Anti-Mesothelin TNaive/SCM hYP218 (TNhYP218) CAR T Cells in Participants With Mesothelin-Expressing Solid Tumors Including Mesothelioma

Background: Mesothelioma is an aggressive cancer that grows in the linings of the body; this can include the membranes that line the heart, lungs, and internal organs. Mesothelin (MSLN) is a protein that appears in high numbers in many tumors, including mesothelioma. Researchers are developing a new treatment that collects a person s own immune cells (T cells); the T cells are genetically modified to target and kill tumor cells with high levels of MSLN. Objective: To test a new treatment (TNhYP218 CAR T cells) in people with solid tumors including mesothelioma. Eligibility: People aged 18 and older with solid tumors including mesothelioma that returned or spread after standard treatment. Design: Participants will be screened. A small piece of tissue will be cut from a tumor (biopsy). The sample will be tested to see if it has enough MSLN. Participants will undergo leukapheresis: Blood will be taken from their body through a vein. The blood will pass through a machine that separates out the T cells. The remaining blood will be returned to the body through a different vein. Participant s T cells will be modified in a lab to produce TNhYP218 CAR T cells. Participants will enter the hospital. For 7 days, they will receive drugs to prepare their bodies for the study treatment. TNhYP218 CAR T cells will be administered into a vein. Participants will remain in the hospital for at least 7 more days. After discharge, participants will have follow-up visits for 5 years. These visits may include imaging scans, blood and heart tests, and a new biopsy. Long-term follow-up will continue another 10 years.