The Avandia scandal

An investigation by the BMJ published this week calls for the withdrawal of the daibetes drug, Avandia, immediately from the market because of the concerns that it may increase the risk of myocardial infarction and the paucity of good evidence to support its use.

Rosiglitazone, also known as Avandia, was GSK's second biggest selling drug, introduced in 1999 and is widely used to lower blood glucose levels in patients with type 2 diabetes. It was approved by the EMA in 2000 despite concerns over its safety.

In 2007, several studies found Avandia having harmful effects and issued serious health warnings. The researchers questioned why Avandia is still available on the market and why physicians would prescribe it to diabetic patients when there are other drugs without these side effects. They called for Avandia to be withdrawn from the market. Since then, the sales of Avandia fell sharply.

The BMJ investigators found that in July, the UK Commission on Human Medicines advised the MHRA to withdraw Avandia as the risks of Rosiglitazone outweigh its benefits. This has raised a lot of questions about the quality of the data used in the studies and the lack of trial results made available to the public. The investigators also ask why the regulators accept such poor evidence on benefit and safety, why patients in the UK and Europe are not make aware of the concerns about this drug and whether the current regulatory body is doing its job properly. They said that doctors are advising that no new patients shoud use this drug, existing diabetic patients should review their options and those at high risk of heart disease should stop taking it.

In the accompanying editorial, the authors said that clinicians had focused on the wrong endpoint and lost sight of the main reason for treating this disease, "which is not to reduce glycaemia but to prevent complications". They went on to say that clinicians need to be "absolutely certain that the long term treatment for type 2 diabetes are not causing the harm they are meant to prevent" and should insist on robust evidence of benefits and harms.

Professor Freemantle noted in the accompanying commentary that the Avandia studies were hindered by inadequate data due to high levels of loss to follow-up. He wrote "In order to learn from our mistakes, we must improve the quality of safety data from clincal trials on all new healthcare interventions, not just antidiabetic drugs" and an overhall in the standards of regulatory trials is needed.


Sources : free f/t
Rosiglitazone: what went wrong? BMJ 2010; 341:c4848 (Published 6 September 2010) Editorial - Licensing drugs for diabetes BMJ 2010; 341:c4805 (Published 6 September 2010)
Commentary: What can we learn from the continuing regulatory focus on the thiazolidinediones?BMJ 2010; 341:c4812 (Published 6 September 2010)