Objectives: Antibodies to infliximab may lead to loss of response to infliximab (IFX) in Crohn's disease. Azathioprine (AZA) coadministration prevents the formation, whereas hydrocortisone (HC) premedication reduces the levels of antibodies to IFX. This pilot study aims at assessing the efficacy of these strategies to prevent loss of response to IFX.
Methods: Eligible patients had active steroid-dependent luminal Crohn's disease and received IFX (5 mg/kg at weeks 0, 2, and 6 for induction and then scheduled q8 week for remission maintenance). Patients were stratified in a 1 : 1 ratio to oral AZA (2-2.5 mg/kg/day, stratum A) or HC premedication (250 mg intravenously, stratum B). Stratum A included only patients naive to AZA; stratum B included both AZA naive and intolerant patients. Steroids were tapered within 6-8 weeks. Patients were followed up with monthly clinical assessments, laboratory tests, Crohn's Disease Activity Index calculations, adverse-events check up, and adherence to treatment.
Results: Overall, 23 patients received IFX/HC and 23 IFX/AZA. There were no differences at baseline in any patient-related or disease-related parameters. Seventeen (74%) patients on IFX/AZA completed the study; six patients were withdrawn for primary nonresponse (one patient), lost response to IFX (two patients), or AZA-related adverse events. Eighteen (78%) patients on IFX/HC completed the study; five patients were withdrawn for primary nonresponse (one patient), loss of response (two patients), or infusion reactions to IFX. No significant differences emerged between strata in clinical remission rates or lost response to IFX.
Conclusion: This prospective 2-year pilot study has not confirmed superiority of any available strategy to maintain the efficacy of IFX.