Xolair Heart Side Effects Lead to FDA Review

The FDA announced Thursday that they are investigating potential heart side effects of Xolair, a popular asthma medication, after preliminary findings of a study suggest that it could lead to heart attacks, strokes and other life-threatening injuries.

Xolair (omalizumab), which is manufactured by Genentech, was approved by the FDA in 2003 for use among adults and children over the age of 12. The medication is prescribed to treat moderate to severe persistent asthma caused by airborne allergens (grass, pollen and dust). It is meant primarily for those whose asthma cannot be controlled by inhaled corticosteroids. Genentech reported $517 million in sales for Xolair in 2008.

The FDA issued the early communication after receiving interim data from an on-going study that showed a disproportionate increase in heart problems potentially caused by Xolair side effects.

The on-going study, Evaluating the Clinical Effectiveness and Long-Term Safety in Patients with Moderate to Severe Asthma (EXCELS), is a Genentech observational study of 7,500 subjects. EXCELS seeks to determine the long-term safety of Xolair, and is comparing 5,000 asthma patients who are taking Xolair, with a control group of 2,500 who are not.

Accoring to the FDA, “interim data, submitted by the manufacturer of Xolair (Genentech), suggests a disproportionate increase in ischemic heart disease, arrhythmias, cardiomyopathy and cardiac failure, pulmonary hypertension, cerebrovascular disorders, and embolic, thrombotic and thrombophlebitic events in patients treated with Xolair compared to the control group of patients not given the drug.”

The FDA Early Communication does not mean that they have concluded there is a causal relationship between Xolair and heart problems. Currently, the agency is not recommending that patients stop taking Xolair or that doctors stop prescribing the drug. After additional information and analyses become available, the FDA indicates that further guidance will be provided.

Xolair already carries a “black box” warning due to the risk of anaphylaxis, which can cause trouble breathing, chest tightness, dizziness, fainting, itching, hives, and swelling of the mouth and throat. The warning indicates that some cases of anaphylaxis happened after the first dose, but patients could take Xolair for more than a year before anaphylaxis symptoms appear.

The FDA is working with Genentech to obtain additional information about the interim results of the EXCELS study and will determine whether any regulatory action may be warranted, such as new warnings. The EXCELS study itself will not be completed until 2012.