Abstract
Poly(ADP-ribose) polymerase inhibitors are an important option for metastatic castration-resistant prostate cancer (mCRPC) with homologous recombination repair gene alterations, although durable complete responses remain rare. We report a 72-year-old man with BRCA2-mutated mCRPC who achieved a sustained complete response to olaparib monotherapy. After progression on androgen deprivation therapy, abiraterone, enzalutamide, and docetaxel, genomic profiling identified a pathogenic BRCA2 alteration. Olaparib induced an undetectable prostate-specific antigen within three months, maintained for over 27 months, with complete resolution of bone metastases. This case highlights the potential for durable responses to olaparib and the importance of early genomic testing.