Individuals 18 years of age and older with Chronic Spontaneous Urticaria (CSU) lasting 6 months or more, may qualify to participate. Eligible participants must have the presence of itch and hives for 6 consecutive weeks or more prior to screening, despite the use of second generation H1-antihistamines. Documentation of hives within 3 months before randomization into the study, is also required.
Participants will receive an oral investigational medication (active study drug) or placebo. Study medication and study-related assessments will be provided at no cost. Reimbursement for study-related expenses may be provided.
Study participation will last about 60 weeks and involve about 13 visits to the study centre.