Phase II study of atezolizumab in combination with bevacizumab in patients with advanced cervical cancer

Abstract

Background There are limited treatment options for patients with metastatic or recurrent cervical cancer. Platinum-based chemotherapy plus the anti-vascular endothelial growth factor antibody bevacizumab remains the mainstay of advanced treatment. Pembrolizumab is Food and Drug Agency approved for programmed death ligand 1 (PD-L1) positive cervical cancer with a modest response rate. This is the first study to report the efficacy and safety of the PD-L1 antibody atezolizumab in combination with bevacizumab in advanced cervical cancer.Methods We report the results from a phase II, open-label, multicenter study (NCT02921269). Patients with advanced cervical cancer were treated with bevacizumab 15 mg/kg intravenous every 3 weeks and atezolizumab 1200 mg intravenous every 3 weeks. The primary objective was to measure the objective response rate (ORR). Secondary endpoints included disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety.Results In the total evaluable population (n=10), zero patients achieved an objective response as assessed by Response Evaluation Criteria In Solid Tumors (RECIST) V.1.1, resulting in a confirmed ORR of 0%. Of note, there were two patients who achieved an unconfirmed PR. The DCR by RECIST V.1.1 was 60% (0% complete response, 0% partial response, 60% stable disease). Median PFS was 2.9 months (95% CI, 1.8 to 6) and median OS was 8.9 months (95% CI, 3.4 to 21.9). Safety results were generally consistent with the known safety profile of both drugs, notably with two high-grade neurologic events.Conclusions The combination of bevacizumab and atezolizumab did not meet the predefined efficacy endpoint, as addition of bevacizumab to PD-L1 blockade did not appear to enhance the ORR in cervical cancer.