Depleted Donor Stem Cell Transplant in Children and Adults With Fanconi Anemia After Being Conditioned With a Regimen Containing Briquilimab

TCRαβ+ T-cell/CD19+ B-cell Depleted Hematopoietic Grafts and a Reduced Intensity Preparative Conditioning Regimen Containing JSP191 (Briquilimab) to Achieve Engraftment and Blood Reconstitution in Patients With Fanconi Anemia

The objective of this clinical trial is to develop a cell therapy for Fanconi Anemia which enables enhanced donor hematopoietic and immune reconstitution with decreased toxicity by transplanting depleted stem cells from a donor with and without using an experimental antibody treatment called JSP-191 as a part of conditioning. This experimental treatment will hopefully cause fewer side effects than chemotherapy (the current standard of care method).

Participants will be administered the conditioning regimen, are assessed until they receive the depleted stem cell infusion, and will be followed for up to 2 years after the cell infusion.

Inclusion Criteria:

All patients must have:

1. Fanconi Anemia diagnosis as demonstrated by abnormal chromosome breakage studies with increased sensitivity to mitomycin-C (MMC) or diepoxybutane (DEB) and at least one mutation in a known Fanconi-associated gene

2. Bone marrow failure (defined by reduction in at least one cell line on two separate occasions at least one month apart (e.g., platelet count of <100,000 per cubic millimeter, hemoglobin <9 gm/dl and/or absolute neutrophil count (ANC) of <1000/mm)

3. Age of ≥2 years

4. Consenting ≥5/10 HLA-matched related or unrelated donor available for apheresis

5. Organ function defined as:

   1. Serum Creatinine <2.0 mg/dL and corrected creatinine clearance/cystatin cL >60 mL/min/1.73m^2 without dialysis
   2. Forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and diffusing capacity of the lung for carbon monoxide (DLCO) corrected for hemoglobin and volume, >50% predicted by pulmonary function tests (PFTs)
   3. For patients unable to cooperate for PFTs, criteria are no evidence of dyspnea at rest, no exercise intolerance, and no requirement for supplemental oxygen with spO2 >93%
   4. Shortening fraction of ≥29% or ejection fraction of ≥45% by echocardiogram
   5. Serum total bilirubin of <4 x ULN
   6. Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) < 5 x ULN
   7. Prothrombin time international normalized ratio (PT INR) and partial thromboplastin time (PTT) <1.5 x ULN

6. Life expectancy of at least 2 years

7. Patients of childbearing potential must be willing to use an effective contraceptive method for the duration of the peri-transplant conditioning through hematopoietic recovery

8. Patients and/or parents or legal guardians must be able to provide written informed consent and authorize use and disclosure of personal health information in accordance with Health Insurance Portability and Accountability Act

Exclusion Criteria:

1. Patients with available and consenting 10/10 HLA-identical sibling donor for apheresis
2. Patients with any acute or uncontrolled infections at the time of enrollment, including bacterial, fungal or viral
3. Patients who are seropositive for HIV-I/II or HTLV-I/II.
4. Patients receiving any other investigational agents or other biological, chemotherapy, or radiation therapy within 14 days of enrollment
5. Patients with any active malignancies, myelodysplastic syndrome or other concerns for high-risk bone marrow disease
6. Patients who received androgens in last 3 months
7. Pregnant or lactating women
8. Women who are nursing and do not wish to discontinue breastfeeding
9. Lansky/Karnofsky performance score <50%.
10. Any other medical condition or history that, in the opinion of the Principal Investigator, could pose a significant safety risk to the participant or jeopardize the integrity of the study
11. Patients who, in the opinion of the Principal Investigator, may not be able to comply with the safety monitoring requirements of the study