• by Thom Forbes , February 23, 2012

In what by most accounts is a “surprising” reversal, a Food and Drug Administration advisory panel has voted 20 to 2 to recommend that Qnexa, an anti-obesity pill made by Vivus that it advised against by 10 to 6 in 2010, be approved for use by doctor’s prescription. The FDA, which usually, but not always, follows the advice of its outside experts, is expected to make a final decision by April 17.

If the FDA gives Qnexa the okay to proceed to market, the pill will find its target sizable in more ways that one: More than one-third of Americans over 20 are classified as obese, according to the Centers for Disease Control and Prevention. Vivus stock, which is listed on NASDAQ, rose 97% on the news in after-hours trading.

Vivus says it will market Qnexa to people who meet the CDC’s definition of obesity -- those who have a Body Mass Index of at least 30 -- leaving the additional one-third of Americans who are merely classified as overweight to rely on exercise and diet for now. It will also advise people who lose less than 3% of their body weight after three months on the drug to stop taking it.

“Some committee members who opposed it last time said they were reassured this time that steps would be taken to minimize the risks, such as by making it hard for pregnant women to get the drug,” writes Andrew Pollack in the New York Times. [Studies show an increase in cleft lip among infants whose pregnant mothers took Qnexa.] “They also seemed persuaded by the view expressed by Vivus and by some obesity specialists who testified at the hearing that obesity itself causes health problems and that there is a pressing need for treatments.”

Vivus has proposed a tightly controlled system for prescribing Qnexa, writes Shari Roan in the Los Angeles Times. Among the precautions: women of child-bearing age will have to take monthly pregnancy tests, heathcare providers will receive special training on risks and benefits and distribution will be limited to registered pharmacies.

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

Elaine H. Morrato, an assistant professor at the University of Colorado, Denver, who had previously voted against approval, was one of the panelists who were won over by the arguments. “I believe that Qnexa demonstrated a meaningful efficacy benefit and that there are consequences to non-treatment of obesity,” she said.

Despite the “near overwhelming support, concerns about [the] drug’s safety continue,” according toWebMD Health News. Although clinical trials demonstrate that Qnexa “has a favorable effect on most heart disease risks, including weight, blood pressure, HDL, and progression to diabetes, it also appears to raise heart rate, which increase heart attack risk, reports WebMD’s Rita Rubin.

“I remember the cases of the anti-arrhythmic drugs. They were supposed to save lives, but they ended up killing people,” said Michael Lauer, M.D, director of the Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute, who was one of the two nay votes yesterday. Writes Rubin: “Approval of Qnexa at this stage, [Lauer] said, would be based on ‘hopes and suppositions.’”

The drug could generate sales of $448 million by 2015, writesBloomberg Businessweek’s Anna Edney, who also reports that diabetes, heart attacks and strokes cost the U.S. economy an estimated $147 billion a year in medical expenses and lost productivity. But even with all that money on the table, developing a magic pill that will melt away the fat has been elusive.

“The development of obesity compounds has been a tough area for companies since the fen-phen drug combination was taken off the U.S. market in 1997, after one of the medication's components was linked to heart-valve damage, points out Jennifer Corbett Dooren in the Wall Street Journal. “Abbott Laboratories removed its weight-loss drug Meridia from the U.S. market in 2010 amid concerns about the drug's risk of side effects like heart attack and stroke.”

The only other prescription drug combating obesity that’s currently on the market, Roche's Xenical, has possible side effects that includes “bowel movement urgency” and “flatus with discharge,” according to Drugs.com. A study published in the Archives of Internal Medicine last year observed kidney problems in a few patients but one of the authors cautioned that it does not “prove causality,” reports Reuters’ Frederik Joelving.

"This is an important study and it illustrates that anyone taking so-called 'weight loss' drugs should be under the care of a trusted physician," Dr. Donald E. Greydanus, a pediatrician who has written on obesity, told Joelving at the time. "There is no safe panacea drug that works and that has no side effects."

For the record, Qnexa is “not a valid Scrabble word” and no recorded pronunciation yet exists on Wordnik, where it has been looked up 131 times. Special Thursday bonus offering: If you’ve got a “q” and “n” but no “u,” try “tranq.”