Overcoming EGFR(T790M) and EGFR(C797S) resistance with mutant-selective allosteric inhibitors.
Overcoming EGFR(T790M) and EGFR(C797S) resistance with mutant-selective allosteric inhibitors.
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DOI：
10.1038/nature17960
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发表时间：
2016-06-02
期刊：
影响因子：
64.8
通讯作者：
Eck MJ
中科院分区：
文献类型：
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作者：
Jia Y;Yun CH;Park E;Ercan D;Manuia M;Juarez J;Xu C;Rhee K;Chen T;Zhang H;Palakurthi S;Jang J;Lelais G;DiDonato M;Bursulaya B;Michellys PY;Epple R;Marsilje TH;McNeill M;Lu W;Harris J;Bender S;Wong KK;Jänne PA;Eck MJ
EGFR酪氨酸激酶抑制剂（TKI）吉非替尼、厄洛替尼和阿法替尼已获批用于治疗携带EGFR激酶激活突变的非小细胞肺癌，但耐药迅速出现，最常见的原因是受体ATP位点内的继发性T790 M突变。最近开发的MUR选择性不可逆抑制剂对T790 M突变体具有高度活性，但其功效可能因C797的获得性突变而受损，C797是与其形成关键共价键的半胱氨酸残基。目前所有EGFR TKI都靶向激酶的ATP位点，这突出了对具有替代作用机制的治疗药物的需求。在这里，我们描述了EAI 045的合理发现，EAI 045是一种变构抑制剂，靶向选定的耐药EGFR突变体，但不影响野生型受体。晶体结构显示，该化合物结合通过置换激酶非活性构象中的调节C-螺旋而产生的变构位点。该化合物在生物化学测定中以低纳摩尔效力抑制L 858 R/T790 M突变型EGFR，但作为单一药物不能有效阻断EGFR驱动的细胞增殖，这是由于对二聚体受体的两个亚基的效力不同，这两个亚基在活性状态下以不对称方式相互作用。我们观察到EAI 045与西妥昔单抗的显著协同作用，西妥昔单抗是一种阻断EGFR二聚化的抗体治疗剂，使激酶均匀地对变构剂敏感。EAI 045与西妥昔单抗联合治疗对L 858 R/T790 M EGFR和L 858 R/T790 M/C797 S EGFR（一种对所有目前可用的EGFR TKI具有抗性的突变体）驱动的肺癌小鼠模型有效。更一般地说，我们的研究结果说明了有目的地靶向变构位点以获得多能选择性抑制剂的效用。
EGFR tyrosine kinase inhibitors (TKIs) gefitinib, erlotinib and afatinib are approved treatments for non-small cell lung cancers harboring activating mutations in the EGFR kinase, but resistance arises rapidly, most frequently due to the secondary T790M mutation within the ATP-site of the receptor. Recently developed mutant-selective irreversible inhibitors are highly active against the T790M mutant, but their efficacy can be compromised by acquired mutation of C797, the cysteine residue with which they form a key covalent bond. All current EGFR TKIs target the ATP-site of the kinase, highlighting the need for therapeutic agents with alternate mechanisms of action. Here we describe rational discovery of EAI045, an allosteric inhibitor that targets selected drug-resistant EGFR mutants but spares the wild type receptor. A crystal structure shows that the compound binds an allosteric site created by the displacement of the regulatory C-helix in an inactive conformation of the kinase. The compound inhibits L858R/T790M-mutant EGFR with low-nanomolar potency in biochemical assays, but as a single agent is not effective in blocking EGFR-driven proliferation in cells due to differential potency on the two subunits of the dimeric receptor, which interact in an asymmetric manner in the active state. We observe dramatic synergy of EAI045 with cetuximab, an antibody therapeutic that blocks EGFR dimerization, rendering the kinase uniformly susceptible to the allosteric agent. EAI045 in combination with cetuximab is effective in mouse models of lung cancer driven by L858R/T790M EGFR and by L858R/T790M/C797S EGFR, a mutant that is resistant to all currently available EGFR TKIs. More generally, our findings illustrate the utility of purposefully targeting allosteric sites to obtain mutant-selective inhibitors.