A group of investors has filed a class action lawsuit against GlaxoSmithKline, the manufacturer of Avandia. The lawsuit alleged that the company misled investors by failing to disclose its knowledge of the risk of Avandia side effects.

Concerns about the potential health risks of Avandia arose in May 2007, when an analysis of GSK’s clinical trial data was published in the New England Journal of Medicine. This meta-analysis showed that patients taking the drug were 64% more likely to die of cardiovascular problems and 43% more likely to suffer a heart attack than other patients.

The investors who filed the Avandia lawsuit allege that GSK had conducted its own meta-analysis of the clinical trial data, but failed to convey information about the potential side effects of Avandia to the public.

As a result, the investors say, potential Avandia lawsuits and the declining sales of the drug could damage the value of GSK stock. Federal regulations require publicly traded companies to report information that could potentially lower profits or sales.