EGFR-IN-2 is a non-covalent, orally available and mutation-selective EGFR inhibitor for the treatment of non-small cell lung cancer (NSCLC), with high selectivity for resistant single and double mutant T790M with IC50 = 27 nm to 33 nM, and low inhibitory activity for wild-type H292 (IC50 = 218 nM).

PC9 (del746–750):0.033 μM, PC9-ER (T790M/del746–750):0.008 μM, H1975 (T790M/L858R):0.027 μM

EGFR-IN-2 (Compound 21) demonstrated excellent inhibitory activity in various EGFR-mutant NSCLC cell lines. Inhibition of EGFR autophosphorylation was evaluated in H1975 (T790M/L858R), PC9-ER (T790M/del746–750), and PC9 (del746–750) cell lines, with IC₅₀ values of 0.027 μM, 0.008 μM, and 0.033 μM respectively. In a kinase panel of 225 kinases, only 12 were inhibited >70% at 0.1 μM, demonstrating high target specificity. EGFR-IN-2 exhibited low clearance in human liver microsomes and hepatocytes (3.8 and 2.7 mL/min/kg, respectively), and good predicted oral bioavailability [1].

In a H1975 xenograft mouse model, EGFR-IN-2 was evaluated for in vivo target engagement and pharmacokinetics. After oral administration at 50 mg/kg, free plasma concentrations remained above the in vitro IC₅₀ (0.027 μM) for up to 8 hours; at 100 mg/kg, this duration extended to 16 hours. Corresponding suppression of phosphorylated EGFR, ERK1/2, and AKT confirmed effective target inhibition in vivo. The EGFR-IN-2 exhibited moderate plasma clearance in mice (104 mL/min/kg) with 19% oral bioavailability, and in dogs, clearance was 13 mL/min/kg with 30% bioavailability[1].