FDA Orders Black Box Anaphylaxis Warning for Omalizumab (Xolair)

ROCKVILLE, Md., Feb. 21 -- Anaphylaxis reports associated with the asthma drug omalizumab (Xolair) led the FDA today to order Genentech to add a black box warning to the agent's label.

The boxed warning states that omalizumab, which is indicated for treatment of asthma related to allergies, may cause life-threatening anaphylaxis at any dose and as long as 24 hours after receiving it.

The FDA said that symptoms and signs reported to MedWatch included bronchospasm, hypotension, syncope, urticaria, and angioedema of the throat or tongue. No reports of death were included in the FDA warning.

The agency said the onset of symptoms, which include trouble breathing, chest tightness, dizziness, fainting, itching and hives, and swelling of the mouth and throat, could be two to 24 hours or longer after receiving omalizumab.

Moreover, anaphylaxis can occur after any dose of omalizumab, including the first dose. And it can occur "even if the patient had no allergic reaction to the first dose."

In addition to the black box warning, the FDA directed Genentech to "provide a medication guide for patients to strengthen the existing warning for anaphylaxis."

Omalizumab was approved in 2003 to treat adults and adolescents (12 years and older) with moderate to severe persistent asthma who have tested positive for a perennial aeroallergen (pollen, grass or dust) and whose symptoms are inadequately controlled with inhaled steroids.

In clinical trials, omalizumab decreased the rate of asthma exacerbations, which were defined as a worsening of asthma that required treatment with systemic corticosteroids or a doubling of baseline inhaled corticosteroid dose.

Anaphylaxis was reported following administration of omalizumab in clinical trials and was, therefore, discussed in the initial product labeling. The cases were reported at a frequency of approximately one in a thousand patients (0.1%).