FLT3/KIT/VEGFR2/PDGFRB inhibitor ETN101

An orally bioavailable inhibitor of the receptor tyrosine kinases (RTKs) FMS-like tyrosine kinase 3 (FLT3; CD135; STK1; FLK2), mast/stem cell factor receptor c-Kit (SCFR; KIT), vascular endothelial growth factor receptor type 2 (VEGFR2) and platelet-derived growth factor receptor beta (PDGFRB), with potential anti-angiogenic and antineoplastic activities. Upon oral administration, FLT3/KIT/VEGFR2/PDGFRB inhibitor ETN101 targets, binds to and inhibits the activity of FLT3, c-Kit, VEGFR2 and PDGFRB. This prevents FLT3, c-Kit, VEGFR2 and PDGFRB-mediated signaling and the activation of downstream signaling pathways. By inhibiting multiple RTKs, ETN101 may be able to inhibit angiogenesis and tumor cell invasion, normalize abnormal blood vessels, and reverse the immunosuppressive state of the tumor microenvironment (TME). This may halt tumor cell proliferation in susceptible tumor cells. FLT3, c-Kit, VEGFR2, and PDGFRB are upregulated in a variety of cancer cell types and play key roles in tumor cell proliferation, angiogenesis, and metastasis.