FDA Approves Belviq As Weight Loss Drug

After 13 years, Arena Pharmaceutical’s Belviq is the first weight loss drug to be approved by the FDA. Here is what it does, how safe it may be and if it really is effective.

What Is Belviq?

The active ingredient in Belviq is lorcaserin, which attaches itself to parts of serotonin, one of the brain’s neurotransmitters and partly responsible for feelings of satiety. Partly responsible, because serotonin is also involved in controlling mood; a lot of antidepressants rely on influencing the amount of serotonin in the brain. Arena Pharmaceutical, however, claims that Belviq only affects the portion of serotonin responsible for appetite.

Belviq apparently works, but its contribution to weight loss so far seems to be rather lightweight, if you excuse the pun. When in studies run by the manufacturer, no less, it was compared to a placebo, people taking Belviq lost an average of 3 – 3.7 percent of their initial body weight over the course of twelve months. In other words: a man weighing 200 lbs may lose a meager 6-7 pounds on Belviq, if he used it for a year.

The Risks

There was a reason why it took the FDA 13 years to approve another weight loss drug: in two of the last three times when the agency went ahead and gave their nod, they later found themselves in the middle of what more or less was a disaster. Fen-phen, approved in 1996, was soon found to cause pulmonary hypertension and heart-valve abnormalities. Sibutramine, approved in 1997, was taken off the market in 2010, when more and more evidence for increased risks of heart attacks and strokes surfaced.

What’s especially interesting about this is that Belviq relies on a mechanism rather similar to fen-phen: fenfluramine, the “fen” in “fen-phen”, worked by influencing serotonin as well. When in 2010 Arena first tried to get Belviq approved, the FDA rejected it, based on studies that showed that it might cause tumors in rats and, indeed here we go again, heart problems in people.

Arena made up for it by presenting some new studies earlier this year, that apparently showed smaller side effects. On June 27, this lead to the drug finally being approved officially, with Arena being required to monitor lorcaserin’s safety with six further studies after it hits the shelves.

Is The FDA Under Pressure?

Are those six studies precaution or a fig leaf in front of an approval process that leaves some questions?

Cardiology professor Dr. Sanjay Kaul, member of the FDA’s approval council, voted against the approval, saying that “given the totality of evidence, the potential benefits of [lorcaserin] do not outweigh the potential risks”. Even a panel member that had voted in favor remarked that he was “not at all convinced” about Arena having provided enough evidence for lorcaserin’s safety.

With statements like these, and knowing about the FDA’s previous experiences with a similar drug, one does wonder why lorcaserin went through at all. The FDA has been under a lot pressure to finally approve another weight loss drug and I dearly hope that it was not this pressure that lead to the approval.

What This Means For You

It will take some time before lorcaserin hits the shelves under the moniker “Belviq”, but I wouldn’t hold my breath for it. The weight loss effect is small, but the risks could be high.

Pictures courtesy of “e-Magine Art“.