High-dose busulfan and melphalan before bone marrow transplantation for acute nonlymphoblastic leukemia

Fourteen patients with acute nonlymphoblastic leukemia (ANLL) (n = 13) or juvenile chronic myelomonocytic leukemia (n = 1) were transplanted after conditioning with high-dose busulfan (4 mg/kg daily on days -7 to -4) and melphalan (180 mg/m2 on day -2). This protocol was designed for patients considered unable to receive standard conditioning regimens with cyclophosphamide and/or TBI. Five patients (4 children and 1 adult) received a second allogeneic BMT in untreated early marrow relapse after a first BMT. There were 3 procedure-related deaths (PRD), 2 during aplasia and 1 from acute GVHD. Two patients survived the procedure; 1 relapsed at 6 months and 1 is alive at 43+ months. Nine subjects (8 children and 1 adult) received an autologous BMT, 7 in first and 2 in second complete remission (CR). Of the 7 patients grafted in first CR, there was 1 PRD, 2 relapses at 3 and 15 months, and four are alive at 38 to 82+ months. One patient grafted in second CR relapsed at 7 months and 1 is alive at 67+ months. Toxicities were mild or moderate in autologous BMT recipients, mainly affecting the gastrointestinal tract. In the allogeneic BMT group, there were more moderate to severe toxicities, including 3 cases of moderate-severe renal toxicity; no cases of such toxicity were seen in ABMT recipients. Two cases of HVOD occurred, 1 in each group. These results are encouraging, although the small patient group does not allow any firm conclusions.