SI-109

SI-109 is a potent STAT3 SH2 domain inhibitor (Ki=9 nM) with antitumor activity. SI-109 effectively inhibits the transcriptional activity of STAT3 (IC50=3 μM). SI-109 and an analog of CRBN ligand lenalidomide have been used to design PROTAC STAT3 degrader SD-36[1].