Treatment of FLT3-ITD-Positive Acute Myeloid Leukemia Relapsing after Allogeneic Stem Cell Transplantation with Sorafenib

Patients with acute myeloid leukemia (AML) and internal tandem duplication of FMS-like tyrosine kinase receptor-3 gene (FLT3-ITD) mutation have poor prognoses and are often treated with allogeneic hematopoietic stem cell transplantation (HSCT). Sorafenib, an inhibitor of multiple kinases including FLT3, has shown promising activity in FLT3-ITD-positive AML. We treated 16 patients with FLT3-ITD-positive AML who relapsed after HSCT with sorafenib alone (n = 8) or in combination with cytotoxic chemotherapy (n = 8). The number of circulating blasts decreased in 80% of cases, but none of the patients achieved complete remission (CR); 3 achieved partial remission. Two patients were bridged to a second transplantation but both relapsed within 3 months of the transplantation. Median overall survival (OS) was 83 days, with none surviving more than a year. Sorafenib is not effective in the treatment of FLT3-ITD-positive AML relapsing after HSCT. Preventive strategies after HSCT may be more suitable for these high-risk patients.