Atezolizumab Combined With Bevacizumab and Platinum-Based Therapy for Platinum-Sensitive Ovarian Cancer: Placebo-Controlled Randomized Phase III ATALANTE/ENGOT-ov29 Trial

J Clin Oncol. 2023 Oct 20;41(30):4768-4778. doi: 10.1200/JCO.23.00529. Epub 2023 Aug 29.


Purpose: Platinum-based doublets with concurrent and maintenance bevacizumab are standard therapy for ovarian cancer (OC) relapsing after a platinum-free interval (PFI) >6 months. Immunotherapy may be synergistic with bevacizumab and chemotherapy.

Patients and methods: ATALANTE/ENGOT-ov29 ( identifier: NCT02891824), a placebo-controlled double-blinded randomized phase III trial, enrolled patients with recurrent epithelial OC, one to two previous chemotherapy lines, and PFI >6 months. Eligible patients were randomly assigned 2:1 to atezolizumab (1,200 mg once every 3 weeks or equivalent) or placebo for up to 24 months, combined with bevacizumab and six cycles of chemotherapy doublet, stratified by PFI, PD-L1 status, and chemotherapy regimen. Coprimary end points were investigator-assessed progression-free survival (PFS) in the intention-to-treat (ITT) and PD-L1-positive populations (alpha .025 for each population).

Results: Between September 2016 and October 2019, 614 patients were randomly assigned: 410 to atezolizumab and 204 to placebo. Only 38% had PD-L1-positive tumors. After 3 years' median follow-up, the PFS difference between atezolizumab and placebo did not reach statistical significance in the ITT (hazard ratio [HR], 0.83; 95% CI, 0.69 to 0.99; P = .041; median 13.5 v 11.3 months, respectively) or PD-L1-positive (HR, 0.86; 95% CI, 0.63 to 1.16; P = .30; median 15.2 v 13.1 months, respectively) populations. The immature overall survival (OS) HR was 0.81 (95% CI, 0.65 to 1.01; median 35.5 v 30.6 months with atezolizumab v placebo, respectively). Global health-related quality of life did not differ between treatment arms. Grade ≥3 adverse events (AEs) occurred in 88% of atezolizumab-treated and 87% of placebo-treated patients; grade ≥3 AEs typical of immunotherapy were more common with atezolizumab (13% v 8%, respectively).

Conclusion: ATALANTE/ENGOT-ov29 did not meet its coprimary PFS objectives in the ITT or PD-L1-positive populations. OS follow-up continues. Further research on biopsy samples is warranted to decipher the immunologic landscape of late-relapsing OC.

Publication types

  • Clinical Trial, Phase III
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • B7-H1 Antigen* / therapeutic use
  • Bevacizumab
  • Carcinoma, Ovarian Epithelial / drug therapy
  • Female
  • Humans
  • Neoplasm Recurrence, Local / drug therapy
  • Ovarian Neoplasms* / drug therapy
  • Ovarian Neoplasms* / pathology
  • Platinum / therapeutic use
  • Quality of Life


  • atezolizumab
  • B7-H1 Antigen
  • Bevacizumab
  • Platinum

Associated data