Durvalumab with carboplatin/paclitaxel and bevacizumab followed by durvalumab and bevacizumab with or without olaparib maintenance in newly diagnosed non-BRCA-mutated advanced ovarian cancer

Abstract

Background: Despite treatment advances in newly diagnosed advanced-stage ovarian cancer (aOC), improved outcomes are needed.

Patients and methods: DUO-O (NCT03737643), a phase III placebo-controlled trial, enrolled patients with newly diagnosed aOC. Following one cycle of carboplatin/paclitaxel ± bevacizumab, patients without a tumor BRCA mutation (non-tBRCAm) were randomly assigned (1 : 1 : 1) at cycle 2 to carboplatin/paclitaxel plus bevacizumab followed by bevacizumab (control); carboplatin/paclitaxel, bevacizumab plus durvalumab followed by bevacizumab plus durvalumab (durvalumab arm); or carboplatin/paclitaxel, bevacizumab plus durvalumab followed by bevacizumab, durvalumab plus olaparib (durvalumab + olaparib arm). Investigator-assessed progression-free survival (PFS; primary endpoint) was tested for the durvalumab + olaparib arm versus control in the non-tBRCAm homologous recombination deficiency (HRD)-positive and non-tBRCAm intention-to-treat (ITT) populations.

Results: One thousand one hundred and thirty patients were randomly allocated to the study. The prespecified interim PFS analysis [data cut-off (DCO): 5 December 2022] qualified as the primary analysis; PFS hazard ratio (HR) for the durvalumab + olaparib arm versus control was 0.49 [95% confidence interval (CI) 0.34-0.69, P < 0.0001; median (m) PFS 37.3 versus 23.0 months] in the non-tBRCAm HRD-positive and 0.63 (95% CI 0.52-0.76, P < 0.0001; mPFS 24.2 versus 19.3 months) in the non-tBRCAm ITT population. For the durvalumab arm versus control, PFS HR was 0.87 (95% CI 0.73-1.04, P = 0.13; mPFS 20.6 versus 19.3 months) in the non-tBRCAm ITT population. At final PFS and interim overall survival (OS) analysis (DCO: 18 September 2023), PFS results were consistent with primary analysis; interim OS HR for the durvalumab + olaparib arm versus control was 0.95 (95% CI 0.76-1.20, P = 0.68; 39.0% maturity) in the non-tBRCAm ITT population. Safety was generally consistent with the profiles of the individual agents.

Conclusions: DUO-O met its primary PFS endpoints for first-line durvalumab plus carboplatin/paclitaxel and bevacizumab followed by durvalumab, bevacizumab plus olaparib maintenance versus carboplatin/paclitaxel and bevacizumab followed by bevacizumab in the non-tBRCAm HRD-positive and non-tBRCAm ITT populations. Further insight into long-term benefit is anticipated with additional follow-up.

Keywords: advanced ovarian cancer; bevacizumab; carboplatin/paclitaxel; durvalumab; non-tumor BRCA mutation; olaparib.