eCF506 is an inhibitor of Src kinases (IC50s = <0.5, 2.1, <0.5 nM for Src, Fyn, and Yes, respectively).1 It is selective for Src kinases over Abl (IC50 = 479 nM), as well as KIT, mTOR, PDGFRα, and RET (IC50s = >100 ?M for all). eCF506 completely inhibits phosphorylation of Src and FAK, a downstream Src substrate, in MCF-7 and MDA-MB-231 cells when used at a concentration of 100 nM. It also inhibits proliferation of MCF-7 cells (EC50 = 9 nM) and induces apoptosis. eCF506 (50 mg/kg per day) reduces levels of activated Src kinase in tumor tissue in an HCT116 mouse xenograft model.
1.Fraser, C., Dawson, J.C., Dowling, R., et al.Rapid discovery and structure-activity relationships of pyrazolopyrimidines that potently suppress breast cancer cell growth via SRC kinase inhibition with exceptional selectivity over ABL kinaseJ. Med. Chem.59(10)4697-4710(2016)