Testing the Addition of Anti-Cancer Drug, Cetuximab, to Standard of Care Treatment (Pembrolizumab) for Returning or Spreading Head and Neck Cancer After Previous Treatment

This phase III trial compares the effect of adding cetuximab to pembrolizumab versus pembrolizumab alone in treating patients with head and neck squamous cell carcinoma (HNSCC) that has come back after a period of improvement (recurrent) and/or that has spread from where it first started (primary site) to other places in the body (metastatic). Cetuximab is in a class of medications called monoclonal antibodies. It binds to a protein called EGFR, which is found on some types of tumor cells. This may help keep tumor cells from growing. Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the tumor, and may interfere with the ability of tumor cells to grow and spread. Giving cetuximab and pembrolizumab together may be more effective at treating patients with recurrent and/or metastatic HNSCC than pembrolizumab alone.