Radiotherapy Combined With Fluzopanib and Abiraterone Acetate Tablets (II) Treatment for mCRPC

This study is an open-label, single-arm, multicenter clinical trial designed to evaluate the efficacy, safety, and quality of life of first-line treatment with the combination of radiotherapy, fluzoparib, abiraterone acetate (II) for patients with metastatic castration-resistant prostate cancer (mCRPC).Eligible subjects who meet the inclusion criteria will be enrolled and assessed for Homologous Recombination Repair (HRR) mutation status. Participants will undergo two phases of treatment: the induction phase and the maintenance phase. During the induction phase, patients will receive Intensity-Modulated Radiation Therapy (IMRT) in combination with fluzoparib, abiraterone acetate (II), and prednisone. In the maintenance phase, patients will continue treatment with fluzoparib, abiraterone acetate (II), and prednisone. Each treatment cycle is 28 days long, and treatment will continue until disease progression is determined by the investigator and the patient is no longer clinically benefiting from the study. Follow-up will continue until the subject withdraws informed consent or the study ends, whichever occurs first.The study plans to enroll 40 eligible subjects. The primary endpoint is the PSA response rate (the proportion of patients with a ≥50% decrease in PSA from baseline). Secondary endpoints include radiographic progression-free survival (rPFS), time to PSA progression (TTPP), PSA depth of response (PSA 90, PSA undetectable rate), time to first subsequent treatment (TFST), failure-free survival (FFS), and overall survival (OS).