ORZORA: Maintenance olaparib in patients with platinum-sensitive relapsed ovarian cancer: outcomes by somatic and germline BRCA and other homologous recombination repair gene mutation status

Abstract

Objectives: The Phase III SOLO2 trial (NCT01874353) showed the significant benefit of maintenance olaparib for patients (pts) with platinum-sensitive relapsed ovarian cancer (PSROC) and a BRCA mutation (BRCAm), compared with placebo (median progression-free survival [PFS] 19.1 vs 5.5 months [m], respectively); however, no pts had a confirmed somatic (s) BRCAm and data prospectively evaluating efficacy of olaparib in this pt group were limited. ORZORA (NCT02476968), an open-label, single-arm, multicenter trial, was conducted to assess efficacy and safety of maintenance olaparib in PSROC pts with a BRCAm (s or germline [g]) who were in response to their most recent platinum-based chemotherapy after ≥2 lines of treatment. Methods: Pts underwent prospective central screening for tumor BRCAm status (myChoice CDx, Myriad Genetic Laboratories, Inc.), then s or g BRCAm status was determined by central g testing (BRACAnalysis CDx, Myriad Genetic Laboratories, Inc.). Pts received maintenance olaparib (400 mg bid; capsules) until disease progression. Co-primary endpoints were investigator-assessed PFS (RECIST v1.1) in BRCAm and s cohorts, conducted at 60% maturity. Secondary endpoints included time to second progression or death (PFS2), health-related quality of life (HRQoL; FACT-O trial outcome index) and tolerability. An additional exploratory cohort comprised pts with predefined homologous recombination repair gene mutations (HRRm) excluding BRCAm (Foundatio CDx, Foundation Medicine, Inc.). Conclusions: PFS in pts with PSROC who received maintenance olaparib was similar irrespective of s or g BRCAm status. Activity of maintenance olaparib was also shown in pts with a non-BRCA HRRm. PFS, HRQoL and tolerability were consistent with previous olaparib studies in this population. Results highlight that PSROC pts beyond those with a gBRCAm can benefit from maintenance olaparib.