BY13

BY13 is an SRC-3 PROTAC degrader with a DC50 of 0.031 μM. It selectively obstructs the ER signaling pathway by downregulating ERα levels, showing greater selectivity over the androgen receptor (AR). BY13 effectively addresses endocrine resistance in breast cancer by inducing cell cycle arrest at the G1 phase and triggering apoptosis. Additionally, it surpasses Fulvestrant in efficacy and significantly inhibits the growth of resistant breast tumors in LCC2 xenograft mouse models, exhibiting no noticeable toxicity.