Successfully screened subjects will be randomized in a ratio of 1：1：1. After a 4-week screening period (day -28-0), subjects will be randomly assigned to treatment for 12 weeks.~Clinical Urticaria Activity Score (UAS), dermatological Quality of Life Index (DLQI), physical exams and Laboratory tests will be performed at baseline, the end of weeks 4, 8 and 12 respectively.
This study is a randomized, double-blind, placebo-controlled, multicenter clinical trial of about 36 subjects with moderate to severe Chronic Spontaneous Urticaria.