TAS-121

TAS-121 is an orally active, selective, covalent, third-generation mutant EGFR-tyrosine kinase inhibitor (EGFR-TKI) . TAS-121 inhibits the L858R mutation (IC50=1.7 nM), Ex19del mutation (IC50=2.7 nM), L858R/T790M mutation (IC50=0.56 nM) and Ex19del/T790M mutation (IC50=1.1 nM) and wild-type EGFR (IC50=8.2 nM) . TAS-121 inhibits HER2 and HER4 with IC50s of 110 and 2.6 nM, respectively. TAS-121 inhibits phosphorylation of EGFR and its downstream signaling targets to block cell proliferation. TAS-121 induces apoptosis and displays antitumor activity in SW48 (EGFR G719S) and NCI-H1975 (EGFR L858R/T790M) xenograft models[1].