Allogeneic hematopoietic stem cell transplantation using reduced intensity conditioning regimen for patients with acute myeloid leukemia not in complete remission.

Abstract

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only potentially curative treatment option for patients with refractory and relapsed acute myeloid leukemia (R/R AML) not in complete remission. Many studies investigating the prognosis of patients with R/R AML not in remission focused on patients who received myeloablative conditioning regimen (MAC). Conversely, reduced intensity conditioning regimen (RIC) could be a considerable conditioning regimen for some patients because of the high frequency of R/R AML in older patients who are not candidates for MAC. This study aimed to evaluate the prognosis and identify factors associated with outcomes in patients with R/R AML who underwent allogeneic HSCT with RIC. This study included 707 adult patients with AML not in complete remission who had received RIC. The primary endpoint was progression-free survival (PFS), which was estimated using the Kaplan-Meier method. Prognostic factors were identified using a Cox proportional hazards model with multiple imputations using a chained equation approach. The 5-year PFS, overall survival, relapse, and nonrelapse mortality were 18.8% (95% confidence interval [CI]: 15.6-22.2), 22.0% (95% CI: 8.5-25.7), 53.6% (95% CI 49.7-57.4%) and 27.5% (95% CI: 24.0-31.2), respectively. Multivariable analysis revealed that male sex, poor performance status, karyotype risk, and blasts in the peripheral blood were significantly associated with PFS. This study identified prognostic factors in patients with R/R AML not in complete remission. These results can help to develop a transplant strategy for the treatment of R/R AML.