T cell-depleted unrelated donor bone marrow transplantation for acute myeloid leukemia

The outcome for 39 patients with. acute myeloid leukemia (AML) in remission who had CAMPATH 1M. T cell-depleted unrelated donor bone marrow transplant ations (BMTs) is described. Conditioning was mainly with cyclophosphamide ( 120 mg/kg) and total body irradiation (TBT) (14.4 Gy), but 5 patients recei ved busulfan in place of TBI and 200 mg/kg cyclophosphamide. All patients r eceived cyclosporin, and short-course methotrexate was given to recipients of mismatched grafts. The patient population was predominantly pediatric (m edian age, 10 years), but one third of the patients was aged 15 years or ab ove. Twenty-five patients were in second complete remission (CR2), and 14 h ad high-risk CR1 disease (primarily failed remission induction or anteceden t myelodysplastic syndrome, often with complex cytogenetic abnormalities). Both recipient and donor were cytomegalovirus seronegative in 15 of 37 case s (38%); 51% of patients were matched for HLA class I and II. Grade II to T V acute graft-versus-host disease (GVHD) occurred in 24% of patients; chron ic GVHD occurred in 5 of 31 evaluable patients (16%), 4 extensive and 1 lim ited. Relapse occurred in 5 cases (13%); 1 of these 5 patients survives, 24 months after a second unrelated donor transplantation. Two of these relaps es were associated with secondary graft failure (incidence rate, 5%). All p atients engrafted primarily. Severe viral infection was the major transplan t-associated complication, with 12 episodes in 9 patients, 5 of them lethal . Twenty-five patients survive at a median follow-up of 44 months (range, 2 -102 months), with estimated actuarial overall and disease-free survival ra tes at 44 months of 61% (SE 8%) and 57% (SE 8%), respectively. Nineteen pat ients are more than 2 years post-BMT and may be cured. The functional statu s of long-term survivors is excellent, with 19 of 21 patients who survive 6 months or more in full-time employment or full-time students. These encour aging results suggest that in patients lacking a sibling donor, unrelated d onor BMT for AML in remission achieves survival figures as good as or bette r than those reported on patients with autologous stem cell transplantation , and that T-cell depletion of grafts is associated with a low relapse rate and an excellent functional status. However, only a randomized study compa ring unrelated donor BMT and autografting will resolve which of these treat ment strategies is better for patients with AML.