Dr Chi on the MAGNITUDE Trial of Niraparib Plus Abiraterone in BRCA-Mutated mCRPC

Kim N. Chi, MD, FRCPC, medical oncologist, vice president, chief medical officer, BC Cancer, professor, Division of Medical Oncology, University of British Columbia, discusses data from the updated and final analysis of the phase 3 MAGNITUDE (NCT03748641) trial in BRCA-positive metastatic castration-resistant prostate cancer (mCRPC).

This phase 3 study investigated the efficacy of niraparib (Zejula) plus abiraterone acetate (Zytiga) and prednisone in patients with mCRPC with homologous recombination repair (HRR) alterations. A subset of those with BRCA mutations (n = 225) were included in the final analysis of the study, during which mature overall survival (OS) and time to cytotoxic chemotherapy (TCC) were formally assessed, Chi states.

Previously reported data from this phase 3 study demonstrated significant improvements in several clinical end points for patients with BRCA-mutated mCRPC who received niraparib plus abiraterone as a first-line treatment, Chi says.

At a median follow-up of 35.9 months, results from the final analysis showed that the niraparib regimen produced a superior survival benefit vs the placebo regimen in this population, Chi reports. Notably, a prespecified multivariate analysis was performed to adjust for baseline numerical imbalances in key prognostic features between the placebo and experimental group, he adds. Results from this analysis showed a greater OS advantage with the experimental regimen, further reinforcing the OS benefit observed with the niraparib combination, Chi states.

The study also reported improvements in time to symptomatic progression (TSP), TCC, and patient-reported outcomes (PROs) among BRCA-positive patients given the niraparib regimen, Chi continues. Notably, no new safety concerns were identified with additional treatment exposure.

Overall, the findings from the MAGNITUDE study support the use of niraparib plus abiraterone as a new standard of care for patients with BRCA-positive mCRPC in the first-line setting. The positive benefit-risk profile of this combination therapy highlights its potential as an effective treatment option for this patient population.