Atezolizumab, Bevacizumab, and Chemotherapy for Newly Diagnosed Stage III or IV Ovarian Cancer: Placebo-Controlled Randomized Phase III Trial (IMagyn050/GOG 3015/ENGOT-OV39)
Background and Purpose
The purpose of this study was to determine the efficacy of the addition of atezolizumab to platinum based chemotherapy and bevacizumab for newly diagnosed stage III or IV ovarian cancer
This study was a multicenter, placebo controlled, double-blind randomized phase 3 trial. Enrolled patients had newly diagnosed untreated FIGO stage III of 4 ovarian cancer. They had either undergone primary cytoreductive surgical intervention with macroscopic residual disease or planned to receive neoadjuvant chemotherapy and interval surgery. Stratification was based off FIGO staging, ECOG status, tumor cell PD-L1 staining, treatment strategy and randomly assigned 1:1 to receive Q3 weekly cycles of atezolizumab 1.2 g or placebo with paclitaxel plus carboplatin plus bevacizumab, omitting perioperative bevacizumab in neoadjuvant patients. The primary endpoint was investigator assessed progression free survival and overall survival.
1,301 patients were enrolled. The median progression free survival was 19.5 versus 18.4 months in the atezolizumab versus placebo arm. The hazard ratio was 0.92 with a P value of 0.28 in the intention to treat population while it was 20.8 vs 18.5 months, with a hazard ratio 0.80, P value of 0.038, in the PD-L1 positive population. The immature overall survival results showed no significant benefit from atezolizumab. The most common grade 3 or 4 adverse events were neutropenia, 21% (2%, hypertension and anemia.
The authors concluded that the use of atezolizumab in newly diagnosed ovarian cancer cannot be recommended, and also generalized the questionable utility of immunotherapy in advanced ovarian cancer.