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Updated: Nov 20, 2025

Covalent Fragment Screening Using the Quantitative Irreversible Tethering Assay
Published on: February 28, 2025
Targeting Cysteine Located Outside the Active Site: An Effective Strategy for Covalent ALKi Design
Guoyi Yan1,2, Xinxin Zhong1, Chunlan Pu1
1State Key Laboratory of Biotherapy, Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital of Sichuan University, Chengdu, 610041, China.
Abstract:
Potent inhibitors of ALK are highly desired because of the occurrence of drug resistance. We herein firstly report the development of a rationally designed inhibitor, Con B-1, which can covalently bind to Cys1259, a cysteine located outside the ALK active site by linking a warhead with Ceritinib through a 2,2'-Oxybis(ethylamine) linker. The in vitro and in vivo assays showed ConB-1 is a potent selective ALKi with low toxicity to normal cells. In addition, the molecule showed significant improvement of anticancer activities and potential antidrug resistant activity compared with Ceritinib, demonstrating the covalent inhibitor of ALK can be a promising drug candidate for the treatment of NSCLC. This work may provide a novel perspective on the design of covalent inhibitors.
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