plus ARSIs or docetaxel was used more frequently to treat high-risk mHNPC than standard ADT/CAB and was associated with more favourable clinical outcomes. Although ADRSIs were reported more in cohort 2, the safety profile was considered tolerable.

Although many treatment options are available for high-risk metastatic prostate cancer, there are limited reports on real-world clinical experience with different therapies outside of the clinical trial setting. In this study, we compared clinical and safety outcomes with different treatment regimens, using a large series of patients with high-risk metastatic hormone-naïve prostate cancer across Japan. We found that androgen deprivation therapy in combination with newer androgen receptor signalling inhibitors resulted in improved response compared with androgen deprivation therapy alone or in combination with a first-generation antiandrogen.

European urology oncology. 2024 Jan 30 [Epub ahead of print]

Hideaki Miyake, Rikiya Matsumoto, Kiyohide Fujimoto, Atsushi Mizokami, Hirotsugu Uemura, Toshiyuki Kamoto, Satoru Kawakami, Kazuyoshi Nakamura, Shigekatsu Maekawa, Kazuhiro Shibayama, Aki Watanabe, Miku Ito, Yohei Tajima, Hideyasu Matsuyama, Hiroji Uemura

Department of Urology, Hamamatsu University Hospital, Shizuoka, Japan., Department of Urology, Chutoen General Medical Center, Shizuoka, Japan., Department of Urology, Nara Medical University Hospital, Nara, Japan., Department of Urology, Kanazawa University Hospital, Ishikawa, Japan., Department of Urology, Kindai University Hospital, Osaka, Japan., Department of Urology, University of Miyazaki Hospital, Miyazaki, Japan., Department of Urology, Saitama Medical Center, Saitama Medical University, Saitama, Japan., Department of Urology, Kimitsu Chuo Hospital, Chiba, Japan., Department of Urology, Iwate Medical University Hospital, Iwate, Japan., Statistics & Decision Sciences Japan, Janssen Pharmaceutical K.K., Tokyo, Japan., Medical Affairs Operations, Global Development, Janssen R&D, Tokyo, Japan., Department of Medical Affairs, Janssen Pharmaceutical K.K., Tokyo, Japan., Department of Urology, Yamaguchi University Hospital, Yamaguchi, Japan. Electronic address: ., Department of Urology and Renal Transplantation, Yokohama City University Medical Center, Kanagawa, Japan.