Allogeneic Hematopoietic Stem Cell Transplant for GATA2 Mutations

Description

Background:

Genetic and sporadic mutations on one allele of the GATA2 gene lead to a syndrome termed MonoMAC. MonoMAC is characterized by: 1) infections with Mycobacterium avium complex (MAC) and other opportunistic infections, 2) deficiency of monocytes, B-lymphocytes, and Natural Killer (NK) cells in the peripheral blood, and 3) progression to myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia (CMML), and acute myelogenous leukemia (AML), and 4) mutations on one allele of GATA2 in most participants. We propose to evaluate the efficacy and safety of allogeneic hematopoietic stem cell transplantation (HSCT) using different conditioning regimens from different donor sources in reconstituting normal hematopoiesis and reversing the disease phenotype in participants with mutations in GATA2, or the clinical syndrome of MonoMAC.

Objectives: Primary:

-To determine whether allogeneic hematopoietic stem cell transplant (HSCT) approach reconstitutes normal hematopoiesis and reverses the disease phenotype by one year posttransplant in participants with mutations in GATA2 or the clinical syndrome of MonoMAC.

Eligibility:

* Recipients ages 6-70 years old with mutations in GATA2 or the clinical syndrome of MonoMAC. Clinical history of at least one serious or disfiguring infection and GATA2 bone marrow immunodeficiency disorder with loss of one or more immune populations in the bone marrow including monocytes, Natural Killer (NK) cells, and B-lymphocytes, with or without additional cytopenias involving the red blood cell, neutrophil, or platelet compartment.
* Have a 10/10 or a 9/10 or an 8/10 HLA-matched related or unrelated donor (HLA -A, -B, -C, DRB1, DQB1 by high resolution typing) or a haploidentical related donor; unrelated donors are identified through the National Marrow Donor Program.

Design: Two Arms

* Participants with mutations in GATA2, or the clinical syndrome of MonoMAC, with a 10/10 (or 9/10 matched if the mismatch is at DQ) HLA-matched related or unrelated donor will receive a pre-transplant conditioning regimen consisting of fludarabine 40 mg/m2 IV once daily for 4 days on days -6, -5, -4, and -3, busulfan based on pharmacokinetic levels from test dose or real time pharmacokinetics (PKs) (3.2 mg/kg IV will be the default dose) once daily on days -6, -5, -4, and -3, and HSCT on day 0.
* Participants with mutations in GATA2, or the clinical syndrome of MonoMAC, with a 9/10 or an 8/10 HLA-matched related or unrelated donor (if the mismatch is not at DQ) or with a haploidentical related donor, will receive a pre-transplant conditioning regimen consisting of cyclophosphamide 14.5 mg/kg IV once daily for 2 days on days -6 and -5, busulfan based on pharmacokinetic levels from test dose or real time PKs ( 3.2 mg/kg IV will be the default dose) once daily on days -4, -3, (if poor or very poor risk clonal cytogenetic abnormalities are present, then three days of busulfan IV once daily on days -4, -3, and -2 will be given), fludarabine 30 mg/m2 IV once daily for 5 days on days -6 to -2, 200 cGy TBI on day -1, and HSCT on day 0.
* Post-transplant immunosuppression for GVHD prophylaxis for recipients of all groups will consist of cyclophosphamide 50 mg/kg IV once daily for 2 days on days +3 and +4, along with mycophenolate mofetil from day +5 to approximately day +35 and tacrolimus from day +5 to approximately day +180. If there is no evidence of graft-versus- host disease, tacrolimus will be stopped or tapered at approximately day +180.