Clovis Oncology, Inc. announced results from a subgroup analysis of data from the monotherapy comparison of the randomized, Phase 3 ATHENA (GOG-3020/ENGOT-ov45) trial (ATHENA-MONO). These data showed that Rubraca as first-line maintenance treatment improved progression-free survival (PFS) versus placebo across disease risk subgroups including surgical outcome, response to first-line chemotherapy, and additional analyses in other subgroups. The data were presented by Rebecca S. Kristeleit, MD, PhD, of Guy's and St.

Thomas' NHS Foundation Trust in London and lead ENGOT/NCRI National Cancer Research Institute investigator of the ATHENA trial as a Mini Oral abstract at the European Society of Medical Oncology (ESMO) Congress 2022 in Paris. ATHENA is a double-blind, placebo-controlled, Phase 3 trial of Rubraca in first-line ovarian cancer maintenance treatment. It has two parts which are statistically independent.

The results presented at ESMO are from the ATHENA-MONO part (Rubraca versus placebo), with results from the ATHENA-COMBO part (Rubraca plus nivolumab versus Rubraca) expected in first quarter 2023. ATHENA-MONO enrolled 538 women with high-grade ovarian, fallopian tube, or primary peritoneal cancer. The primary efficacy analysis evaluated two prospectively defined molecular subgroups in a step-down manner: homologous recombination deficiency (HRD)-positive (inclusive of BRCAm tumors and BRCAwt/LOH high tumors), and all patients randomized (overall intent-to-treat population [ITT]) in ATHENA-MONO.

Patients who received Rubraca as maintenance therapy showed benefit regardless of surgical outcome, whether there was complete resection (R0) during cytoreductive surgery or not. In HRD-positive patients: Patients who had a complete resection following cytoreductive surgery (R0): Rubraca (n=107), median PFS not yet reached (NR); placebo (n=33), median PFS of 22.1 months. Hazard ratio of 0.52 (95% [Confidence Interval] CI: 0.30-0.92).

Patients who did not have a complete resection following cytoreductive surgery (non-R0): Rubraca (n=78), median PFS of 20.3 months; placebo (n=16), median PFS of 9.1 months; Hazard ratio of 0.29 (95% CI: 0.15-0.56). Among the ITT population: Patients who had a complete resection following cytoreductive surgery (R0): Rubraca (n=263), median PFS of 25.1 months; placebo (n=73), median PFS of 12.0 months; Hazard ratio of 0.60 (95% CI: 0.43-0.84). Patients who did not have a complete resection following cytoreductive surgery (non-R0): Rubraca (n=164), median PFS of 13.9 months; placebo (n=38), median PFS of 6.4 months; Hazard ratio of 0.41 (95% CI: 0.27-0.62).