Ahead of the Bell: FDA reconsiders diabetes drugs

The Food and Drug Administration will hear from diabetes experts, cardiologists and statisticians at a two-day meeting that begins Tuesday. A panel of outside experts are expected to weigh-in on whether drug companies should be required to show that their drugs reduce heart problems and death to win FDA approval.

If FDA adopts such a standard, companies like GlaxoSmithKline, Merck & Co. Inc. and Takeda Pharmaceuticals could be forced to conduct expensive, multi-year studies previously not required of diabetes medicines.

FDA has traditionally cleared drugs for type 2 diabetes, which represents 90 percent of all cases, based on their ability to control blood sugar levels. But the value of that criterion was questioned last year after an analysis of GlaxoSmithKline's Avandia showed it increased heart attack risk, despite lowering blood sugar.

After conducting its own research, FDA concluded the drugs' heart risks were unclear and asked Glaxo to study the issue. Results from that trial aren't expected until 2014.

FDA will ask its panel of outside experts whether heart safety studies should be mandatory for new diabetes drugs and those already on the market.

Despite pressure to adopt such standards from consumer advocates, the agency's own scientists seem wary of that approach. In briefing documents posted online ahead of the meeting they point out that no diabetes treatment, including insulin, has yet been proven to lower heart attack. They go on to warn that "establishing a hurdle of long-term, costly trials to exclude cardiovascular harm may also affect drug development for type two diabetes."

FDA is under pressure from some lawmakers to demand more thorough data on drugs before approving them. Sen. Charles Grassley, R-Iowa, asked the Government Accountability Office earlier this year to investigate FDA's approval of Avandia and another drug called Vytorin.

The agency approved Vytorin, made by Merck and Schering-Plough, based on its ability to lower bad cholesterol. But a study released earlier this year showed Vytorin was no more effective at limiting plaque buildup than a low-cost generic drug.

Grassley questions whether FDA should approve drugs based on biological measures, like cholesterol and blood sugar, without evidence they improve more meaningful measures like heart attack and lifespan.