L1CAM

This phase I trial studies the side effects and best dose of autologous CD8+ and CD4+ lentivirally transduced to express L1CAM-specific chimeric antigen receptor (CAR) and EGFRt mutation specific T cells and to see how well they work in treating patients with small cell neuroendocrine prostate cancer (SCNPC) that has spread to nearby tissue or lymph nodes (locally advanced) and cannot be removed by surgery (unresectable) or has spread from where it first started (primary site) to other places in the body (metastatic). CAR T-cell therapy is a type of treatment in which a patient's T cells (a type of immune system cell) are changed in the laboratory so they will attack tumor cells. T cells are taken from a patient's blood. Then the gene for a special receptor that binds to a certain protein on the patient's tumor cells is added to the T cells in the laboratory. Some solid tumor cells have an L1CAM protein on their surface, and T cells can be modified with a receptor, called a chimeric antigen receptor (CAR), to help recognize this protein and kill these tumor cells. Large numbers of the CAR T cells are grown in the laboratory and given to the patient by infusion for treatment of certain cancers. These L1CAM mutation specific T cells may help the body's immune system identify and kill L1CAM locally advanced and unresectable or metastatic small cell neuroendocrine prostate cancers' tumor cells.

This is a Phase 1 study of central nervous system (CNS) locoregional adoptive therapy with autologous CD4 and CD8 T cells lentivirally transduced to express a HER2-specific chimeric antigen receptor (CAR) and EGFRt, delivered by an indwelling catheter in the tumor resection cavity or ventricular system in children and young adults with recurrent or refractory HER2-positive CNS tumors. A child or young adult with a refractory or recurrent CNS tumor will have their tumor tested for HER2 expression by immunohistochemistry (IHC) at their home institution or at Seattle Children's Hospital. If the tumor is HER2 positive and the patient meets all other eligibility criteria, including having a CNS catheter placed into the tumor resection cavity or into their ventricular system, and meets none of the exclusion criteria, then they can be apheresed, meaning T cells will be collected. The T cells will then be bioengineered into a second-generation CAR T cell that targets HER2-expressing tumor cells. The patient's newly engineered T cells will then be administered via the indwelling CNS catheter for two courses. In the first course they will receive a weekly dose of CAR T cells for three weeks, followed by a week off, an examination period, and then another course of weekly doses for three weeks. Following the two courses, patient's will undergo a series of studies including MRI to evaluate the effect of the CAR T cells and may have the opportunity to continue receiving additional courses of CAR T cells if the patient has not had adverse effects and if more of their T cells are available.
The hypothesis is that an adequate amount of HER2-specific CAR T cells can be manufactured to complete two courses of treatment with three doses given on a weekly schedule followed by one week off in each course. The other hypothesis is that HER-specific CAR T cells safely can be administered through an indwelling CNS catheter to allow the T cells to directly interact with the tumor cells for each patient enrolled on the study safely can be delivered directly into the brain via indwelling catheter. Secondary aims of the study will include to evaluate CAR T cell distribution with the cerebrospinal fluid (CSF), the extent to which CAR T cells egress or traffic into the peripheral circulation or blood stream, and, if tissues samples from multiple time points are available, also evaluate the degree of HER2 expression at diagnosis versus at recurrence.

Patients with relapsed or refractory CD 19+ leukemia who have achieved remission after CD19 CAR-T cell treatment sometimes relapse because the CD 19 CAR-T cells decrease in number over time. Study PLAT-03 will test whether administering T cell antigen presenting cells (T-APCs) at intervals following treatment with CAR-T cells improves CD 19 CAR-T cell persistence and reduces the incidence of leukemia relapse.