Second-gen take on Acomplia significantly trims body weight

Scientists working on a new obesity drug program at Denmark's 7TM Pharma say they've seen dramatic weight loss in rodents treated with a second-generation cannabinoid receptor blocker. And they say that they could be on to a successor to rimonabant, also known as Acomplia, which was yanked from the European market two years ago due to the troubling risk of psychiatric side effects.

This new drug, TM38837, is designed to work in human tissue and organs, but not the brain. This is where rimonabant ran into trouble--a number of patients on Acomplia complained of severe depression and suicidal thoughts. In fact, the experimental therapy looks just as effective as rimonabant in trimming weight. In mice, the drug was associated with a 22 percent to 26 percent drop in body weight compared with a placebo. Furthermore, drug-treated rats had 14 percent lower body weights than placebo-treated rats, PhysOrg reports.

"This is, to our knowledge, the first peripheral CB1 drug candidate being tested in humans and these results indicate its development as a potential new treatment should be advanced," says Christian Elling, a vice president at 7TM. "These findings, together with what we have seen in our first human study regarding the safety and tolerability, make this drug candidate a promising therapy for obesity and diabetes. The lack of significant exposure in the brain seen in our preclinical experiments provides optimism that blockade of the CB1 receptor may still be an effective and safe approach to treat obesity and related diseases." 

TM38837 has already passed a small human safety study and is being pushed further along in the clinic. Investigators say they're particularly pleased to see that this new therapy appears far less likely than rimonabant to cross the blood/brain barrier.

- here's the 7TM release
- here's the story from PhysOrg