Pembrolizumab & Cabozantinib in Patients With Head and Neck Squamous Cell Cancer

Inclusion Criteria: * The subject has a histologic or cytologic diagnosis of squamous cell carcinoma of the oral cavity, oropharynx, paranasal sinuses, hypopharynx, nasopharynx, or larynx; squamous cell carcinoma of unknown primary in cervical lymph node can be included only if human papillomavirus (HPV) status is positive * Patients must have refractory, recurrent or metastatic disease, which is deemed to be inoperable * In case patients received prior systemic therapy within the definitive or metastatic setting, disease progression must be documented following prior therapy; this can be in the recurrent or metastatic setting or in the concurrent setting * Measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 as determined by the investigator * A maximum of one prior radiotherapy regimen, curative or palliative, to the head and neck is allowed; if the radiation is combined with chemotherapy, a minimum of 4 months must elapse between the end of radiotherapy and registration; if the radiation is given alone, a minimum of 8 weeks must elapse between the end of radiotherapy and registration; a minimum of 3 weeks must elapse between prior radiation to other areas and registration; treatment areas should be healed with no sequelae from radiation therapy (RT) that would predispose to fistula formation * The subject has had an assessment of all known disease sites eg, by computerized tomography (CT) scan, magnetic resonance imaging (MRI), bone scan or pos…