Design,Synthesis And Biological Evaluation Of Irreversiblc EGFR Inhibitors For Overcoming Drug Resistance And The Synthesis Of Drug-Like Libraries

Cancer has baffled researchers over the years. Due to their multidimensional role in the progression of cancer, EGFR and its family members have emerged as attractive candidates for anti-cancer therapy. As is common therapy, challenges with respect to treatment resistance emerge over time. This situation is certainly true of EGFR inhibitor therapy. Clinical studies have demonstrated the occurrence of resistance to Gefitinib and the T790M mutation occurred in60%patients. Covalent EGFR irreversible inhibitors showed promising potential for the treatment of Gefitinib-resistant tumors.Based on the SAR studies of a series of EGFR inhibitors at the trials and ligand binding model in the literature, we designed and synthesized5series of4-anilinoquinazoline and3-cyano-4-anilinoquinoline derivatives, totally100compounds, either by introducing a fluorine atom on an original acrylamide (Series A, B, C and D) or characterizing a novel Cysteine reactive portion at the position6of the traditional scaffolds (Series E). Meanwhile, the general preparation for the100compounds was described in this thesis and all of them were identified by1H NMR、 HPLC-HRMS and m.p..Most of the synthesized compounds potently inhibited the cell proliferation, including on the human epidermal carcinoma cell A431(with EGFR overexpression) and Gefitinib-resistant NSCLC cell H1975(bearing EGFR[L858R/T790M]). In Series A, some of the compounds displayed better potencies comparable to the reference Afatinib in the cell and kinase assay. Importantly, one advantage of our series is that compound TKI-100has excellent pharmacokinetic profiles and safety index. Further extensive druggability is undergoing and will be reported in due course.The introduction of a terminal basic group significantly improved the solubility, as expected in Series C and D. And the Z/E configuration would be the most key factor in these series. The biological evaluation results revealed that the Z configuration could be the favor one. And meanwhile, we characterized some other basic groups, of which N, N-dimethyl substitution would be the best one for the biological activity. Some of the compounds showed better potencies toward cell assay (A431cell line and Gefitinib-resistance NSCLC cell line H1975) and kinase assay (EGFRWT, EGFR[T790M] and HER2) comparable to the reference Afatinib. The excellent microsomal stability and pharmacokinetic profiles of the above compounds in mice clearly demonstrate its merit for further investigating a novel candidate for EGFR. Furthermore, the result of in vitro cardiac hERG activities showed that they could not block the hERG potassium channel and would be the candidate ones for further in vivo antitumor efficacy. Moreover, the in vivo antitumor efficacy study demonstrated that TKI-038and TKI-054siginificantly inhibited the tumor growth in a EGFR[L858R/T790M] driven human NSCLC xenograft nude model of H1975by orally dosing at30mg/kg/daily.Besides the traditional acrylamide, we focused on some other interesting covalent EGFR inhibitors, expecting to show promising potential for the treatment of Gefitinib-resistant tumors.2-oxazolidinones in principle could initiate a nucleophilic substitution from chemical propriety and may be considered as a cysteine-reactive warhead for irreversible inhibitor in cancer treatment. Promising results were observed in the cell proliferation assay of Series E. And the possible irreversible binding mode to EGFR was confirmed by a cell washout test in A431and flexible docking. Further extensive evaluation is undergoing.HTS of thousands of compounds is still the main source of drug discovery. During the Ph.D. Program in Zhejiang University, I developed7structurally diverse libraries with1200compounds via novel methodologies. Of them, three important libraries were discussed in detail. Further extensive biological evaluation is undergoing and will be reported in due course.