Dupilumab in Chronic Spontaneous Urticaria

Inclusion Criteria: Diagnosis: chronic spontaneous urticaria (defined as ongoing disease) 1. Patient is informed about study procedures and medications and has given written informed consent before any assessment. 2. Patient is able to communicate with the investigator, understands and complies with the requirements of the study. 3. Male or Female 4. Patient is 18-75 years of age 5. Patient is diagnosed with moderate to severe CSU and refractory to standard of care treatment at the time of randomization, as defined by the following: 1. The presence of itch and hives for more than 6 consecutive weeks at any time prior to enrollment despite current use of H1 antihistamine 2. Urticaria activity score UAS7 score (range 0-42) equal or more than 16, 7 days prior to randomization (Day 1) 3. CSU diagnosis for 6 months 6. Willing and able to complete a daily symptom diary for the duration of the study and adhere to the study visit schedules. 7. Patients must not have more than one missing diary entry in the 7 days prior to randomization. Re-screening may be considered. 8. Women of childbearing potential have to agree to use an acceptable form of contraception (as determined by the site investigator) and have to continue its use for the duration of the study. Exclusion Criteria: 1. Patients whose urticaria is solely due to inducible urticaria. 2. Other diseases with symptoms of urticaria or angioedema, including urticarial vasculitis, erythema multiforme, cutaneous mastocytosis (urticaria pigmentosa), and hereditary or acquired angioedema (e.g., due to C1 inhibitor deficiency) 3. Any other active skin disease associated with chronic itching that might confound the study evaluations and results (e.g., atopic dermatitis, bullous pemphigoid, dermatitis herpetiformis, etc.) 4. Patients who have received concomitant prohibited medication within the last 3 months prior to screening * Anti-IgE therapy (e.g. omalizumab) * Routine (daily or every other day during 5 or more consecutive days) doses of systemic corticosteroids or other immunosuppressants * Intravenous immunoglobulins * Biological therapy * Systemic immunosuppressants * Live/attenuated vaccines * Other investigational drug 5. History of anaphylactic shock 6. Active helminthic parasite infection or treatment of helminthic parasites within 6 months of screening