Tacrolimus and Methotrexate for the Prophylaxis of Graft-Versus-Host Disease After Unrelated Donor Cord Blood Transplantation for Adult Patients With Hematologic Malignancies

Eighteen patients with hematologic malignancies underwent cord blood transplantation (CBT) from unrelated donors after being conditioned with myeloablative or reduced-intensity regimens, and received tacrolimus and methotrexate (15 mg/m² on day 1, 10 mg/m² on days 3 and 6) as graft-versus-host disease (GVHD) prophylaxis. The median number of nucleated cells in infused cord blood was 2.66 × 10⁷/kg (range 1.90 to 4.15 × 10⁷/kg). Engraftment was achieved in 16 of 18 patients. The median time to absolute neutrophil count >0.5 × 10⁹/L was 21.5 days (range 17 to 32), and the median time to platelet count >2.0 × 10⁹/L was 36 days (range 26 to 57). Of the 16 evaluable patients, five and eight had grades I and II acute GVHD, respectively, and none had grades III/IV acute GVHD. The cumulative incidence of grade II acute GVHD was 44.4%. Chronic GVHD occurred in 7 of 15 evaluable patients: limited type in three patients, extensive type in four patients. Of the 18 patients, 14 were alive and disease-free between 173 and 1514 days after CBT (median 746 days). The probability of disease-free survival at 2 years was 79.1%. These results, although in a retrospective study, suggested that tacrolimus and short-term methotrexate effectively prevented the occurrence of severe acute GVHD after unrelated CBT, and may contribute to a high survival rate.