To Assess the Efficacy and Safety of Olaparib Maintenance Monotherapy in the Treatment of Ovarian Cancer

The study will recruit approximately 250 patients with sBRCAm disease or gBRCAm disease, with the aim to accrue a minimum of 50 patients with sBRCAm disease. Patients with an unknown germline BRCA mutated status or gBRCAwt disease or previously identified as having a BRCAm disease by a tumour test will be considered for screening and will undergo, upon informed consent signature, central tumor and blood testing to determine their BRCA mutation status. In addition to central BRCA testing, patients screened for the study with unknown BRCA status or with known gBRCAwt status, for whom an adequate archival tumour tissue sample is available, will be tested for qualifying HRR gene alterations. Patients confirmed to carry a deleterious or suspected deleterious BRCA-independent genetic alteration in any of 13 genes involved in the Homologous Recombination Repair (HRR) pathway (HRRm cohort) will be allowed into an additional exploratory cohort (HRRm cohort). It is expected that approximately 25 patients will be included in the HRRm cohort before the target number of 250 patients with BRCAm disease is reached. Patients will be assigned olaparib capsules orally 400 mg twice daily. They should initiate olaparib treatment within 8 weeks after their last dose of platinum-containing chemotherapy (last dose is the day of the last infusion) and will be assessed every 4 weeks whilst on treatment. All patients will have clinical and objective radiological tumour assessments according to modified Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 guidelines at baseline and every 12 weeks relative to date of enrolment, until objective radiological disease progression as determined by the investigator. Patients could continue to receive olaparib for as long as determined by the investigator, until objective radiological disease progression or as long as in the investigator's opinion they are benefiting from treatment in relation to other clinical assessments and they do not meet any other discontinuation criteria. Once a patient has discontinued olaparib she will be managed as per local clinical practice but will remain in the study and data will be collected on subsequent treatments, progression, overall survival and safety. For exploratory analysis purposes, patients will be asked to provide consent to: 1. Optional tumour samples at baseline and at disease progression 2. An optional blood sample only for patients with a confirmed sBRCAm or HRRm disease