OBJECTIVE: Maintenance olaparib demonstrated clinical activity for progression-free survival in patients without a germline BRCA1 and/or BRCA2 mutation (non-gBRCAm) who had platinum-sensitive relapsed ovarian cancer in the phase IIIb, open-label, single-arm, non-comparator, international OPINION trial (NCT03402841). We report final overall survival (OS; secondary endpoint), prespecified secondary endpoint updates and ad hoc OS analysis by homologous recombination deficiency (HRD) and somatic BRCAm (sBRCAm) status. METHODS: Patients with non-gBRCAm platinum-sensitive relapsed ovarian cancer, ≥2 prior lines of platinum-based chemotherapy, and in response following their last platinum-based chemotherapy received 300 mg olaparib tablets twice daily until disease progression or unacceptable toxicity. RESULTS: 279 patients were enrolled and treated. With a median follow-up in patients censored for OS of 33.1 months (data cut-off September 17, 2021), median OS was 32.7 months (95 % CI 29.5-35.3); the 24-month OS rate was 65.8 %. In ad hoc subgroup analyses, OS rates tended to be higher in patients with HRD-positive tumors; 24-month OS rates were 81.5 %, 74.2 %, 72.0 % and 55.8 % in the sBRCAm, HRD-positive including sBRCAm, HRD-positive excluding sBRCAm, and HRD-negative subgroups, respectively. Grade ≥ 3 treatment-emergent adverse events were reported in 82 patients (29.4 %), most commonly anemia (13.6 %). Overall, two cases of myelodysplastic syndrome were reported (no new cases since the primary analysis). CONCLUSION: These data provide additional evidence of olaparib as maintenance therapy in patients with non-gBRCAm platinum-sensitive relapsed ovarian cancer, with longer OS observed in those with HRD-positive tumors. The safety profile was consistent with the primary analysis and known safety profile of olaparib, with no new safety findings.

Cancer Center Clinica Universidad de Navarra Madrid Spain; CIMA Pamplona Spain

General University Hospital Prague 1st Faculty of Medicine Charles University Prague Czech Republic

Hospital Universitario Reina Sofía Córdoba Spain

Initia Oncology Valencia Spain

Institute of Oncology Ljubljana Ljubljana Slovenia

IVO Valencia Spain

Medical Oncology Service Vall d'Hebron Institute of Oncology Vall d'Hebron Barcelona Hospital Campus Barcelona Spain

Medical University Karol Marcinkowski Poznań Poland

Olsztyn Provincial Specialist Hospital Olsztyn Poland

Oncology R and D AstraZeneca Cambridge UK

Oslo University Hospital Norwegian Radium Hospital Oslo Norway

Ottawa Hospital Research Institute Ottawa ON Canada

Princess Margaret Hospital Toronto ON Canada

Skåne University Hospital Lund University Lund Sweden

UCL Cancer Institute University College London and UCL Hospitals London UK

University of Milan Bicocca and European Institute of Oncology IRCCS Milan Italy

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