PRIMARY OBJECTIVE:~I. To evaluate the safety of personalized neoantigen peptide vaccine in combination with pembrolizumab in advanced solid cancers.~SECONDARY OBJECTIVES:~I. To evaluate the feasibility of personalized neoantigen peptide vaccine in combination with pembrolizumab in advanced solid cancers.~II. To obtain preliminary information on the immunogenicity of neoantigen in induction of specific cellular immune responses and humoral immune response.~EXPLORATORY OBJECTIVES:~I. To obtain preliminary estimates of efficacy as measured by objective response rate (ORR based on Response Evaluation Criteria in Solid Tumors [RECIST]) of personalized neoantigen peptide vaccine and pembrolizumab in patients with selected advanced solid tumors.~II. To obtain preliminary information of immunity persistence, as well as pre-existing immunity.~OUTLINE:~Patients receive cyclophosphamide intravenously (IV) on day -3. Patients then receive personalized neoantigen vaccine with sargramostim (GM-CSF) SC on days 1, 4, 8, and 15 of cycle 1, and day 1 of cycles thereafter. Patients also receive pembrolizumab IV over 30 minutes on day 1. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity.~After completion of study treatment, patients are followed up at 30 days and then every 3 months up to 2 years from study enrollment.
This phase I trial tests the safety and tolerability of an experimental personalized vaccine when given by itself and with pembrolizumab in treating patients with solid tumor cancers that have spread to other places in the body (advanced). The experimental vaccine is designed target certain proteins (neoantigens) on individuals' tumor cells. Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Giving the personalized neoantigen peptide-based vaccine with pembrolizumab may be safe and effective in treating patients with advanced solid tumors.