This is a phase I dose-escalation study to determine the safety and feasibility of autologous CAR-TA T cells (B7-H3 CAR+ T cells administered with DNR-PRAME Tumor Antigen-specific T cells) following lymphodepleting chemotherapy in participants with relapsed/refractory rhabdomyosarcoma, Ewing sarcoma, neuroblastoma and Wilms tumor. Patients will be enrolled to one of three planned dose levels with B7-H3 CAR T cell dose determined based on the percentage of B7-H3 transduced cells (B7-H3+ population of cells), and dTBRII-transduced PRAME TA-specific T cell dose based on the total cell population. Both doses will be based on the recipient's body weight. The safety of the CAR-TA T cell product will be evaluated and the maximum tolerated dose (MTD) will be determined. The safety endpoint will be assessed by monitoring for dose limiting toxicities for 28 days following CAR-TA T cell administration.
This protocol is designed as a phase I dose-escalation study. Procurement phase: During the procurement phase of this protocol, upon SABRE Procurement Consent and procurement eligibility confirmation, participants will undergo a non-mobilized apheresis for collection of mononuclear cells to be used for the CAR-TA T cell product manufacturing. Treatment phase: Once the CAR-TA T cell products are released and patients are confirmed eligible for CAR-TA T cell product infusion, participants will undergo protocol therapy at Children's National Hospital, consisting of a standard Lymphodepleting chemotherapy preparative regimen with fludarabine and cyclophosphamide, followed by intravenous infusion of the combined CAR-TA T cell product. The DNR-TA T cells and B7-H3 CAR T cells will be generated and combined into a final product comprised of the two T cell components combined at a 1:1 ratio. Patients will be enrolled to one of three CAR-TA T cell product dose levels (dose levels 1, 2 and 3). There are provisions in place to dose de-escalate for safety concerns (dose level -1). Fludarabine will be administered intravenously once daily over 30 minutes, days -5 through -2 (4 doses in total). The dose of fludarabine will be 30 mg/m2 /day. Cyclophosphamide will be administered intravenously once daily over 30 minutes, days -5 and -4 (2 doses in total). The dose of cyclophosphamide will be 500 mg/m2 /day. The first 3 patients enrolled on study will be ≥ 12 years of age at enrollment and treated at dose level 1 (1 x 10e6/kg). If no DLTs are observed in this cohort, enrollment at dose levels 2 (3 x 10e6/kg) and 3 (10 x 10e6/kg) will expand to include patients aged ≥ 1 year and \< 24 years. Patients will remain admitted for at least 7 days following the CAR-TA T cell infusion. All infused patients will be followed with weekly visits during the 28-day dose-limiting toxicity monitoring period where they will be clinically assessed, and safety and research blood draws will be performed. Ideally, patients should not receive other systemic or local cancer-directed therapies for at least 28 days after the CAR-TA T cell infusion. Participants will be followed closely for 1 year following the CAR-TA T-cell infusion. After 1 year, yearly assessments will be done up to 15 years. The visits will consist of labs and examinations as well as talking to participants about how they are feeling. Participants will be followed for toxicity until the last follow-up post CAR-TA T cell product administration. This study will be conducted at Children's National Hospital (CNH). Cell culture manipulations will be carried out in the CETI Good Manufacturing Practice (GMP) facility within Children's National Hospital using current standard operating procedures (SOPs). Up to 18 participants will be treated on this protocol to meet the primary objective over an estimated accrual period of 5 years
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
18
Selective Antigen Specific dTβRII-expressing T cells combined with B7-H3 CAR T cells
Children's National Hospital
Washington D.C., District of Columbia, United States
RECRUITINGChildrens National Hospital
Washington D.C., District of Columbia, United States
NOT_YET_RECRUITINGGrade 3 or more immediate infusion-related adverse event
Number of patients experiencing Grade 3 or higher immediate infusion-related adverse events, assessed using the Common Terminology Criteria for Adverse Events (CTCAE, version 5.0; Grades 1-5; higher grades indicate worse severity), occurring during or immediately following the CAR-TA T cell infusion.
