HPB-143

HPB-143 is a phase 1-ready, orally bioavailable proteolysis-targeting chimera (PROTAC) designed to selectively degrade interleukin-1 receptor-associated kinase 4 (IRAK4), a key mediator in innate immune signaling and inflammation. By harnessing the cell’s ubiquitin-proteasome system, HPB-143 targets IRAK4 for degradation rather than simple inhibition, offering enhanced specificity and efficacy compared to traditional small-molecule inhibitors. Preclinical studies have demonstrated its efficacy in multiple models of autoimmune and inflammatory diseases—including atopic dermatitis—and superior oral bioavailability (49% in mice) with an excellent safety profile. The drug was originally developed by Hangzhou Polymed Biopharmaceuticals and has been outlicensed to Photys Therapeutics for global development outside greater China and Southeast Asia[1][3][5][6].