A Food and Drug Administration (FDA) advisory panel voted on Wednesday to allow the controversial diabetes drug Avandia (rosiglitazone) to remain on the market, but about half of the panel members called for sales restrictions and/or stronger label warnings about the risk of heart attacks. The FDA, which will be reviewing the recommendations and issuing a final decision on the fate of the medicine, is not required to follow the advice of its advisory panels, but it typically does.
Avandia is in the thiazolidinedione class of diabetes medicines, which work by improving insulin sensitivity and decreasing the production of glucose by the liver. In the past few years, several studies have been published that link Avandia with a higher risk of heart problems. The medicine first came under fire in 2007 following a study showing that people using it had a 43% higher risk of heart attack and a 64% higher risk of dying from heart disease compared to people taking other common diabetes treatments. In response to that data, the FDA added a black box warning to Avandia’s packaging, noting the increased risk of heart attack, and requested that the drug’s maker, GlaxoSmithKline (GSK), conduct a long-term study to evaluate Avandia’s cardiovascular risk compared to a control treatment.
More recently, in February 2010, safety concerns were raised again when David Graham, MD, MPH, associate director of drug safety at the FDA, published a report calling for Avandia’s removal from the market. The report claimed that roughly 500 more heart attacks and 300 more cases of heart failure would occur each month with the continued use of Avandia than would occur if Actos (pioglitazone), the only other drug on the market in the thiazolidinedione class, were used exclusively. In May, GSK settled roughly 700 cases brought by patients alleging that Avandia had caused their heart attacks for $60 million. And in June, two large studies published in The Journal of the American Medical Association indicated that Avandia carried an increased risk of heart failure, stroke, and death compared to Actos. Other allegations have also recently swirled around Avandia, including that GSK intimidated physicians and played down the cardiovascular risk posed by the drug, as well as that SmithKline Beecham, GSK’s corporate predecessor, concealed data from a 1999 study indicating that drug carried an increased heart risk.
In response to the FDA’s 2007 request for a long-term study evaluating Avandia’s cardiovascular risk, GSK is beginning a large trial known as Thiazolidinedione Intervention With Vitamin D Evaluation, or TIDE, comparing Avandia to Actos. The trial aims to study 16,000 people in 14 countries before the year 2015.
On Wednesday, an FDA advisory panel consisting of 33 health experts was asked to vote on a number of matters relating to the future of Avandia, including whether the TIDE trial should proceed and whether Avandia should remain on the market; the panelists heard testimony from people taking Avandia, as well as physicians and company representatives. On the question of whether Avandia should remain on the market, 12 members of the panel voted that it should be withdrawn, 10 voted that it should be allowed to remain on the market but with serious label revision and possibly sales restrictions, 7 voted to add additional warnings to the label, and 3 voted for sales to continue unchanged. (One panelist abstained.) Most who voted to keep Avandia on the market indicated that their opinion was based on a lack of solid evidence showing harm from the drug. On the matter of whether to allow the TIDE trial to continue, the panel was split 19 to 11, with the majority in favor of the study continuing. Should TIDE proceed, however, it will be several years before any results become available.
Ellen Strahlman, MD, MHSc, Chief Medical Officer for GSK, said that Avandia would remain on the market pending a decision from the FDA. She said that “Patients taking Avandia should speak with their physician about their treatment and any questions they may have regarding the safety of the medicine.” And in a joint statement by the Endocrine Society, the American Diabetes Association, and the American Association of Clinical Endocrinologists, these organizations “urge[d] patients not to make any changes to their medication use without discussing their treatment with their physician.”