BU-CTX(2) as conditioning regimen for allogeneic hematopoietic stem cell transplantation in sixty patients with...

To evaluate the long-term outcome of 60 leukemia patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) prepared with busulphan-cyclophosphamide (BU-CTX(2)) conditioning regimen.

From April 1994 to August 2000, 60 leukemia patients (35 male, 25 female; median age 32 years old), including 20 acute myeloid leukemia (AML, CR(1) n = 19, CR(2) n = 1), 15 acute lymphocytic leukemia (ALL, CR(1) n = 8, CR(2) n = 6, CR(3) n = 1), and 25 chronic myeloid leukemia (CML, CP(1) n = 24, CP(2) n = 1) received allogeneic hematopoietic stem cells from HLA-identical siblings (n = 53), 1-locus mismatched siblings (n = 4), or HLA-identical unrelated donor (n = 3). BU-CTX(2) was used as conditioning regimen. All patients received cyclosporine A and either methotrexate (n = 54) or methylprednisolone (n = 6) for graft-versus-host disease (GVHD) prophylaxis.

All 60 patients got sustained engraftment. Acute GVHD (aGVHD) occurred in 22 patients (36.7%), while the incidence of aGVHD was 48.0% for the CML, 30.0% for the AML and 26.7% for the ALL patients. Thirty-eight patients are still alive in complete remission with a median follow-up of 30 (12 approximately 84) months and 22 died. The main causes of death were aGVHD in 3, CMV-IP in 7, and relapse in 11 patients. The remaining one died of pulmonary infection. Among 11 patients who died of relapse, 8 were ALL relapsed in the early posttransplant stage. All 4 long-term survivors of ALL developed chronic GVHD. The probability of DFS at 3 year for CML, AML and ALL patients was 80.0%, 70.0% and 26.7%, respectively.

BU-CTX(2) is an effective conditioning regimen for patients with AML and CML, resulting in a low relapse and high long-term survival rate. However, it is not effective enough for patients with ALL, because of a higher incidence of relapse.