Discovery and Preclinical Evaluations of Potent, Selective, and Allosteric Covalent WRN Inhibitors with Improved PK Properties

Werner syndrome helicase (WRN) has received significant interest due to its implication as a synthetic lethal target in microsatellite instability-high (MSI-H) cancers. Here we report the discovery of a novel allosteric covalent WRN inhibitor, compound <b>22</b>, via structure-based medicinal design and pharmacokinetic optimization from VVD-214. Compound <b>22</b> occupied a new cavity and formed an additional hydrogen bond with K894, thereby improving its activities. Compound <b>22</b> exhibited high antiproliferation inhibitory activity against HCT116, an MSI-H colorectal cancer cell line. It also demonstrated favorable preclinical pharmacokinetic properties with superior plasma stability and exposure compared with VVD-214. Furthermore, compound <b>22</b> showed statistically significant antitumor activity in the HCT116 xenograft mouse model with clear dose dependence.