SABRE Study: T-Cell Therapy for Relapsed/Refractory Embryonal Tumors
This study, called SABRE, is testing a new approach for children and young adults (ages 1 to 23) with certain relapsed or hard-to-treat embryonal tumors like rhabdomyosarcoma, Ewing sarcoma, neuroblastoma, or Wilms tumor. It uses a combination of two types of special immune cells: Selective Antigen Specific dTβRII-expressing T cells and B7-H3 CAR T cells. These cells are designed to find and fight cancer. The main goal of this early-phase study is to see how safe this treatment is and to find the right dose. Researchers will be looking for serious side effects, especially those related to the infusion or nerve-related issues, within 28 days of treatment. The study plans to enroll 18 participants.
- Study design
- This is a Phase 1 dose-escalation study, meaning it will test increasing doses of the treatment in a small number of participants (18 planned). It is an interventional study, where participants receive the study treatment.
- What's involved
- You would undergo apheresis to collect your immune cells, receive chemotherapy to prepare your body, and then have the combined CAR-TA T cell product infused intravenously. The study involves monitoring for side effects after the infusion.
- Compensation
- Not stated in the trial record.
- Follow-up
- The primary safety outcomes are measured within 28 days from the CAR-TA T cell infusion.
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NCT07172958
Selective Antigen Specific T Cells and CAR T Cells in Subjects With Relapsed/Refractory Embryonal Tumors (SABRE)
Recruiting
PHASE1Ages 1–23InterventionalTreatmentChildren's National Research InstituteInvestigator-initiated
~18 participants
Updated 2026-08-13 on ClinicalTrials.gov
What's tested:Selective Antigen Specific dTβRII-expressing T cells combined with B7-H3 CAR T cells
At a glance
Recruiting sites
1 of 2 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
To determine the safety of autologous CAR-TA T cells following LD chemotherapy in participants with relapsed/refractory rhabdomyosarcoma, Ewing sarcoma, neuroblastoma and Wilms tumor.
Measured over Within 28 days from the CAR-TA T cell infusion
+2 more outcomes measured
Conditions
Where it's being run
2 sites across 1 statesDistrict of Columbia2
Study leadership
- Holly Meany, MD · PRINCIPAL_INVESTIGATOR · Children's National Research Institute
- Amy Hont, MD · PRINCIPAL_INVESTIGATOR · Children's National Research Institute
Who to contact
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Do you actually qualify for this trial?
Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.
Eligibility criteria
Inclusion
Diagnosis of relapsed/refractory rhabdomyosarcoma, Ewing sarcoma, neuroblastoma, or Wilms tumor
Refractory disease, residual detectable disease or relapsed disease following available standard of care therapies with known clinical benefit for their specific tumor type, or unable to receive such therapies due to unacceptable toxicity or contraindication
Measurable or evaluable disease by imaging, as determined following most recent therapy
Age ≥ 1 year and \< 24 years
Weight ≥ 10 kg
No systemic steroid exposure within 1 week of procurement
Karnofsky/Lansky score of ≥ 60 (See Appendix 3)
Participants of childbearing potential or capable of fathering a child must agree to use effective contraceptive measure/s (as described in Appendix 5) during study protocol participation through 6 months following the administration of the CAR-TA T cells
ANC \> 500/µL
ALC \> 1000/µL
Platelet count \> 50,000/uL (level can be achieved with transfusion)
Bilirubin ≤ 2.5 mg/dL
Aspartate aminotransferase (AST)/Alanine transaminase (ALT) ≤ 5x the upper limit of normal for age
Serum creatinine Maximum serum creatinine (mg/dL) Age Male Female
For FOCBP: Negative pregnancy test
Pulse oximetry of \> 90% on room air
Adequate cardiac function defined as:
Shortening fraction of ≥ 27% by echocardiogram, or
Ejection fraction of \> 50% by echocardiogram or radionuclide angiogram (i.e., MUGA).
No acute neurological toxicity \> grade 1 (with the exception of peripheral sensory neuropathy or controlled seizure disorder on anti-epileptics).
The following time frames must have elapsed between prior therapy completion and apheresis cell collection:
Myelosuppressive chemotherapy/immunomodulatory medications: At least 3 weeks, or 6 weeks if prior nitrosourea.
Hematopoietic growth factors: At least 7 days since the completion of therapy with a growth factor. At least 14 days after receiving pegfilgrastim.
Biological agent, tyrosine kinase inhibitor, targeted agent, metronomic chemotherapy: At least 7 days since the completion of therapy with a biologic agent, tyrosine kinase inhibitor, targeted agent, or metronomic non-myelosuppressive regimen.
Monoclonal antibodies and checkpoint inhibitors: At least 3 weeks or 5 half-lives (whichever is shorter) since the last dose of a monoclonal antibody or checkpoint inhibitor.
Radiotherapy (XRT): At least 3 weeks since XRT, and at least 6 weeks if radiation involved the CNS or lung fields. Exception: There is no time restriction for palliative radiation with minimal bone marrow involvement and the patient has measurable/evaluable disease outside the radiation port or the site of radiation has documented progression.
