Real-world treatment patterns and outcomes of novel androgen receptor axis-targeted agents in non-metastatic castration-resistant prostate cancer: A multi-institutional retrospective study.

Abstract

368 Background: Recently, three phase III trials have demonstrated that novel androgen receptor axis-targeted agents (ARATs) significantly improved metastasis-free survival (MFS) and overall survival (OS) compared to placebo in patients with non-metastatic castration-resistant prostate cancer (nmCRPC). However, the treatment patterns and outcomes of novel ARATs in real-world settings remain unclear. Methods: This multi-institutional retrospective study included 245 patients with nmCRPC treated between September 2003 and April 2024. Trends in the use of novel ARATs were evaluated. Patients were divided into two groups: those who were treated with any novel ARATs, including apalutamide, enzalutamide, darolutamide, and abiraterone acetate, during any line of nmCRPC treatment (novel ARATs group) and those who were not (control group). Multivariable Cox proportional hazards regression analyses were performed to evaluate the effects of novel ARATs on MFS and OS. Adverse events (AEs) associated with novel ARATs were evaluated using the Common Terminology Criteria for Adverse Events version 5.0. Results: The median age and follow-up period after nmCRPC diagnosis were 77 years and 45 months, respectively. Of the 245 patients, 175 (71%) were treated with novel ARATs after nmCRPC diagnosis. Novel ARATs use in first line and any line was gradually increased from 2014 to 2023 (0% to 85% and 38% to 92%, respectively). The MFS and OS in the novel ARATs group were significantly longer than those in the control group ( P < 0.001 and P = 0.001, respectively). In multivariable analyses, a prostate-specific antigen doubling time (PSADT) and novel ARATs were independently and significantly associated with MFS and OS (Table). The rate of grade 3 AEs and discontinuation due to AEs were 1.1% and 6.0%, respectively. Conclusions: The use of novel ARATs for the treatment of nmCRPC increased over time. Novel ARATs use was safe and associated with improved oncological outcomes in a real-world setting. Multivariable analyses for MFS and OS. MFS Factor P value Hazard ratio 95% CI Age Continuous 0.003 0.956 0.928–0.984 Time of nmCRPC diagnosis Before 2014 0.706 0.917 0.584–1.439 PSADT <2.5 months <0.001 2.040 1.339–3.107 Novel ARATs Positive <0.001 0.364 0.238–0.557 OS Factor P value Hazard ratio 95% CI Age Continuous 0.418 1.014 0.980–1.049 Time of nmCRPC diagnosis Before 2014 0.626 0.883 0.537–1.454 PSADT <2.5 months <0.001 2.138 1.360–3.360 Novel ARATs Positive 0.001 0.479 0.306–0.748