Testing the Addition of an Anti-Cancer Drug, Camonsertib, to Radiation Therapy for Recurrent Head and Neck Squamous Cell Carcinoma

This phase I trial tests the safety, side effects, and best dose of camonsertib in combination with stereotactic body radiation therapy in controlling disease in patients with head and neck squamous cell cancer that has come back after a period of improvement (recurrent) or that cannot be removed by surgery (unresectable). Camonsertib may stop the growth of tumor cells and may kill them by blocking some of the enzymes needed for cell growth. Stereotactic body radiation therapy is a type of external radiation therapy that uses special equipment to position a patient and precisely deliver radiation to tumors in the body (except the brain). The total dose of radiation is divided into smaller doses given over several days. This type of radiation therapy helps spare normal tissue. Giving camonsertib in combination with stereotactic body radiation therapy may help control disease in patients with recurrent or unresectable head and neck squamous cell cancers.