Allogeneic bone marrow transplantation in juvenile myelomonocytic leukemia without total body irradiation

Allogeneic bone marrow transplantation (BMT) without a total body irradiation (TBI) conditioning regimen was investigated in children with juvenile myelomonocytic leukemia (JMML). Eight consecutive patients with JMML (n = 6) or monosomy 7 (n = 2) underwent BMT at a median age of 20 months. Donor source included fully matched related (n = 3), mismatched related (n = 2), or fully matched unrelated (n = 3). The conditioning regimen included busulfan, cyclophosphamide, and etoposide (VP16) (melphalan was substituted for VP16 in one patient). The first patient in the series underwent TBI. Graft-versus-host disease prophylaxis was with cyclosporin and methotrexate and in vivo T-cell depletion (Campath 1 g) for mismatched and unrelated transplants. Seven and two patients, respectively, received chemotherapy and splenectomy before BMT. At a median follow-up of 48 months after BMT, five patients remained in remission. The overall survival rate was 63% at 5 years. All deaths occurred in patients with refractory disease at the time of BMT. Allogeneic BMT without TBI appears to be effective therapy for JMML and avoids some of the potential late sequelae of TBI in preschool children.