Thal-Fabs: Reduced Toxicity Conditioning for High Risk Thalassemia

NCT ID: NCT05426252

Last Updated: 2023-12-19

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE1/PHASE2
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-03-22
• Study Completion Date: 2026-12-31

Brief Summary

The purpose of this study is to evaluate a novel transplant strategy for the long-term benefit of patients with transfusion dependent high-risk thalassemia.

Detailed Description

Patients with high-risk thalassemia meeting the eligibility criteria for this study will be entered sequentially until completion or closure of the study.

The hypothesis is that a reduced-toxicity conditioning regimen combined with pre-transplant immunosuppression, followed by abatacept and sirolimus as graft-versus-host disease (GVHD) prophylaxis for allogeneic transplant with either Human Leukocyte Antigen (HLA)-matched sibling donors or haploidentical donors is feasible and safe and can be delivered with less toxicity, durable donor engraftment, and minimal GVHD.

Conditions

Thalassemia in Children

Keywords

thalassemia; reduced toxicity; abatacept; sirolimus; pre transplant immunosuppression

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

PTIS followed by abatacept and sirolimus

Administration of reduced-toxicity conditioning regimen combined with pre-transplant immunosuppression, followed by abatacept and sirolimus as graft-versus-host disease (GVHD) prophylaxis for allogeneic transplant with either Human Leukocyte Antigen (HLA)-matched sibling donors or haploidentical donors

Group Type: EXPERIMENTAL

Abatacept

Intervention Type: DRUG

Abatacept, co-stimulation blockade, to be given for GVHD prophylaxis in combination with sirolimus post allogeneic hematopoietic stem cell transplantation.

Sirolimus

Intervention Type: DRUG

Sirolimus, mTOR inhibitor, to be given for GVHD prophylaxis in combination with abatacept post allogeneic hematopoietic stem cell transplantation.

Interventions

Abatacept

Abatacept, co-stimulation blockade, to be given for GVHD prophylaxis in combination with sirolimus post allogeneic hematopoietic stem cell transplantation.

Intervention Type: DRUG

Sirolimus

Sirolimus, mTOR inhibitor, to be given for GVHD prophylaxis in combination with abatacept post allogeneic hematopoietic stem cell transplantation.

Intervention Type: DRUG

Other Intervention Names

Orencia; Rapamicin

Eligibility Criteria

Inclusion Criteria

1. Patients with a diagnosis of transfusion dependent beta or alpha thalassemia (3 or 4 gene deletion) between the age of 1-18 years.

2. Thalassemia genotype must be confirmed by molecular genetic testing.

3. Patients with thalassemia must have at least one of the high-risk features:

• Age >7 years
• Hepatomegaly (2 cm below costal margin)
• Inadequate iron chelation (liver iron content >7mg/g dry weight)
• Severe alloimmunization
• Unable to tolerate iron chelation

3. Patients must have had a complete evaluation of their iron status including measurement of serum ferritin, MRI of the heart and liver (within the previous 6 months prior to referral). Liver elastography (within the preceding 3 months) will be also obtained but not required.

4. Ability to take oral medication and be willing to adhere to the study regimen.

5. Patients who have a performance status of at least 70% Karnofsky or Lansky status prior to transplantation.

6. Patients who are acceptable candidates for marrow transplantation based on their pre-BMT evaluation.

7. Patients who have histocompatibility sibling or HLA haplo identical family member and have been medically approved as hematopoietic progenitor cell donors.

8. Patients who are not candidates for gene therapy.

9. Patients/legal guardians who sign informed consent for the protocol approved by the Research Ethical Board of the Hospital for Sick Children/University of Toronto.

Exclusion Criteria

1. Patients will not be excluded based on sex, race, or ethnic background.

2. Patients will be excluded if they demonstrate significant functional deficits in major organs, which could interfere with the outcome following bone marrow transplant, including:

• Cardiac: Evidence of significant cardiac dysfunction (resting left ventricular ejection fraction of < 50% with absence of improvement with exercise), marked cardiomegaly or uncontrollable hypertension.
• Renal: Evidence of > 50% reduction in expected creatinine clearance or GFR < 60mL/min/1.73m2
• Hepatic: Evidence of hepatic dysfunction evidenced by a serum direct (conjugate) bilirubin of > 2.5 mg/dl, or ALT > 5 times the upper limit of normal for age.
• Pulmonary: Evidence of focal or diffuse active infection or pneumonitis and the patient demonstrates a FEV1 < 50% or carbon monoxide diffusing capacity (DLCO) of < 50% predicted value (adjusted for hemoglobin). The patient should not require ventilation support.

