The following is a summary of “A Randomized, Phase III Trial to Evaluate Rucaparib Monotherapy as Maintenance Treatment in Patients With Newly Diagnosed Ovarian Cancer (ATHENA–MONO/GOG-3020/ENGOT-ov45)” published in the December 2022 issue of Oncology by Monk et al.

A large patient group, including individuals without BRCA1 or BRCA2 (BRCA) mutations, other signs of homologous recombination deficiency (HRD), or high-risk clinical traits like residual illness, was included for ATHENA’s evaluation of rucaparib as a first-line maintenance medication. For a study, researchers presented the findings of the rucaparib versus placebo ATHENA-MONO comparison.

Stage III-IV high-grade ovarian cancer patients receiving first-line platinum-doublet chemotherapy and undergoing surgical cytoreduction (R0/complete resection authorized) were randomly randomized to receive either oral rucaparib 600 mg twice a day or a placebo. The timing of surgery, the results of the HRD test, and the persistence of the illness following chemo were stratification variables. The primary endpoint of investigator-assessed progression-free survival was evaluated in a step-down process, first in the intent-to-treat group and then in the HRD population (BRCA-mutant or BRCA wild-type/loss of heterozygosity high tumor).

A total of 111 patients were randomly randomized to receive placebo on March 23, 2022, whereas 427 individuals were randomly assigned to receive rucaparib (HRD population: 185 v 49). In the population with HRD, the median progression-free survival (95% CI) was 28.7 months (23.0 to not reached) with rucaparib, compared to 11.3 months (9.1 to 22.1) with placebo (log-rank P =.0004; HR, 0.47; 95% CI, 0.31 to 0.72); 20.2 months (15.2 to 24.7) versus 9.2 months (8.3 to 12.2) in the population intended for treatment (log-rank P< .0001; HR, 0.52; 95% CI, 0.40 to 0.68); & 12.1 months (11.1 to 17.7) versus 9.1 months (4.0 to 12.2) in the HRD-negative population (HR, 0.65; 95% CI, 0.45 to 0.95). The most common grade ≥ 3 treatment-emergent adverse events were anemia (rucaparib, 28.7% v placebo, 0%) & neutropenia (14.6% v 0.9%). Rucaparib (28.7% against 0% for placebo) and neutropenia (14.6% v 0.9%) were the most frequent grade 3 treatment-emergent side events.

When used as first-line maintenance, rucaparib monotherapy significantly outperformed the placebo in treating advanced ovarian cancer in both patients with and without HRD.