Outpatient Ulcerative Colitis Primary Anti-TNF Responders Receiving Adalimumab or Infliximab Maintenance Therapy Have Similar Rates of Secondary Loss of Response

Goals:To compare the proportion of secondary loss of response to adalimumab and infliximab during maintenance treatment of ulcerative colitis (UC) after primary response to induction therapy.Background:The efficacy of anti-tumor necrosis factor- (TNF-) therapy used to maintain response in patients with UC after primary response to induction therapy wanes with time, resulting in secondary loss of response.Methods:A retrospective cohort study evaluating anti-TNF-naive UC outpatients who were primary responders to adalimumab and infliximab induction therapy and who advanced onto a maintenance regimen with the respective anti-TNF agent from 2003 to 2013 was conducted. The primary outcome was the proportion of patients in each treatment group that had secondary loss of response. The secondary outcome was time to secondary loss of response, analyzed by the Kaplan-Meier method analysis.Results:A total of 102 UC primary anti-TNF responders met inclusion criteria. Thirty-six patients (35.3%) were treated with adalimumab and 66 patients (64.7%) with infliximab. Mean follow-up was 139.0 weeks for adalimumab and 158.8 weeks for infliximab. A total of 21/36 (58.3%) adalimumab-treated patients and 39/66 (59.1%) infliximab-treated patients experienced a secondary loss of response during maintenance therapy. Mean time to secondary loss of response was similar for adalimumab (55.8 wk) and infliximab (59.4 wk) (P=0.82). Sex, extent of colitis, previous or concomitant azathioprine, and concurrent corticosteroids with anti-TNF induction were not associated with increased risk of secondary loss of response.Conclusions:In this real-life cohort of anti-TNF-naive primary responders with UC, the proportion of secondary loss of response and the time to secondary loss of response are similar for adalimumab and infliximab.