On Wednesday, an FDA Advisory Committee overwhelmingly voted in favor of recommending the approval of a diet pill, Qnexa. This recommendation reverses years of caution with regards to diet pill drugs by the FDA after fen-phen was withdrawn from the market in 1997.
Fen-phen was an anti-obesity drug that utilized two anorectics – Fenfluramine and phentermine. Ultimately Fen-phen was shown to cause potentially fatal pulmonary hypertension and heart valve problems leading to legal damages of over $13 billion. PBS.org published a thorough report by Kate Cohen that explains the rise of Fen-Phen and the National Obesity epidemic which is worth a read to anyone interested in the diet drug phenomenom. That article can be linked to here.
Qnexa is also a combination of two drugs – the stimulant phentermine, which was the surviving part of the fen-phen combination and was not shown to have harmful effects, and the epilepsy and migraine drug topiramate, also known as Topamax. In recent years, litigation has been mounting for Topamax as a result of birth defects from women taking it while pregnant.
Although the FDA advisory committee acknowledge the risk of heart problems and birth defects likely to be linked to Qnexa use, they voted in favor of its approval because they believed the benefits from weight loss provided by the drug would outweigh the risk. There is a plan in place to make sure that pregnant women do not take Qnexa.
Vivus, the manufacturer of this diet drug, did not present the FDA Advisory Panel with a large clinical trial with regards to the heart problem issue in order to get this recommendation. Instead, the Advisory Panel agreed that Vivus would be able to assess whether Qnexa carries an an increased risk of heart attacks and strokes AFTER approval.
One wonders how the marketing for this diet drug will look – will Vivus market usage of this drug as one large human clinical trial? If approved for prescription usage, will the public understand that they are taking a drug whose assumed risks have not been studied on a long term basis?
Dr. Michael S. Lauer, a cardiologist of the National Heart, Lung and Blood Institute, and one of the two FDA advisory committee members that voted to reject the drug points out, "The consequence of making a mistake here is huge…We've unfortunately had many examples of having made mistakes before (citing hormone replacement therapy as an example)."
Doctors are at a loss for helping patients with obesity as there are currently no effective drugs on the market. Obesity is something that needs to be taken more seriously as it creates all sorts of health issues. But, rushing a drug to market that is suspected to increase the risk of heart attacks PRIOR to running studies certainly seems like a large mistake.
The FDA is expected to decide the fate of Qnexa by April 17th.
Source: New York Times, PBS.org