KH103 is a highly potent, catalytically-driven glucocorticoid receptor (GR) PROTAC degrader, demonstrate excellent performance in passively preventing ligand-induced gene expression activation in the absence of partial agonistic transcriptional triggering and crosstalk inhibition. KH 103 efficiently degrades glucocorticoid receptor (GR) in vitro and in vivo. In HEK293 cells, KH-103 (1 µM) induced rapid and nearly complete GR degradation within one hour. This degradation was highly potent, with significant depletion observed at 10 nM and near-complete depletion at 100 nM. KH-103 demonstrated effective and reversible GR degradation across diverse in vitro models from multiple tissues and species.Mechanistically, KH-103 promoted GR nuclear translocation but did not activate GR-mediated gene transcription and exhibited no nonspecific transcriptional effects alone. Furthermore, KH-103 effectively blocked dexamethasone (DEX)-induced GR signaling, demonstrating greater potency than comparator inhibitors.Critically, KH-103 also effectively depleted GR protein in the mouse pituitary gland in vivo and modulated corticosterone levels, confirming pharmacological activity beyond cell-based systems.
