A Study of Atezolizumab (Anti-PD-L1 Antibody) as Adjuvant Therapy After Definitive Local Therapy in Patients With High-Risk Locally Advanced Squamous Cell Carcinoma of the Head and Neck

Inclusion Criteria

• Histologically or cytologically confirmed Squamous Cell Carcinoma of the Head andNeck (SCCHN)

• Human Papilloma Virus (HPV) status

• Completed definitive local therapy

• Absence of metastatic disease as documented by radiographic scans

• Adequate hematologic and end-organ function

• For patients receiving therapeutic anticoagulation: stable anticoagulant regimen

• For women of childbearing potential: agreement to remain abstinent or usecontraceptive methods with a failure rate of < 1% per year during the treatmentperiod and for 5 months after the last dose of study treatment. Women must refrainfrom donating eggs during this same period.

• Confirmed response of Complete Response (CR), Partial Response (PR), or StableDisease (SD) to definitive local therapy documented by CT with contrast or MRI withcontract to head and neck region done >= 8 weeks after completion of definitivelocal therapy and within 28 days prior to initiation of study drug.

Exclusion Criteria:

• Patients who have received surgery alone or radiotherapy alone as definitive localtherapy

• Squamous cell carcinoma of the nasopharynx or paranasal sinuses or non-squamoushistology

• Evidence of disease progression or metastatic disease during or following definitivelocal therapy documented in post-definitive local therapy screening scans

• Uncontrolled or symptomatic hypercalcemia

• Active or history of autoimmune disease or immune deficiency

• Active tuberculosis

• Significant cardiovascular disease

• History of malignancy, including prior SCCHN primary tumors within 5 years prior toscreening, with the exception of malignancies with a negligible risk of metastasisor death

• Prior allogeneic stem cell or solid organ transplantation

• Current treatment with anti-viral therapy for Hepatitis B Virus (HBV)

• Treatment with systemic immunostimulatory agents

• Treatment with systemic immunosuppressive medication

• History of severe allergic anaphylactic reactions to chimeric or humanizedantibodies or fusion proteins

• Pregnancy or breastfeeding, or intention of becoming pregnant during study treatmentor within 5 months after the last dose of study treatment

• Patients who have received a non-FDA or non-EMA approved anti-EGFR agent or anyother non-FDA or non-EMA, approved agent as part of definitive local therapy, unlessthe unapproved agent was given in addition to an approved agent

• Any systemic therapies after permitted definitive local therapies