(46) Outcomes of Vedolizumab Therapy in Bio-naïve versus Bio-exposed Children with Inflammatory Bowel Disease

Background: The incidence of inflammatory bowel disease (IBD) is rising in children. Approved advanced therapies have risks of side effects and treatment failure due to nonresponse. Vedolizumab is a monoclonal antibody that offers a gut-specific mechanism with fewer systemic side effects. Vedolizumab is considered first-line therapy in adults; however, access in pediatric IBD is limited and often only available following failure of anti-TNF therapy. Adult studies demonstrate a lower likelihood of response when vedolizumab is used after anti-TNF therapy.

Objectives: We aim to characterize differences in response to vedolizumab between bio-naïve and bio-exposed children with IBD.

Design/Methods: We reviewed medical records of children with IBD treated with vedolizumab at Lurie Children’s Hospital between 2014 and 2024. Patients were excluded if they did not complete induction dosing. Data collected included demographics, diagnosis, disease extent, and prior therapies. Outcomes, including need for dose escalation, concomitant therapies, endoscopic response and remission, and surgical outcomes, were compared between children who had prior exposure to biologic therapy ("bio-exposed") to those who were naïve to biologics ("bio-naïve").

Results: We identified 98 patients treated with vedolizumab. 28% had Crohn's Disease (CD), 49% had Ulcerative Colitis (UC), and 23% had IBD unclassified (IBD-U). 52 (53%) were declared bio-naïve (BN) and 46 (47%) were bio-exposed (BE). For the BE subjects, 63% had prior treatment with one biologic, 30% with two, and 7% with three or more. Compared to BE, fewer BN patients were on concomitant therapy (39% vs. 58%) and fewer had escalated dosing of vedolizumab (25% vs 54%). Endoscopic response and remission were more common in the BN group (77% and 46%, respectively), compared to those who were BE (44% and 19%). Surgery was less common for BN vs. BE (8% vs 41%). Side effects occurred in 13% of patients and were mild.

Conclusions: Our large single-center cohort demonstrates that vedolizumab is safe and effective for treating pediatric IBD regardless of previous biologic exposure. While data analysis is ongoing and may identify differences between the groups, our findings suggest that subjects on vedolizumab as their first biologic therapy have improved outcomes, with less concomitant therapy, lower likelihood of dose intensification, higher rates of mucosal healing, and decreased rates of surgery. This comports with adult experience describing decreased efficacy of vedolizumab after anti-TNF therapy and supports consideration of vedolizumab as first-line biologic therapy for children with IBD.