Change in study design

This is an open-label study designed to evaluate safety and efficacy of enoblituzumab in combination with MGA012 or MGD013 in first-line treatment of patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN).

The study will initially be conducted in 2 modules, Module X (enoblituzumab plus MGA012) and Module Y (enoblituzumab plus MGD013). Enrollment into Modules X and Y, with approximately 30 patients each, will occur independently in a non-randomized fashion. Data from these modules will determine if further evaluation will occur in randomized Module A (Phase 2) and randomized Module B (Phase 3).

Inclusion Criteria:

• Histologically proven, recurrent or metastatic SCCHN not curable by local therapy
• No prior systemic therapy for SCCHN in the recurrent or metastatic setting (with the exception of systemic therapy completed > 6 months prior of given as part of multimodal treatment for locally advanced disease)
• Primary tumor locations of oropharynx, oral cavity, hypopharynx, or larynx
• At least one radiographically measurable lesion
• HPV test results available (positive and negative eligible)
• ECOG Performance status of 0 or 1
• Adequate end organ function
• Positive PD-L1 expression level (CPS ≥ 1%)

Exclusion Criteria:

• Disease suitable for local therapy administered with curative intent
• Progressive disease within 6 months of completion of curatively intended systemic treatment for locoregionally advanced SCCHN
• Radiation or other non-systemic therapy within 2 weeks of first dose of study drug
• Diagnosis of immunodeficiency, or use of immunosuppresive therapy within 14 days of first dose of study drug