Dr. Efstathiou on updated MAGNITUDE data for niraparib/abiraterone in mCRPC
The updated data sustained the previous radiographic progression-free survival benefit observed with the niraparib combination and showed that the combination also met several secondary end points.
Eleni Efstathiou, MD, PhD, medical oncologist, and section chief of Genitourinary Medical Oncology at Houston Methodist Cancer Center in Texas, discusses data from the second interim analysis of the phase 3 MAGNITUDE study (NCT03748641), which she presented at the 2023 Genitourinary Cancers Symposium.
The study compared niraparib (Zejula) plus abiraterone acetate (Zytiga) and prednisone versus abiraterone and prednisone alone in patients with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair gene alterations.
The results Efstathiou shared showed that after an additional 8 months of follow-up since the previous interim analysis, the median radiographic progression-free survival (rPFS) was 16.7 months in the niraparib group vs 13.7 months in the placebo arm (HR, 0.76; 95% CI, 0.60-0.97; nominal P = .0280).
Niraparib also yielded a statistically significant benefit in time to symptomatic progression (TSP) vs placebo, with a hazard ratio of 0.60 (95% CI, 0.42-0.84; P = .0029), as well as in TCC, with a hazard ratio of 0.67 (95% CI, 0.47-0.94; P = .0206).
Notably, among patients with BRCA alterations, the median rPFS was 19.5 months and 10.9 months in the niraparib and placebo arms (HR, 0.55; 95% CI, 0.39-0.78; nominal P = .0007), respectively. TSP progression in the BRCA subgroup was not evaluable (NE) in the niraparib arm vs 23.6 months in the placebo (HR, 0.54; 95% CI, 0.35-0.85; P = .0071). Additionally, the TCC in the BRCA subgroup was NE in the niraparib arm and had a median of 27.3 months in the placebo arm (HR, 0.56; 95% CI, 0.35-0.90; P = .0152), respectively.
Overall survival showed an uptick in the BRCA subgroup, with a median of 29.3 months in the niraparib arm vs 28.6 months in the placebo arm (HR, 0.88; 95% CI, 0.58-1.34; P = .5505).
Niraparib treatment also resulted in a delayed time to worst pain intensity (HR, 0.70; 95% CI, 0.44-1.12; nominal P = .1338) and pain interference (HR, 0.67; 95% CI, 0.40-1.12; nominal P = .1275) in the BRCA subgroup vs placebo.
