Discovery of Highly Potent and Selective EZH2 Covalent Inhibitors via Incorporating Basic Amines

Targeted covalent inhibition is a promising strategy to address the high dose and acquired drug resistance issues of the first-generation EZH2 noncovalent inhibitors. Recently we have reported a new generation of highly potent EZH2 covalent inhibitors, but further optimization to enhance aqueous solubility is required. Here, we described the systematic optimization of <b>EPZ-6438</b> by preserving the aqueous groups, resulting in the identification of a highly potent and selective EZH2 covalent inhibitor <b>13</b>, which displayed nanomolar potency in biochemical and cellular assays. Moreover, SAM competition experiments preliminarily confirmed that <b>13</b> was noncompetitive with SAM, leading to the remarkable reduction of the H3K27Me3 marker. In addition, <b>13</b> exhibited superior cell growth inhibition in the EZH2 mutant cancer cell lines. The discovery of <b>13</b> holds promise for the development of highly potent EZH2 covalent inhibitors.