Introduction/Background In ATHENA-MONO (GOG-3020/ENGOT-ov45; NCT03522246), progression-free survival (PFS) improvement was observed with first-line (1L) rucaparib maintenance treatment vs placebo in pts with advanced OC, regardless of molecular characteristics (median PFS, 20.2 vs 9.2 months, log-rank P<.0001; HR, 0.52; 95% CI, 0.40–0.68). Pts with or without high-risk clinical characteristics for disease progression were enrolled in ATHENA-MONO. In the subgroup analyses presented here, we sought to evaluate if all pts benefited from rucaparib 1L maintenance treatment, including those with more favourable prognostic factors at baseline.

Methodology Pts with high-grade, FIGO stage III-IV OC who had completed cytoreductive surgery and 4–8 cycles of 1L platinum-doublet chemotherapy with a response (partial [PR] or complete [CR]) were randomised 4:1 to oral rucaparib 600 mg BID or placebo. Investigator-assessed PFS was evaluated in pt subgroups based on FIGO stage, timing of surgery, and disease status post-chemotherapy.

Results As of 23 March 2022 (data cutoff), 427 and 111 pts were randomised to rucaparib monotherapy vs placebo. The majority of pts had FIGO stage III disease (75%); approximately half underwent primary surgery (49%) and most had no residual disease post-chemotherapy (75%). In the intent-to-treat (ITT) population, investigator-assessed PFS was improved with rucaparib vs placebo across all subgroups based on FIGO stage, timing of surgery, and residual disease (table 1).

Conclusion In the ITT population, 1L rucaparib maintenance treatment improved PFS vs placebo across subgroups regardless of timing of surgery or prognostic disease characteristics, including FIGO stage or residual disease. These results confirm a new maintenance treatment option for OC pts with or without high risk factors for progression at baseline irrespective of molecular characteristics.

Disclosures Per COI.