Eight months after their European counterparts told doctors to stop prescribing Abbott Labs’ Meridia diet pill, the FDA will now ask an advisory panel meeting this Wednesday whether the drug should be withdrawn from the US market. At issue are cardiovascular risks highlighted in a trial called SCOUT that was released last November, which showed Meridida patients with heart disease had a more than 11 percent risk of cardiovascular risks compared with 10 percent of those on a placebo.

Since then, the FDA has been criticized for not moving faster, although the agency had preferred to wait for full results to be issued. And so the advisory committee can now choose among four options: besides recommending withdrawal, the experts can urge continued marketing with the same labeling; continued marketing with revised labeling, such as a black box warning; allow continued marketing, revise the labeling with boxed warnings and limit use; or simply withdraw Meridia from the US market. A recent editorial in The New England Journal of Medicine pushed for withdrawal (read here).

“While (Meridia) may improve some cardiac risk factors (e.g. increasing HDL cholesterol), it may have detrimental effect on others (e.g. increasing in blood pressure and pulse rate). No direct evidence supporting that moderate weight loss with (Meridia) reduces cardiovascular morbidity and mortality was found in the published literature. The lack of cardiovascular morbidity and mortality endpoints in obesity trials represents a major gap in knowledge. However, given the modest decrease in body weight associated with sibutramine and the potentially substantial weight regain with discontinuation of therapy, even a small increase in cardiovascular risk seems unwarranted,” writes FDA staffers in briefing documents.

Another FDA memo states that “reports submitted by the sponsor suggested low number of cardiovascular events among on-label patients. Additionally, no major cardiovascular adverse events were identified thorough a literature search of published reports of trials that examined the effects of sibutramine on weight loss or weight maintenance. However, several important limitations, including failure to use validated outcomes and potential failure to capture outcomes from patients who discontinue trial, combined with a low number of events, precludes drawing of definitive conclusions. Due to their limitations, these studies may not provide convincing evidence to support a low or lack of cardiovascular risk associated with” Meridia.

Want to read what Abbott has to say about its pill? Read the briefing documents here.

pic thx to alan cleaver on flickr