New sequential treatment with chemotherapy and reduced-intensity conditioning for allogeneic stem-cell transplantation in very high-risk acute myeloid leukemia.

A new sequential regimen for allogeneic stem-cell transplantation, comprising cytoreductive chemotherapy immediately followed by reduced-intensity conditioning (RIC), was evaluated in 17 intensively treated patients with refractory or early relapsed acute myeloid leukemia (AML). Cytoreductive chemotherapy comprised thiotepa (3 x 200 mg/m 2 ), etoposide (3 x 200 mg/m 2 ) and six mercapto-purine (75 mg/m 2 for 14 days) followed 2 days later, by RIC consisting of busilvex, Fludarabine and antithymocyte globulin. For six patients, the donor was a sibling and for 11, unrelated. The results showed that the procedure was safe. There were seven transplant-related deaths, mainly due to acute graft-versus-host disease and/or severe infection. Complete remission was observed in 13 patients at post-transplant Day 30. With a median follow-up of 14 months, overall survival and relapse-free survival were 29.4 and 17.7%, respectively. These results indicate a degree of antileukemia activity, which could probably be improved.