Multinational phase 1 nonrandomized trial of tiragolumab with or without atezolizumab for advanced solid tumors

TIGIT (‘T-cell immunoreceptor with Ig and ITIM domains’) is a novel immune checkpoint expressed on activated T cells and natural killer cells in multiple cancers. The multinational nonrandomized phase 1 GO30103 trial evaluated the anti-TIGIT monoclonal antibody tiragolumab with or without atezolizumab in patients with advanced solid tumors. In this study including 73 patients, no dose-limiting toxicities occurred, and the recommended phase 2 dose of tiragolumab was identified as 600 mg every three weeks. There were no objective responses with single-agent tiragolumab although some patients experienced tumor shrinkage. The combination of tiragolumab and atezolizumab showed promising activity in patients with immunotherapy-naïve non-small cell lung cancer and esophageal cancer. The authors conclude that these findings support the continued investigation of dual TIGIT/PD-L1 inhibition in patients with advanced solid tumors.