CONCURRENT IMMUNOMODULATOR THERAPY IN CROHNʼS DISEASE; DOES IT IMPROVE INITIAL RESPONSE TO INFLIXIMAB?

Abstract

Purpose: It has been proposed that concurrent immunomodulator (IM-MUNO) rx may improve long term response to rx with infliximab (INFLIX) by reducing antibody formation against INFLIX. What impact IMMUNO rx has on the initial response to INFLIX rx is less clear. Aim: To determine if concurrent IMMUNO rx improves the initial complete response to INFLIX in Crohn's disease (CD). Methods: A retrospective cohort analysis of 137 pts who received INFLIX for rx of their active CD (1/'99 - 1/'02). Clinical outcome definitions: complete response (achieved previous baseline), partial response (> 50% improvement), and no response (no/minimal change in symptoms) as assessed by patients and physicians. Concurrent IMMUNO therapy was defined as being treated with IMMUNO rx at the 1st infusion of INFLIX. Smoking definition: >7 cigarettes per wk within 6 mos of INFLIX treatment. Logistic regression was used to adjust for potential confounders including sex, age, duration of disease, smoking, presence of stricture, prior bowel resection, and disease location. Results: 6MP/AZA was used at the time of infusion in 66 (48%) pts. Of these 66 pts, 32(48%)had a complete response and 23 (35%) had apartial response. The duration of response to INFLIX did not statistically differ amongst pts who had used 6MP/AZA previously or who were naive to 6MP/AZA. Among the 71 pts not currently on 6MP/AZA, 41 (58%) had a complete response and 21 (30%) had a partial response. The relative risk of having a complete response given concurrent 6MP/AZA use was 0.84 (95% CI 0.61-1.15). After adjusting for potential confounders, use of 6MP at the time of the initial INFLIX infusion was not associated with complete response (OR = 0.72, 95% CI 0.34-1.54). The mean duration of complete response was similar in those not receiving 6MP/AZA at the time of initial infusion (2.3 mos vs 2.6 mos, p = 0.38 by t-test). Conclusions: IMMUNO rx concurrent with INFLIX treatment was no more effective than INFLIX therapy alone for obtaining a complete response during the initial 12 wks of therapy. In addition, the duration of response to INFLIX did not differ amongst pts using 6MP who had prior 6MP use or who were naive to 6MP. This data suggests that concurrent IMMUNO rx with INFLIX did not add benefit to pts initial response to INFLIX rx. Future prospective trials should test this further.