Patients with homologous recombination repair gene altered (HRR+) metastatic castration-resistant prostate cancer (mCRPC) have a poor prognosis but achieved clinical benefits when treated with first-line niraparib and abiraterone acetate plus prednisone (niraparib + AAP) in the MAGNITUDE trial. We report final exploratory results from MAGNITUDE for the subgroup of patients with Breast Cancer gene-positive (BRCA+) mCRPC enrolled in Asia (NCT03748641).
Participants with HRR + mCRPC were randomized 1:1 to treatment with niraparib + AAP or placebo + AAP. The primary endpoint of radiographic progression-free survival (rPFS) by blinded independent central review (BICR) and secondary survival endpoints were calculated for the BRCA+ Asian subgroup. Safety was assessed in the Asian HRR+ population.
The Asian subgroup included 35 participants with BRCA + mCRPC (all BRCA2+). After 34.99 months of follow-up, median rPFS by BICR was 38.6 months in the niraparib + AAP group versus 8.3 months in the placebo+AAP group (hazard ratio [HR] 0.33, 95% confidence interval [CI] 0.13-0.83, nominal p-value = 0.0141). Clinically relevant benefits were also observed in time to PSA progression (HR 0.32, 95% CI 0.13-0.83), and time to cytotoxic chemotherapy (HR 0.098, 95% CI 0.01-0.68). Median overall survival was not reached in the niraparib+AAP group and was 24.0 months in the placebo+AAP group (HR 0.67, 95% CI 0.27-1.71). The safety profile of niraparib+AAP was consistent with the main study population.
In this final exploratory analysis of the Asian subgroup, participants with BRCA + mCRPC continued to benefit from first-line treatment with niraparib + AAP in comparison to placebo + AAP, with efficacy and toxicity profiles consistent with the global study population.
United States National Library of Medicine (https://clinicaltrials.gov); NCT03748641.
International journal of urology : official journal of the Japanese Urological Association. 2026 Apr [Epub]
Dingwei Ye, Marniza Saad, Ji Youl Lee, Wonho Jung, See-Tong Pang, Lei Li, Howard Gurney, Gerhardt Attard, Kim N Chi, Suneel Mundle, Jianmin Zhuo, Anildeep Singh, Yun Lin, Shahneen Sandhu
Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China., Department of Clinical Oncology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia., Department of Urology Cancer Center, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea., Department of Urology, Keimyung University Dongsan Hospital, Daegu, South Korea., Department of Urology, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan., Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China., Macquarie University Hospital, Sydney, New South Wales, Australia., Research Department of Oncology, University College London, London, UK., Department of Medical Oncology, University of British Columbia, BC Cancer - Vancouver Center, Vancouver, British Columbia, Canada., Johnson & Johnson, New Brunswick, New Jersey, USA., Johnson & Johnson, Shanghai, China., Johnson & Johnson, Singapore., Division of Cancer Medicine, Peter MacCallum Cancer Center and the University of Melbourne, Melbourne, Victoria, Australia.