Pain and health-related quality of life with olaparib versus physician's choice of next-generation hormonal drug in patients with metastatic castration-resistant prostate cancer with homologous recombination repair gene alterations (PROfound): an open-label, randomised, phase 3 trial

Abstract

Background: The PROfound study showed significantly improved radiographical progression-free survival and overall survival in men with metastatic castration-resistant prostate cancer with alterations in homologous recombination repair genes and disease progression on a previous next-generation hormonal drug who received olaparib then those who received control. We aimed to assess pain and patient-centric health-related quality of life (HRQOL) measures in patients in the trial.

Methods: In this open-label, randomised, phase 3 study, patients (aged ≥18 years) with metastatic castration-resistant prostate cancer and gene alterations to one of 15 genes (BRCA1, BRCA2, or ATM [cohort A] and BRIP1, BARD1, CDK12, CHEK1, CHEK2, FANCL, PALB2, PPP2R2A, RAD51B, RAD51C, RAD51D, and RAD54L [cohort B]) and disease progression after a previous next-generation hormonal drug were randomly assigned (2:1) to receive olaparib tablets (300 mg orally twice daily) or a control drug (enzalutamide tablets [160 mg orally once daily] or abiraterone tablets [1000 mg orally once daily] plus prednisone tablets [5 mg orally twice daily]), stratified by previous taxane use and measurable disease. The primary endpoint (radiographical progression-free survival in cohort A) has been previously reported. The prespecified secondary endpoints reported here are on pain, HRQOL, symptomatic skeletal-related events, and time to first opiate use for cancer-related pain in cohort A. Pain was assessed with the Brief Pain Inventory-Short Form, and HRQOL was assessed with the Functional Assessment of Cancer Therapy-Prostate (FACT-P). All endpoints were analysed in patients in cohort A by modified intention-to-treat. The study is registered with ClinicalTrials.gov, NCT02987543.

Findings: Between Feb 6, 2017, and June 4, 2019, 245 patients were enrolled in cohort A and received study treatment (162 [66%] in the olaparib group and 83 [34%] in the control group). Median duration of follow-up at data cutoff in all patients was 6·2 months (IQR 2·2-10·4) for the olaparib group and 3·5 months (1·7-4·9) for the control group. In cohort A, median time to pain progression was significantly longer with olaparib than with control (median not reached [95% CI not reached-not reached] with olaparib vs 9·92 months [5·39-not reached] with control; HR 0·44 [95% CI 0·22-0·91]; p=0·019). Pain interference scores were also better in the olaparib group (difference in overall adjusted mean change from baseline score -0·85 [95% CI -1·31 to -0·39]; p_nominal=0·0004). Median time to progression of pain severity was not reached in either group (95% CI not reached-not reached for both groups; HR 0·56 [95% CI 0·25-1·34]; p_nominal=0·17). In patients who had not used opiates at baseline (113 in the olaparib group, 58 in the control group), median time to first opiate use for cancer-related pain was 18·0 months (95% CI 12·8-not reached) in the olaparib group versus 7·5 months (3·2-not reached) in the control group (HR 0·61; 95% CI 0·38-0·99; p_nominal=0·044). The proportion of patients with clinically meaningful improvement in FACT-P total score during treatment was higher for the olaparib group than the control group: 15 (10%) of 152 evaluable patients had a response in the olaparib group compared with one (1%) of evaluable 77 patients in the control group (odds ratio 8·32 [95% CI 1·64-151·84]; p_nominal=0·0065). Median time to first symptomatic skeletal-related event was not reached for either treatment group (olaparib group 95% CI not reached-not reached; control group 7·8-not reached; HR 0·37 [95% CI 0·20-0·70]; p_nominal=0·0013).

Interpretation: Olaparib was associated with reduced pain burden and better-preserved HRQOL compared with the two control drugs in men with metastatic castration-resistant prostate cancer and homologous recombination repair gene alterations who had disease progression after a previous next-generation hormonal drug. Our findings support the clinical benefit of improved radiographical progression-free survival and overall survival identified in PROfound.

Funding: AstraZeneca and Merck Sharp & Dohme.