Information
EAI045 EAI045 is an allosteric inhibitor that targets selected drug-resistant EGFR mutants but spares the wild-type receptor.
Targets
EGFR mutants
In vitro
EAI045 potently inhibits EGFR Y1173 phosphorylation in H1975 cells (half maximal effective concentration (EC50)=2nM), but not in HaCaT cells, a keratinocyte cell line with wild-type EGFR. Despite potent inhibition of mutant EGFR, EAI045 shows no anti-proliferative effect in the H1975 and H3255 cell lines with concentrations as high as 10μM. EAI045 inhibits L858R/T790M mutant with an IC50 of 3 nM. However, EAI045 is not able to completely abolish EGFR autophosphorylation in H1975 NSCLC cell line harboring the L858R/T790M mutant. Dimerization-defective/independent mutants are markedly more sensitive to EAI045. Since EGFR dimerization is required for kinase enzyme activation, EAI045 may be active against one subunit of an EGFR heterodimer/asymmetric dimer.
In vivo
Mouse pharmacokinetic studies with EAI045 reveals a maximal plasma concentration of 0.57μM, a half-life of 2.15 h, and oral bioavailability of 26% after dosing at 20mg/kg. When combined with cetuximab that blocks EGFR dimerization, EAI045 markedly reduces tumor growth in a mouse model of L858R/T790M-mutant-driven lung cancer. The mice treated alone with EAI045 do not respond. EAI045 in combination with cetuximab also induces marked tumor shrinkage in the mouse model carrying L858R/T790M/C797S, a mutant known to be resistant to all third-generation EGFR TKIs. EAI045 and cetuximab exhibits mechanistic synergy.
Cell Research(from reference)
Cell lines：H1975, H3255 and HaCaT cell lines
Concentrations：Serial dilution (0-100 μM)
Incubation Time：3 days
