Remibrutinib Efficacy and Safety in Adult Chronic Spontaneous Urticaria

This study focuses on adults with Chronic Spontaneous Urticaria (CSU), a condition that causes recurring hives. The main goal is to evaluate the safety and effectiveness of a drug called remibrutinib, which participants have previously used in other Phase 3 studies. The importance of this study lies in its potential to provide valuable insights into how well remibrutinib works for CSU patients over an extended period, ultimately aiming to improve treatment options and quality of life for those affected by this condition. Participants in this study will either receive remibrutinib or a placebo, depending on their Urticaria Activity Score (UAS7), a measure of hive severity over a week. Those with a score below 16 may receive the drug or a placebo for 24 weeks, while those with a score of 16 or higher will receive remibrutinib. If participants experience a relapse, they will be given remibrutinib for another 24 weeks. The study measures the time until the first relapse or discontinuation of the study drug due to lack of efficacy or use of prohibited medication. Throughout the study, participants may continue their background H1-antihistamine treatment, except for those with a UAS7 score less than 16 in the previous treatment period, who will receive remibrutinib alone.