ABSTRACT
BACKGROUND: Long-term data on the effectiveness and safety of omalizumab for chronic inducible urticaria (CIndU) in large populations are lacking. OBJECTIVE: To evaluate the effectiveness, safety, estimated omalizumab treatment duration and its predictors, as well as differences between CIndU subtypes, in a large long-term CIndU cohort. METHODS: A multinational multicenter study was conducted at 14 specialized urticaria centres (UCAREs), including all CIndU patients ever treated with omalizumab from 2009 until July 2022. Kaplan-Meier survival and regression analyses were performed. RESULTS: Across 234 CIndU patients (55% female; mean age 37 years), 76% (n = 178) had standalone CIndU and 24% (n = 56) had predominant CIndU plus minor CSU, with an observation period up to 13 years. Most CIndU patients (73%, n = 145/200 with available data on response) had complete/good response to omalizumab treatment, without significant differences between CIndU subtypes. Sixty-two (26%) patients discontinued omalizumab; due to well-controlled disease (47%, n = 29), ineffectiveness (34%, n = 21), side effects (3%, n = 2), combination of ineffectiveness and side effects (3%, n = 2) and other reasons (13%, n = 8). The median estimated omalizumab treatment duration exceeded 5 years (54% drug survival at 5 years) and was mostly determined by well-controlled disease. Higher age predicted a lower chance to discontinue omalizumab due to well-controlled disease (HR 0.969, 95%CI 0.945-0.995). CIndU subtype and presence of minor CSU were not related to response and time until omalizumab discontinuation for any reason. CONCLUSION: Omalizumab is highly effective and safe in CIndU patients, with long estimated treatment duration mainly reflecting long disease duration. Our data show omalizumab's high potential as treatment in any subtype of CIndU and support its clinical use for these patients.