Multinational phase 3 trial of niraparib versus placebo added to abiraterone plus prednisone for mCRPC in patients with HRR gene alterations

In the multinational phase 3 MAGNITUDE trial, patients with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair gene alterations (HRR+), particularly BRCA1/2, had better radiographic PFS with addition of niraparib versus placebo to first-line abiraterone acetate plus prednisone (AAP). A second interim analysis of the trial has now been published. The analysis confirmed the rPFS benefit with niraparib, and found improvement in time to symptomatic progression and time to initiation of cytotoxic chemotherapy. In the BRCA1/2 subgroup, prespecified inverse probability censoring weighting analysis of overall survival demonstrated an HR=0.54 (nominal p=0.0181) with niraparib plus AAP versus placebo plus AAP.