XOLAIR | omalizumab 

Drug Class: Anti-IgE Antibody
Manufacturer:  Genentech USA, Inc
Approval Date: June 2003

What is Xolair and it’s mechanism of action?

Xolair is an injectable biologic medication approved for treatment of chronic allergic asthma and chronic urticaria (hives). Xolair is an anti-IgE medication that binds to and blocks the attachment of immunoglobulin E (IgE) to its receptor on the surface of immune cells called mast cells and basophiles. Antibodies are proteins that protect the body from foreign substances and they are major components of the immune system. IgE is a type of antibody that binds to specific receptors in response to foreign proteins such as bacteria and allergens. IgE activates immune cells causing the release of histamine, a chemical which is responsible for symptoms of asthma and chronic urticaria (hives). Blocking the action of IgE means less histamine is released, reducing symptoms of asthma and hives. 

What does Xolair treat?

• Moderate to sever chronic asthma in patients inadequately treated with inhaled steroids
• Chronic urticaria (hives) in adults older than 12 years of age who do not respond to treatment with antihistamines

Who should not use Xolair?

• Pediatric patients younger than 12 years old
• Patients who may be allergic to an ingredient in Xolair  
• Patients in need of emergency treatment in an asthmatic attack
• Patients experiencing sudden outbreak of urticaria

How effective is Xolair?

Allergic Asthma: In a clinical trial studying the efficacy of Xolair, 546 asthmatic patients on a steroid treatment were randomly given Xolair or placebo every 2 to 4 weeks. At the end of 16 weeks with the same dose of steroids 14.6% of patients on Xolair had worsening of asthmatic symptoms compared to 23.3% of patients on placebo. At the end of a second 16-week therapy with a decreased dose of steroids 21.3% of patients on Xolair plus a low dose inhaled steroid had worsening asthma symptoms compared to 32.3% of patients on placebo plus a low dose inhaled steroid.

Chronic Urticaria: In a 12-week long trial, the efficacy of different dosages of Xolair in the treatment of chronic urticaria was studied in comparison to placebo. At the end of 12 weeks 36% of patients treated with Xolair 300 mg, 15% of patients treated with Xolair 150 mg, 12% of the patients treated with Xolair 75 mg, and 9% of patients treated with a placebo had no symptoms of urticaria such as itching or hives.

Interesting facts about Xolair

• Xolair is the first biologic agent approved by the FDA in March 2014 for treatment of chronic urticaria.
• Xolair is an antibody.
• Unlike other agents used in treatment of allergic asthma, Xolair acts at steps in the immune cascade before mast cell activation and histamine release. Therefore, it may reduce the need for inhaled corticosteroids.
• Xolair like other drugs that inhibit the immune system increases the risk of infections, including parasitic infections.
• The injections are given at the doctor's office and under supervision due to possible risk of severe allergic reaction caused by the drug.

What is the dosing of Xolair?

Xolair is supplied as a sterile powder in a 5 mL vial containing 150 mg of the drug.

• Xolair 150 to 375 mg injection every 2 to 4 weeks is the recommended dose for treatment of allergic asthma.
• Xolair 150 or 300 mg injected every 4 weeks is the recommended dose for treatment of chronic urticaria (hives).

Xolair is administered subcutaneously (under the skin) for both indications. Unlike in treatment of chronic urticaria dosing for allergic asthma is dependent on the blood IgE level. Total IgE level of the blood and body weight is measured to determine the correct patient specific dose. Dosing in treatment of chronic urticaria is not dependent on the blood IgE level or the body weight of the patient.

Only 150 mg can be injected per site. In order to prevent administration of more than 150 mg per site the total dose should be divide and injected at different sites. 

What are side effects of Xolair?

Allergic Asthma: Joint pain, Leg/arm pain, fatigue, dizziness, ear ache, fracture, and inflammation of the skin.

Chronic Urticaria: Nausea, headache, common cold, sinus inflammation, upper respiratory infection, joint pain, and cough.

Xolair impairs the immune system and increases the risk of serious infections. Xolair was associated with increased risk of breast, non-melanoma skin, prostate, melanoma, and parotid cancers in clinical trials. Xolair may also cause severe allergic reactions called anaphylaxis. 

What is the price of Xolair?

Xolair 150 mg vial costs $969.71

How to obtain prescription cost assistance for Xolair

To download a free drug discount card visit:

The Xolair Co-pay Card Program

Genentech Access to Care Foundation 

References

Xolair Prescribing Information. Genentech. March 21, 2014 

Busse W, Corren J, Lanier BQ, et al. Omalizumab, anti-IgE recombinant humanized monoclonal antibody, for the treatment of severe allergic asthma. J Allergy Clin Immunol 2001; 108:184