PRIMARY OBJECTIVES:~I. To correlate circulating tumor DNA (ctDNA) levels measured using cancer personalized profiling by deep sequencing (CAPP-Seq) with radiographic tumor assessments using Response Evaluation Criteria in Solid Tumors (RECIST) version (v)1.1 criteria in patients with metastatic non-squamous non-small cell lung cancer (NSCLC) treated with pembrolizumab.~SECONDARY OBJECTIVES:~I. To correlate PD-L1 assessment on pre-treatment tumor samples with objective response using RECIST v1.1 criteria in patients with metastatic non-squamous NSCLC treated with pembrolizumab.~II. To determine the overall response rate (ORR) using RECIST v1.1 criteria in patients with metastatic non-squamous NSCLC treated with pembrolizumab.~III. To determine the progression-free survival (PFS) using RECIST v1.1 in patients with metastatic non-squamous NSCLC treated with pembrolizumab.~IV. To determine the overall survival (OS) in patients with metastatic non-squamous NSCLC treated with pembrolizumab.~V. To determine the safety and tolerability of pembrolizumab in patients with metastatic non-squamous NSCLC.
This phase II trial studies how well pembrolizumab works in treating patients with non-squamous non-small cell lung cancer which has spread to other places in the body. Monoclonal antibodies, such as pembrolizumab, may interfere with the ability of tumor cells to grow and spread.