Cetuximab & Nivolumab in Patients With Recurrent/Metastatic Head & Neck Squamous Cell Carcinoma

Inclusion Criteria: * Participants must have histologically or cytologically confirmed squamous cell carcinoma of oral cavity, oropharynx, paranasal sinuses, nasal cavity, hypopharynx, or larynx. Squamous cell carcinoma of unknown primary in cervical lymph node can be included only if p16 status is positive. * Must have recurrent or metastatic HNSCC stage III/IV that is not amenable to local therapy with curative intent (surgery or radiation therapy with or without chemotherapy).Patients with persistent disease following radiation therapy administered with a chemotherapy sensitizer may also be included. * Must have progressed on at least one prior line of chemotherapy, targeted therapy, palliative radiation, and/or biological therapy regimen for their recurrent and/or metastatic HNSCC. However, if patients are likely to be intolerant to standard first-line systemic chemotherapy, the patients are eligible to enroll to this study as the first-line therapy. Additionally, patients with persistent disease or platinum-refractory recurrent disease may enroll in this study as a first-line therapy. * Must NOT have any systemic therapy for recurrent and/or metastatic disease except if given as a part of a multimodality treatment (i.e. re-irradiation and systemic therapy for curable intent of locally recurrent disease). * Must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded) as outlined i…