[Improved clinical outcome of acute myeloid leukemia with FLT3-ITD mutation treated with sorafenib].

Objective: To analyze the efficacy of sorafenib on the treatment of patients diagnosed as acute myeloid leukemia(AML) with FLT3-ITD mutation.

Methods: From January 2012 to February 2015, 42 cases of AML with FLT3-ITD mutation according to MICM (morphology, immunology, cytogenetics and molecular) diagnosis system in our hospital were retrospectively analyzed. Thirty-two cases were refractory to chemotherapy or relapsed, who were treated with sorafenib or combined with chemotherapy. Ten patients relapsed after allogeneic hematopoietic stem cell transplantation (allo-HSCT), who were retreated with sorafenib or combined with donor lymphocyte infusion (DLI) or chemotherapy. In the first group, 13 of 32 patients accepted allo-HSCT.

Results: The overall response rate of all 42 patients was 73.8%, including 4 (9.5%) complete molecular remission (CMR), 9 (21.4%) complete remission (CR), 8 (19%) complete remission with incomplete hematologic recovery (CRi), 10 (23.8%) partial remission (PR), and 11 (26.2%) none remission (NR). The response rate of sorafenib alone for 17 patients was 70.6%, and that of sorafenib plus chemotherapy was 66.7% (P=0.555). Thirteen patients who received allo-HSCT included 6 CMR/CR/CRi, 4 PR, and 3 NR before transplant. The 2-year overall survival (OS) rate and progress free survival (PFS) rate in all patients were 36.9% and 28.7%, and the corresponding median time were 18 months and 9 months respectively. The 2-year OS rate in 23 patients who received sorafenib combined with allo-HSCT was superior to that in 19 patients not receiving allo-HSCT (45.5% vs 23.9%, P=0.041), so was PFS rate (44.0% vs 9.7%, P=0.014). Twelve cases died of disease progression, four of infection, and one of chronic graft versus host disease after transplant.

Conclusions: Sorafenib combined with chemotherapy improves response rate of AML patients with FLT3-ITD mutation. Those who are treated with sorafenib plus allo-HSCT obtain better long-term survival.