Objective: Existing findings on outcomes of anti-tumor-necrosis-factor (TNF) therapy in patients with inflammatory bowel diseases (IBD) are largely based on retrospective studies. We aimed to investigate real-world outcomes of anti-TNF therapy and predictors thereof in a prospective IBD cohort.

Methods: In a Danish multicenter cohort of adult bio-naïve patients with IBD treated with anti-TNF, we assessed clinical response and remission to induction therapy using clinical disease activity scoring indices at Week 14. In patients who continued treatment beyond the induction period, we also assessed loss of response (LOR), drug withdrawal, and major IBD surgery during maintenance therapy.

Results: This study included 774 patients (706 infliximab, 68 adalimumab) followed for a median duration of 125 weeks Clinical response was achieved in 209/331 (67.4%) of ulcerative colitis (UC) and 125/197 (74.0%) of Crohn's disease (CD) patients, while 143/331 (46.1%) UC and 81/197 (47.9%) CD patients achieved clinical remission. In 294 UC and 309 CD patients received maintenance therapy, while 86/294 (29.3%) UC and 78/309 (25.2%) CD patients experienced LOR. Active smoking and less severe disease activity predicted favorable outcomes in UC, while short disease duration, colonic disease, nonstricturing behavior, and concomitant immunomodulator therapy predicted favorable outcomes in CD.

Conclusions: Clinical response was achieved in 2 in 3 UC and 3 in 4 CD patients, meanwhile, one-third of UC and one-fourth of CD patients experienced LOR despite the short disease duration in this study. Several clinical features were associated with outcomes and may be useful predictors of anti-TNF treatment response.