S1033 Upending Ustekinumab: IV Dosing as Maintenance Dosing

Abstract

Introduction: Ustekinumab is indicated for moderate to severe Crohn’s disease (CD) patients who failed previous treatment. Standard dosing is combining a single intravenous (IV) weight-based induction with subcutaneous (subQ) maintenance every 8 weeks. Although effective, secondary loss of response occurs despite dose optimization. Our aim was to evaluate the safety and effectiveness of Ustekinumab re-induction and IV maintenance in patients with refractory CD. Methods: We identified four individuals with CD at a single tertiary Veterans Affairs medical center. Each patient received IV induction with Ustekinumab after failed previous treatment with corticosteroids and anti-TNF inhibitors. Following transition to subQ maintenance dosing, these individuals had loss or inadequate response as seen with objective measures (C-reactive protein, fecal calprotectin, endoscopy, radiography). Despite dose optimization to every four weeks, drug trough levels remained subtherapeutic (< 4.5 µg/dL) with ongoing active disease. As salvage therapy, these patients then received weight-based IV maintenance dosing every four weeks. Disease activity was reassessed after three months. Results: All achieved endoscopic and/or radiographic remission with therapeutic drug troughs. No adverse effects were reported. Conclusion: In our early observation, ustekinumab re-induction with continued IV maintenance was a safe and effective treatment. This novel approach may be an option for patients with a loss or inadequate response to standard ustekinumab therapy. Our sample size is small, so our study may be underpowered; however, data collection is ongoing.