Fludarabine and melphalan conditioning with tacrolimus as GVHD prophylaxis for allogeneic stem cell transplant recipients is an effective reduced-intensity combination regimen compared to the conventional regimen.

Background: As a reduced-intensity stem-cell transplantation (RIST) regimen, the combination of fludarabine and melphalan (FM) with an appropriate immunosuppressant reduces nonrelapse mortality (NRM).

Methods: We retrospectively compared the efficacy of a RIST regimen with FM with that of a conventional stem cell transplantation (CST) regimen. Eighty-two consecutive hematological patients who underwent allogeneic stem-cell transplantation (SCT) at our hospital were enrolled. Preparation for RIST consisted of 25 mg/m(2) fludarabine and melphalan 70 mg/m(2). The conventional regimen employed high-dose cyclophosphamide and total-body irradiation (12 Gy) or busulfan and high-dose cyclophosphamide. Graft-versus-host disease (GVHD) prophylaxis for RIST consisted of tacrolimus alone or in conjunction with short-term methotrexate for unrelated donors.

Results: Of the 82 patients, 42 received the conventional CST regimen (median age, 35 years) and 40 received the RIST regimen (median age, 51 years). The probability of NRM was 17% (7/42) in the CST group and 8% (3/40) in the RIST group. Grade II to IV GVHD occurred in significantly more CST patients (38%) than RIST patients (28%). However, the overall survival was the same in the two groups (43%).

Conclusion: The RIST regimen with FM incorporating tacrolimus and methotrexate demonstrated low TRM incidence and moderate control of GVHD and had efficacy comparable to that of the CST regimen, despite the advanced age of the RIST patient group.