RecruitingPhase 4Drug trialExtending Omalizumab Treatment Intervals in Patients With Chronic Spontaneous UrticariaThis study is a multicentre, randomized, open-label, non-inferiority clinical trial. The purpose and aim of this study is to investigate if patients with well controlled (UCT score score ≥ 12) chronic spontaneous urticaria (CSU) on omalizumab 300 mg every four weeks can extend treatment intervals and maintain disease control.