FDA to Determine Diet Drug's Fate

Coming up with a viable weight loss drug is tricky business for pharmaceuticals nationwide; despite a relatively poor track record, however, three drugs are ready to seek approval from the FDA.

Qnexa

Qnexa, which is manufactured by Vivus came under scrutiny at the beginning of the week; the FDA is expected to announce the fate of the drug on Thursday afternoon.

The great thing about Qnexa is that as a tool for weight loss, it not only works, it works well.  To be considered for approval by the FDA, a diet drug must reduce body weight by at least 5%; in that regard, Qnexa shines by allowing obese patients a 13-15% reduction in girth.  However, of the three drugs under scrutiny, Qnexa had the highest drop-out rate in clinical trials.

The problem is that Qnexa has some risks; in essence, the FDA must determine whether or not the weight loss benefit outweighs those risks.  There is a small, but increased threat of both heart palpitations and cognitive problems, such as memory loss.

The drug’s effectiveness is due to the fact that it is a combination of two different drugs already on the market, phentermine and topiramate.     Phentermine is a stimulant that has been approved by the FDA for weight loss; topiramate, an anti-convulsive used to treat seizures, provides feelings of satiety. 

The Competition

Meanwhile, Arena Pharmaceuticals is slated to present lorcaserin to the FDA panel in September.  Lorcaserin had the least number of side effects, but alas, just as with Qnexa, there is a downside to the drug:  it’s not as effective as the others.  In clinical trials, the drug caused study participants to lose the bare minimum requirement to be considered a viable diet drug, 5% of body weight.

Orexigen Therapeutics’ contribution to the weight-loss mix is Contrave, which will come under review in December, according to the Associated Press.
 
Problematic Diet Drug History

For all of the pharmaceutical breakthroughs over the last couple of decades, diet drugs have consistently come under fire.  Many times, the side effects outshine the positives.  At no time was this more true than with fen-phen, which was manufactured by Wyeth.

Pulled off the market in 1997, the drug dramatically increased risks of a rare heart valve disorder discovered by the Mayo Clinic.  Like Qnexa, fen-phen was also a combination drug comprised of phentermine and fenfluramine; fenfluramine was deemed to be the source of both health issues.  Phentermine, an amphetamine, is also half of the Qnexa equation.

More recently, alli and its prescribed counterpart Xenical were required to enhance label warnings to advise the public of a small risk of liver injury.

On Thursday, stocks of Arena Pharma “skyrocketed”, according to the Wall Street Journal.