Qnexa is one of the most advanced new diet drugs in clinical development that has shown promising results in terms of weight loss for obese patients. However, following review of clinical data on July 15 2010, the FDA advisory committee voted against the approval of the new weight loss drug.
What is Qnexa – the New Weight Loss Pill?
Qnexa is a late-stage weight loss drug that has been in clinical development for the treatment of obesity and other associated conditions such as hypertension and diabetes. It consists of two well-known drugs that are already available separately; phentermine, which is approved in the USA as a short-term treatment for weight loss in obese patients, and the antiepileptic and migraine treatment, topiramate.
Clinical studies for Qnexa have shown that the proposed new diet drug can induce significant amounts of weight loss, which is greater than that seen with available FDA approved antiobesity drugs; in one study, the average weight loss seen for Qnexa-treated patients was nearly 15%, while a maximum of 10% is reported to be seen with current agents.
New Diet Drug Qnexa Poses Safety Concerns
In December 2009, Vivus filed a marketing application with the FDA for Qnexa to be approved for the treatment of obese patients or overweight patients with a body mass index (BMI) greater than 27kg/m2 who have weight-related co-morbidities, including hypertension, diabetes and dyslipidemia.
An FDA advisory committee met on July 15 to review the clinical data submitted by Vivus. However, by the conclusion of the meeting, the panel had voted 10 to 6 against the approval of Qnexa due to a number of safety concerns.
The concerns raised included long-term side effects such as increased heart rate, possible birth defects psychiatric problems. Scrutinisation of the safety data was expected following a long history of safety concerns among antiobesity drugs.
Although the FDA advisory panel held no concerns regarding the effectiveness of Qnexa as a weight loss pill, the vote indicates that the majority of the members believe that the benefits of Qnexa do not outweigh the risks for the new diet pill.
How Will Safety Concerns Affect New Diet Pill Qnexa’s Availability?
The FDA will take the advisory committee’s recommendation into consideration when undertaking its own evaluation of the clinical data submitted in Qnexa’s marketing application; however, the agency can still approve the weight loss drug and is expected to make the final decision regarding Qnexa's availability by October 2010.
In a Vivus press release issued the same day, CEO Leland Wilson commented, "While the final vote was close, and we are encouraged that the Committee recognized the efficacy demonstrated in the Qnexa clinical trials, we will work closely with the FDA leading up to our October 28, 2010 PDUFA date to address the labeling and safety questions raised during today's proceedings."
Following the concerns raised regarding the potential long-term side effects of Qnexa, it is likely that the FDA will request Vivus to undertake further long-term studies in certain patient populations in order to help establish the safety profile for the new weight loss drug before it comes to market.
The safety concerns for Qnexa are also expected to impact on the approval of two other late-stage diet drugs, lorcaserin and Contrave, which have also been filed for FDA approval as weight loss pills in the treatment of obesity and overweight patients with comorbid conditions.
Sources:
Polack, A, 2010 "F.D.A. Panel Votes Against Obesity Drug", New York Times, July 15 2010
Vivus, 2010, "VIVUS Comments on FDA Advisory Committee Panel Meeting on QNEXA(R) (phentermine/topiramate) Controlled Release Capsules for the Treatment of Obesity", July 15 2010
Christine Redmond - My interest in science and healthcare has seen me working in the laboratory with tiny cells and DNA to helping set up a cancer clinical ...
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