In a single-center study of consecutive adults with FLT3 - internal tandem duplication (ITD) acute myeloid leukemia (AML), 29 patients transplanted in first complete remission (CR1) who received the tyrosine kinase inhibitor sorafenib post-transplant had significantly better outcomes than 55 patients in a control cohort. Patients were transplanted between 2008 and 2014 at the Dana-Farber Cancer Institute and the median time to initiation of sorafenib was 68 days post-HCT.
Patients receiving post-transplant maintenance with sorafenib had improved 2-year overall survival (OS) compared to controls: 81% vs. 62%, respectively; (p=0.029). Sorafenib was significantly associated with improved 2-year progression-free survival (PFS) compared to controls: 82% vs. 53%, respectively; (p=0.0081). In multivariate analysis, sorafenib significantly improved OS [Hazard ratio (HR) 0.26, p=0.021] and PFS [HR 0.25, p=0.016].
Sorafenib was significantly associated with lower 2-year cumulative incidence of relapse compared to controls: 8.2% vs. 37.7%, respectively; (p=0.0077). There was no difference in the sorafenib and control cohorts in 2-year non-relapse mortality (9.8% vs. 9.3%, respectively; p=0.82) or 1-year chronic GVHD (55.5% vs. 37.2%, respectively; p=0.28).
The researchers concluded that their results indicate a potential benefit of post-HCT sorafenib in FLT3-ITD AML, and support further evaluation of post-HCT FLT3 inhibition.