Tofacitinib HCl

Tofacitinib HCl, also known as tasocitinib, CP-690550, is a Janus kinase (JAK) inhibitor. Tofacitinib HCl modulates the signaling pathway at the point of JAKs, preventing the phosphorylation and activation of STATs. JAK enzymes transmit cytokine signaling through pairing of JAKs (e.g., JAK1/JAK3, JAK1/JAK2, JAK1/TyK2, JAK2/JAK2) . Tofacitinib HCl inhibited the in vitro activities of JAK1/JAK2, JAK1/JAK3, and JAK2/JAK2 combinations with IC50 of 406, 56, and 1377 nM, respectively.