P555. A prospective, controlled, single center pilot study comparing the efficacy of infliximab maintenance therapy (5 mg/kg) every 8 vs. 10 weeks based on successive measurements of fecal calprotectin
P. Karatzas, N. Kyriakos, E. Archavlis, X. Tzannetakou, I. Internos, S. Anastasiadis, K. Papamichael, G.J. Mantzaris, Evangelismos Hospital, A' Department of Gastroenterology, Athens, Greece
The STORI trial has documented that patients with Crohn's disease (CD) in deep remission can stop treatment with infliximab (IFX) without risking future loss of response (LoR) to IFX. It has also been shown that mucosal healing (MH) is associated with normal levels of fecal calprotectin (FC) in IBD patients. Aim: Based on successive measurements of FC to assess whether increasing the dose interval of IFX from 8 to 10 weeks in CD patients in complete deep remission (CDR) increases the risk of LoR to IFX.
This was a single-center, pilot, prospective, controlled, open-label study. Sixteen CD patients [6F:10M, aged 25 (range 18–48) years, 12 patients with phenotype A2L1/L3B1 and 4 with A2L2B1] in remission for at least 3 years agreed to receive IFX 5 mg/kg q10 weeks (group S - study group). Complete Deep Remission at baseline was assessed by the combination of a Harvey–Bradshaw Index (HBI) <4, normal serum C-reacting protein (CRP) levels, MH (at ileocolonoscopy performed up to 3 months prior to study entry) and FC levels <100 µg/g of fecal tissue (FT) (quantitative method, Quantum Blue, Bühlmann, Switzerland). A group of 15 CD patients also in CDR matched for age, smoking habits, CD phenotype, and duration of IFX treatment who continued on 5 mg/kg IFX q8 weeks served as controls (group C - control group). Patients and controls were followed for 2 years clinically (HBI) and by serum CRP measurements every 10 and 8 weeks, respectively, and FC measurements before every other IFX infusion. If FC values exceeded 200 µg/g FT patients were followed closely by repeated FC measurements and if serum CRP levels rose above normal range with or without clinical recurrence patients were endoscoped to assess recurrence of CD.
FC levels at baseline were 52.8 (<30–89) µg/gFT in group S and 49.6 (<30–92) µg/gFT in group C. At 1 year follow up, 15/16 patients in group S remain in CDR as indicated by a HBI <4, serum CRP <0.5 mg/dl) and FC 78 (<30–129) µg/gFT. One A2L2B1 patient relapsed [HBI = 9, CRP = 4 mg/dl) at 7 months, 3 months after FC rose steadily from <30 to >300 µg/gFT. 10/15 of group S patients underwent endoscopy at 1 year and remain in complete MH. In group C, 14/15 patients remain in CDR with normal FC values and only one patient withdrew for LoR to IFX at 7 months. The dose of IFX remains unchanged in patients of both groups.
CD patients in complete deep remission can receive IFX q10 weeks without risking losing response if FC levels are maintained in the normal range. This trial continues to complete a follow up period of two years.