Objective
1.1.1 Demonstrate sustained engraftment after T cell replete HLA-mismatched haploidentical bone marrow stem cell transplantation and post- transplant cyclophosphamide in patients with severe aplastic anemia using fludarabine, Cytoxan and total body irradiation as a conditioning regimen.
Treatment
Study design:
Days ?6 ?2 Fludarabine 30 mg/M2 IV qd x 5 days (day -6 to -2)
Day ?6 -5 Cyclophosphamide 14.5 mg/kg/day IV x 2 dose (day -6 and -5)
Day -1 Total Body Irradiation 300 cGy x 1 dose
Day 0 Infuse mobilized Bone Marrow Stem Cells
(Begin antibiotic prophylaxis)
Days 3, 4 Cyclophosphamide 50 mg/kg IV q d
(hydration/Mesna)
(First dose of Cyclophosphamide must be administered 48-72 hr after infusion of
PBSCs)
Day 5 Begin G-CSF until ANC>1000x3 consecutive days
Begin Tacrolimus (target plasma level 5-15)
Begin MMF 15 mg/kg po tid with maximum daily dose 3 gm/d
Day 35 Discontinue MMF
Day 180 Discontinue Tacrolimus
Description
Severe aplastic anemia is a rare and serious form of bone marrow failure related to an immune mediated mechanism that results in severe pancytopenia and a high risk for infections and bleeding. Allogeneic bone marrow transplantation is currently the therapy of choice for young adults with SAA who have matched sibling donors with 80%-90% chance of survival and lower risk of complications long term1.
A trial of upfront matched unrelated transplants among SAA patients found survival rates similar to that seen among recipients of matched related donor. The limitation to using unrelated donors in the upfront is the time needed to identify a donor, leaving patients at high risk of infections and bleeding. Almost all patients will have a haploidentical family member readily available and using such a donor in the upfront setting will help save time, and decrease the risk of prolonged cytopenias.
Key Eligibility
Select Inclusion Criteria Recipient:
?No available matched related donor
?Availability of a 3/6 ? 5/6 matched (HLA-A, B, DR) related donor
?Donor must have negative HLA cross-match in the host vs. graft direction
?Age ≤65 years for previously untreated and ≤ 75 for previously treated aplastic anemia
?Karnofsky ≥70
?Aplastic Anemia as outlined by accepted criteria. These criteria are:
Peripheral Blood: (must fulfill 2/3)
?< 500 PMN/mm3
? < 20,000 platelets
?Anemia with a absolute reticulocyte count < 40,000/micro
Bone Marrow (must be either)
?markedly hypocellular <25% of normal cellularity
?moderately hypocellular with >70% non-myeloid precursors and the patient meets the peripheral blood criteria above