Design,Synthesis And Biological Evaluation Of EGFR/HER2 Dual-Target Inhibitors

Lung cancer is one of the malignant diseases with high mortality.According to the latest data released by the National Cancer Center in 2022,the mortality rate of lung cancer in China ranks first.85%of lung cancer patients are non-small cell lung cancer（NSCLC）.The epidermal growth factor receptor（EGFR）gene is an important oncogenic gene of NSCLC.Therefore,pharmaceutical chemists believe that drugs targeting EGFR can be used to treat NSCLC.EGFR tyrosine kinase inhibitors（EGFR TKIs）have been developed for four generations.EGFR TKIs have greatly saved the lives of NSCLC patients,but with the progress of treatment,most pa-tients will develop resistance to EGFR TKIs.The resistance mechanisms of EGFR TKIs include EGFR target-dependent resistance（such as EGFR T790M and EGFR C797X）and EGFR tar-get-independent resistance（such as MET amplification and HER2 amplification）.HER2 and EGFR are highly homologous,but the strong repulsive force between HER2 makes them more likely to exist in the form of heterodimers.The heterodimer involved in HER2 has higher sta-bility and is easier to activate the downstream signal pathway.Based on this,it is believed that EGFR/HER2 dual-target inhibitors can overcome EGFR TKIs resistance caused by HER2 over-expression.In this paper,quinazoline was used as the scaffold and the existing EGFR TKIs compound ZY in our laboratory was used as the starting point.Three series of 21 compounds were de-signed and synthesized.The structures of the compounds were confirmed by HRMS,¹H NMR,and ¹³C NMR.SeriesⅠcompounds were designed to explore the effects of different hydropho-bic substituents on the anti-HER2 activity of the compounds.Based on seriesⅠcompounds,SeriesⅡcompounds studied the effect of the distance between quinazoline scaffold and cova-lent warhead on the anti-HER2 activity of compounds,and SeriesⅢcompounds studied the effect of different covalent warheads on the anti-HER2 activity of compounds.In this paper,the inhibition rates of EGFR and HER2 kinase were tested at 200 nM.Ac-cording to the kinase inhibition rate,some compounds were selected to test their kinase IC₅₀and cell GI₅₀.The results of the kinase inhibition rates showed that the anti-HER2 activity of the five compounds was better than that of the starting compound ZY and the anti-EGFR ac-tivity of the five compounds was equivalent to that of compound ZY.Compound ZY,the kinase inhibition rates were EGFR:96.4%±3.2%,HER2:53.4%±2.2%;The hydrophobic group of compoundⅠ-12 was 1-methylindole,and the kinase inhibition rates were EGFR:103.6%±7.9%,HER2:81.2%±8.4%;CompoundⅡ-1 was obtained by limiting the conformation of the piper-azine ring.The kinase inhibition rates were EGFR:102.3%±7.1%,and HER2:95.8%±7.1%;After removing the piperazine ring,compoundⅡ-2 was obtained.The kinase inhibition rates were EGFR:104.2%±4.7%,HER2:71.5%±8.7%;CompoundⅢ-3 was obtained by introduc-ing-CF3 substituent into the covalent warhead.The kinase inhibition rates were EGFR:101.4%±7.0%,HER2:82.7%±3.4%;CompoundⅢ-4 was obtained by using propionyl as the cova-lent warhead.The inhibition rates were EGFR:95.4%±0.8%,HER2:94.0%±1.9%.Based on the results of kinase inhibition rates,the kinase IC₅₀ and cell GI₅₀ of the above five compounds were further determined,and the activity of compoundⅡ-1 was the best(EGFR IC₅₀=0.30nM;HER2 IC₅₀=6.07 nM;NCI-H358 GI₅₀=23.30 nM;PC-9 GI₅₀=1.95 nM;Calu-3 GI₅₀=23.13 nM;NCI-H1781 GI₅₀=41.61 nM).From the above data,it can be seen that changing hydrophobic substituents（SeriesⅠ）has a limited effect on the anti-HER2 activity of the com-pounds,but 1-methylindole has certain advantages in binding with HER2;Changing the space distance between the covalent warhead and the scaffold（SeriesⅡ）and changing the covalent warhead（SeriesⅢ）have a great impact on the anti-HER2 activity of the compounds.In this paper,the structure-activity relationship of quinazoline EGFR/HER2 dual-target inhibitors was described,and compoundⅡ-1 with in-depth research value was selected.