DURATION OF CROHNʼS DISEASE DOES NOT INFLUENCE PATIENTʼS RESPONSE TO INFLIXIMAB

Abstract

Purpose: It has been suggested that short duration of Crohn's disease (CD) ≤ 2 years may be predictive of a prolonged response to infliximab. Kugathasan et al. (Am. J. Gastroenterol, 2002; 95: 3189–3194) concluded that in pediatric inflammatory CD patients, there is an improved response in those with early disease defined as a disease duration less than 2 years. This 15 patient retrospective study only assessed pediatric patients with medically refractory CD. Aim: To determine if duration of CD impacts on patient's response to infliximab. Methods: A retrospective cohort analysis of pts who received infliximab for treatment of active CD between January, 1999 and January, 2002. Clinical outcome improvement definitions: complete response (pts achieved previous baseline), partial response (patients had >50% improvement), and no response (patients had no/minimal change in symptoms) as assessed by pts and physicians. Smoking definition: greater than 7 cigarettes per week within 6 months of infliximab treatment. Duration of disease was analyzed as <2 years (early) or >than 2 years (late)- similar to the Kugathasan study. Logistic regression was used for univariate and multivariate analysis adjusting for gender, age, use of 6MP/AZA, smoking, presence of stricture, prior bowel resection, and disease location. Secondary analyses used 1 and 3 years of disease to define early therapy. Results: 137 pts (mean age 38 years, 46% male) received infliximab, of whom 73 (53%) had a complete response. 30 pts (22%) had CD for ≤2 years at the time of therapy (20 pts (15%) had disease ≤ 1 year and 41 pts (30%) had disease ≤ 3 years). The complete response rate in those with early therapy was 50% vs. 54% for those with late therapy (OR = 0.84, 95% CI 0.38-1.90). Adjusting for potential confounders (gender, age, use of 6MP/AZA, smoking, presence of stricture, prior bowel resection, and disease location) reduced the OR, but this did not reach statistical significance (adjusted OR = 0.52, 95% CI 0.20-1.39). Analyses looking at treatment in those with disease duration of ≤ 1 year or ≤3 years yielded similar results. Conclusions: The duration of CD up to 3 years does not appear to significantly influence individual pt's response to infliximab.