Atezolizumab Does Not Prolong Progression-Free Survival in Newly Diagnosed, Advanced Ovarian Cancer

Adding atezolizumab to bevacizumab plus chemotherapy did not improve progression-free survival (PFS) in patients with newly diagnosed, stage III/IV ovarian cancer, regardless of PD-L1 status, according to results from the phase 3 IMagyn050/GOG 3015/ENGOT-OV39 trial.

Results from the trial (ClinicalTrials.gov Identifier: NCT03038100) were presented at the European Society for Medical Oncology (ESMO) Gynaecological Cancers Virtual Congress 2021.

“IMagyn050 tested the hypothesis that incorporating the anti-PD-L1 agent atezolizumab into a bevacizumab-containing frontline chemotherapy regimen would impart clinical efficacy with acceptable safety,” said presenter Kathleen Moore, MD, of the Stephenson Cancer Center at the University of Oklahoma in Oklahoma City.

The trial enrolled patients with treatment-naive epithelial ovarian, primary fallopian tube, or peritoneal cancer. Patients had to have postoperative stage III disease with macroscopic residual disease, have stage IV disease, or be a candidate for neoadjuvant therapy with planned interval surgery.

In all, 1301 patients were randomly assigned to receive atezolizumab (n=651) or placebo (n=645) in addition to bevacizumab, carboplatin, and paclitaxel. The study’s primary endpoints were PFS and overall survival (OS).

The median PFS was 19.5 months for the atezolizumab group and 18.4 months for the placebo group (hazard ratio [HR], 0.92; 95% CI, 0.79-1.07; P =.2785).

In the PD-L1-positive population, the median PFS was 20.8 months in the atezolizumab group and 18.5 months in the placebo group (HR, 0.80; 95% CI, 0.65-0.99; P =.0376).

The full OS analysis is not yet available, but an interim analysis suggested no significant difference in OS between the treatment arms, regardless of PD-L1 status.

The rate of treatment-related serious adverse events was higher in the atezolizumab group than in the placebo group — 35% and 21%, respectively.

Treatment discontinuation due to adverse events occurred in 26% of patients in the atezolizumab group and 22% of patients in the placebo group.

Disclosures: This research was supported by F. Hoffmann-La Roche Ltd. Dr Moore declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Moore K. IMagyn050/GOG 3015/ENGOT-OV39, a double- blind placebo-controlled randomised phase 3 trial of bevacizumab-containing therapy ± atezolizumab for newly diagnosed stage III/IV ovarian cancer. Presented at: ESMO Gynaecological Cancers Virtual Congress; June 25-26, 2021.

This article originally appeared on Cancer Therapy Advisor