EMBARQ-CSU2Barzolvolimab for Chronic Spontaneous Urticaria in Patients Unresponsive to H1 Antihistamines

This clinical trial is focused on testing a medicine called barzolvolimab for adults who have Chronic Spontaneous Urticaria (CSU), a condition that causes itchy hives and swelling without an apparent cause. These participants continue to experience symptoms even after taking higher doses of standard allergy medications known as H1-antihistamines. The study is important because it seeks to find out if barzolvolimab can effectively reduce the symptoms of CSU in those who do not find relief with current treatments, potentially offering a new option to improve their quality of life. Participants in this study will first go through a screening period of up to four weeks to ensure they meet the study requirements. They will then be placed randomly into two groups; one will receive barzolvolimab and the other a placebo, for 24 weeks without knowing which treatment they are receiving. After this period, every participant will get barzolvolimab for 28 weeks. Later, there will be a 16-week period where no treatment is given. This design helps researchers compare the effects of barzolvolimab against the placebo and evaluate its safety and tolerability over time.