Report raises safety concerns over Avandia
pharmafile | May 24, 2007 | News story | Sales and Marketing |
GlaxoSmithKline has been forced on the defensive after its blockbuster diabetes treatment Avandia was linked to an increased risk of heart attack.
US and European regulators have not demanded any action from the company but GSK shares fell nearly 8% following publication of a meta analysis of 42 clinical trials on the medicine in the New England Journal of Medicine.
The study concluded Avandia (rosiglitazone) was associated with a significant increase in the risk of myocardial infarction and with an increase in the risk of death from cardiovascular causes that had borderline significance.
"Our study was limited by a lack of access to original source data, which would have enabled time-to-event analysis," said the authors – Dr Steven Nissen, a prominent cardiologist, and statistician Kathy Wolski.
"Despite these limitations, patients and providers should consider the potential for serious adverse cardiovascular effects of treatment with rosiglitazone for type II diabetes."
Responding to the study the company issued a statement saying Avandia was a widely used and highly effective treatment for type II diabetes.
"GSK strongly disagrees with the conclusions reached in the NEJM article, which are based on incomplete evidence and a methodology that the author admits has significant limitations," the company said.
Patients with diabetes are already at an increased risk of cardiovascular disorders due to the underlying condition and there is contradictory evidence about the drugs risks from other published and unpublished long-term trial data.
However, since it was approved in 2000, it has carried warnings about the risk of fluid retention, which could exacerbate some heart problems or lead to heart failure.
In Europe the EMEA has advised patients to discuss the treatment with their doctors and said the majority of the studies included in the NEJM paper have already been assessed by the CHMP.
The FDA also said patients taking Avandia should talk to their doctors, but the US regulator stopped short of asking GlaxoSmithKline to take any specific action.
Meanwhile, the US Senate Committee that controls the Medicare and Medicaid programmes quickly weighed into the debate, demanding stronger post-marketing surveillance.
Chuck Grassley, chairman and ranking member of the Committee on Finance, said: "We need to know if this is another Vioxx, where the FDA sat on its hands and endangered lives.
"The FDA has talked a good game about how it's beefed-up post-market surveillance over the last two years, but a case like this undermines that claim. It'll take more than administrative reforms to fix the system within the FDA.
Responding to the committee's concerns, GSK said in a statement: "The suggestion that GlaxoSmithKline has placed patients at risk and attempted to silence independent investigation of data is absolutely false.
"Any fair examination of the company's record will show that GSK has been fully transparent in its efforts to thoroughly study the safety and effectiveness of Avandia, and to widely communicate that information to governments, scientists, physicians, and the public in the best interests of both patients and scientific debate."
