AS2863619

AS2863619 is a small molecule **cyclin-dependent kinase 8 (CDK8) and cyclin-dependent kinase 19 (CDK19) inhibitor**, developed for oral administration[1][3][5]. It selectively inhibits CDK8 (IC50 ≈ 0.61 nM) and CDK19 (IC50 ≈ 4.28 nM), disrupting the repressive phosphorylation of STAT5 at the serine-rich PSP motif, thereby **promoting activation of STAT5 via phosphorylation at a tyrosine residue in the C-terminal domain**[1][2][8]. This distinctive mechanism leads to strong upregulation of **Foxp3 expression and the induction and stabilization of Foxp3+ regulatory T cells (Tregs)** from antigen-stimulated effector/memory and naïve CD4+ and CD8+ T cells, independent of TGF-β[2][8]. In murine models, AS2863619 not only increased Treg differentiation but led to their epigenetic stabilization, producing functionally stable Tregs with immunosuppressive capacity, and conferred protection in mouse models of autoimmune and allergic diseases such as rheumatoid arthritis and encephalomyelitis[2][4][6][8][9]. The compound is primarily considered a **tool compound and research tool to study immune regulation and Treg biology**, with a current development status in the preclinical stage[5].

Other names

AS2863619AS-2863619AS 28636194-[1-(2-methyl-1-benzimidazol-5-yl)-1-imidazo[4,5-c]pyridin-2-yl]-1,2,5-oxadiazol-3-amine dihydrochlorideCAS 2241300-51-4CAS2241300-51-4CAS-2241300-51-4CAS 2241300-50-3CAS2241300-50-3CAS-2241300-50-3