KEY TAKEAWAYS
- The MAGNITUDE phase III trial aimed to assess the long-term efficacy and safety of NIRA+AAP in BRCA+ Asian mCRPC patients within the MAGNITUDE study’s second interim analysis.
- The primary endpoint was to determine rPFS.
- The results demonstrated sustained benefit in Asian patients with BRCA-positive mCRPC receiving NIRA+AAP, consistent with the overall MAGNITUDE study.
Patients facing metastatic castration-resistant prostate cancer (mCRPC) and BRCA alterations often experience unfavorable outcomes with existing standard treatments. The pivotal Phase 3 MAGNITUDE study has revealed that individuals having BRCA-positive mCRPC derive significant benefits from a first-line therapeutic approach involving a combination of niraparib (NIRA) and abiraterone acetate plus prednisone (AAP).
Marniza Saad and her team conducted the study’s second interim analysis that aimed to o report results for the subgroup of Asian patients, with a specific focus on those with BRCA1/2-positive (BRCA+) status.
The subgroup analysis determined the primary endpoint of radiographic progression-free survival (rPFS) assessed by blinded independent central review (BICR). Secondary endpoints included time to symptomatic progression (TSP), time to cytotoxic chemotherapy (TCC), and overall survival (OS) within the BRCA+ cohort, as well as time to PSA progression (TPP) in the BRCA+ cohort and safety in the HRR+ cohort, were explored.
The results demonstrated a significant improvement in rPFS by BICR compared to PBO+AAP, showing a 71% reduced risk of progression or death (HR 0.29, 95% CI 0.11, 0.77). Median rPFS extended to 22 months with NIRA+AAP, contrasting with 8 months for PBO+AAP. Clinically relevant delays were observed in TSP, TCC, and TPP. Although OS data were immature, the 24-month OS was 66.9% for NIRA+AAP versus 58.6% for PBO+AAP. In the broader HRR+ Asian population (N = 68).
Adverse events (AEs) were consistent with known effects, with higher Grade 3/4 AEs in the NIRA+AAP group. Serious AEs and discontinuations were higher in the NIRA+AAP group, aligning with IA1 safety findings, indicating no new safety signals.
The study found that extended follow-up of the Asian subgroup validates the initial findings, affirming the favorable outcomes associated with NIRA+AAP in BRCA+ metastatic castration-resistant prostate cancer (mCRPC) patients. These results aligned with the broader conclusions drawn from the overall MAGNITUDE study. Research was sponsored by Janssen Research & Development, LLC.
Source: https://cslide.ctimeetingtech.com/asia2023/attendee/confcal/show/session/32
Clinical Trial: https://clinicaltrials.gov/study/NCT03748641
Saad M, Chi KN, Sandhu SK, et al.’’ Niraparib plus abiraterone acetate plus prednisone (NIRA+AAP) as first-line treatment in patients with BRCA+ metastatic castration-resistant prostate cancer (mCRPC): Second interim analysis in the Asian subgroup of the MAGNITUDE study.’’ Presented at ESMO ASIA 2023 (258MO)
