Background: PROpel (NCT03732820) met its primary endpoint and showed significantly prolonged investigator-assessed rPFS with abi + ola vs abi + pbo at primary analysis (data cut-off [DCO]: 7/30/21; median 24.8 vs 16.6 months (m); hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.54–0.81; P<0.001). HRQoL (based on The Functional Assessment of Cancer Therapy-Prostate [FACT-P] total score) was not different when ola was combined with standard-of-care abi. We present data at the final prespecified overall survival (OS) DCO (10/12/22). Methods: PROpel is a randomised, double-blind trial in 1L mCRPC. Time to pain progression (TTPP) was based on the Brief Pain Inventory-Short Form (BPI-SF) Item 3 ‘worst pain in 24 hours’ and opiate analgesic use (analgesic quantification algorithm) score. Time to first symptomatic skeletal related event (SSRE) was time to use of therapy to prevent/relieve skeletal symptoms, new bone fractures, spinal compression or surgery on bone metastases. HRQoL was assessed by change from baseline (BL) in FACT-P total and subscale scores, BPI-SF pain severity, pain interference and worst pain score between arms using a mixed model for repeated measures. Results: At median follow-up of 33.6 m with abi + ola and 32.1 m with abi + pbo, 17.0% pts (68/399) in the abi + ola arm and 15.1% pts (60/397) in the abi + pbo arm had pain progression (PP) events. The % of pts who had not experienced PP with abi + ola vs abi + pbo was 76.9% vs 77.2% at 24 m and 70.7% vs 71.0% at 36 m. No meaningful difference in TTPP was observed (16% maturity, HR 1.06, 95% CI 0.75–1.50, P=0.75 [nominal], median not reached [NR] either arm). The % of pts who had not had a SSRE with abi + ola vs abi + pbo was 86.1% vs 82.2% at 24 m and 80.8 vs 78.5% at 36 m. No meaningful difference in time to SSRE was observed (12% maturity, HR 0.82, 95% CI 0.55–1.22, P=0.32 [nominal], median NR vs NR). Least-squares mean changes from BL between arms in BPI-SF pain severity (difference, −0.06; 95% CI −0.23–0.12), pain interference (difference, −0.12; 95% CI −0.31–0.06), worst pain score (difference, −0.12; 95% CI −0.35–0.11) and FACT-P total score (difference, −0.54; 95% CI –3.00–1.92) suggest no clinically meaningful difference in HRQoL with abi + ola vs abi + pbo. Least-squares mean change from BL values for FACT-P subscale scores were consistent with FACT-P total score result. Conclusions: PROpel demonstrated a significant delay in rPFS for pts receiving abi + ola vs abi + pbo. Most pts in the trial did not experience a PP event. Abi + ola showed no difference in HRQoL (assessed by FACT-P total and subscale scores, BPI-SF domain and worst pain scores) vs abi + pbo, suggesting pts can derive clinical benefit from abi + ola while maintaining a similar HRQoL compared with a current standard-of-care treatment. Clinical trial information: NCT03732820.