By doing this study, the research team would like to learn if using a blood test that measures the amount of tumor DNA in blood can help guide how to use chemotherapy combined with immunotherapy for individuals with head and neck cancer. Using this blood test, the research team hopes to learn if intermittent (occasional) chemotherapy added to immunotherapy will work better than immunotherapy alone. Participation in this research will last about two years.
Have clinically confirmed head and neck cancer that is recurrent (comes back/returns to the body) or metastatic (spreads to other parts of the body).
Participants should not have had prior systemic therapy administered in the recurrent or metastatic setting. Systemic therapy which was completed more than 3 months prior to signing consent if given as part of multimodal treatment for locally advanced disease is allowed.
Greater than or equal to 18 years old.
Eastern Cooperative Oncology Group performance status of 0 or 1.
Has disease that is suitable for local therapy administered with curative intent.
Has progressive disease (PD) within three (3) months of completion of curatively intended systemic treatment for locoregionally advanced head and neck cancer.
Participants who are receiving any other investigational agents.
Participants in whom signatera ctDNA is not measurable at baseline.