Allogeneic bone marrow transplantation from partially mismatched related donors as therapy for primary induction failure acute myeloid leukemia

The outcome of acute myeloid leukemia patients with primary refractoriness to conventional chemotherapy is extremely poor. Allogeneic bone marrow transplants with matched sibling or matched unrelated donors provide 10-20% disease-free survival in this setting. We analyzed our transplant experience using readily available partially mismatched related donor (PMRD) in patients with primary induction failure (PIF) AML. Between March 1994 and December 1998, 13 patients with PIF AML were transplanted from 0-3 HLA antigen mismatched donors. All 12 evaluable patients engrafted at a median of day +16. Ten (77%) patients survived at least 100 days after transplant. Acute GVHD (grade II) was observed in one of 12 patients. Chronic GVHD was seen in one of 10 patients surviving beyond day 100. The major cause of failure was relapse of disease in six occurring 3-12 months after PMRD BMT. Three patients are alive without disease 14, 36 and 45 months post BMT with Karnofsky scores of 100%. The actuarial 3-year probabilities of relapse and disease-free survival were 0.54 and 0.19, respectively. We concluded that a PMRD graft is a viable option, comparable to the use of matched related or unrelated donors, in patients with PIF AML in whom time is of the essence.