Use of Serial Plasma NGS as a New Efficacy Metric to Guide Immunotherapy Treatment Discontinuation

The goal of this prospective study to investigate the use of circulating tumor DNA (ctDNA) to guide end of therapy decisions in patients with melanoma or non-small-cell lung cancer. The main question it aims to answer is: • Do patients with metastatic melanoma or non-small-cell lung cancer, who have received at least 12 months of immune checkpoint inhibition (monotherapy or in combination) with evidence of disease response/control on imaging and have no evidence of circulating tumor DNA, have an increased 12-month disease free survival in comparison to historical controls?