Omalizumab (Xolair) is a medicine approved by the U.S. Food and Drug
Administration (FDA) for use in people age 12 and older with moderate or severe
persistent
asthma. It should be used only after first-line
treatments (such as corticosteroids and long-acting beta2-agonists) have
failed. Omalizumab is much more expensive than any of the conventional
treatments for asthma, and its role in asthma treatment is not clear.
Omalizumab works by blocking immunoglobulin E (IgE) from attaching to
allergens. When IgE attaches to an allergen, it sets
off a process that eventually leads to the symptoms of an
allergic reaction.
Initial studies indicate that omalizumab reduces asthma episodes,
improves
peak expiratory flow (PEF), reduces the need for other
medications, and reduces emergency room visits and hospitalization.1 But it has been studied only in people with positive skin
tests to indoor allergens such as
dust mites,
animal dander, cockroaches, and molds.
Omalizumab is injected, and the dose is determined by a person's body
weight and IgE level. It can be given only to adults with a total serum IgE of
30
IU per milliliter to 700 IU per milliliter. It has
been studied in children age 12 and older who have a total serum IgE of up to
1300 IU per milliliter.
Omalizumab appears to be effective in people who:1
- Are age 12 and older.
- Have moderate
or severe persistent asthma.
- Have asthma that can be
improved.
- Have had a positive skin or blood test for a specific
allergen.
- Have blood levels of immunoglobulin E of 30 IU per
milliliter or more.
Omalizumab can be considered in people who meet the above criteria
and whose asthma is not well controlled after using inhaled
corticosteroids and long-acting beta2-agonists or
leukotriene pathway modifiers for 3 months. People who use oral or injected
(systemic) corticosteroids or who require high doses of inhaled corticosteroids
for daily control can also consider using omalizumab.
Severe allergic reactions, including
anaphylaxis, are possible when taking omalizumab,
although this is rare.