DOP79 Promising efficacy of biologicals and small molecules for microscopic colitis: results from a large real-life multicenter cohort

Abstract Background Microscopic colitis (MC) is a chronic inflammatory condition of the colon, resulting in an impaired quality of life due to debilitating watery diarrhea. First-line therapy consists of budesonide, though a subset of patients is refractory or becomes budesonide- dependent. Evidence for the efficacy of biologicals or small molecules in MC is sparse and limited to small case series. Hence, we aimed to generate more real-life efficacy data. Methods This retrospective series was collected as part of the CONFER project by ECCO and supported by the European Microscopic Colitis Group (EMCG). Cases of MC patients treated with advanced therapies were included through a standardised collection form. Clinical response was defined as a 50% reduction in stool frequency (SF); clinical remission was defined according to the Hjortswang criteria as < 3 stools/day or < 1 watery stool/day. Results Ninety-nine patients were identified (Table 1), of whom all but one were previously treated with budesonide. Reasons for budesonide discontinuation included primary non-response (PNR, 16.3%), refractory disease (34.7%), budesonide dependency (38.8%), or adverse events (AE, 10.2%). In total, 165 treatment cycles with advanced therapy (47 IFX, 40 ADA, 47 VDZ, 10 UST, 14 JAK inhibitors, 7 other) were reported. First-line advanced therapies included mainly anti-TNF (76.8%) and VDZ (20.2%) (Figure 1A). Patients were exposed to anti-TNF therapy for a median of 1.4 [0.5-3.1] years, with a significant drop in SF after induction (p