Study was cancelled prior to enrolling any patients.

The purpose of this study is to evaluate the safety and efficacy of the combination of nivolumab plus epacadostat in combination with chemotherapy in first-line recurrent or metastatic patients with squamous cell carcinoma of the head and neck (SCCHN) when compared to the standard of care (EXTREME regimen).

Inclusion Criteria:

• Histologically confirmed SCCHN from any of the following primary sites: oral cavity, oropharynx, hypopharynx, and larynx.
• Must have recurrent or metastatic disease that is not amenable to therapy with curative intent (surgery and/or radiation therapy with or without chemotherapy).
• No prior treatment with systemic anti-cancer therapy for SCCHN unless protocol-defined conditions are met.
• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to1.
• Measurable disease by computed tomography (CT) or magnetic resonance imaging (MRI) per RECIST v1.1.
• Documentation of program death ligand-1 (PD-L1) status prior to randomization.

Exclusion Criteria:

• Recurrent or metastatic carcinoma of the nasopharynx and paranasal sinuses, squamous cell carcinoma that originated from the skin and salivary gland or non-squamous histologies (e.g., mucosal melanoma) and SCCHN of unknown primary origin.
• Untreated central nervous system (CNS) metastases.
• Carcinomatous meningitis.
• Active, known or suspected autoimmune disease.
• Physical and laboratory test findings outside the protocol-defined range.