Approximately one-third of patients with irritable bowel disorders (IBDs) do not respond to treatment with anti-TNF agents (primary failure) and a significant number experience a loss of response (secondary failure) or therapy intolerance. Second-line treatments of other anti-TNF drugs are common if the first one has failed, but the efficacy of an anti-TNF therapy after the failure of a previous anti-TNF remains questionable.

A systematic review in the journal Alimentary Pharmacology and Therapeutics identified 46 studies evaluating the efficacy of one-second-line anti-TNF treatment in IBD patients after failure (primary or secondary) or intolerance to a first anti-TNF treatment. Infliximab, adalimumab, or certolizumab for Crohn’s disease (CD), ulcerative colitis (UC), or pouchitis were targeted treatments and conditions in the research. The primary outcome was the percentage of remission and/or response obtained with the second anti-TNF.

For CD patients, overall remission after primary failure was 30%, with short-term remission lower than that obtained in the medium and long-term (18%, 30%, and 28%, respectively). In CD patients switching from infliximab to adalimumab, the overall response rate after primary failure was 53%; the short-, medium-, and long-term response rates were 35%, 67%, and 42%, respectively. Remission rates in CD patients were higher when the first anti-TNF was withdrawn due to intolerance (61%) than after secondary (45%) or primary failure (30%). Only four of the UC studies on switching from infliximab to adalimumab reported remission rates, ranging from 0–50%.

For CD, the efficacy of a second anti-TNF may be dependent on the reason for switching; for UC, more research is needed that includes data on remission rates.