WEDNESDAY, July 2 (HealthDay News) -- Drugs designed to control
type 2 diabetes should be subjected to more thorough safety reviews
to ensure they don't raise the risk of heart problems, U.S. Food
and Drug Administration advisers said Wednesday.
The panel of outside experts voted 14-to-2, at the end of a
two-day meeting, to recommend that all makers of these drugs
conduct long-term cardiovascular trials, even if the drugs show no
signs of heart problems in initial trials.
Most of the panel members also said that trials assessing
cardiovascular risk should be done before a drug is approved; these
could be a part of a phase III trial to rule out any significant
heart risk. Long-term trials could follow once the drug was on the
market, the advisers said.
Currently, the FDA only requires that drugs for type 2 diabetes
lower blood sugar, which is thought to protect diabetics from the
debilitating side effects of the disease.
Although the FDA is not required to follow its advisory panels'
recommendations, it usually does.
The panel's vote comes less than a year after the FDA was
harshly criticized for its handling of the type 2 diabetes drug
Avandia (rosiglitazone), made by GlaxoSmithKline. The drug was
approved in 1999, but the FDA added a "black box" warning about an
increased risk of heart attack last November. And the agency
decided to keep Avandia on the market because it concluded that the
risk of heart attack wasn't any higher than that associated with
similar medications.
Dr. Steven Nissen, chairman of the Cleveland Clinic's department
of cardiovascular medicine, first raised concerns about Avandia and
heart attack risk in a study published last year. He said in
November that he welcomed "the addition of a black box warning for
the risk of heart attack from Avandia," but would have preferred a
warning "written with greater clarity," like the one used by Health
Canada, the FDA's counterpart in Canada.
The Canadian label says Avandia is not to be used as the sole
medication for type 2 diabetes except for patients who can't take
metformin, another drug that also lowers blood sugar. The label
also states that Avandia is not to be used by any patient with
heart failure.
The controversy over Avandia started in May 2007, when a study
by Nissen and colleague Kathy Wolski, published in the
New England Journal of Medicine, found a 43 percent
increased risk of heart attack among patients taking the drug.
Nissen said he uncovered the risk after poring over data from 42
studies of Avandia.
On Tuesday, Nissen told the FDA advisers that the agency should
make companies demonstrate that their type 2 drugs do not increase
risks of cardiovascular disease before being approved, the
Wall Street Journal reported.
"Merely lowering blood-glucose levels in diabetes is too
simplistic," Nissen told the panel. "We must reduce the
complications of diabetes, including cardiovascular disease."
Should the agency adopt the panel's recommendation, the
additional clinical trials could add years and millions of dollars
to the development of any new type 2 diabetes drug. Companies such
as Bristol-Myers Squibb and AstraZeneca are currently working on
such drugs, the
Journal reported.
An estimated 20.4 million Americans have type 2 diabetes, which
can lead to kidney failure, blindness and heart disease. About 75
percent of diabetics die from cardiovascular disease.
Sen. Charles Grassley, R-Iowa, is investigating the FDA's
approval of Avandia and the cholesterol-lowering drug Vytorin,
which did not reduce the build-up of plaque in the arteries.
Recently, the FDA denied approval of another
cholesterol-lowering drug from Merck & Co. The denial sparked
speculation that the agency has tightened its approval standards
for these medications. However, the FDA hasn't said whether changes
in its approval process are being considered, the
Associated Press reported.
More information
For more on diabetes drugs, visit the
FDA.
