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 and combined in a 1:1 ratio. 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 participating site(s), 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 toxicity-evaluable 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_RECRUITINGTo determine the safety of autologous CAR-TA T cells following LD chemotherapy in participants with relapsed/refractory rhabdomyosarcoma, Ewing sarcoma, neuroblastoma and Wilms tumor.
The safety endpoint will be assessed by monitoring for dose limiting toxicities (DLT) for 28 days following CAR-TA T cell investigational product administration.
Time frame: Within 28 days from the CAR-TA T cell infusion
To determine the manufacturing feasibility of autologous CAR-TA T cells following LD chemotherapy in participants with relapsed/refractory rhabdomyosarcoma, Ewing sarcoma, neuroblastoma and Wilms tumor.
Manufacturing feasibility will be determined by the number of CAR-TA T cell products produced in sufficient quantities to meet the participant's assigned dose level for at least one infusion, with all product release testing criteria met.
Time frame: Within 28 days from the CAR-TA T cell infusion
To determine the clinical feasibility of autologous CAR-TA T cells following LD chemotherapy in participants with relapsed/refractory rhabdomyosarcoma, Ewing sarcoma, neuroblastoma and Wilms tumor.
Clinical feasibility will be determined by the number of participants with a released product who are eligible and receive at least 1 infusion.
Time frame: Within 28 days from the CAR-TA T cell infusion
Determine number of patients who respond to CAR-TA T cell therapy for treatment of diseases under study
To determine the number of patients who respond to CAR-TA T cell therapy for treatment of relapsed or refractory rhabdomyosarcoma, Ewing sarcoma, neuroblastoma and Wilms tumor as defined by those that achieve a complete response, partial response, or stable disease following infusion of the CAR-TA T cell product.
Time frame: Within 15 years of infusion of CAR-TA T cell therapy.
Overall Survival
To determine overall survival at 3-, 6-, and 12-months following CAR-TA T cell infusion.
Time frame: Within 12 months of CAR-TA T cell infusion.
To characterize the in vivo immune milieu pre- and post-infusion of CAR-TA T cell product.
To measure levels of circulating cytokines all assessed pre-infusion and post-infusion.
Time frame: Within 15 years of infusion of CAR-TA T cell therapy.
To characterize transgene transduction efficiency (B7-H3 CAR and dTBRII) of the CAR-TA T cell product generated prior to infusion.
To characterize the CAR-TA T cell products generated prior to infusion in terms of transduction efficiency (B7-H3 CAR and dTBRII), with correlation to clinical and immune response.
Time frame: Within 15 years of infusion of CAR-TA T cell therapy.
To characterize reconstitution of anti-tumor immunity following infusion.
Reconstitution of anti-tumor immunity, with evaluation of antigen spreading as an indicator of anti-tumor immunity, and evaluation of patient sample specificity to targeted and non-targeted tumor-associated antigens pre-infusion and post infusion.
Time frame: Within 15 years of infusion of CAR-TA T cell therapy.
To determine in vivo persistence of infused DNR-TA T cells and B7-H3 CAR T cells at 1-,3-, 6-, and 12-months following infusion of CAR-TA T cell product and evaluate the association with clinical response
To determine persistence of infused DNR-TA T cells and B7-H3 CAR T cells at months 1, 3, 6, and 12 post-infusion and correlate with clinical response.
Time frame: Within 12 months of CAR-TA T cell infusion
To characterize the in vivo immune milieu pre- and post-infusion of CAR-TA T cell product.
To measure proportions of in vivo circulating lymphocytes all assessed pre-infusion and post-infusion.
Time frame: Within 15 years of infusion of CAR-TA T cell therapy.
To characterize the in vivo immune milieu pre- and post-infusion of CAR-TA T cell product.
To measure markers of activation and exhaustion all assessed pre-infusion and post-infusion.
Time frame: Within 15 years of infusion of CAR-TA T cell therapy.
To characterize PRAME specificity of the CAR-TA T cell product generated prior to infusion.
To characterize the CAR-TA T cell products generated prior to infusion in terms of PRAME specificity with correlation to clinical and immune response.
Time frame: Within 15 years of infusion of CAR-TA T cell therapy.
To characterize phenotype of the CAR-TA T cell product generated prior to infusion.
To characterize the CAR-TA T cell products generated prior to infusion in terms of phenotype with correlation to clinical and immune response.
Time frame: Within 15 years of infusion of CAR-TA T cell therapy.
Progression
To determine progression-free survival at 3-, 6-, and 12- months following CAR-TA T cell infusion.
Time frame: Within 12 months of CAR-TA T cell infusion.
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