| June
7, 2007--Safety concerns over rosiglitazone
(GlaxoSmithKline’s Avandia) have sparked a firestorm of
debate. In a study published last month in The
New England Journal of Medicine, Steven
E. Nissen and Kathy Wolski concluded that rosiglitazone,
which is widely used for treatment of type 2 diabetes, is
associated with an increased risk of heart attack and
death from cardiovascular causes. These findings sent
GlaxoSmithKline shares on a downward spiral and put the
FDA back on the drug safety hot seat. The agency will
convene a meeting of outside experts on July 30 to discuss
Avandia and similar drugs.
Like investors, doctors shunned the drug on hearing
the news. An Impact RX report showed that Avandia’s
share of the market for newly prescribed oral
anti-diabetics fell to around zero from around 10% in the
two days after Nissen and Wolski’s article appeared. At
the same time, Takeda's rival drug Actos' (pioglitazone
hydrochloride) share of the new prescription market
increased from 10–22%.
Weeks later, evaluations
of rosiglitazone continue to emerge. On Tuesday, NEJM
released early findings from a study called Record, which
is scheduled to end next year. The findings from this
interim analysis were inconclusive regarding the effect of
rosiglitazone on the overall risk of hospitalization or
death from cardiovascular causes. The authors reported the
data were insufficient to determine whether rosiglitazone
was associated with an increase in the risk of heart
attack. Moncef Slaoui, head of research and development at
GlaxoSmithKline, said in a statement that “Patients and
physicians should find these data reassuring.”
In response to this preliminary analysis,
cardiologist Edmund Herrold, of the Weill Cornell Medical
College in New York, said “I would continue to leave it
there, leave it on the market. I think at this point
what’s needed are continued, ongoing studies over longer
periods of time to determine the true effect.” Herrold
made the comments on Bloomberg TV's Money & Politics
with Peter Cook.
On
Wednesday, in prepared testimony before the House
Committee on Oversight and Government Reform, FDA
Commissioner Dr. Andrew von Eschenbach said the agency had
asked that both Avandia and Actos carry a “black box”
warning on the potentially heightened risk of congestive
heart failure in some patients. According to von
Eschenbach's testimony, the request for the warning was
issued to GlaxoSmithKline and Takeda Pharmaceuticals on
May 23, two days after publication of Nissen and
Wolski’s study. Takeda has said it will add the boxed
warning to prescription labels for Actos. A "black
box" warning is the most serious warning placed in
the labeling of a prescription medication.
Three editorials
accompanying the interim analysis were also released
Tuesday, raising questions about its results.
Two earlier PharmaWeek
articles explore safety issues with rosiglitazone and
other members of the same drug class.
Copyright 2007, Cambridge Healthtech Institute. All Rights
Reserved. |
