Background Poly ADP-ribose polymerase inhibitors (PARPi) treatment has radically changed the treatment strategy for epithelial ovarian cancer. Cancer progression with PARPi maintenance is a new problem that has arisen in clinical practice, and the value of secondary cytoreduction surgery remains unknown.

Primary Objective To evaluate the benefits of secondary cytoreductive surgery and to clarify the sensitivity to platinum in patients with firstline or secondline recurrent epithelial ovarian cancer who have completed ≥6 months of PARPi maintenance.

Study Hypothesis Carefully selected patients who progress on PARPi maintenance will benefit from secondary cytoreductive surgery.

Trial Design This is a multicenter phase III trial. Eligible patients will be randomly assigned at a ratio of 1:1 to either the experimental or standard arm. Patients in the experimental arm will receive secondary cytoreductive surgery followed by platinum based chemotherapy, while patients in the standard arm will be provided with chemotherapy alone.

Major Inclusion/Exclusion Criteria Patients diagnosed with firstline or secondline recurrent epithelial ovarian cancer who had previously received ≥4 cycles of platinum based chemotherapy in initial treatment followed by PARPi maintenance therapy for ≥6 months prior to recurrence.

Primary Endpoint Progression free survival.

Sample Size 400 patients.

Estimated Dates for Competing Accrual and Presenting Results Accrual completion is expected in December 2024 with results mature after 2 years of follow-up in 2026.

Trial Registration ClinicalTrials.gov NCT05607329