Spacing the Administration Interval of Anti-TNF Agents: A Valid Strategy for Patients with Inflammatory Bowel Disease?

Background: Increasing the interval of administration of anti-TNF agents over the duration specified in the data sheet is not common in inflammatory bowel disease (IBD).
Aim: To evaluate the outcomes of IBD patients treated with this strategy.
Methods: Patients with IBD who were treated with infliximab or adalimumab at intervals > 8 weeks or > 2 weeks, respectively, because of persistent clinical remission, were identified at local databases of the ENEIDA registry (a nationwide registry promoted by the Spanish Working Group in Crohn's disease and Ulcerative Colitis-GETECCU) of two referral centers. Treatment success was considered if patients remained in clinical remission with the same schedule or without biological therapy at the end of follow-up, and if no return to the conventional schedule, dose-escalation, change in biological agent, or a course of systemic corticosteroids or surgery were required.
Results: Eighty-five patients were included, 60 treated with infliximab and 25 with adalimumab. The spaced schedule was initiated after a median of 25 months on anti-TNF treatment (IQR 14-49). Throughout a median follow-up of 34 months (IQR 21-47), fifty patients (59%) fulfilled the success criteria of the spaced strategy. No differences were found regarding type of IBD or anti-TNF agent. Baseline C-reactive protein levels and disease duration at the time of starting anti-TNF treatment were the only factors associated with treatment success.
Conclusions: Anti-TNF administration at longer intervals than those provided in the data sheet may be an efficacious, convenient, and cheaper treatment option, particularly in patients in whom anti-TNF treatment was initiated early.