Tiragolumab/Atezolizumab

This is a Phase Ib/II, open-label, multicenter, randomized, umbrella study in participants with locally advanced squamous cell carcinoma of the head and neck (SCCHN). The study will enroll treatment-naive participants with resectable Stage III-IVA human papillomavirus (HPV)-negative, programmed death-ligand 1 (PD-L1)-positive SCCHN with measurable disease, as assessed by the investigator according to Response Evaluation Criteria in Solid Tumors, Version 1.1 (RECIST v1.1) who have not received systemic treatment for their disease.