Although advisors to the US Food and Drug Administration have now recommended that GlaxoSmithKline’s Avandia should remain on the market, three leading doctor groups have urged patients not to stop taking the controversial diabetes drug.

After a highly-publicised two-day hearing, the FDA’s joint Endocrinologic and Metabolic Drugs and Drug Safety and Risk Management Advisory Committee has backed continual use of Avandia (rosiglitazone) despite fears that it may raise the risk of heart attacks. However, the Endocrine Society, the American Diabetes Association and the American Association of Clinical Endocrinologists have issued a statement saying that “even with the panel’s recommendation, the amount of scrutiny the drug has received may lead some diabetes patients who currently take rosiglitazone to want to stop taking the drug”.

As such, the influential groups are urging patients to not make any changes to their medication without discussing their treatment with their physician. Daniel Einhorn, president of the AACE, says that “the worst outcome would be to not treat diabetes properly, thereby risking its complications”. He added that “this unintended consequence has happened with past inquiries into diabetes medications, and we very much want to avoid it happening again”.

However, Richard Bergenstal, president of medicine and science at the ADA, said patients should be aware that “regardless of the opinion and decisions on rosiglitazone, there are numerous drugs available to maintain glucose control in people with type 2 diabetes”. He went on to say that patients should discuss these options with their doctors.

More opportunities for competition
As the dust settles following the FDA advisory review, more analysts have been reviewing the implications. Aparna Krishnan at IHS Global Insight noted that despite the favourable panel decision, “Avandia is likely to witness a declining trend in its sales as increasing restrictions on its prescribing patient population will affect revenues”. She adds that GSK has anticipated this fall, particularly as the drug faces patent expiry in 2012 in the USA and generic competition will bring down its overall market share.

Datamonitor analyst Christine Henry claims that Avandia’s decline “further opens the door for the antidiabetics that have already filled the gap created after the first Avandia safety scare in 2007”, ie Takeda’s class leader Actos (piogltazone) as well as Merck & Co’s blockbuster dipeptidyl peptidase-4 (DPP-4) inhibitor, drug Januvia (sitagliptin). She goes on to say that with Avandia hit by safety fears and Actos approaching patent expiry in 2011, “there is also the possibility for newer drug classes to seize market share, maintaining the attractiveness of type 2 diabetes as a commercial and clinical target”.