WASHINGTON — Federal health scientists have panned a GlaxoSmithKline study that the company used to defend the safety of its embattled diabetes drug Avandia, a once blockbuster-seller that fell out of favor because of potential ties to heart attacks.
The Food and Drug Administration posted an exhaustive 700-page review of Avandia on Friday ahead of a meeting next week to decide whether the drug should stay on the market.
The FDA finds itself in a difficult position that’s all too familiar: reviewing a drug approved a decade ago that now appears tied to deadly side effects. Experts say the FDA’s predicament is a result of shifting standards for the agency: increased scrutiny on safety and stepped-up pressure from Capitol Hill.
The FDA reviewed dozens of studies of Avandia, including one Glaxo has pointed to as proof of the drug’s safety. But an FDA reviewer said the study was plagued by “serious flaws” and actually supports the case against Avandia.
The drug works by increasing the body’s sensitivity to insulin, a key protein needed for digestion that diabetics don’t adequately produce.
People with diabetes are unable to properly break down carbohydrates, either because their bodies do not produce enough insulin or because of resistance to insulin. They are at higher risk for heart attacks, kidney problems, blindness and other serious complications.
Avandia was Glaxo’s third-best-selling drug in 2006 with U.S. revenue of $2.2 billion, according to health care statistics firm IMS Health. But safety concerns swirling around the drug have pummeled sales over the past three years, with sales falling 75 percent to $520 million last year.
