Real-World Treatment Patterns in Patients with Metastatic Castration-Sensitive Prostate Cancer in Japan: A...

Area of Science:

• Oncology
• Pharmacology
• Health Services Research

Background:

• Several androgen receptor signaling inhibitors (ARSIs) have been approved for metastatic castration-sensitive prostate cancer (mCSPC) in Japan since 2020.
• The study evaluates changes in the mCSPC treatment landscape in Japan post-ARSI approvals.

Purpose of the Study:

• To analyze treatment patterns and time to treatment discontinuation (TTD) in mCSPC patients in Japan since 2020.
• To assess the impact of ARSI approvals on mCSPC treatment strategies.

Main Methods:

• Retrospective cohort study using Japanese health administrative data (May 2020 - March 2024).
• Analysis of patient characteristics, first-line and subsequent-line treatment patterns, and TTD for first-line therapies and ARSIs.
• Inverse probability of treatment weight-adjusted Cox proportional hazards models used to calculate hazard ratios for TTD.

Main Results:

• Treatment with androgen-deprivation therapy (ADT) plus ARSI increased, while ADT plus nonsteroidal antiandrogens (NSAAs) decreased.
• Patients receiving first-line ADT plus ARSI showed a lower risk of treatment discontinuation compared to ADT alone or ADT plus NSAA.
• ADT plus enzalutamide demonstrated the longest median time to treatment discontinuation among ARSIs.

Conclusions:

• ARSI use for mCSPC is rising, though ADT alone and ADT plus NSAA remain common.
• Extended treatment duration with ARSIs highlights their importance for effective mCSPC disease control.
• Treatment intensification with ARSIs is crucial for managing mCSPC.