Today, the FDA refused to approve the new drug application for Qnexa (Vivus Pharmaceuticals: VVUS), a combination weight loss drug that has been touted as one of the best new weight loss drugs in 10 years. The vote by the panel was 6 in favor, and 10 opposed.

What is interesting is that the panel had no issue with the effectiveness of this drug. In fact, the data presented was extremely compelling as to not only weight loss, but reduction of blood pressure, lipids and blood sugar levels. It also resulted in significant improvements in sleep apnea.

Where the panel had issues was in the safety data. There were several concerns raised:

• Elevated heart rate: no mystery here... phentermine, the other half of Qnexa, raises blood levels of norepinephrine (a cousin of adrenaline.) This would clearly result in higher resting heart rates. However blood pressure readings in patients on the drug actually dropped, and there were no cardiovascular problems (heart attacks, stroke) in the users (but there were in the placebo group!) And phentermine has been around for at least 40 years without any concerns.
• Depression: here there was an increase incidence of reports of depression. It was generally considered mild to moderate, and reversed with withdrawl of the drug. There were no suicides in the treatment group. Since patients will always be under doctor supervision, it is a simple matter of the treating physician telling the patient to stop the drug if they have such side effects.
• Metabolic Acidosis: a very small number of patients seems to develop this during treatment, and again it reversed completely with stopping the drug. Mechanism is unclear and should warrant further study.
• Cognitive problems:  Topiramate is known to cause drowsiness, especially at higher doses. However the balancing effect of the phentermine seems to offset this in clincial practice. Should carry same warning as would Topamax but should not stop approval. One panel member was concerned that pilots be warned of this effect. Seems he doesn't know that Topiramate is on a "no fly" list of drugs from the FAA already, so this seems a moot point.
• Safety in pregnancy:  this one is a bit baffling to me. There were 13 pregnancies in the Qnexa group, despite subjects being required to use 2 forms of birth control. However there were no birth defects seen. One of the components contained in Qnexa is Topiramate (Topamax^TM) which has been shown to increase birth defects. However the doses used in Qnexa are about 25% of the doses studied for Topamax^TM. In addition, obesity itself creates a huge preganancy risk for both mother and baby. Any weight loss prior to pregnancy could be helpful. And since no other drug is ever approved for use in pregnant women, what is the panel's concern?

So what's the bottom line? The FDA panel wanted more safety data, and felt that one year's worth of studies was not enough to satisfy them. Reasonable stance, considering how much heat they've taken from other recently pulled drugs (Vioxx, Redux, etc.) 

On the other hand, obesity is projected to directly cause over 400,000 deaths each year. This is a medical crisis crying out for new treatment options. I've personally been prescribing this combination as an off-label treatment for obesity for over one year now. I can assure you that it is a safe and effective alternative to current treatment options and a tremendoulsy powerful addition to my tools to help patients struggling with obesity. »click here for video on Qnexa

My prediction:  this drug will eventually gain FDA approval (12-24 months) and will be a blockbuster. The stock will take a hit tomorrow, but for investors with a strong stomach and cash to burn.. this could be a great deal!