This is a randomized, parallel-group, participant and investigator-blinded, placebo controlled, multi-center study in approximately 44 adult participants that are diagnosed with a form of CU and have symptoms despite treatment with H1-antihistamines. The following nine subtypes of CU are included:
* CINDU cohorts: Symptomatic dermographism, Cold urticaria, Cholinergic urticaria, Heat urticaria, Solar urticaria, Delayed pressure urticaria, Aquagenic urticaria, Contact urticaria
* CSU The study will attempt to enroll approximately 4-5 participants for each subtype. Participants will undergo a screening period for completion of the assessment to check eligibility criteria which will take approximately up to 4 weeks. After enrollment, the treatment will be initiated. Participants will either receive remibrutinib or placebo for 12 weeks. Participants have an end of study visit approximately 7 days after the last dose. All participants will have a safety follow-up phone call approximately 30 days after last treatment administration.
