TCR Alpha Beta T-cell Depleted Haploidentical HCT in the Treatment of Non-Malignant Hematological Disorders in Children

Phase 2

Recruiting

• Conditions: Severe Aplastic Anemia; Hemoglobinopathy (Disorder); Bone Marrow Failure Syndrome
• Interventions: Biological: Haploidentical Hematopoietic Cell Transplantation

• Registration Number: NCT04356469
• Lead Sponsor: Johns Hopkins All Children's Hospital

Brief Summary

This research is being done to learn if a new type of haploidentical transplantation using TCR alpha beta and CD19 depleted stem cell graft from the donor is safe and effective to treat the patient's underlying condition. This study will use stem cells obtained via peripheral blood or bone marrow from parent or other half-matched family member donor. These will be processed through a special device called CliniMACS, which is considered investigational.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2020-04-19
• Study First Submitted QC: 2020-04-21
• Study First Posted: 2020-04-22
• Study Start: 2020-07-22
• Status Verified: 2025-06
• Last Update Submitted: 2025-06-18
• Last Update Posted: 2025-06-24
• Primary Completion: 2026-06-30
• Study Completion: 2026-06-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 17

Inclusion Criteria

1. Severe sickle cell disease (HbSS, HbSC, HbSB0, HbSB+, HbSD, HbSE) with at least one of the following criteria:

   1. Cerebrovascular accident lasting longer than 24 hours
   2. Impaired neuropsychological function with abnormal brain MRI/MRA
   3. Patients with frequent (≥ 3 per year for preceding 2 years) painful vaso-occlusive episodes
   4. Recurrent (≥ 3 in lifetime) acute chest syndrome events which have necessitated erythrocyte transfusion therapy
   5. Any combination of ≥ 3 acute chest syndrome episodes and vaso-occlusive pain episodes yearly for 3 years and have failed treatment with hydroxyurea (HU) (at least 6 months on maximum tolerated dose) or who are intolerant to HU therapy

2. Thalassemia major with at least one of the following criteria:

   1. Transfusion dependency defined as receiving 8 or more transfusions per year
   2. Thalassemia diagnosis documented by clinical assessment, laboratory evidence with microcytic anemia and absence of HbA (< 10%) on electrophoresis and or confirmation by DNA analysis of alpha and beta gene loci
   3. Genotypically proven thalassemia major for children < 2 years of age even in the absence of transfusion dependency
   4. Lucarelli class 1 or 2 risk status (i.e. with only 0-2 of the following factors: hepatomegaly, portal fibrosis, or poor response to chelation therapy)

3. Bone marrow failure syndromes and autoimmune cytopenias:

   1. Severe Aplastic Anemia refractory to immunosuppressive therapy
   2. Diamond Blackfan Anemia refractory to conventional therapy
   3. Inherited Bone Marrow Failure Syndromes such as Fanconi anemia and Shwachman-Diamond syndrome with progressive marrow failure (without cytogenetic evidence of MDS/AML)
   4. Severe Congenital Neutropenia
   5. Congenital Amegakaryocytic Thrombocytopenia
   6. Glanzmann Thrombasthenia
   7. Autoimmune Cytopenias refractory to conventional treatment (including Pure red cell aplasia, Evan's syndrome, Immune thrombocytopenia, autoimmune hemolytic anemia)
   8. Other marrow failure disorders not otherwise specified

Inclusion Criteria:

1. Patient has a suitable genotypic identical match of 5/10. The donor and recipient must be identical, as determined by high resolution typing, at least one allele of each of the following genetic loci: HLA-A, HLA-B, HLA-C, HLA-DRB1 and HLA-DQB1.

2. Patients must have adequate organ function measured by:

   1. Cardiac: asymptomatic or if symptomatic then LVEF at rest must be ≥ 40% or SF ≥ 26%
   2. Pulmonary: asymptomatic or if symptomatic DLCO ≥ 40% of predicted (corrected for hemoglobin) or pulse oximetry ≥ 92% on room air if the patient is unable to perform pulmonary function testing.
   3. Renal: Creatinine clearance (CrCl) or glomerular filtration rate (GFR) must be > 50 mL/min/1.73 m2.
   4. Hepatic: Serum conjugated (direct) bilirubin < 2.0 x ULN for age as per local laboratory unless attributable to Gilbert's syndrome; AST and ALT < 5.0 x ULN for age as per local laboratory. Patients with hyperbilirubinemia as a consequence of hyperhemolysis, or a profound change in serum hemoglobin post blood transfusion, are not excluded.
   5. Karnofsky or Lansky (age-dependent) performance score ≥ 50

3. Signed written informed consent

Exclusion Criteria

1. Participants who have an HLA-matched sibling who is able and willing to donate bone marrow. Patients with a HLA-matched unrelated donors are not excluded.
2. Pregnant or breastfeeding females.
3. Patient has HIV or uncontrolled fungal, bacterial or viral infections.
4. Patient has received prior solid organ transplant.
5. Patient has active GVHD (> grade II) or chronic extensive GVHD due to a previous allograft at the time of inclusion.
6. For patients with hemoglobinopathy, liver biopsy is necessary if the patient has received chronic transfusions for over a year and has two ferritin levels of ≥ 1000 ng/ml. Patients with cirrhosis, extensive bridging hepatic fibrosis, or active hepatitis are excluded from enrollment.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
TCR alpha beta T cell depletion	Haploidentical Hematopoietic Cell Transplantation	The leukapheresis product will undergo TCR alpha beta negative selection following a standardized protocol

Primary Outcome Measures

Name	Time	Method
Incidence of successful donor engraftment	Day 100 after transplantation	The incidence of engraftment at day 100 will be described based on donor chimerism in the whole blood and or fractions sorted for T-cell and myeloid subsets. The donor chimerism will be scored as autologous reconstitution (\< 5% donor), mixed chimerism (5-49%=low mixed, 50-95%=high mixed), \> 95%=full donor chimerism.

Secondary Outcome Measures

Name	Time	Method
Overall survival and Event-free survival	Up to 2 years post transplant	Overall survival is defined as the time of enrollment to death from any cause or last follow up.; Event-free survival is defined as the time of enrollment to death, primary or secondary graft failure, graft failure necessitating a second HCT procedure, DLI or stem cell boost given for treatment of falling chimerism, or disease recurrence
Kinetics of neutrophil and platelet engraftment	Up to 42 days post transplant	Neutrophil engraftment defined as absolute neutrophil count ≥500/μL for 3 consecutive measurements on different days and platelet engraftment defined as sustained platelet count \>20,000/μL and \>50,000//μL with no platelet transfusions in the preceding seven days.
Transplant-related mortality	Up to 100 days post transplant	Rate of transplant-related mortality
Primary and secondary graft failure	Up to 2 years post transplant	Rates of primary and secondary graft failure
Transplant-related complications and infections	Up to 2 years post transplant	Frequency of transplant-related complications and rate of infections following transplantation
Cellular and Immunological reconstitution by laboratory evaluations	Up to 2 years post transplant	The recovery of different lymphocyte subpopulation (CD3+; CD4+; CD8+; CD3+CD45RA+and CD45RO; TCR alpha beta; TCR gamma delta; CD19+)
Acute grade II-IV GvHD and Chronic GvHD	Up to 2 years post transplant	Incidence and severity of acute and chronic graft versus host disease

Trial Locations

Locations (1)

Johns Hopkins All Children's Hospital; 🇺🇸 Saint Petersburg, Florida, United States