Augmenting Androgen Inhibition in Metastatic Castration-Sensitive Prostate Cancer

In men with metastatic castration-resistant prostate cancer harboring homologous recombination repair (HRR) gene alterations such as BRCA1 and BRCA2, use of poly(ADP-ribose) polymerase (PARP) inhibitors combined with androgen-receptor pathway inhibitors (ARPI) demonstrates meaningful clinical activity. Could a PARP/ARPI combination also prove effective in men with metastatic castration-sensitive prostate cancer (mCSPC) with HRR mutations? To answer this question, investigators randomized 700 patients (about half with BRCA1 or BRCA2 mutations) to receive abiraterone acetate and prednisone (AAP) plus either the PARP inhibitor niraparib or placebo. Median follow-up was 2.5 years.