Discovery of High-Affinity SMARCA2/4 Bromodomain Ligands and Development of Potent and Exceptionally Selective SMARCA2 PROTAC Degraders

In the SWI/SNF chromatin-remodeling complex, the mutually exclusive catalytic ATPase subunits SMARCA2 and SMARCA4 proteins have a synthetic-lethal relationship. Selectively targeting SMARCA2 for degradation is a promising and new therapeutic strategy for human cancers harboring inactivated mutated SMARCA4. In this study, we report the design, synthesis, and biological evaluation of novel SMARCA2/4 ligands and our subsequent design of PROTAC degraders using high-affinity SMARCA ligands and VHL-1 ligands. Our efforts led to the discovery of high-affinity SMARCA2/4 bromodomain ligands and the development of a potent and selective SMARCA2 degrader and a highly potent SMARCA2/4 and PBRM1 degrader.