Autologous stem cell transplant/infusion: At least 6 weeks from their infusion after an autologous stem cell infusion following myeloablative therapy. Patients who received an autologous stem cell infusion following non-myeloablative therapy do not have a wash-out period; they are eligible once they meet all other eligibility requirements, including recovery from acute side effects.
Investigational agent: at least 28 days since receiving an investigational agent.
Adult participant or the legally authorized representative (LAR) of a minor (defined as \<18 years of age) must be capable of providing informed consent. When appropriate, pediatric participants ≥7 years of age will participate in an age-appropriate discussion and provide assent, unless an IRB-approved waiver of assent applies and documentation of the participant's eligibility for the waiver is maintained.
No systemic steroid exposure within 1 week prior to protocol therapy initiation
Karnofsky/Lansky score of ≥ 60
ANC \> 750/uL
Platelet count \> 75,000/uL
Bilirubin ≤ 2.5 mg/dL
AST/ALT ≤ 5x the upper limit of normal for age
Serum creatinine Maximum serum creatinine (mg/dL) Age Male Female
For FOCBP: Negative pregnancy test
Participants of childbearing potential or capable of fathering a child must agree to use effective contraceptive measure/s through 6 months following the administration of the CAR-TA T cells
Adequate respiratory function defined as oxygen saturation 90% or higher on room air
For participants who underwent prior mediastinum-directed therapies (e.g., post radiation to chest): resolution of any respiratory symptoms
Adequate respiratory rate, defined as \<30 breaths per minute for patients aged \<18 years, and \<25 breaths per minute for patients aged ≥18 years (respiratory rate may be repeated if initial value is thought to be temporarily abnormal; if repeated, 2 consecutive readings obtained ≥30 minutes apart must be adequate to be eligible)
No acute neurological toxicity \> grade 1 (with the exception of peripheral sensory neuropathy or controlled seizure disorder on anti-epileptics).
Adequate cardiac function defined as:
Shortening fraction of ≥ 27% by echocardiogram, or
Ejection fraction of \> 50% by echocardiogram or radionuclide angiogram
The following time frames must have elapsed between completion of prior therapy and the initiation of SABRE protocol therapy:
Myelosuppressive chemotherapy: At least 2 weeks from last dose of chemotherapy.
Hematopoietic growth factors: At least 7 days since the completion of therapy with a growth factor. At least 14 days after receiving pegfilgrastim.
Biological agent, tyrosine kinase inhibitor, targeted agent, metronomic chemotherapy: At least 7 days since the completion of therapy with a biologic agent, tyrosine kinase inhibitor, targeted agent, or metronomic non-myelosuppressive regimen.
Monoclonal antibodies and checkpoint inhibitors: At least 3 weeks or 5 half-lives (whichever is shorter) since the last dose of a monoclonal antibody or checkpoint inhibitor.
Radiotherapy (XRT): At least 3 weeks since XRT, and at least 6 weeks if radiation involved CNS or lung fields. Exception: There is no time restriction for palliative radiation with minimal bone marrow involvement and the patient has measurable/evaluable disease outside the radiation port or the site of radiation has documented progression.
Investigational agent: At least 28 days since receiving an investigational agent.
Adult participant or the legally authorized representative (LAR) of a minor (defined as \<18 years of age) must be capable of providing informed consent. When appropriate, pediatric participants ≥7 years of age will participate in an age-appropriate discussion and provide assent, unless an IRB-approved waiver of assent applies and documentation of the participant's eligibility for the waiver is maintained.
Exclusion
Patients with known CNS disease.
Patients with uncontrolled infection/s or known HIV infection
Pregnant or lactating females.
Patients who have undergone previous allogeneic stem cell transplant.
Inability to tolerate leukapheresis (including any contraindication to the use of Anticoagulant Citrate Dextrose solution).
Patients with uncontrolled infections or known HIV infection.
Pregnant or lactating females
Whole lung/mediastinal radiation within 12 weeks
Clinically significant systemic illness or medical condition likely to interfere with assessment of safety or efficacy
Patients who have received any live vaccine in the six weeks prior to planned initiation of lymphodepletion
Any contraindication to lymphodepletion or to the use of Cyclophosphamide or Fludarabine, as per the clinical judgment of the PI or treating Sub-I
History of allergy or hypersensitivity to study product excipients (e.g., DMSO)
What this trial measures
- To determine the safety of autologous CAR-TA T cells following LD chemotherapy in participants with relapsed/refractory rhabdomyosarcoma, Ewing sarcoma, neuroblastoma and Wilms tumor.Within 28 days from the CAR-TA T cell infusion
The safety endpoint will be assessed by monitoring for dose limiting toxicities (DLT) for 28 days following CAR-TA T cell investigational product administration.
- 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.Within 28 days from the CAR-TA T cell infusion
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.
- 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.Within 28 days from the CAR-TA T cell infusion
Clinical feasibility will be determined by the number of participants with a released product who are eligible and receive at least 1 infusion.