Background: Elective switching of biological therapy in patients with Crohn's disease (CD) in remission is generally discouraged, given the theoretical risk of antibody formation and loss of response. The aim of this study was to assess efficacy and tolerability of adalimumab (ADA) therapy after an elective switch from infliximab (IFX) in patients with stable CD.
Methods: Patients with CD with stable disease for >6 months (Harvey-Bradshaw Index ≤ 8) on IFX were eligible for this prospective, open-label single-center study. The primary endpoint was termination of ADA therapy. Disease activity (Harvey-Bradshaw Index, laboratory results) and adverse events were documented during the follow-up.
Results: We enrolled 29 patients with CD (19 women, mean age, 39 years; interquartile range, 23-58 years) who switched from IFX to ADA. At the end of the 54-week follow-up period, 72% of patients continued ADA therapy. Eight patients discontinued ADA therapy due to disease activity (n = 3), side effects (n = 4), or general symptoms (n = 1). After discontinuation of ADA, 4 patients switched back to IFX, and no infusion reactions occurred. No significant changes were observed in Harvey-Bradshaw Index scores, C-reactive protein, and leukocyte counts at 0 versus 54 weeks. Half of the patients who discontinued ADA showed an elevated baseline C-reactive protein.
Conclusions: The majority of patients with CD (72%) continued therapy and maintained remission after an elective switch from IFX to ADA, although switching back to IFX, if required, was well tolerated. However, elective switching of anti-tumor necrosis factor therapy in stable CD should be carefully considered, given the risk of loss of response and the limited options for alternative maintenance therapies.