GlaxoSmithKline Dispels Avandia Heart Attack Risk
GlaxoSmithKline has rapidly rejected claims made in the New England Journal of Medicine that its Avandia (rosiglitazone) diabetes treatment could be linked to the risk of heart attacks among its users.
However, the article has triggered a slide in the Pharmaceutical giant's stock price, which shed 5 per cent. A safety alert has also been issued by the US Food and Drug Administration (FDA).
The article, written by Steven Nissen and Kathy Wolski, presented the findings of a study involving 15,560 recipients of Avandia, and 12,283 recipients of other medication. It concluded that the Avandia patients were 64% more likely to suffer from cardiovascular-related conditions, with heart attack risk quantified at 43%. In all, 158 heart attacks and 61 deaths were recorded across the board; however, the number of events linked to rosiglitazone were minimal - 86 myocardial infections in patients taking Avandia, compared to 71 for those on other medication, and 39 deaths from cardiovascular causes against 22.
The authors have raised the possibility of weaknesses in this data, with chance taking the place of reliable events. However, the NEJM's Editor, Jeffrey Drazen, has stated: "We view this as the best publicly available data on a very important question. It shows what we regard as a preliminary, but worrisome, signal about cardiovascular toxicity of this drug."
An editorial presented in tandem with the main article, written by Bruce Psaty and Curt Furberg, highlighted the inherent restrictions of a test of this nature, stating: "...the possibility that the findings were due to chance cannot be excluded...In view of the potential cardiovascular risks and in the absence of evidence of other related advantages, except for laboratory measures of glycaemic control, the rationale for prescribing rosiglitazone at this time is unclear."
Drs Psaty and Furberg also heavily attacked the FDA in approving Avandia for use in the US, commenting that "insofar as the findings of Nissen and Wolski represent a valid estimate of the risk of cardiovascular events, rosiglitazone represents a major failure of the drug-use and drug-approval processes in the USA".
GlaxoSmithKline's reaction to the findings was that of strong denial, stating it: "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", reinforcing this with, "...in contrast to a meta-analysis, the most scientifically rigorous way to examine the safety and benefits of a medicine is to conduct large scale, long-term clinical trials in patients with the disease. Several trials of this type have been ongoing for many years."
GlaxoSmithKiine markedly highlighted the case of its in-house ADOPT study, which gathered cumulative evidence over a six year period, regarding the performance of Avandia as compared to a number of alternative anti-diabetics. The findings from this indicated Avandia was in the same bracket as the diabetics Metformin and Sulfonylurea in terms of its potential cardiovascular risk posed.
The FDA's safety alert commented on the "potential safety issue" linked to Avandia, but does not require GlaxoSmithKline to take immediate action, with other test results pending publication. The FDA did state firmly that, however, it is analysing the safety implications of this drug.
Source - Pharmaceutical International's Foreign Correspondent
