NEoadjuvant Olaparib Combination OvArian Cancer Targeted Study

This is a single arm, proof of concept phase 2 study. Subjects with a suspected or confirmed diagnosis of high grade serous ovarian cancer who are not thought to be candidates for primary debulking surgery and are considered candidates for neoadjuvant chemotherapy and are not known to have BRCA mutation associated HGSOC will be considered for the trial. Patients will be given the following triplet therapy for 2 cycles: Olaparib 300mg PO BID continuous dosing, Durvalumab 1500mg IV day 1, Bevacizumab 10mg/kg IV on day 1 and 15 of a 28-day cycle. Patients that respond to the therapy following 2 cycles will receive 1 further cycle followed by interval cytoreductive surgery planned 3-4 weeks after completion of cycle 3 and at least 28 days from the last dose of Bevacizumab. Following surgery, patients will revert back to standard of care (SOC) treatment and receive up to 6 cycles of chemotherapy followed by SOC recommended maintenance treatments as determined by the local treating oncology teams. All subsequent treatments received and their response will be recorded as part of the study data collection up to and including first documented progression. Patients that do not respond to the therapy after 2 cycles will discontinue the triplet therapy and switch to salvage standard of care treatment.