Overall survival with maintenance olaparib in platinum-sensitive relapsed ovarian cancer by somatic or germline BRCA and homologous recombination repair mutation status

Background: The open-label, single-arm, multicentre ORZORA trial (NCT02476968) evaluated maintenance olaparib in patients with platinum-sensitive relapsed ovarian cancer (PSR OC) with a germline (g) or somatic (s) BRCA1 and/or BRCA2 mutation (BRCAm) or a non-BRCA homologous recombination repair mutation (non-BRCA HRRm). Methods: Patients were in response to platinum-based chemotherapy after ≥2 prior lines of treatment and underwent prospective central screening for tumour BRCA status, then central gBRCAm testing to determine sBRCAm or gBRCAm status. An exploratory cohort evaluated non-BRCA HRRm in 13 predefined genes. Patients received olaparib 400 mg (capsules) twice daily until investigator-assessed disease progression. Secondary endpoints included overall survival (OS) and safety. Results: 177 patients received olaparib. At the final data cutoff (25 June 2021), median OS from study enrolment was 46.8 (95% confidence interval [CI] 37.9-54.4), 43.2 (31.7-NC [not calculated]), 47.4 (37.9-NC) and 44.9 (28.9-NC) months in the BRCAm, sBRCAm, gBRCAm and non-BRCA HRRm cohorts, respectively. No new safety signals were identified. Conclusion: Maintenance olaparib showed consistent clinical activity in the BRCAm and sBRCAm cohorts; exploratory analysis suggested similar activity in the non-BRCA HRRm cohort. These findings highlight that patients with PSR OC, beyond those with gBRCAm, may benefit from maintenance olaparib.