Dr. Bekaii-Saab on the Rationale to Evaluate Atezolizumab/Bevacizumab in MSS mCRC

Tanios S. Bekaii-Saab, MD, FACP, medical oncologist, medical director, Cancer Clinical Research Office, vice chair and section chief, Medical Oncology, Department of Internal Medicine, Mayo Clinic, discusses the rationale to evaluate atezolizumab (Tecentriq) and bevacizumab (Avastin) in patients with microsatellite stable (MSS) metastatic colorectal cancer (mCRC).

A strong body of evidence suggests agents that target VEGF facilitate immune modulation in otherwise “cold tumors,” says Bekaii-Saab. VEGF inhibitors in combination with PD-1/PD-L1 agents have also been shown to be synergistic in preclinical models and preliminary clinical trials. Following reports of activity in hepatocellular carcinoma, investigators sought to assess the combination’s activity in mCRC, particularly in patients who would not derive significant benefit from atezolizumab alone, adds Bekaii-Saab.

In the randomized phase II trial, approximately 120 patients with MSS mCRC who had failed biologics and ≥2 prior lines of chemotherapy were randomized to receive the combination plus capecitabine, or atezolizumab, capecitabine, and placebo. Progression-free survival served as the primary endpoint of the trial.