a new obesity drug cross at least one of two thresholds to win an approval: patients on the treatment have to show at least 5 percentage points of body weight loss improvement over a placebo group, or at least twice as many patients on the drug have to lose 5 or 10 percent of their total body weight compared to those on a placebo. It almost goes without saying that for a condition that millions of people have, and that doesn’t imminently threaten them with death, the safety profile of such a drug had better be squeaky-clean.
So how did Orexigen do? About half of the patients in two big trials (48 percent and 56 percent) lost at least 5 percent of their body weight on the Orexigen treatment after little more than a year, which is about three times as many people who did that well in the placebo group (16 percent and 17 percent, respectively.) So far, so good.
Here’s where things get into a little more of a gray zone. The average patient taking the drug in the first trial, COR-1, lost 6.1 percent of his or her body weight, compared with 1.3 percent for those on placebo. The second trial known as COR-2 showed a similar effect, with 6.4 percent average body weight on the Orexigen drug, compared with 1.2 percent in the placebo group. If these trials are pooled together, that means the average patient had exactly 5 percentage points of more weight loss than placebo—the minimum of benefit the FDA wants to see on that important measurement.
The full details of these studies—including a more detailed picture of risk and benefit that the FDA will get to see—will be further analyzed and submitted at scientific conferences and peer-reviewed journals, the company said. The company, as we have written before, will have to compete for market share for this drug with two other companies in the final stages of developing obesity drugs—San Diego-based Arena Pharmaceuticals (NASDAQ: [[ticker:ARNA]]) and Mountain View, CA-based Vivus (NASDAQ: [[ticker:VVUS]]). This battle to create the next big thing for obesity is going to be a story to watch for the next couple years.
