Degrading FLT3-ITD Protein by Proteolysis Targeting Chimera (PROTAC)

Abstract Clinical FLT3 mutations caused poor therapeutic benefits toward the present FLT3 inhibitors, and degradation of the FLT3 mutant protein may be a promising alternative approach to protect against acute myeloid leukemia (AML). Herein, we report the discovery of small molecule FLT3 degraders based on the proteolysis targeting chimera (PROTAC). FLT3 degraders were designed, synthesized, and evaluated for FLT3 degradation. Promising PF15 significantly inhibited the proliferation of FLT3-ITD-positive cells, induced FLT3 degradation and downregulated the phosphorylation of FLT3 and STAT5. An in vivo xenograft model and survival period evaluation verified the efficacy of PROTAC. These findings laid a robust foundation for FLT3-PROTAC molecules as an effective strategy for treating AML.