Study of MEDI4736 Monotherapy and in Combination With Tremelimumab Versus Standard of Care Therapy in Patients With Head and Neck Cancer

This is a randomized, open-label, multi-center, global, Phase III study to determine the efficacy and safety of MEDI4736 + tremelimumab combination therapy and MEDI4736 monotherapy versus SoC therapy in the target patient population. The main objectives of the study are to: * assess the efficacy of MEDI4736 + tremelimumab combination therapy versus SoC in patients with squamous cell carcinoma of the head and neck (SCCHN), in terms of overall survival (OS), regardless of PDL-1 status * assess the efficacy of MEDI4736 monotherapy versus SOC in patients with SCCHN, in terms of OS, regardless of PDL-1 status Patients will undergo a screening assessment on their tumor tissue sample to determine PD-L1 expression per a pre-specified cut-off level. Patients with ≥25% of tumor cells with membrane staining will be considered PD-L1 positive while those with 0% to 24% of tumor cells with membrane staining will be considered PD-L1 negative. Based on the underlying PD-L1 status, patients will be randomized in a 1:1:1 ratio to receive treatment with MEDI4736 monotherapy, MEDI4736 + tremelimumab combination therapy, or SoC therapy. Patients who discontinue treatment in 1 treatment group may not switch to treatment in a different group. Stratification factors include PD-L1 status, human papillomavirus status, (in patients with oropharyngeal cancer only), and smoking status. Tumor assessments will be performed every 8 weeks until objective tumor response by Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1).

Inclusion Criteria: - Age ≥18 years; - Written informed consent obtained from the patient/legal representative; - Histologically or cytologically confirmed recurrent or metastatic SCCHN; - Tumor progression or recurrence during or after only one palliative systemic treatment regimen for recurrent or metastatic disease that must have contained a platinum agent OR progression within 6 months of the last dose of platinum given as part of multimodality therapy with curative intent; - Confirmed PD-L1-positive or -negative SCCHN by the Ventana PD-L1 SP263 IHC assay; - WHO/Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1; At least 1 measurable lesion, - Not previously irradiated; - No prior exposure to immune-mediated therapy; - Adequate organ and marrow function; Evidence of post-menopausal status or negative urinary or serum pregnancy test for female pre-menopausal patients. Exclusion Criteria: - Histologically or cytologically confirmed squamous cell carcinoma of any other primary anatomic location in the head and neck; - Received more than 1 palliative systemic regimen for recurrent or metastatic disease; -Any concurrent chemotherapy, Investigational Product, biologic, or hormonal therapy for cancer treatment; - Receipt of any investigational anticancer therapy within 28 days or 5 half-lives; - Receipt of last dose of an approved (marketed) anticancer therapy (chemotherapy, targeted therapy, biologic therapy, mAbs, etc) within 21 days prior to the first dose of study treatment; - Major surgical procedure within 28 days prior to the first dose of Investigational Product; - Any unresolved toxicity NCI CTCAE Grade ≥2 from previous anticancer therapy with the exception of alopecia, vitiligo, and the laboratory values defined in the inclusion criterion; - Current or prior use of immunosuppressive medication within 14 days before the first dose of their assigned Investigational Product; - History of allogeneic organ transplantation; - Active or prior documented autoimmune or inflammatory disorders; - Uncontrolled intercurrent illness; - Patients with a history of brain metastases, spinal cord compression, or leptomeningeal carcinomatosis; - Mean QT interval corrected for heart rate (QTc) ≥470 ms calculated from 3 electrocardiograms (ECGs) using Fridericia's Correction; - History of active primary immunodeficiency; - Active tuberculosis; - Active infection including hepatitis B, hepatitis C or human immunodeficiency virus (HIV); - Receipt of live, attenuated vaccine within 30 days prior to the first dose of Investigational Product; - Pregnant or breast-feeding female patients; - Known allergy or hypersensitivity to Investigational Product