Adalimumab is approved for the treatment of moderate to severe ulcerative colitis after failure of aminosalicylates plus corticosteroids and/or immunomodulators.1-4 In the registration studies for adalimumab in ulcerative colitis prior anti-tumor necrosis factor (TNF) treatment was restricted; in ULTRA 1, prior anti-TNF treatment was an exclusion criterion,5 while in ULTRA 2, 40% of patients had been exposed to infliximab prior to start of adalimumab, but primary non-responders to infliximab were excluded.6 Open label real life studies have shown good responses to adalimumab in UC. However typically, these cohorts were small and most patients were anti-TNF naïve. One Italian open label study on 88 patients reported clinical remission rates of 28% and 43% at week 12 and year 1, respectively.7 No significant differences were observed between infliximab naïve and infliximab exposed UC patients. In a Belgian open label study of 73 patients previously failing infliximab, overall clinical response at week 12 and 52 were 75% and 52%, respectively.8 Adalimumab was continued without need for dose escalation throughout year 1 in 16 patients, 22 needed dose escalation and 35 discontinued treatment within 1 year. Prior response to infliximab and early serum concentrations correlated with response.