Tofacitinib, an Oral Janus Kinase Inhibitor, in Active Ulcerative Colitis

Ulcerative colitis is a chronic inflammatory disease of the colon for which current treatments are not universally effective. One additional treatment may be tofacitinib (CP-690,550), an oral inhibitor of Janus kinases 1, 2, and 3 with in vitro functional specificity for kinases 1 and 3 over kinase 2, which is expected to block signaling involving gamma chain-containing cytokines including interleukins 2, 4, 7, 9, 15, and 21. These cytokines are integral to lymphocyte activation, function, and proliferation.

In a double-blind, placebo-controlled, phase 2 trial, we evaluated the efficacy of tofacitinib in 194 adults with moderately to severely active ulcerative colitis. Patients were randomly assigned to receive tofacitinib at a dose of 0.5 mg, 3 mg, 10 mg, or 15 mg or placebo twice daily for 8 weeks. The primary outcome was a clinical response at 8 weeks, defined as an absolute decrease from baseline in the score on the Mayo scoring system for assessment of ulcerative colitis activity (possible score, 0 to 12, with higher scores indicating more severe disease) of 3 or more and a relative decrease from baseline of 30% or more with an accompanying decrease in the rectal bleeding subscore of 1 point or more or an absolute rectal bleeding subscore of 0 or 1.