Dose escalation for secondary loss of response in inflammatory bowel disease: 3-year outcomes and treatment persistence.

BACKGROUND: Dose escalation of biologic therapies is commonly used to manage secondary loss of response in inflammatory bowel disease, although long-term real-world outcomes remain limited. AIMS: To evaluate long-term clinical outcomes and treatment persistence following biologic dose escalation for secondary loss of response in inflammatory bowel disease. METHODS: We conducted a retrospective cohort study of patients with inflammatory bowel disease who underwent dose escalation of infliximab, adalimumab or vedolizumab at a tertiary referral centre between 2018 and 2024. Outcomes included clinical disease activity scores, biochemical markers and treatment persistence, assessed at 3-12 months and annually up to 36 months following escalation. RESULTS: A total of 155 patients were included (median age 31 years; 46% female), of whom 76% had Crohn's disease. A total of 89 patients received infliximab, 48 adalimumab and 18 vedolizumab. Dose escalation was undertaken for secondary loss of response in 68% and low drug concentrations in 42%. Infliximab escalation was associated with improvement in disease activity scores at 3 months, sustained to 36 months, with reductions in C-reactive protein across follow-up. Adalimumab escalation improved Harvey-Bradshaw Index at 3, 12 and 24 months, with reduction in faecal calprotectin at 3 months. Vedolizumab escalation improved Simple Clinical Colitis Activity Index at 3 months only. Treatment persistence at 36 months was 58% for infliximab, 65% for adalimumab and 73% for vedolizumab. Nine patients experienced minor adverse events. CONCLUSIONS: Biologic dose escalation was associated with improvement in disease activity and modest treatment persistence following secondary loss of response in inflammatory bowel disease.