Early Results Arrive on Weight-Loss Pills That Expand in the Stomach

It is a tantalizingly simple idea for losing weight: Before meals, swallow a capsule that temporarily swells up in the stomach, making you feel full.

Now, some early results for such a pill are in. And they are only partly fulfilling.

People who took the capsule lost 6.1 percent of their weight after 12 weeks, compared with 4.1 percent for those taking a placebo, according to results presented Sunday, June 22, 2014, at an endocrinology meeting in Chicago.

Gelesis, the company developing the capsule, declared the results a triumph and said it would start a larger study next year aimed at winning approval for the product, called Gelesis100.

In fact, the physical mode of action could make the product safer than many existing diet drugs, which act chemically on the brain to influence appetite.

But an endocrinologist at the University of Colorado who was not involved in the study, said weight loss of 2 percent beyond that provided by a placebo was “very modest.”

“It doesn’t look like a game changer,” he said.

Gelesis, a privately held company based in Boston, is one of many trying to come up with a product that can provide significant weight loss without bariatric surgery.

Two new drugs — Qsymia from Vivus, and Belviq from Arena Pharmaceuticals and Eisai — have had disappointing sales since their approvals in 2012. Reasons include modest effectiveness, safety concerns, lack of insurance reimbursement and a belief among some doctors and overweight people that obesity is not a disease.

Two other companies, Orexigen Therapeutics and Novo Nordisk, hope to win approval for their obesity drugs this year.

Last week, investors clamored to buy shares in the initial public offering of Zafgen, whose obesity drug beloranib produced an average weight loss at least 5 percentage points greater than placebo in a 12-week clinical trial. Patients who took the highest dose for all 12 weeks lost 10.3 percentage points more than those on placebo, though most people on that dose quit early because of side effects.

Also last week, an advisory committee to the Food and Drug Administration endorsed, though somewhat weakly, a device developed by EnteroMedics that is surgically implanted and delivers electric pulses to a nerve that helps control hunger and digestion.

Gelesis100, which is considered a medical device rather than a drug, consists of tiny particles made of two substances already used in food. The company has not identified those substances.

The particles absorb the water and swell to 100 times their original size in the stomach, mixing with food to create greater volume. After the particles travel through the small intestine, enzymes in the large intestine degrade them, and they release the water and are excreted.

The study involved 128 overweight or obese Europeans who swallowed a capsule before lunch and dinner along with half a liter, or about 17 fluid ounces, of water. They were also put on a reduced-calorie diet.

The 6.1 percent weight loss occurred in the patients who took the lower-dose pill. Those who got a higher dose lost an average of 4.5 percent of their weight, basically the same as the placebo group.

Gelesis executives said that was probably because 24 percent of patients on the higher dose stopped taking the capsules, which could cause bloating, flatulence, abdominal pain and diarrhea. Only 5 percent of patients on the lower dose dropped out, none because of side effects. 

Yishai Zohar, chief executive of Gelesis, said weight loss was continuing and would have been greater if the trial had been longer. He added that the placebo might have helped people lose weight because it was made of cellulose, which is already used as a fat substitute in foods.

He also noted that the weight loss was much greater in people with higher blood sugar levels and that the capsule helped lower blood sugar.

Gelesis100 is similar in concept to balloons that are inserted through the mouth into the stomach and then inflated. These are not approved in the United States because of issues of safety with an older model.

A company called ReShape Medical plans to apply this year to the F.D.A. for approval of a balloon it says solves some of the earlier problems. It could become the first nonsurgical weight-loss device to win approval in decades.

The advantage of a capsule like Gelesis100 is that the stomach filling occurs only at mealtimes, while the balloon stays in place round the clock, though it should be taken out after six months. But that could also be its disadvantage. Someone anticipating a sumptuous feast could simply not take their Gelesis capsule. And over time, people tend to stop taking diet pills altogether.

With the balloon process, the patient makes a commitment up front. The balloon is in.