P0841Disease phenotype affects therapeutic choice in late-onset IBD: a large-scale analysis

Background The prevalence of the inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn’s disease (CD), in older adults is rising1,2. Late-onset (LO, diagnosis ≥60 years) IBD accounts for around 15% of diagnoses3. Few studies in LO-IBD have accounted for how disease phenotype affects therapeutic choice.4 More granular analysis of large cohorts is required. Methods This study used the UK IBD BioResource (IBD BR), an open-access national platform recruiting patients with IBD. Patients with UC and CD diagnosed between 2000 and May 2023 were included. The IBD phenotype was analysed; medication and surgery were compared in LO-IBD, young-onset (YO, 17-39 years), and mid-onset (MO, 40-59 years) IBD following propensity score-matching (PSM) accounting for variables including comorbidities and disease phenotype, using multivariable logistic regression and Cox proportional hazards models. Results A total of 22,601 patients were included: 12,023 UC (1629 LO-UC), and 10,578 CD (965 LO-CD). LO-UC patients had less proctitis than YO and MO-UC (YO, 19.0%; MO, 19.4%; LO, 14.8%, both P < 0.001), and equivalent rates of extensive UC (YO, 32.8%; MO, 29.0%; LO, 31.4%). Patients with LO-CD most often had ileal (45·9%) and colonic (33·9%) disease, with less ileocolonic (18·6%) disease. Perianal disease was less prevalent in LO-CD (15·2%) than YO-CD (32·9%) and MO-CD (21·1%; both P < 0.001). Compared with both younger cohorts, patients with LO-UC and LO-CD had significantly lower use of corticosteroids, thiopurines, and anti-TNF (Table 1). Vedolizumab use was higher in LO-CD than both younger cohorts (YO vs LO-CD, OR 0.30 [0.16-0.54]); MO vs LO-CD, OR 0.37 [0.20-0.66]). Patients with LO perianal CD (pCD) were equally likely to receive thiopurines as those with MO-pCD (OR 1.11 [0.60-2.06]), and equally likely to receive anti-TNF as both YO-pCD (OR 1.44 [0.76-2.73]) and MO-pCD (OR 1.37 [0.73-2.58]). Hazard ratio for perianal surgery was lower in LO-pCD compared with both YO-pCD (YO vs LO, HR 2.51 [1.57-4.02]) and MO-pCD (MO vs LO, HR 1.72 [1.05-2.83]). Conclusion In this comprehensive, large-scale analysis of LO-IBD, we found a distinct disease phenotype. Therapeutic choice was associated with a combination of age and IBD phenotype. Vedolizumab use was higher in LO-CD than younger patients. Older adults had less perianal CD than younger groups, but patients with LO-pCD were as likely to receive anti-TNF as younger patients, suggesting use of anti-TNF in older adults may be influenced by IBD phenotype and consideration of a higher benefit versus risk. Further research to assess whether adverse events and response to treatment in older adults justifies the observed differential treatment is essential. References: 1. Ng SC, Shi HY, Hamidi N, et al. Worldwide incidence and prevalence of inflammatory bowel disease in the 21st century: a systematic review of population-based studies. Lancet. Dec 23 2017;390(10114):2769-2778. doi:10.1016/S0140-6736(17)32448-0 2. Loftus EV, Jr., Sandborn WJ. Epidemiology of inflammatory bowel disease. Gastroenterol Clin North Am. Mar 2002;31(1):1-20. doi:10.1016/s0889-8553(01)00002-4 3. Sturm A, Maaser C, Mendall M, et al. European Crohn’s and Colitis Organisation Topical Review on IBD in the Elderly. J Crohns Colitis. Mar 1 2017;11(3):263-273. doi:10.1093/ecco-jcc/jjw188 4. Rozich JJ, Dulai PS, Fumery M, Sandborn WJ, Singh S. Progression of Elderly Onset Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis of Population-Based Cohort Studies. Clin Gastroenterol Hepatol. Oct 2020;18(11):2437-2447 e6. doi:10.1016/j.cgh.2020.02.048 Conflict of interest: Dr. Foulser, Peter: No conflict of interest Balarajah, Sharmili: Other: Received financial support to attend conferences by Ferring and Falk Martinez-Gili, Laura: No conflict of interest Sundramoorthi, Rohan: No conflict of interest Alexander, James: James has received speaker fees from Pfizer, Abbvie, Takeda and Janssen. He has received travel grants and support to attend meetings from Lilly, Tillotts Pharma, Takeda and Celltrion. Mullish, Benjamin: No conflict of interest Marchesi, Julian: Received fees for consultation from Cultech Ltd. and EnteroBiotix Ltd. Parkes, Miles: Grant: Gilead, Pfizer, AstraZeneca, Galapagos, Lilly, Takeda Orchard, Timothy: No conflict of interest Hicks, Lucy: No conflict of interest Williams, Horace: Fees from Pfizer, Takeda, Tillotts Pharma.