A Study to Investigate Efficacy, Safety and Tolerability of Barzolvolimab Versus Placebo in Adults With Cold Induced Urticaria and Symptomatic Dermographism Inadequately Controlled by H1-antihistamines (EMBARQ - ColdU and SD)

Inclusion Criteria

• •1. Males and females, \>/= 18 years of age.
• •2. Diagnosis of cold induced urticaria or symptomatic dermographism \>/= 3 months.
• •3. Diagnosis of cold induced urticaria or symptomatic dermographism despite the use of a stable regimen of second generation non-sedating H1-antihistamine as defined by:
• •1. The presence of hives for \>/= 6 weeks at any time prior to Visit 1 despite the use of H1-antihistamines.
• •2. Must be on a stable regimen of second generation non-sedating H1-antihistamine for \>/= 4 weeks prior to study treatment.
• •3. Cold induced urticaria: A Critical Threshold Temperature (CTT) of ≥ 10 °C and \< 37 °C using the TempTest® and a numerical rating scale score of ≥ 3 for itch after the provocation test.
• •4. Symptomatic dermographism: A Critical Friction Threshold (CFT) of ≥ 3 using the FricTest® and a numerical rating scale score of ≥ 3 for itch after the provocation test.
• •4. Cold induced urticaria: Positive ice-cube test resulting in hives at the provocation site during Screening
• •5. Normal blood counts and liver function tests.
• •6. Both males and females of child-bearing potential must agree to use highly effective contraceptives during the study and for 150 days after treatment.
• •7. Willing and able to complete a daily symptom electronic diary and comply with study visits.
• •8. Participants with and without prior biologic experience are eligible.