Pilot Phase II Study to Evaluate Effect of Cetuximab Given as Single Agent After Immunotherapy With PD-1 Inhibitors in Patients With Head and Neck Squamous Cell Carcinoma

Inclusion Criteria: * Patients must have histologically or cytologically confirmed head and neck squamous cell carcinoma. * Measurable disease by scans- at least one measurable lesion. * Patients must have received previous treatment with immunotherapy with PD-1 inhibitor alone or in combination with chemotherapy. * Patients must have a Performance Status of 0-2. * Patients must be greater than or equal to 18 years old. * Participant is willing and able to comply with the protocol for the duration of the study. * Ability to understand and the willingness to sign an Institutional Review Board-approved informed consent document. Exclusion Criteria: * Prior treatment with Cetuximab or prior therapy that specifically and directly targets the epidermal growth factor receptor (EGFR) pathway in the last five (5) years. * Prior allergic reaction to Cetuximab. * History of allergic reactions attributed to compounds of chemical or biologic composition similar to those of Cetuximab. * Patients receiving any other investigational agents. * Patient is on medications that need to be continued and that might interact with Cetuximab. * Any uncontrolled condition, which in the opinion of the investigator, would interfere in the safe and timely completion of study treatment and procedures. * Participant with a history of interstitial lung disease (e.g. pneumonitis or pulmonary fibrosis) or evidence of interstitial lung disease on screening chest imaging. Any of the following conditions: * Serious or non-healing wound, ulcer, or bone fracture at the discretion of treating physician * history of abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within 28 days of study enrollment * history of cerebrovascular accident (CVA) or transient ischemic attack within 12 months prior to study enrollment * history of myocardial infarction, ventricular arrhythmia, stable/unstable angina, -symptomatic congestive heart failure, coronary/peripheral artery bypass graft or stenting or other significant cardiac disease within 6 months prior to study enrollment * history of arterial or venous thrombosis/thromboembolic event, including pulmonary embolism within 6 months of study enrollment * any condition requiring the use of immunosuppression, excluding rheumatologic conditions treated with stable doses of corticosteroids. Pregnancy, breastfeeding, or expecting to conceive or father children within the projected duration of the trial, starting with the screening visit through 6 months after the last dose of trial treatment.