Gelesis declares a weight-loss victory, but a critic pans new therapy

The Boston-based biotech Gelesis has a pair of high-profile godfathers from the research world, a fresh $12 million venture round and an intriguing new approach to treating obesity that steers clear of the brain-targeting chemicals now struggling to gain traction on the market. But the new data put out this morning fell flat with at least one of the experts in the weight-loss field.

The bottom line on the experimental Gelesis100, which is made up of particles found in food designed to swell up in the stomach ahead of mealtime, is that the low-dose arm lost an average of 6.1% of their weight, compared to a 4.1% loss in the placebo arm. There was no difference in results between the high-dose arm and the placebo. But that two-point difference for one group looked like a big win to Gelesis, especially when a larger effect was tracked for a group of "prediabetic" patients in the study.

"These results are exciting and show that Gelesis100 has the potential to provide a truly novel alternative for weight loss that does not involve surgery, injections, or systemically absorbed drugs," said lead study investigator--and Gelesis advisor--Professor Arne Astrup, from the University of Copenhagen.

The New York Times' Andrew Pollack got an early look at the results ahead of today's release. He ran the numbers by Daniel H. Bessesen, an endocrinologist at the University of Colorado, who was anything but excited. The result, he said, was "very modest. It doesn't look like a game changer," he added to the Times.

That's not something any biotech would like to read about itself in The New York Times.

Gelesis execs take a radically different tack, telling Pollack that they are now on track to execute a pivotal study on the treatment, which will be developed as a medical device and is expected to be prescribed much like a new drug. The key advantage to this treatment, says the biotech, is that patients can safely take the therapy ahead of a meal and then quickly excrete the product.

 "Gelesis100 is a new class of therapy, an orally administered capsulated device, where each capsule contains thousands of tiny hydrogel particles that expand in the stomach and small intestine," said Gelesis CEO Yishai Zohar, whose company has been bankrolled in part by PureTech, a venture group run by his wife, Daphne Zohar. "The product is designed to increase the volume and elasticity of the stomach and small intestine contents, delaying gastric emptying, and leading to longer post-meal satiety with subsequent weight loss."

That's an approach that won the support of John LaMattina, the former Pfizer ($PFE) R&D chief who's chairman of Gelesis, and the influential MIT scientist Robert Langer, who has helped spawn a long lineup of biotechs, including Bind ($BIND) and Selecta.

The data, though, fall short of the impact seen from new weight-loss drugs like Vivus's ($VVUS) Qsymia and Belviq, now marketed by Arena and Eisai. Orexigen is a few months away from getting another verdict from the FDA on its new drug and Zafgen has been toiling away at a drug that so far has produced very promising results.

The market for weight-loss drugs has been badly hampered by insurer's reluctance to cover the therapies, marginal weight-loss results seen in the clinic and lingering worries about their safety. Gelesis just may have tackled one element in that equation, but the rest are still troublesome threats to the company's quest.

- here's the release
- here's the article from The New York Times (sub. req.)