Health-related quality of life (HRQoL) and pain in the MAGNITUDE study of niraparib (NIRA) with abiraterone acetate and prednisone (AAP) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) gene alterations.

Abstract

5060 Background: Results from the international, randomized, double-blind, phase 3 MAGNITUDE study demonstrated that NIRA + AAP improved radiographic progression-free survival, time to cytotoxic chemotherapy, and time to symptomatic progression, with manageable toxicity in pts with mCRPC and HRR alterations (9-gene panel). Here, we report HRQoL and pain in MAGNITUDE. Methods: Eligible pts with mCRPC and HRR alterations were randomized 1:1 to NIRA + AAP or placebo (PBO) + AAP orally daily in 28-day cycles. Pts had ECOG status ≤1 and a Brief Pain Inventory–Short Form (BPI-SF) worst pain score ≤3 in prescreening. HRQoL assessments on day 1 of specified cycles included Functional Assessment of Cancer Therapy–Prostate (FACT-P) and BPI-SF. Changes from baseline were compared between treatment arms using repeated measures analysis. Proportional hazards regression models were used to compare time to deterioration (TTD) in worst pain intensity between arms. Results: Compliance for FACT-P and BPI-SF was > 80%. Most pts maintained low pain levels over time. Repeated measures analyses showed no clinically meaningful differences in pain over time or between arms. Median TTD in pain intensity was not reached in either arm. At the 25th percentile, there was a trend toward longer TTD in pain intensity with NIRA + AAP vs PBO + AAP (11.1 vs 10.1 mo; HR, 0.87; 95% CI, 0.61-1.24). HRQoL was maintained with NIRA + AAP, with no clinically meaningful differences in FACT-P total score over time or between arms. There was a trend toward greater worsening in early cycles on FACT-P physical wellbeing with NIRA + AAP vs PBO + AAP, driven by events within the known safety profile of NIRA + AAP (worsening of side effect bother, lack of energy, and nausea); however, overall, most pts reported minimal side effect burden (Table). Conclusions: In MAGNITUDE, most pts maintained low pain levels and positive HRQoL over time, with no clinically meaningful differences between treatment arms, further supporting the use of NIRA + AAP in pts with mCRPC and HRR alterations. Side effect burden was perceived as low in both arms. Although more pts on NIRA+AAP reported worsening side effects, the symptoms were generally perceived as mild. Clinical trial information: NCT03748641. [Table: see text]