Key Inclusion Criteria:

        Female patients with newly diagnosed, histologically confirmed, advanced (Stage III-IV)
        high grade epithelial ovarian cancer including high grade serious, high grade endometriod,
        clear cell ovarian cancer or carcinosarcoma, primary peritoneal cancer and / or
        fallopian-tube cancer

          -  Patients must be aged ≥18 years of age. For patients enrolled in Japan that are aged
             <20 year

          -  All patients should be candidates for cytoreductive surgery either: upfront primary
             surgery OR plan to undergo chemotherapy with interval debulking surgery

          -  Evidence of presence or absence of BRCA1/2 mutation in tumour tissue

          -  Mandatory provision of tumour sample for centralised tBRCA testing

          -  ECOG performance status 0-1

          -  Patients must have preserved organ and bone marrow function

          -  Postmenopausal or evidence of non-childbearing status for women of childbearing
             potential: negative urine or serum pregnancy test

        Key Exclusion Criteria:

        Non-epithelial ovarian cancer, borderline tumors, low grade epithelial tumors or mucinous
        histology

          -  Prior systemic anti-cancer therapy for ovarian cancer

          -  Inability to determine the presence or absence of a deleterious or suspected
             deleterious BRCA mutation

          -  Prior treatment with PARP inhibitor or immune mediated therapy

          -  Planned intraperitoneal cytotoxic chemotherapy

          -  Active or prior documented autoimmune or inflammatory disorders

          -  Patients considered a poor medical risk due to a serious, uncontrolled intercurrent
             illness

          -  Clinically significant cardiovascular disease

          -  Patients with known brain metastases

          -  History of another primary malignancy except for:

               -  Malignancy treated with curative intent and with no known active disease ≥5 years
                  before the first dose of study treatment and of low potential risk for recurrence
                  (patients who have received prior adjuvant chemotherapy for early stage breast
                  cancer may be eligible, provided that it was completed ≥3 years prior to
                  registration, and that the patient remains free of recurrent or metastatic
                  disease)

               -  Adequately treated non-melanoma skin cancer or lentigo maligna without evidence
                  of disease

               -  Adequately treated carcinoma in situ without evidence of disease

               -  Endometrial cancer FIGO Stage IA, Grade 1 or Grade 2

          -  Persistent toxicities CTCAE Grade >2 caused by previous cancer therapy

          -  Patients with a known hypersensitivity to olaparib, durvalumab or any of the
             excipients of these products and to the combination/comparator agents

          -  Breast feeding women