Preliminary results from a study of 5,000 patients taking the drug suggest an increased risk of heart problems and stroke, according to a statement from the Food and Drug Administration. Because of the preliminary nature of the data, the agency said patients should continue taking the drug as directed.
"FDA has not made any conclusions regarding these data," the agency said. Regulators cautioned that some patients enrolled in the study could have been predisposed to irregular heart rhythms, hypertension and other heart problems.
Genentech, a unit of Swiss pharmaceutical giant Roche, designed the study to track the long-term safety of the drug over five years. Final results are not expected until 2012.
Xolair was first launched in the U.S. in 2003 and is marketed abroad by Swiss drugmaker Novartis. The injectable drug is approved for adults and children older than 12 with moderate to severe asthma that cannot be controlled with inhalable treatments.
A spokeswoman for South San Francisco-based Genentech said the company and partner Novartis are "committed to patient safety," and will continue gathering safety information about the drug. No changes are planned for the drug's labeling.
