Clofarabine followed by haploidentical stem cell transplant using fludarabine, busulfan, and total-body irradiation with post-transplant cyclophosphamide in non-remission AML.

Approximately 30-40% of patients with acute myeloid leukemia (AML) experience induction failures. In these patients who do not achieve remission with two cycles of standard induction therapies, the probability of achieving remission with subsequent inductions is very limited. Hematopoietic stem cell transplantation (HSCT) is the only curative option for these patients, but high relapse rate and transplant-related mortality often preclude them to proceed to transplant. Thus, AML not in remission at time of HSCT remains a huge unmet need in current HSCT practice, particularly if the patient does not have an HLA-matched donor identified by the time of two induction failures. We used clofarabine cytoreduction immediately followed by fludarabine (Flu) and busulfan (Bu) × 3 with total-body irradiation (TBI) conditioning (Flu/Bu3/TBI) for haploidentical peripheral blood stem cell transplant with post-transplant cyclophosphamide for two cases of refractory AML with a very high tumor burden at transplant and achieved complete remission by day + 30 in both cases.