Efficacy and safety of olaparib according to age in BRCA1/2-mutated patients with recurrent platinum-sensitive ovarian cancer: Analysis of the phase III SOLO2/ENGOT-Ov21 study

Background: Olaparib has significantly improved outcome and patient-centered endpoints in BRCA1/2-mutated patients with recurrent platinum-sensitive ovarian cancer (PSOC). Specific information on efficacy and safety of olaparib for older patients appears of special interest. Methods: 295 patients from the SOLO2 trial randomly assigned to olaparib or placebo were categorized according to age-cutoff at 65 years. Efficacy, tolerability, and quality of life (QoL) of olaparib relative to placebo within in each age group was analyzed. Results: Baseline characteristics were similar in patients ≥65 years (N = 62;21.0%) compared to patients <65 years (N = 233;78.9%). No significant difference in the magnitude of progression-free survival (PFS) benefit from olaparib for older patients (N = 40, hazard ratio [HR]≥65 0.43, 95%-confidence interval [CI] 0.24–0.81) as compared with younger patients (N = 155, HR<65 0.31 (95%-CI 0.22–0.43) was seen (interaction P = 0.33). The overall survival (OS)benefit seen in younger patients in the olaparib arm was not observed in older patients. Older and younger patients had comparable safety profiles and QoL scores although higher discontinuation rates for toxicity, and higher frequency of AML/MDS were noted in the older subset. TWiST analysis revealed clinically meaningful duration of good QoL on olaparib for both age groups (≥65: 13.5 vs <65: 18.4 months, P = 0.05). Conclusions: Results of this large phase III cohort of BRCA1/2-mutated PSOC patients treated with olaparib underline impressive efficacy of olaparib maintenance irrespective of age. Although toxicity and tolerability did not raise significant concerns, some caution, close monitoring, and follow-up needs to be exercised for older patients given higher discontinuation rates, frequency of AML/MDS, and no clear effects on OS.