Xolair is one of the few drugs specifically for allergic asthma. It binds to immunoglobulin E (IgE), an antibody type produced in response to an allergen.
It won’t help non-allergic asthma, a type triggered by exercise, cold air, or other non-allergy irritants. (About 10% to 40% of all asthma cases are non-allergic).
Xolair is expensive so it is usually given in more severe cases, says Dr. Mitchell, such as people who have repeat trips to the emergency room. It’s an injected drug and has a boxed warning about a risk of anaphylaxis, a potentially life-threatening allergic reaction. (Doctors monitor for such reactions after giving the injections.)