Cord Blood Transplantation from Unrelated Donors in Adults with High-Risk Acute Myeloid Leukemia

Clinical studies focused on disease-specific outcomes of cord blood transplant (CBT) from unrelated donors are limited. We analyzed the outcome and prognostic factors of 49 adults with high-risk acute myelogenous leukemia (AML) receiving single-unit CBT from unrelated donors after myeloablative (MA) conditioning at a single institution. Conditioning regimens were based on the combination of thiotepa, busulfan (Bu), cyclophospamide (Cy), or fludarabine (Flu), and antithymocyte globulin (ATG). Cumulative incidence of myeloid and platelet engraftment was 96% and 73% at a median time of 20 and 62 days, respectively. Engraftment was significantly faster for patients receiving higher doses of CD34+ cells. Confidence Interval of graft-versus-host disease (GVHD), acute GVHD (aGVHD) grade II-IV, III-IV, and extensive chronic GVHD (cGVHD) were 26%, 15%, and 30%, respectively. Leukemia-free survival (LFS), nonrelapse mortality (NRM), and relapse at 2 years were 42%, 39%, and 19%, respectively. Low number of total nucleated cells (TNC) had a negative impact on NRM and LFS. Patients transplanted in first complete remission (CR1) receiving TNC above 2 × 107/kg had a 4-year LFS of 75%. These results show that CBT from unrelated donors is a curative treatment for a substantial number of patients with high-risk AML, particularly if transplant is performed with highly cellular units in patients in first CR.