P1031 Effectiveness and safety of oral vancomycin in the treatment of non-primary sclerosing cholangitis paediatric Inflammatory Bowel Disease (non-PSC PIBD) patients: a real-world single-center cohort study
Authors: Gianolio L , Ancona S , Armstrong K , Rabone R , Merrick V , Henderson P , Wilson D C , Russell R K 
Published: January 2025

Abstract

Background
Oral vancomycin has had limited use in paediatric Inflammatory Bowel Disease (PIBD), with reported efficacy in primary sclerosing cholangitis (PSC-PIBD)1, acute severe colitis as part of a quadruple antibiotic regimen2, and very early onset IBD3. This study evaluates its effectiveness and safety as single-agent therapy in non-PSC PIBD patients.

Methods
This single-centre retrospective cohort study included PIBD patients started on oral vancomycin for active IBD or steroid/topical therapy dependency from 01/2017 to 08/2024. Exclusion criteria were PSC diagnosis, positive/equivocal stool test for C. difficile, another induction treatment started within 3 weeks prior and vancomycin use solely in a quadruple regimen2. Disease activity was assessed using PUCAI/wPCDAI, faecal calprotectin (FC), blood parameters at baseline, 1, 3, 6 and 12 months. Treatment regimen, duration, reasons for discontinuation and adverse events (AEs) were recorded. Vancomycin was started at 250mg in patients ≥30kg or 125mg in those &lt;30kg TDS/QDS and tapered in responders after ≥1 month.

Results
Of 72 patients identified, 31 were included (16 males): 23 (74%) had Ulcerative Colitis (UC), 4 (13%) IBD unclassified (IBDU), 4 (13%) Crohn’s Disease (CD). At baseline, 5/31 were in clinical remission, with 2 also in biochemical remission but drug dependent. Initial vancomycin dosage was 17.5mg/kg/day (IQR 15.3-21.6), with a median duration of 4 (IQR 1-9) months. Concomitant medications are shown in Table 1: 10/31 (32%) were on biologics, with 4 able to discontinue and 2 to reduce biologic doses later. Overall, 17/31 (55%) patients (13 UC, 3 IBDU, 1 CD) achieved/maintained clinical and biochemical remission (Group 1), with 15 reducing/stopping other treatments. Conversely, 14/31 (45%) discontinued vancomycin due to non-response (11) or intolerance (3) (Group 2), with 11 stopping within 1 month. At baseline, Group 1 had lower disease activity score and platelet count than Group 2 (Table 1). A striking difference in response was noticed at 1 month (Figure 1), with FC in Group 1 dropping from 686μg/g (IQR 376-1143) at baseline to 60μg/g (IQR 25-160) at 1 month (p=0.001), while remaining high in Group 2 (p=0.52). In Group 1, 5/17 (29%) stopped vancomycin while in stable remission after 4 (IQR 2-9) months, with 3 restarted due to relapse, recapturing remission in 2/3. No severe AEs were reported.

Conclusion
Oral vancomycin was rapidly effective and safe, with 55% of non-PSC PIBD patients achieving/maintaining remission and 48% able to reduce/stop concomitant treatments. It was most effective in mildly active disease, especially UC/IBDU, and may offer a medium to long-term treatment option, with promising results in biologic-resistant but antibiotic-responsive PIBD patients.

References
1.Ricciuto A, Liu K, El-Matary W, et al. Oral vancomycin is associated with improved inflammatory bowel disease clinical outcomes in primary sclerosing cholangitis-associated inflammatory bowel disease (PSC-IBD): A matched analysis from the Paediatric PSC Consortium. Aliment Pharmacol Ther. 2024;59(10):1236-1247. doi:10.1111/apt.17936.
2.Turner D, Bishai J, Reshef L, et al. Antibiotic cocktail for pediatric acute severe colitis and the microbiome: The PRASCO randomized controlled trial. Inflamm Bowel Dis. 2020;26(11):1733-1742. doi:10.1093/ibd/izz298.
3.Lev-Tzion R, Ledder O, Shteyer E, Tan MLN, Uhlig HH, Turner D. Oral Vancomycin and Gentamicin for Treatment of Very Early Onset Inflammatory Bowel Disease. Digestion. 2017;95(4):310-313. doi:10.1159/000475660