P545. Disease duration does not influence the rates of loss of efficacy to anti-TNF therapy in Brazilian Crohn's disease patients
P.G. Kotze1, J. Ludvig2, F.V. Teixeira3, H. Kleinubing Jr.4, E.F. Malluta5, E.F. Miranda1, M. Hardt1, M. Olandoski6, L.M.S. Kotze7, 1Catholic University of Parana, Colorectal Surgery Unit, Curitiba – PR, Brazil, 2Esadi, Gastroenterology unit, Blumenau – SC, Brazil, 3Gastrosaude, Colorectal Surgery Unit, Marilia – SP, Brazil, 4Univille, Colorectal Surgery unit, Joinville – SC, Brazil, 5Univali, Gastroenterology unit, Itajai – SC, Brazil, 6Catholic University of Parana, Statistics, Curitiba – PR, Brazil, 7Catholic University of Parana, Gastroenterology unit, Curitiba – PR, Brazil
It is known that efficacy of both Infliximab (IFX) and Adalimumab (ADA) can be reduced over time. There is lack of real life data in Crohn's disease (CD) patients regarding the influence of disease duration (DD) in loss of efficacy (LOE) to anti-TNF therapy. The aim of this study was to analyze the incidence of LOE to both IFX and ADA, and outline the influence of DD on its occurrence.
This was a retrospective, multicenter, observational cohort study, with CD Brazilian patients treated with anti-TNF therapy. Inclusion criteria: CD patients, responders to the first biological agent (anti-TNF naive). Exclusion criteria: undetermined IBD, primary non-responders and patients previously exposed to anti-TNF agents. Patients were allocated in two groups, regarding the drug administered (IFX or ADA). Variables analyzed: demographic data, Montreal classification, concomitant medications, smoking, perianal CD, presence of LOE and duration of CD at initiation of therapy. LOE was defined as one of the following: need for steroids, occurrence of major abdominal surgery during treatment, dose increase, interval shortening or switching of the anti-TNF agent. Patients were allocated in three subgroups regarding DD: <24 months, between 24 and 60 months and >60 months. Our hypothesis was that DD did not influence the rates of LOE in these specific subgroups. The influence of DD on LOE rates was analyzed with Fischer and chi-square tests (p < 0.05).
A total of 175 patients were included in the study (117 under IFX and 58 under ADA therapy). The groups were considered homogeneous. Medium follow-up period was 17.3 (±12.4) months on the IFX and 13.1 (±11.3) months on the ADA group. Overall, LOE occurred in 47/117 (40.2%) of the IFX and in 9/58 (15.5%) ADA patients (p = 0.001). The average disease duration was 40.2 months in the IFX group and 60.3 in the ADA patients (p = 0.130). LOE occurred in 32% of patients with DD <24 months, in 33.3% with DD between 24 and 60 months and in 31.3% of subjects with DD over 60 months (p = 0.975). The distribution of the patients in these subgroups did not differ regarding the agent administered, IFX or ADA (p = 0.455).
Loss of efficacy (LOE) was observed in 40.2% of the IFX and in 15.5% of the ADA patients. Disease duration (DD) did not influence LOE rates. These results suggest that patients with early CD might have the same rates of LOE than patients with long lasting disease. Controlled studies are needed to better address this issue.