Xolair Heart Problems Being Reviewed by Health Canada

Nearly one month after the FDA initiated an investigation of potential heart problems with Xolair, Canadian health officials indicate that they are also conducting a safety review of the asthma medication’s potential side effects, which could include heart attacks, abnormal heart rhythms, heart failure, fainting, mini-strokes and blood clots.

In a statement released on August 13, Health Canada notified healthcare providers and Canadians that the review of potential Xolair heart side effects was initiated in response to the same interim findings of an ongoing U.S. study cited by the FDA on July 16.

Xolair (omalizumab) is used for treatment of moderate to severe persistent asthma caused by airborne allergens, such as grass, pollen and dust. It is prescribed for patients ages 12 and up, and is intended primarily for those whose asthma cannot be controlled by inhaled corticosteroids.

Interim data from a study known as EXCELS (Evaluating the Clinical Effectiveness and Long-Term Safety in Patients with Moderate to Severe Asthma) suggests that there is a disproportionate increase in heart problems among Xolair users. The observational study compares long-term outcomes for 5,000 asthma patients taking Xolair with a control group of 2,500 who are not.

When compared to the control group of patients not taking the drug, potential Xolair heart problems seen in the study include ischemic heart disease, arrhythmias, cardiomyopathy and cardiac failure, pulmonary hypertension, cerebrovascular disorders, and embolic, thrombotic and thrombophlebitic events.

The final results of the Xolair study are not expected until 2012, but health regulators in the United States and Canada are assessing the interim data and working with the manufacturer and distributors to obtain further information.

Neither the FDA nor Health Canada have determined that there is a casual relationship between Xolair and heart attacks or other heart problems. At this point, neither agency is recommending that patients stop taking Xolair or that doctors stop prescribing the drug.

Xolair currently carries a “black box” warning due to 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 symptoms appear.

In Canada, Xolair is distributed by Novartis Pharmaceuticals Canada. The medication is sold by Genentech in the United States, and Genentech reported $517 million in Xolair sales for 2008.