Autologous T Cells Lentivirally Transduced to Express L1CAM-Specific Chimeric Antigen Receptors in Treating Patients With Locally Advanced and Unresectable or Metastatic Small Cell Neuroendocrine Prostate Cancer

OUTLINE: This is a dose-escalation study of autologous L1CAM-specific CAR+EGFRt+ T cells. Patients undergo leukapheresis to obtain peripheral blood mononuclear cells (PBMCs) for T cell product manufacturing and may undergo bridging therapy at the discretion of the treating clinician on study. Patients then undergo lymphodepleting chemotherapy with cyclophosphamide intravenously (IV) and fludarabine IV on days -5, -4 and -33 or single agent bendamustine on days -4 and -3 at the discretion of the treating clinician and/or principal investigator (PI). Patients receive an autologous L1CAM-specific CAR+EGFRt+ T cell infusion on day 0. Based on disease response and persistence of CAR T cells, patients may receive additional lymphodepletion chemotherapy and an autologous L1CAM-specific CAR+EGFRt+ T cell infusion as soon as 6 weeks and no later than 24 weeks after the first infusion, or at the discretion of the PI. Patients undergo echocardiography (ECHO) or multigated acquisition scan (MUGA) during screening. Patients undergo x-ray imaging, computed tomography (CT), bone scan, and blood sample collection throughout the trial. Additionally, patients may undergo tissue biopsy on the trial. After completion of study treatment, patients are followed up monthly for 3 months, then every 3 months up to 12 months then may undergo long-term follow-up annually for up to 15 years.