Qnexa awaits FDA green light

March 31, 2012

If the odds be ever in their favour, Qnexa could be the first new obesity drug to receive Food and Drug Administration (FDA) approval in 13 years. The last was Xenical that hit the market in 1999. Last February, a panel of medical experts endorsed the controversial weight-loss drug Qnexa. The vote was a 20-2 in favor to approve Qnexa for the treatment of obesity. The FDA will issue a final ruling later this April, but the agency typically follows the recommendations of its advisory committees.

In a clinical trial involving 4,323 people, Qnexa — a combination of the anticonvulsant drug topiramate and the appetite suppressant phentermine — led to an average loss of about 10% of total body weight in the first year of use. Many users also saw improvements in blood pressure.

But the trials also found that that the drug caused a slight increase in heart rate, which can boost the odds of a heart attack or stroke. In addition, researchers detected an increased risk of birth defects — typically cleft lip — in women who became pregnant while taking the drug.

Vivus Inc., the drug’s manufacturer, addressed those concerns by proposing a tightly controlled system for prescribing Qnexa. To prevent birth defects, patients who take the drug will have to undergo monthly pregnancy testing and healthcare providers will get special training on the medication’s risks and benefits. Vivus will also restrict distribution of the drug to registered pharmacies, among other measures.

“We will know who the prescribers are. We will know who has been trained,” Dr. Barbara Troupin, Vivus’ senior director of global medical affairs, told the advisory committee. “We are confident the Qnexa [risk management program] balances the safeguards while allowing access for appropriate patients.”

Several members of the Endocrinologic and Metabolic Drugs Advisory Committee said they worried about Qnexa’s side effects but believed the benefits outweighed the risks.

Health Care Asia
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