Adalimumab for Crohn's disease after infliximab treatment failure: a systematic review

The tumor necrosis factor inhibitors infliximab and adalimumab are effective treatments for Crohn's disease (CD); however, some patients treated with infliximab experience a loss of efficacy. There is a lack of high-quality evidence available on whether adalimumab is an effective treatment for patients who have failed infliximab treatment. A systematic review was carried out to examine the efficacy and safety of adalimumab for the treatment of CD in patients who have failed infliximab treatment. PubMed, Google Scholar, and the Cochrane Library were searched using the terms 'adalimumab AND infliximab AND Crohn's'. Randomized-controlled trials and cohort studies were included if they involved patients treated with adalimumab after failing infliximab. Outcomes were response and remission rates, adverse event (AE) rate, and the rate of discontinuations because of AEs. Ten studies (one randomized-controlled trial and nine cohort studies) involving 1009 patients were included. Luminal disease remission rates ranged from 12 to 67% during induction and 29 to 72% during maintenance therapy. Fistulizing disease remission rates ranged from 5 to 50% during induction and 27 to 68% during maintenance therapy. Luminal disease response rates ranged from 29 to 83% during induction and 31 to 59% during maintenance therapy. Fistulizing disease response rates ranged from 15 to 44% during induction and 41 to 56% during maintenance therapy. The overall AE rate ranged from 13 to 69%. Most AEs were mild to moderate in severity. The rate of discontinuation because of AEs ranged from 0 to 14%. The findings reported in the current literature support adalimumab as an efficacious and safe treatment for CD in patients who have failed infliximab treatment.