Common brand names

• Xolair

How it is administered

Omalizumab is given as a subcutaneous (under the skin) injection. It is available in several forms, including prefilled syringes, autoinjectors, and vials containing a lyophilized powder that must be reconstituted by a healthcare provider. The injection is typically administered every 2 or 4 weeks, depending on the condition being treated, the patient's weight, and their baseline IgE levels. The injection can be given in the thigh or abdomen, and the outer area of the upper arms may be used if administered by a caregiver or healthcare provider. For some patients, after initial doses are given in a healthcare setting, self-administration may be considered if appropriate.

How it works

Omalizumab is a monoclonal antibody that targets immunoglobulin E (IgE), a key player in allergic responses. By binding to IgE, omalizumab prevents it from attaching to receptors on immune cells like mast cells and basophils. This action reduces the release of inflammatory substances that cause allergic symptoms.

In conditions such as asthma and chronic spontaneous urticaria, omalizumab lowers the levels of free IgE in the blood, which leads to a decrease in allergic inflammation and related symptoms. The medication also causes a down-regulation of IgE receptors on immune cells, further reducing the body's allergic response. Omalizumab's effects are reversible, and IgE levels gradually return to baseline after stopping the medication.

Who should take it

Omalizumab is approved for:

• Moderate to severe persistent asthma in adults and children 6 years and older who have a positive skin test or in vitro reactivity to a perennial aeroallergen and whose symptoms are not adequately controlled with inhaled corticosteroids.
• Chronic rhinosinusitis with nasal polyps (CRSwNP) in adults 18 years and older who do not respond adequately to nasal corticosteroids.
• IgE-mediated food allergy in adults and children 1 year and older, to reduce allergic reactions (including anaphylaxis) that may occur with accidental exposure to certain foods, used alongside food allergen avoidance.
• Chronic spontaneous urticaria (CSU) in adults and adolescents 12 years and older who remain symptomatic despite H1 antihistamine treatment.

For blood cancer patients, omalizumab is not specifically indicated for treatment of blood cancers, but may be considered in those with concurrent severe allergic conditions as described above.

Who should not take it

Omalizumab should not be used in patients who have had a severe hypersensitivity reaction to omalizumab or any of its ingredients. This includes life-threatening allergic reactions such as anaphylaxis.

It is also not indicated for the emergency treatment of allergic reactions, including anaphylaxis, or for acute asthma attacks (acute bronchospasm or status asthmaticus). People with a known allergy to latex should avoid the prefilled syringe form, as the needle cap contains a latex derivative. Caution should be used in patients with a history of malignancy, as malignancies have been observed in clinical studies, though a definitive risk has not been established.

Commonly used with

Omalizumab is often used in combination with other medications to manage allergic conditions. For asthma, it is typically added to inhaled corticosteroids and sometimes long-acting beta-agonists. For chronic urticaria, it is used alongside H1 antihistamines. In patients with food allergies, it is used in addition to strict food allergen avoidance.

It is not specifically combined with blood cancer treatments, but may be used in patients with blood cancers who also have severe allergic diseases.

Commonly tested with

Omalizumab has been tested in combination with standard therapies for asthma (such as inhaled corticosteroids and beta-agonists), nasal corticosteroids for nasal polyps, and H1 antihistamines for chronic urticaria. In food allergy studies, it is used alongside food allergen avoidance.

No formal drug interaction studies have been performed with omalizumab, and its use with immunosuppressive therapies or allergen immunotherapy has not been specifically studied.