on the walls of the stomach, which is thought to send a signal to the brain that says the person is full, and it’s time to stop eating. Eventually, stomach acids then shrink the particles during digestion, so they release the water, and they can travel with any food to the small intestine. The particle can re-swell to an extent at that part of the journey, Gelesis says, which increase the viscosity in the small intestine so that sugars and fatty acids get absorbed more slowly there. The hydrogels then proceed to the large intestine, release their water, and disintegrate. The Gelesis product is designed so it never gets absorbed into the bloodstream like a drug.
That’s the idea, and the rat study offers some incremental support for the concept. It’s important to note that the Gelesis capsules don’t last in the stomach for a full 18 hours. So if the drug was only working there, it would likely have a much more temporary effect. The longer-lasting effect in rats suggests that the Gelesis capsule is having an effect during the digestive process, as food passes through the small intestine, says Hassan Heshmati, Gelesis’ chief medical officer, and the lead author of the study.
Not every rat responded exactly the same way to the Gelesis treatment, the scientists noted in their poster presentation. That’s probably because some rats were young and actively growing, and doses of the capsule weren’t adjusted accordingly, Heshmati says.
The idea behind Gelesis has been around in academia for more than 15 years, but it got a big commercial push back in January 2008 when the company raised $16 million from OrbiMed Advisors, Queensland BioCapital Funds, Puretech Ventures, and others.
A number of other drugs that work through central nervous system pathways have failed in the past because they were linked to damaged heart valves, or suicidal thinking. That has created plenty of regulatory risk in the field, as expert advisors to the FDA have in the past couple of months in public meetings to review new drug applications from Mountain View, CA-based Vivus (NASDAQ: [[ticker:VVUS]]) and San Diego-based Arena Pharmaceuticals (NASDAQ: [[ticker:ARNA]]).
While Gelesis notes that its treatment is designed to work in a different way, the FDA is on high alert about any safety concerns with weight loss drugs that could potentially be taken by millions of people with a non-life threatening condition. Plus, there’s still a lot of basic research being done to identify multiple genetic factors that might contribute to obesity, meaning scientists don’t really know what causes some people to become more overweight or obese than others.
All of that makes obesity one of the toughest markets to crack for drug developers. The clinical trials will be long, expensive, and risky, but there’s no question that if Gelesis can prove its concept in later trials, it will have a big commercial opportunity.
