[Description]
EGFR-IN-2 is a a noncovalent, irreversible, mutant-selective second generation EGFR inhibitor. EGFR-IN-2 (Compound 21) inhibits EGFR autophosphorylation with IC50s of 0.027 μM, 0.009 μM ,0.033 μM , and 0.218 μM in double mutant TMLR cell line H1975, double mutant TMdel cell line PC9-ER, activating mutant del70% when tested at 0.1 μM, 61-fold over the TMLR Ki and 63-fold over the TMdel Ki)[1]. To examine its inhibitory effect on pEGFR levels in vivo, EGFR-IN-2 (Compound 21) is studied in a mouse H1975 (TMLR) xenograft model. After a single oral dose of 21 at 50 mg/kg, free plasma concentrations of EGFR-IN-2 at or exceeding the in vitro p-EGFR IC50 of 0.027 μM are sustained over 8 h. When administered at 100 mg/kg, the coverage of p-EGFR IC50 is extended to the last measured time point of 16 h postdose. Corresponding knockdown of p-EGFR and the downstream effectors pERK1/2 and AKT levels are observed at those time points, suggesting target engagement in vivo. In mouse, after intravenous and oral administration, the plasma clearance of EGFR-IN-2 is determined to be 104 mL/kg per min with a bioavailability of 19%. In dogs, the plasma clearance is 13 mL/kg per min with an oral bioavailability of 30%[1]. |