P1095Effectiveness of First- and Second-Line Advanced Therapy in Microscopic Colitis: A Real-World Cohort Study

Abstract Background Microscopic colitis (MC), comprising collagenous colitis (CC) and lymphocytic colitis (LC), is a common cause of chronic diarrhea. First-line treatment includes budesonide, mesalazine, and cholestyramine. However, many patients are refractory or lose response over time. Advanced therapies are increasingly used, but evidence remains limited, particularly beyond first-line treatment. Methods This single-centre retrospective cohort study included 22 patients with MC treated with advanced therapies. The primary endpoint was clinical remission at month 6, using Hjortswang criteria (≤3 stools and ≤1 watery stool per day). Remission rates were compared between advanced therapies using Fisher’s exact test. Results There were 38 advanced therapies initiated in 22 patients (45% LC, 55% CC). 82% of patients were female, with a mean age of 48.1 ± 15.7 years and a median disease duration of 23 months. Detailed baseline patient characteristics are summarised in Table 1. Clinical remission at month 6, occurred in 14 of 38 (37%) who commenced advanced treatments (Figure 1) among all first-, second-, and later-line advanced therapies. Achieved remission rates varied between advanced therapeutic agents, but these differences were not statistically significant (p = 0.60). First-line therapies encompassed vedolizumab (VDZ, n = 8), infliximab (IFX, n = 11), and adalimumab (ADA, n = 3). Initiated first-line biologic therapies resulted in 45% (10/22) remission rates at month 6 (VDZ n = 3, IFX n = 6, ADA n = 11), with no significant differences between therapies (p = 0.85). Second-line therapy was initiated in 9 patients (VDZ n = 5, IFX n = 2, ustekinumab UST n = 2). Remission was achieved in 22% (2/9) of patients at month 6, who were both treated with vedolizumab; no significant differences were observed between agents. Third-line therapy was applied in 5 patients (VDZ n = 2, UST n = 1, risankizumab n = 1, and upadacitinib UPA n = 1). 40% (2/5) patients went into remission (VDZ n = 1; UPA n = 1) at month 6. No comparative statistical analysis between agents was performed due to the low number of included third-line therapy patients. Two patients received fourth-line therapy with golimumab and failed to achieve clinical remission. Three treatment-related adverse events occurred under ongoing IFX treatment (lupus-like syndrome, systemic infection, and impetigo), which all led to the discontinuation of treatment. Conclusion In this study, initiation of advanced therapies demonstrated clinical effectiveness in refractory MC patients, with an acceptable safety profile. Advanced therapies represent a promising treatment option in refractory MC. However, prospective controlled studies are urgently needed to confirm these findings and to define optimal treatment strategies for MC. Conflict of interest: Dr. Jefremow, André: No conflict of interest Fousekis, Fotios: No conflict of interest Neurath, Markus Friedrich: Personal Fees: Janssen-Cilag GmbhConsulting BMA houseConsulting Pentax GmbHConsulting S. KargerConsulting Galapagos NVConsulting Boehringer Ingelheim International GmbHConsulting Aclaris TherapeuticsConsulting TRex Bio, Inc.Consulting SciRhom GmbHConsulting Pfizer Biopharmaceuticals GroupConsulting Aditum Bio Management Company, LLCConsulting Carpamel Ransford LLPConsulting Pfizer Pharma GmbHConsulting Janssen-Cilag GmbHSpeaker activities Falk Foundation e.v.Speaker activities Affiliate Faculty, Skaggs School of Pharmacy & Pharmaceutical Sciences Speaker activity Medi K S.r.lSpeaker activity AOCCSpeaker activity Lilly Deutschland GmbH Speaker activity Northwell FoundationSpeaker activity Takeda pharma GmbHSpeaker activity, Consulting AbbVie NV/SASpeaker activity, Consulting Fondazione Internazionale MenariniSpeaker activity ARIX Bioscience Holding Limited Speaker activity Takeda Pharma Vertrieb gmbH & Co. KGSpeaker activity, Consulting Atreya, Raja: RA has served as a speaker, or consultant, or received research grants from AbbVie, Abivax, AlfaSigma, Arena Pharmaceuticals, Astra-Zeneca, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Celltrion Healthcare, Dr Falk Pharma, Galapagos, Gilead, GlaxoSmithKline, InDex Pharmaceuticals, Johnson & Johnson, Lilly, Materia Prima, Merck Sharpe & Dohme, Pfizer, Roche Pharma, Takeda Pharma, Viatris.