Weeks before the FDA will decide the fate of Avandia to remain on the market, two new studies link the drug to increased heart attacks, heart failure and stroke.

The diabetes drug Avandia (aka rosiglitazone), once the world's top-selling diabetes medication, was approved in 1999 to help people with Type 2 diabetes control their blood sugar. At the time, it was considered a safer alternative than existing diabetes drugs used instead of insulin. Soon after approval, however, the drug was linked to an increased risk of heart failure and bone fractures.

Both studies are scheduled for print publication in July. They were released early in advance of a Food and Drug Administration hearing on July 13 and 14 that will consider whether Avandia should remain on the market.

The drug's manufacturer, GlaxoSmithKline, defended Avandia on Monday, saying that the new studies stand in contrast to a randomized clinical trial of 4,447 patients conducted by Glaxo. That study found rates of hospitalization and deaths from cardiovascular events were similar among Avandia patients and those taking other diabetes medications, such as metformin and sulfonylurea.