Must not have a cause, other than CSU, for itching, hives, and/or angioedema (swelling beneath the skin)

Must not have a current or recent active infection requiring antibiotics

Must not have a history of anaphylaxis (severe, life threatening allergic reaction)

Must not have asthma requiring medications other than short acting beta agonists (albuterol, etc.)

Must not have received prior treatment with omalizumab, ligelizumab, or other experimental biologic for CSU

A Study of LY3454738 in Adults With Chronic Spontaneous Urticaria