February 23, 2012
FDA Panel Votes Approves Weight Loss Pill
Another review by the Food and Drug Administration (FDA) for a new drug yesterday resulted in a 20-2 judgment in favor of allowing Qnexa to be placed on the market to combat obesity, reports Rita Rubin for WebMD Health News.
Qnexa is a combination of two drugs that have long been on the market -- appetite suppressant phentermine and topiramate, which is used to treat seizures and migraines.
Obesity specialists and patient advocates agree there is a huge need for obesity drugs to bridge a treatment gap between diet and exercise, which do not work for many people, and bariatric surgery, which is expensive and not suitable for those with specialized medical conditions.
The FDA, however, has been cautious with approving diet drugs, in part because with two-thirds of American adults overweight or obese, such drugs might be used for a long time by millions of people.
When the FDA previously turned Qnexa down, it asked Vivus for more clinical data on the medication´s potential impact on major adverse cardiovascular events and birth defects.
One question the advisory committee considered is whether Vivus should be required to conduct a large new clinical trial before the final approval is given to assess whether the drug increases the risk of heart attack. Facing more delays, possibly by several years, Vivus has proposed doing the study after approval.
Studies also show that the use of topiramate during pregnancy increases the risk of oral clefts, such as cleft lip, by a factor of two to five, according to the FDA staff review released last week. That is a concern, the reviewers said, because “the major consumers of weight-loss drugs are women of childbearing potential,” leading to “the potential for large numbers of pregnancy exposures.”
Qnexa was picked as the most suitable weight loss drug because of the high level of weight loss reported in company studies, with an average of more than 10 percent total body mass reduced among participants of the study, USA Today is reporting.
Reviewers for the FDA were still guarded in their approval. “Overall, the long-term clinical impact of the observed modest improvements in comorbidity outcomes is uncertain, particularly in a population with higher risk of CV adverse events,” the FDA wrote, referring to cardiovascular events such as heart attacks.
The main cardiovascular concern is that Qnexa increases heart rate. Still, the reviewers did say that the effect of the drug in lowering blood pressure was “somewhat reassuring.”
Vivus proposes to market Qnexa only to those who meet the government´s definition of obesity: a BMI of 30 or greater. The labeling would advise people who lose less than 3 percent of their body weight in three months on the drug to stop taking it.
The company will also put a plan in place to try and make sure pregnant women do not take the drug.
The FDA has faced complaints from the public and drug companies for several years for acting too cautiously in its drug approvals. Perhaps this is a sign that the agency is allowing some leeway in its approval process.
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