P117 Predictors of colchicine treatment failure in mucocutaneous Behçet’s disease

Abstract

Colchicine is the first-line therapy for Behçet’s disease (BD); however, treatment failure is frequently observed. Data identifying predictors of colchicine failure in dermatology practice remain limited. We aimed to identify predictors of colchicine failure and characterize failure phenotypes to support earlier treatment decision in patients with BD. This retrospective cohort study was conducted by screening patients followed between November 2006 and November 2025. Among 654 patients, 113 with mucocutaneous BD receiving colchicine were included. Treatment failure was defined as insufficient clinical response, discontinuation due to adverse events or patient preference, or development of systemic involvement requiring additional therapy. Univariable and multivariable logistic regression analyses were performed to identify predictors. Failure-free probability was assessed using Kaplan–Meier analysis with log-rank testing, and Cox proportional hazards regression was used to estimate hazard ratios (HRs). Colchicine failure occurred in 59 of 113 patients (52.2%). In multivariable logistic regression, experiencing more than three mucocutaneous flares per year was independently associated with higher odds of treatment failure [odds ratio 5.96, 95% confidence interval (CI) 1.84–15.2; P < 0.001]. Male sex was independently associated with lower odds of failure (odds ratio 0.21, 95% CI 0.06–0.73; P = 0.01). Less frequent oral ulceration (less than one episode per month) and absence of arthritis were also independently protective (P = 0.04 and P = 0.05, respectively). Kaplan–Meier analysis showed a median time to failure of 22 months for those with more than three flares per year, compared with 210 months for those with three or fewer flares per year (P < 0.001). Cox regression confirmed that having more than three flares per year (HR 6.14, 95% CI 3.35–11.3; P < 0.001) and frequent oral ulceration (HR 4.55, 95% CI 2.39–8.67; P < 0.001) markedly increased the risk of failure. Failure of colchicine treatment in mucocutaneous BD is primarily driven by mucocutaneous disease activity rather than inflammatory laboratory indices. Patients with frequent flares may require closer monitoring and earlier therapeutic optimization.