Semi-rigid linkers improve the pharmacokinetic properties and therapeutic efficacy of BET PROTACs for cancer therapy.

PROTACs offer a novel therapeutic strategy for addressing diseases driven by aberrant expression of pathogenic proteins. In this study, we identified a series of PROTAC molecules capable of degrading BRD2, BRD3, and BRD4. Structure-activity relationship analysis led to the discovery of CR10, a highly potent degrader that exhibited remarkable activity in MV4-11 cells. Mechanistic studies demonstrated that CR10 induced sustained degradation of target proteins via the ubiquitin-proteasome system. In mice models, intraperitoneal administration at 20 mg/kg achieved an exceptional bioavailability of 108.27%. Furthermore, CR10 significantly inhibited the growth of MV4-11 and A549 xenograft tumors at a dose as low as 2 mg/kg, without apparent toxicity. This semi-rigid linker-containing degrader represented a promising new mechanism-based candidate for the treatment of hematologic malignancies and lung cancer, warranting further investigation.