S230 Poster presentations [2] Desmond AN, et al. Crohn’s disease: factors associated with exposure to high levels of diagnostic radiation. Gut 2008;57:1524 1529 P548 Deep remission: a recurrent feature in patients with Crohn’s disease and long term biologic therapy R. Vadan 1 *, L. Gheorghe 1 , R. Cerban 1 , B. Cotruta 1 , L. Tugui 1 , I. Stanel 1 , C. Angelescu 1 , I. Bancila 1 , M. Diculescu 1 , C. Gheorghe 1 . 1 Fundeni Clinical Institute, Gastroenterology and Hepatology Center, Bucharest, Romania Background: The new therapeutic goal in patients with Crohn’s disease (CD) is long term mucosal healing, due to its proven association with better outcome (better quality of life, fewer complications, less hospitalization). Not all CD patients treated with biologics achieve deep remission and in those patients that achieve it, it can be shortly lived. The aim of our study was to assess the frequency and durability of deep remission in CD patients on biological treatment in a clinical setting. Methods: All CD patients treated with biologics in our department were followed prospectively. Demographical data (age, sex), disease characteristics (Montreal classification, time between diagnosis and start of biological therapy, previous surgeries), type of biologic therapy, other treatments, endo- scopic findings were noted. All patients had ileocolonoscopy performed at 6 12 months interval. Deep remission was defined when both clinical (CDAI <150) and endoscopic (no ulcers) remissions were achieved. Results: 49 CD patients, mean age 37±13.06 (20 65) years were followed for a median of 38 (12 72) months. Localization of the disease was ileal in 12.24%, ileocolonic in 32.65% and colonic in 55.1% patients, with 26.53% having associated perianal fistulas. Mean time from diagnosis till biologic therapy was started was of 4.83±4.66 (0 18) years. The majority of patients (41) received Infliximab, the rest Adalimumab. Mean treatment time with biologics was 30.57±15.73 (12 72) months. During this time a mean number of 5.36 (2 11) ileocolonoscopies were performed per patient. Deep remission was achieved in 79.6% of cases after a mean of 8.23±7.52 (2 36) months and was sustained in 51.28% of cases. 48.71% of patients lost deep remission after a mean time of 12±6.48 (3 30) months. In 42.10% of cases (8 patients) after 8.25±3.1 months deep remission was induced again: in 5 cases with biologic dose escalation +/ immunosupressor, one with local budesonide treatment and in 2 cases (with clinical remission) spontaneous healing of ulcerations was observed at follow up ileocolonoscopies, without any therapeutic intervention. Conclusions: In clinical setting deep remission can be achieved in a great proportion of patients after a variable time interval, sometimes over one year of biologic therapy. In patients with flares while on biologic treatment deep remission can be re induced with various therapeutic strategies. Our study showed that transitory, clinically silent, endoscopic relapse is possible during biologic maintenance therapy. P549 Dose optimization is effective in patients with ulcerative colitis losing response to infliximab: a collaborative multicentre retrospective study M. Cesarini 1 *, K. Katsanos 2 , P. Ellul 3 , P. Lakatos 4 , K. Papamichael 5 , F. Caprioli 6 , E. Tsianos 2 , G. Mantzaris 5 , S. Danese 7 , G. Fiorino 7 . 1 Sapienza University of Rome, Medicina Interna e Specialit`a Mediche, Rome, Italy, 2 University of Ioannina, Greece, 3 Mater Dei Hospital, Malta, 4 Semmelweis University, Budapest, Hungary, 5 Evangelismos Hospital, Athens, Greece, 6 University of Milan, Italy, 7 IRCCS Humanitas, IBD Center, Rozzano, Italy Background: Approximately 13% of Crohn’s disease (CD) pa- tients maintained on infliximab (IFX) require dose optimization (DO) per year of treatment, because of loss of response (sLoR). Shortening the interval (IS) to 6 or 4 weeks may be as effective as doubling the IFX dose (DD, 10mg/kg q8 weeks). However, there is limited data on DO for ulcerative colitis (UC) patients with LoR to IFX. We aimed to evaluate and compare efficacy and safety of DO (DD or SI) in UC patients with sLoR. Methods: This was a European retrospective multicentre collaborative study including all consecutive UC patients maintained by IFX scheduled therapy between 2009 and 2012, requiring dose optimization (DO) due to sLoR. The primary outcome was rapid clinical response (decrease of >30% from baseline in the Mayo score, with no partial score >1, at the next administration of IFX after DO). Secondary outcomes were rapid clinical remission, and clinical response, remission and colectomy rate at week 52 following IFX DO. DD vs. IS were compared. Safety of DO was also evaluated. Comparison was made using c 2 test, and potential risk factors were evaluated using logistic regression analysis. Differences were statistically significant if p < 0.05. Results: Forty consecutive patients from 6 European centres met the inclusion criteria. DO was chosen on a clinical basis, according to the clinician’s judgement: 15 subjects were treated with DD, 25 were treated by IS. Mean time of LoR onset was 11 months (ranges 1.5 36). Rapid response was achieved in 36/40 patients (90%), by which 19/40 (47.5%) achieved rapid clinical remission; at week 52, 28 patients (70%) achieved clinical remission, and 4 patients (10%) underwent colectomy. No statistically significant differences were found between DD and IS. Survival analysis showed that subjects achieving rapid response and remission had significantly higher colectomy-free rate at week 52 than patients who did not (respectively p = 0.002 and p = 0.04). Figure: Comparison between the two optimization strategies. Conclusions: DO seems to be effective in regaining response and to avoid colectomy in patients who lose response to infliximab scheduled maintenance regimen. DD or IS seem both effective. Patients achieving rapid response and remission are more likely to avoid colectomy at week 52. Downloaded from https://academic.oup.com/ecco-jcc/article-abstract/7/Supplement_1/S230/412741 by guest on 14 June 2020