For patients with high-grade serous ovarian cancer, the chance of long-term survival is poor. This is despite initial good responses to chemotherapy and breakthroughs such as PARP inhibitors. PARP inhibitors work best in cancers with mutations in the BRCA1 or BRCA2 genes, or defects in a specific DNA repair pathway (“homologous recombination deficiency”, HRD) – collectively these are found in half of patients with high-grade serous ovarian cancer.

Better treatments are needed to improve outcomes for all patients. One way is to combine PARP inhibitors with other targeted drugs. The NEoadjuvant Olaparib Combination ovArian cancer Targeted Study (NEOCATS) is a phase 2 clinical trial to test the safety and effectiveness of three drugs: Olaparib (a PARP inhibitor), Durvalumab (an immunotherapy) and Bevacizumab (targets the cancer’s blood supply). This treatment combination is administered before surgery (called ‘neoadjuvant’), in patients whose cancer is too advanced to have surgery first. An estimated 40 patients from across 6 Canadian sites will be asked to participate.

This funding will be used to support laboratory-based research using clinical samples from patients in the trial, including biopsies and blood samples. The study team will analyse how cancers change at the immune level and genetically in response to treatment, and how resistance develops. We will create mouse models from patients’ cancers and use a new technology called ‘single cell sequencing’ to enable us to break the cancers down to an individual cell.