tofacitinib an oral small molecule janus kinase inhibitor was shown to have potential efficacy as induction therapy for ulcerative colitis in a phase 2 trial we further evaluated the efficacy of tofacitinib as induction and maintenance therapy we conducted three phase 3 randomized double blind placebo controlled trials of tofacitinib therapy in adults with ulcerative colitis in the octave induction 1 and 2 trials 598 and 541 patients respectively who had moderately to severely active ulcerative colitis despite previous conventional therapy or therapy with a tumor necrosis factor antagonist were randomly assigned to receive induction therapy with tofacitinib 10 mg twice daily or placebo for 8 weeks the primary end point was remission at 8 weeks in the octave sustain trial 593 patients who had a clinical response to induction therapy were randomly assigned to receive maintenance therapy with tofacitinib either 5 mg or 10 mg twice daily or placebo for 52 weeks the primary end point was remission at 52 weeks in the octave induction 1 trial remission at 8 weeks occurred in 18 5 of the patients in the tofacitinib group versus 8 2 in the placebo group p 0 007 in the octave induction 2 trial remission occurred in 16 6 versus 3 6 p 0 001 in the octave sustain trial remission at 52 weeks occurred in 34 3 of the patients in the 5 mg tofacitinib group and 40 6 in the 10 mg tofacitinib group versus 11 1 in the placebo group p 0 001 for both comparisons with placebo in the octave induction 1 and 2 trials the rates of overall infection and serious infection were higher with tofacitinib than with placebo in the octave sustain trial the rate of serious infection was similar across the three treatment groups and the rates of overall infection and herpes zoster infection were higher with tofacitinib than with placebo across all three trials adjudicated nonmelanoma skin cancer occurred in five patients who received tofacitinib and in one who received placebo and adjudicated cardiovascular events occurred in five who received tofacitinib and in none who received placebo as compared with placebo tofacitinib was associated with increased lipid levels in patients with moderately to severely active ulcerative colitis tofacitinib was more effective as induction and maintenance therapy than placebo funded by pfizer octave induction 1 octave induction 2 and octave sustain clinicaltrials gov numbers nct01465763 nct01458951 and nct01458574 respectively.