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 the primary outcome clinical response at 8 weeks occurred in 32 48 61 and 78 of patients receiving tofacitinib at a dose of 0 5 mg p 0 39 3 mg p 0 55 10 mg p 0 10 and 15 mg p 0 001 respectively as compared with 42 of patients receiving placebo clinical remission defined as a mayo score 2 with no subscore 1 at 8 weeks occurred in 13 33 48 and 41 of patients receiving tofacitinib at a dose of 0 5 mg p 0 76 3 mg p 0 01 10 mg p 0 001 and 15 mg p 0 001 respectively as compared with 10 of patients receiving placebo there was a dose dependent increase in both low density and high density lipoprotein cholesterol three patients treated with tofacitinib had an absolute neutrophil count of less than 1500 patients with moderately to severely active ulcerative colitis treated with tofacitinib were more likely to have clinical response and remission than those receiving placebo funded by pfizer clinicaltrials gov number nct00787202.