World J Urol. 2026 May 11;44(1):354. doi: 10.1007/s00345-026-06460-8.
ABSTRACT
PURPOSE: Although olaparib plus abiraterone and prednisone has significantly prolonged radiographic progression-free survival (rPFS) in metastatic castration resistant prostate cancer patients (mCRPC), little is known about the effects of this combination therapy on metastatic hormone-sensitive prostate cancer (mHSPC), especially for those with homologous recombination repair (HRR) genes. We conducted a phase II clinical trial to evaluate the efficacy and safety of olaparib plus abiraterone for mHSPC with HRR gene mutations.
METHODS: Thirty patients with mHSPC who had at least one HRR gene mutation were enrolled. Patients were administered Olaparib 300 mg BID plus abiraterone 1000 mg QD and prednisone 5 mg QD. The primary endpoint was 1-year rPFS rate per PCWG3-modified RECIST 1.1 by investigator assessment, and the secondary endpoints included median rPFS, PSA response rate, PSA-PFS, ORR.
RESULTS: A total of 30 patients administered combination therapy with mutations in 7 HRR genes. All the patients had de novo mHSPC. The median follow-up was 19.0 months. The 1-year rPFS rate was 77.7% (95% CI: 63.4-95.3%). All patients achieved PSA50 response. Among the 13 patients who had measurable disease at baseline, the confirmed ORR was 84.6% (n = 11). One patient achieved a complete response, ten patients obtained a partial response, and two had progressive disease. The treatment was well tolerated, with 8(26.6%) patients experienced≥ grade 3 treatment-related adverse events (TRAEs). Common TRAE was anemia (13 patients, 43.3%).
CONCLUSION: In this phase II single-arm study, olaparib plus abiraterone and ADT showed preliminary activity and a manageable safety profile in patients with HRR-mutated mHSPC, but these findings need to be confirmed in larger phase III studies.
TRIAL REGISTRATION: This trial is registered with ClinicalTrials.gov, number NCT05167175.
PMID:42115448 | DOI:10.1007/s00345-026-06460-8
