Real-world Comparative Study of Androgen Receptor Signaling Inhibitors in Japanese Patients With Non-metastatic...

Area of Science:

• Oncology
• Urology
• Pharmacology

Background:

• Androgen receptor signaling inhibitors (ARSIs) are standard for non-metastatic castration-resistant prostate cancer (nmCRPC).
• Limited real-world data exists on ARSI comparative outcomes in Asian populations.
• Japanese real-world data on ARSI effectiveness and tolerability in nmCRPC is needed.

Purpose of the Study:

• To evaluate the real-world effectiveness and tolerability of ARSIs in Japanese patients with nmCRPC.
• To compare clinical outcomes and treatment persistence among enzalutamide, apalutamide, and darolutamide.
• To identify factors influencing ARSI effectiveness in nmCRPC.

Main Methods:

• Retrospective review of 100 Japanese nmCRPC patients treated with enzalutamide (ENZ), apalutamide (APA), or darolutamide (DARO).
• Analysis of progression-free survival (PFS), overall survival (OS), prostate-specific antigen (PSA) response, and adverse events.
• Kaplan-Meier and log-rank tests were used for statistical analysis.

Main Results:

• Median PFS was 21.5 months; ENZ showed longer PFS than APA (p=0.03), DARO was comparable.
• First-line ARSI therapy and initiation at PSA <2.0 ng/ml were associated with significantly longer PFS.
• Adverse events led to dose modification/discontinuation, impacting PFS; dermatologic toxicity was a key issue with APA.

Conclusions:

• ARSI effectiveness in Japanese nmCRPC patients is influenced by treatment persistence, initiation timing, and sequencing.
• Early ARSI initiation and proactive adverse event management can optimize outcomes.
• Sequential ARSI therapy demonstrated limited clinical benefit in this cohort.