Introduction/Background Ovarian cancer (OC) is the most lethal gynecologic cancers. The first-line (1L) treatment of newly diagnosed advanced OC is surgery and platinum-based chemotherapy, up to 85% of patients (pts) may experience a recurrence. Poly ADP-ribose polymers (PARP) inhibitors are recommended as maintenance therapy to prolong the benefit of platinum. Senaparib (IMP4297) is a novel, high potency PARP inhibitor. The phase 3 study FLAMES is to confirm the efficacy and safety of Senaparib as 1L maintenance therapy in Chinese pts with newly diagnosed advanced OC.

Methodology Eligible pts are those with high-grade serous or endometrioid tumors staged FIGO (International Federation of Gynecology and Obstetrics) III or IV, who completed 1L platinum-based chemotherapy with complete response (CR) or partial response (PR). Pts were randomized 2:1 to receive senaparib (Sena) or placebo (PBO) 100 mg/day orally, stratified by CR/PR and breast cancer susceptibility gene (BRCA) mutation positive/negative. Primary endpoint was progression-free survival (PFS ) evaluated according to RECIST v1.1.

Results As of Mar of 16 ,2023, 404 pts have been randomized. 268 and 135 pts received Sena and PBO with median follow-up x months. Sena significantly improved PFS (mPFS x vs x mo; HR 0.xx, p<0.01) over placebo. All subgroup analysis demonstrated consistent benefit. Incidence rates of grade ≥3 treatment emergent adverse events (AEs) were x% vs x%, AEs leading to dose reduction and discontinuation were x% vs x% and x% vs x%. No AE leading to death. The most common grade ≥3 TEAEs were anemia (x%) , thrombocytopenia (x%), and neutropenia (x%).

Conclusion Pts who received Sena had a meaningful and significant improvement in PFS compared to those who received PBO and the PFS is much longer than other PARP inhibitors, regardless of biomarker status. Sena was well tolerated, no new safety signals were identified.

Disclosures All of the authors have no conflict of interest to report.