Interleukin-1 receptor-associated kinase 4 (IRAK4) and Fms-like tyrosine kinase 3 (FLT3) (IRAK4/FLT3)

Interleukin-1 receptor-associated kinase 4 (IRAK4) and Fms-like tyrosine kinase 3 (FLT3) represent a synergistic dual-target profile primarily utilized in the treatment of hematologic malignancies such as acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) [1, 5]. FLT3 is a receptor tyrosine kinase frequently mutated in AML, driving constitutive cell proliferation, while IRAK4 is a central mediator of the toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) signaling pathways [5, 14]. Research indicates that IRAK4 signaling, particularly through the oncogenic long isoform (IRAK4-L) generated by spliceosome mutations, serves as a key survival mechanism and a bypass pathway for resistance to standard FLT3 inhibitors [1, 9]. Dual inhibitors like emavusertib (CA-4948) are designed to simultaneously block these pathways, effectively inhibiting NF-κB activation and inducing apoptosis in malignant cells [3, 4]. This approach is particularly relevant for patients with FLT3 mutations or spliceosome mutations (e.g., SF3B1, U2AF1), offering a strategy to overcome adaptive resistance and improve clinical outcomes in relapsed or refractory settings [2, 7]. Clinical development of these dual inhibitors has highlighted specific safety considerations, including the risk of rhabdomyolysis and myelosuppression [1, 13].

Other names

IRAK-4/FLT3Interleukin-1 receptor-associated kinase 4Fms-like tyrosine kinase 3CD135STK1FLK2NY-REN-64

Dual inhibition of IRAK4 and FLT3 kinases, which blocks both the toll-like receptor (TLR)/interleukin-1 receptor (IL-1R) innate immune signaling and the FLT3-mediated growth factor signaling pathways, leading to the suppression of NF-κB activation and induction of apoptosis in malignant cells [1, 3, 5].