3. Presence of donor specific antibody (DSA) with mean fluorescence intensity (MFI) greater than 3,000.

4. Previous stem cell transplant or gene therapy.

5. Presence of cardiomyopathy with a T2* < 10ms per Cardiac MRI.

6. Presence of significant liver iron deposition defined as liver iron content >15mg/g liver dry weight. If iron chelation were optimized and reassessment within 6 months shows a decrease of LIC to <15 with no evidence of cardiomyopathy, patient may still be considered for enrollment.

7. Active HIV, hepatitis B or hepatitis C disease.

8. Severe liver cirrhosis or bridging fibrosis on liver biopsy if previously done.

9. Prior or current malignancy or myeloproliferative or immunodeficiency disorder.

10. Evidence of active, deep seated, life-threatening infections despite therapy (e.g., certain fungal species, HIV, etc.).

11. Patients will be excluded if they are women of childbearing potential who are currently pregnant (b-HCG+) or who are not practicing adequate contraception.

12. Any condition that would preclude serial follow up.

13. Patients with a known life-threatening allergy to components of the pre transplant immunosuppression (fludarabine), conditioning (treosulfan, cyclophosphamide or anti-thymocyte globulin) or graft versus host prophylactic regimen (abatacept, sirolimus).

14. Any condition or diagnosis, that could in the opinion of the Principal Investigator or delegate interfere with the participant's ability to comply with study instructions, might confound the interpretation of the study results, or put the participant at risk

Donor Eligibility:

Donors will not be considered research subjects as the stem cell collection procedure is standard of care and will not be considered part of the research.

In order to be eligible to participate in this study, the donor must meet all of the following criteria:

1. May have thalassemia or sickle trait.

2. Will also consider ABO match and lack of donor specific anti-HLA antibodies.

3. Donors must be minimal of 15 kg weight and have completed routine donor evaluations as per our standard of care.

4. Donors must have signed (by patient or legal guardian) informed consent for the protocol approved by the Research Ethical Board of the Hospital for Sick Children/University of Toronto.

5. No evidence of transmissible diseases in compliance with the Health Canada CTO regulations

6. Not pregnant or lactating

7. Must not be allergic to granulocyte colony stimulating factor (G-CSF)

• Minimum Eligible Age: 1 Year
• Maximum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Thalassemia Foundation of Canada

UNKNOWN

Sponsor Role: collaborator

The Hospital for Sick Children

OTHER

Sponsor Role: lead

Responsible Party

Yogi Chopra

Staff Physician

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Yogi Chopra, MD

Role: PRINCIPAL_INVESTIGATOR

The Hospital for Sick Children

Locations

Yogi Chopra

Toronto, Ontario, Canada

Site Status: RECRUITING

Countries

Canada

Central Contacts

Yogi Chopra, MD

Role: CONTACT

Phone: +1 (416) 813-7654

Email: yogi.chopra@sickkids.ca

Erilda Kapllani

Role: CONTACT

Phone: +1 (416) 813-7654

Email: bmt.cra@sickkids.ca

Facility Contacts

Yogi Chopra

Role: primary

Erilda Kapllani

Role: backup

References

Raffa EH, Harris TM, Choed-Amphai C, Kirby-Allen M, Odame I, Ali M, Krueger J, Hermans KG, Tole S, Seelisch J, Klaassen RJ, Abbott L, Chopra YR, Wall DA, Chiang KY. Early Engraftment and Immune Kinetics Following Allogeneic Transplant Using a Novel Reduced-Toxicity Transplant Strategy in Children/Adolescents with High-Risk Transfusion-Dependent Thalassemia: Early Results of the ThalFAbS Trial. Transplant Cell Ther. 2025 Mar;31(3):180.e1-180.e12. doi: 10.1016/j.jtct.2024.12.016. Epub 2024 Dec 24.

Reference Type: DERIVED

PMID: 39722321 (View on PubMed)

Other Identifiers

1000075672

Identifier Type: -

Identifier Source: org_study_id