Rucaparib for maintenance treatment of platinum-sensitive, recurrent ovarian carcinoma: Final results of the phase 3, randomized, placebo-controlled ARIEL3 trial

Background: In ARIEL3, rucaparib maintenance significantly improved progression-free survival (PFS; primary endpoint) and long-term follow-up (LTFU) outcomes (including PFS2: time to disease progression on subsequent therapy or death) versus placebo in patients with recurrent, platinum-sensitive ovarian cancer. Here we report the final analysis of overall survival (OS; key secondary endpoint), LTFU outcomes, and safety. Methods: OS and updated LTFU efficacy outcomes were analyzed (data cutoff date: April 4, 2022) across three nested populations (BRCA-mutated, homologous recombination deficient [HRD], and intention to treat [ITT]). Results: Patients were randomized 2:1 to rucaparib (600 mg BID; n = 375) or placebo (n = 189). Median follow-up was 77.0 months. 168 patients in the placebo arm received subsequent treatment; of these, 77 (46 %) received a poly(ADP-ribose) polymerase inhibitor–containing treatment. Median OS from randomization post chemotherapy for rucaparib vs placebo was 45.9 vs 47.8 months (HR 0.83, 95 % CI 0.58–1.19) for the BRCA-mutated population; no OS benefit was found with rucaparib in the HRD and ITT populations. Median PFS2 for rucaparib vs placebo was 26.1 vs 18.4 months (HR 0.67, 95 % CI 0.48–0.94) for the BRCA-mutated population. Rucaparib numerically improved PFS2 and other LTFU outcomes versus placebo in the HRD and ITT populations. Safety was consistent with prior reports; myelodysplastic syndrome and/or acute myeloid leukemia occurred in 4 % and 3 % of patients in the rucaparib and placebo arms, respectively. Conclusions: OS was similar between treatment arms. PFS benefit with rucaparib was maintained through the subsequent therapy line. These data support rucaparib as maintenance treatment for recurrent ovarian carcinoma.