Amylin, Dark Horse of the Obesity Drug Battle, Follows Fast Behind Arena, Orexigen

as less-obese patients. The full one-year results aren’t in yet, and haven’t been presented at a medical meeting or in a peer-reviewed journal. And the Amylin combination still has to be injected twice daily, while other drugs can be taken as oral pills, so it remains to be seen how many injections obese patients will be willing to put up with.

How well does the Amylin drug combo stack up against competitors? That’s hard to answer because none of the clinical trials results released this year have directly compared new drugs head-to-head. But all compared themselves to a placebo, and measured the percentage of body weight lost in the drug and the placebo groups. The FDA has said it wants to see at least 5 percentage points of greater weight loss with a drug than with placebo, meaning that if people lose 1 percent of their body weight on a placebo, they should lose at least 6 percent on the drug.

This spread between the drug and placebo is called “placebo-adjusted weight loss.” So based on the high-doses in the moderately overweight population Amylin had a 9.2 score on placebo-adjusted weight loss—easily clearing the FDA’s standard.

Vivus (NASDAQ: [[ticker:VVUS]]) made national headlines last week when it offered what it called “unprecedented” effectiveness. Its best reported clinical trial produced a 9.4 percentage points of greater weight loss on average than placebo. In separate studies, Orexigen’s biggest advantage over placebo was 5.2 percentage points, and Arena Pharmaceuticals showed a 3.6 percentage point advantage earlier this year.

To be fair, weight loss isn’t the only thing being measured in these studies, and the FDA has other criteria for determining whether an obesity drug is effective enough

Author: Luke Timmerman

Luke is an award-winning journalist specializing in life sciences. He has served as national biotechnology editor for Xconomy and national biotechnology reporter for Bloomberg News. Luke got started covering life sciences at The Seattle Times, where he was the lead reporter on an investigation of doctors who leaked confidential information about clinical trials to investors. The story won the Scripps Howard National Journalism Award and several other national prizes. Luke holds a bachelor’s degree in journalism from the University of Wisconsin-Madison, and during the 2005-2006 academic year, he was a Knight Science Journalism Fellow at MIT.