Allogeneic hematopoietic stem cell transplantation with non-myeloablative conditioning in patients with acute myelogenous leukemia eligible for conventional allografting: a prospective study.

Using a non-myeloablative stem cell trasplantation (NST) program, 25 allografts were prospectively given to 24 patients with acute myelogenous leukemia (AML) eligible for conventional allografting; 2 individuals had secondary forms of AML. The median age of the patients was 35 years, with a range of 12 to 56. All patients engrafted; median time to achieve an absolute neutrophil count > 0.5 x 10(9)/1 was 12 days (range 0-26), whereas the median time to a platelet count > 20 x 10(9)/1 was 13 days (range 0-26). Patients developed mixed chimerism 15 to 100 (median 30) days after the allograft. The follow-up periods range between 33 and 2670 days (median 450). The median post-transplant overall survival of the patients has not been reached and is above 89 months, whereas the 683 days both overall and progression-free survival is 66%. In 14 grafts (56%) acute GVHD ensued; in 12 cases grades I-II and in 2 cases grade IV which was fatal in both. In 9/19 patients (47%) limited chronic GVHD developed. In 22 cases (88%), the procedure could be completed fully on an outpatient basis. The 100-day and the transplant-related mortality were both 8%. NST appears to be an effective additional therapeutic option for patients with AML in remission and a matched donor available.