Bone marrow transplantation for patients with Fanconi anemia: reduced doses of cyclophosphamide without irradiation as conditioning.

Fanconi anemia (FA), a rare autosomal recessive disease, frequently evolves to bone marrow failure and acute myeloid leukemia, and BMT is the treatment of choice for patients with FA. However, their exquisite hypersensitivity to DNA cross-linking agents is associated with severe complications and several investigators have been looking for the ideal preparatory regimen. We have been involved in a program of progressively decreasing doses of cyclophosphamide (CY) as conditioning therapy, in an attempt to identify the lowest dose of CY capable of maintaining the graft with minimum complications. Here, we describe our experience of allogeneic BMT offered to 16 patients with FA and an HLA-compatible sibling donor, conditioned with 100 mg/kg of CY. The actuarial survival is 88% at approximately 37 months. Mucositis >/= grade II was the most common complication (94%), followed by bacteremias (38%). Veno-occlusive disease and hemorrhagic cystitis did not occur. Sustained engraftment was obtained in 94% of patients, and acute and chronic GVHD was diagnosed in 13% and 7%, respectively. The lowest dose of CY for transplant in FA patients is yet to be determined, but further reductions seem possible.