Allogeneic bone marrow transplantation following busulfan and 90 mg/kg of cyclophosphamide.

Ten patients with AML or CML aged 40-55 years underwent allogeneic marrow transplantation from HLA-identical siblings following a preparation regimen of busulfan 16 mg/kg and cyclophosphamide (CY) 90 mg/kg. The CY dose was substantially lower than has been previously used in combination with busulfan. All 10 individuals engrafted. Cytogenetic analysis of marrow and peripheral blood cells demonstrated similar patterns of chimerism to those previously described using higher CY doses. This study demonstrates that when administered with busulfan 16 mg/kg a dose of 90 mg/kg CY is adequately immunosuppressive to permit consistent engraftment of marrow from HLA-identical sibling donors.