Patients with metastatic castration-resistant prostate cancer ( mCRPC ) and BRCA alterations experience subpar prognosis. Patients with homologous recombination repair gene alterations ( HRR +), particularly BRCA1 / 2, were found by MAGNITUDE to benefit from first-line therapy with niraparib plus abiraterone-acetate and prednisone( AAP ). Longer follow-up from the second prespecified interim analysis( IA2 ) is reported here.