P227 Efficacy of infliximab in paediatric Crohn's disease patients

Abstract

Background: In recent years, the therapeutic application of the anti-tumour necrosis factor (TNF)-a antibody, infliximab (IFX) has expanded for both inducing and maintaining remission in young Crohn’s disease (CD) patients. However, there are very few outcome reports from Japan in this clinical setting. With this in mind, we became interested to evaluate the clinical efficacy and safety of IFX in paediatric CD patients. Methods: In a single centre setting, we enrolled 15 paediatric CD patients, age 11 17yr, with mild to severe disease, CD activity index (CDAI) 256.3±88.7, and CD duration 4.1±2.5yr. All patients had received 5-aminosalicylic acid based medications, but none had received an immunomodulator (IM) like azathioprine or 6-mercaptopurine. The primary and secondary end points were weeks 10 and 54 following the first IFX infusion. Clinical response was defined as a decrease in CDAI by at least 70 points, while clinical remission was defined as CDAI <150. Further, loss of response was defined as the need for escalating IFX dose to maintain clinical remission. Results: At the primary end point, 12 of 15 patients (80%) responded, of these, 10 patients (66.7%) achieved clinical remission (Remission group). The age at CD diagnosis was shorter in the non-remission group vs remission group, 15.2±1.5 vs 12.8±1.5. At the secondary end point, 6 of 15 patients (40%) had maintained clinical remission (IFX effective group). Nine of 15 patients (60%) had lost response to IFX (IFX failure group). Patients’ weight at first IFX infusion was smaller in the IFX failure group vs IFX effective group, 42.5±11.7 vs 53.4±7.2. Additionally, the L2 type (disease location, colon) and high serum C-reactive protein (CRP) before the first IFX infusion were associated with IFX failure. Only one patient developed mild dyspnoea at the 15th IFX infusion. No other serious adverse event or opportunistic infection during our observation time. Conclusions: The short-term response and remission rate in the present paediatric cohort are similar to the levels in the REACH study and also the study by Colombel JF, et al., while the long-term outcome is less impressive. Likewise, IFX-failure rate was higher in our study as compared with the aforementioned studies. We believe that IFX mono-therapy (without IM) s one factor for weaker long-term efficacy in our cohort vs earlier studies. Accordingly, IFX therapy in paediatric CD patients may be influenced by concomitant IM, CD refractoriness, poor nutrition, and disease location.