It is being billed as a propitious moment: The Vivus investigational weight-loss drug Qnexa got a ringing 20-2 endorsement from an FDA advisory panel this month. That vote marked a sharp turnaround from the panel’s verdict just two years ago and one that bodes well for approval.

However, there remain many hurdles, including how to go about marketing the drug if it gets regulatory approval April 17.  “We have limited sales and marketing experience and no sales capabilities,” the company noted in a recent quarterly filing.

The sector has a wide range of touch points in the healthcare industry that includes family practitioners and internists, a category that spans tens of thousands of professionals in the US. How Vivus intends to reach them  remains to be seen. The company refused to comment on its commercial strategy or whether it will consider a contract sales firm.

Vivus has would-be competitors Orexigen and Arena on its heels. Both of these companies’ weight-loss products had poor showings in front of the same FDA panel in 2010 and both are hoping for better results this year. Orexigen’s Contrave combines bupropion, which is used in smoking cessation therapy and to treat depression, and naltrexone, which is used for alcohol and opiate addiction. The company lost out two years ago because its results just missed the FDA’s heart safety requirements and had to go back and do another study. Arena’s second-chance drug, lorcaserin, is a selective uptake agonist that the FDA panel dismissed in 2010 over heart valve concerns and reports that it caused cancer in lab rats.

Of particular note is that an FDA nod would not necessarily mean Vivus could simply seize the marketplace with a massive promotional push. In addition to REMS that could limit the patient pool and other restrictions (as noted by Forbes’ Matthew Herper), Qnexa would be in uncharted waters as the first blockbuster weight-loss drug.

In fact, the category’s sales records follow the yo-yo trends that many dieters experience in their own efforts to lose weight. Roche’s Xenical (orlistat), the only approved prescription anti-obesity brand, hit a relative sales high point in 2007 before succumbing to an uninterrupted sales slide. Sales of the drug totaled just $33.3 million last year, according to Wolters Kluwer Pharma Solutions. Even generic phentermine HCL, which answers our American fondness for swift results, has been somewhat lackluster: last year’s US sales were just shy of $232.5 million, a number which has budged only slightly over the last three years.

Price does not appear to be a reason for lack of traction among drugs in the category. Take Alli, GlaxoSmithKline’s over-the-counter version of Xenical. It is everywhere and is relatively cheap: a quick scan of Amazon shows that a 120-pill bottle can be had for just over $100. Yet sales have not been on fire, and GSK has put Alli up for sale along with a number of other consumer brands.

The problem behind the slack sales may have something to do with the patient. Consumers tend to stop taking the pills, but weight-loss and maintenance require a sustained effort. Even Vivus’ two-year study notes that success requires a combination of pharmaceutical therapy and lifestyle modifications.

Dr. Louis Aronne, Director of the Comprehensive Weight Control Program at NY-Presbyterian/Weill Cornell told MM&M in a phone interview that this all-points component toward weight-loss is a critical part of the success narrative, as is a distinction between how the medical community and patients need to frame the issue of obesity.
Nor will Qnexa necessarily be appropriate for the masses. “This is an obesity treatment not to be confused with a weight-loss medicine. This is not for someone who wants to lose 10 pounds. This is a treatment for someone who has a BMI of 30. For people who have health problems associated with their weight” he said.

Aronne also notes that Qnexa is also stepping in just as physicians are getting a better lock on what triggers obesity, such as the biological changes that make it more difficult to lose weight once it’s packed on, diluting the credence that diet and exercise are the sole remedies.

“We have to step up and start using these things in a carefully controlled manner.  This is one of the key issues, which is it can’t be ‘you want to lose five pounds, sure, take Qnexa. This is not what it’s all about,” he said.

The drugs themselves also have serious risks. Qnexa has been linked to memory loss, heart damage and birth defects. This is in addition to contending with the category’s baggage, which extends far beyond the hallmark 1997 Fen-Phen recall over heart valve damage.

For example, Abbott Labs had to yank Meridia from shelves two years ago because of an increased risk of heart attack and stroke, and orlistat continues to face hurdles. Although Xenical retains the FDA’s seal of approval, the government agency issued a warning in 2010 that orlistat may cause severe liver damage, a setback for the Roche drug as well as GSK’s version, Alli. Consumer watchdog group Public Citizen is pushing for the drug to be pulled. There are also the more visible side effects: orlistat works by blocking fat absorption and may affect bowel control.

There are surgical options, but  gastric banding and gastric bypass have their drawbacks. With banding, a process that cinches the stomach to reduce food intake, those include the possibility that the band may slip or leak. With gastric bypass, which essentially rearranges the digestive tract, they include a high risk for nutritional deficiencies as well as nausea, dizziness and bloating.

Aronne says these limits are why Vivus, Orexigen and Arena are being so dogged about getting their drugs into the market. There is a clear need for more options. He said part of this need includes a new approach that includes “having physicians lead the treatment and it needs to be led by medical treatments that have been proven to be safe and effective and less invasive [than] surgical options.”

The demand is clearly there. A ComPsych study released on Monday shows that excess weight was the top health concern of the 43% of polled employees, and the Centers of Disease Control is unsparing it its assessment of obesity, calling it out as a national epidemic that is the trigger for multiple conditions including diabetes and cancer.