Time frame: Within 28 days from the CAR-TA T cell infusion
Grade 4 or more Immune Effector Cell Associated Neurotoxicity Syndrome (ICANS)
Number of patients experiencing Grade 4 or higher Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS), assessed using the American Society for Transplantation and Cellular Therapy (ASTCT) CRS and ICANS Consensus Grading Criteria (Grades 1-5; higher grades indicate worse severity).
Time frame: Within 28 days from the CAR-TA T cell infusion
Grade 3 neurotoxicity or ICANS persisting for more than 72 hours
Number of patients experiencing Grade 3 neurotoxicity or ICANS with a duration greater than 72 hours. (severity grades assessed as per American Society for Transplantation and Cellular Therapy (ASTCT) CRS and ICANS Consensus Criteria)
Time frame: Within 28 days from the CAR-TA T cell infusion
Grade 4 or more Cytokine Release Syndrome (CRS)
Number of patients experiencing Grade 4 or higher Cytokine Release Syndrome (CRS), assessed using ASTCT CRS Consensus Grading Criteria (Grades 1-5; higher = worse).
Time frame: Within 28 days from the CAR-TA T cell infusion
Grade 3 Cytokine Release Syndrome (CRS) lasting more than 14 days
Number of patients experiencing Grade 3 CRS with a duration greater than 14 days
Time frame: Within 28 days from the CAR-TA T cell infusion
Grade 3 or more Hemophagocytic Lymphohistiocytosis (HLH)
Number of patients experiencing Grade 3 or higher Hemophagocytic Lymphohistiocytosis (HLH), assessed using CTCAE v5.0.
Time frame: Within 28 days from the CAR-TA T cell infusion
Grade 3 or more fever lasting for more than 14 days
Number of patients experiencing fever of Grade 3 or higher, persisting longer than 14 days, assessed using CTCAE v5.0.
Time frame: Within 28 days from the CAR-TA T cell infusion
Grade 4 or more infection uncontrolled for more than 7 days
Number of patients experiencing infection of Grade 4 or higher severity that is uncontrolled for more than 7 days, assessed using CTCAE v5.0.
Time frame: Within 28 days from the CAR-TA T cell infusion
Any unexpected toxicity of Grade 2 or more
Number of patients experiencing unexpected toxicities of Grade 2 or higher, assessed using CTCAE v5.0.
Time frame: Within 28 days from the CAR-TA T cell infusion
Any expected toxicity above Grade 4
Number of patients experiencing expected toxicity above Grade 4 (i.e., Grade 5 toxicity), assessed using CTCAE v5.0.
Time frame: Within 28 days from the CAR-TA T cell infusion
Any expected toxicity above Grade 3 lasting longer than 72 hours
Number of patients experiencing expected toxicity greater than Grade 3, persisting longer than 72 hours, assessed using CTCAE v5.0.
Time frame: Within 28 days from the CAR-TA T cell infusion
Grade 2 toxicity persisting for more than 7 days AND considered intolerable to the patient and/or not controlled with standard supportive care
Number of patients experiencing Grade 2 toxicity persisting for more than 7 days that is intolerable to the patient and/or not controlled with standard supportive care, assessed using CTCAE v5.0.
Time frame: Within 28 days from the CAR-TA T cell infusion
Response to CAR-TA T cell therapy
Number of patients who respond to CAR-TA T cell therapy for treatment of relapsed or refractory rhabdomyosarcoma, Ewing sarcoma, neuroblastoma and Wilms tumor, defined as complete response, partial response, or stable disease following infusion of the CAR-TA T cell product. Disease response will be assessed using protocol-specified criteria.
Time frame: Up to 5 years from the CAR-TA T cell infusion
Progression-free survival
Time from infusion of the investigational product to the first documented disease progression or death from any cause
Time frame: Up to 12 months from the CAR-TA T cell infusion
Overall survival
Time from the from infusion of the investigational product to death from any cause.
Time frame: Up to 12 months from the CAR-TA T cell infusion
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