Mayo Endoscopic Subscore at Week 24 Is a Predictor of Future Loss of Response to Vedolizumab in Patients with Ulcerative Colitis in Clinical Remission.

Introduction: Vedolizumab (VDZ) is a gut-selective integrin antagonist approved for the treatment of ulcerative colitis. While its efficacy and safety have been demonstrated in clinical trials, real-world data on long-term treatment persistence and factors associated with loss of response are limited. Methods: We conducted a retrospective single-center observational study to evaluate the persistence of treatment and factors influencing loss of response in 59 patients with ulcerative colitis treated using VDZ. Clinical outcomes, endoscopic findings, and the impact of concomitant immunomodulator or 5-aminosalicylic acid use were analyzed. Results: Thirty-two patients (54.2%) had achieved clinical remission at week 24 and 27 (45.8%) had not. The cumulative VDZ persistence rate at 3 years was 39.7%. Patients who had achieved endoscopic improvement at 24 weeks exhibited a significantly higher persistence rate. The incidence of adverse events was low (1.7%). The impact of immunomodulator and 5-aminosalicylic acid co-administration on treatment persistence was minimal. Conclusion: Endoscopic improvement at week 24 was a key predictor of long-term VDZ persistence.