Swallowable gas-filled balloon: a new weight-loss aid?

Last Updated: 2016-05-24

By Megan Brooks

NEW YORK (Reuters Health) - People with obesity might soon have a new non-invasive treatment option - swallowing gas-filled balloons that help them eat less.

In a study, obese adults lost nearly 7% of their weight, on average, after using the Obalon 6-Month Balloon System from Obalon Therapeutics. They also saw significant improvement in other health measures, such as blood pressure and cholesterol levels.

Dr. Shelby Sullivan, director of bariatric endoscopy at Washington University School of Medicine in St. Louis, reported the findings May 24 in San Diego at Digestive Disease Week (DDW) 2016.

The study shows that this balloon system can help patients lose "almost twice as much weight compared with lifestyle changes alone. This is important because weight loss is very difficult and a significant number of people are not successful in achieving their weight loss goals with diet changes and exercise," Dr. Shelby said during a conference press briefing.

The study was conducted at 15 sites in the United States and included adults with a body mass index (BMI) between 30 and 40 kg/m2. They were randomly allocated to a treatment group or a control group. Those in the treatment group swallowed three capsules (one every three weeks) that each contained an Obalon balloon. Immediately after swallowing the capsules, the balloons were filled with 250 cc of a nitrogen-based gas through a small catheter attached to the capsule. The control group swallowed three sugar-filled capsules on the same schedule and the researchers mimicked the process of filling the sugar capsule with gas.

Of the 387 people who initially enrolled, 366 swallowed at least two capsules and completed 18 weeks of lifestyle therapy that included diet, exercise, and behavior modification, and were subsequently included in the per protocol analysis, with 185 in the active treatment group and 181 in the control group. Twenty-four weeks after the patients swallowed the first capsule, the balloons were removed endoscopically and pertinent assessments made.

In the active balloon treatment group, average total body weight loss was 6.81% compared with 3.59% in the inactive control group, Dr. Sullivan reported.

"Significantly," she said, 64.3% of adults with the gas-filled balloon achieved at least a 5% total body weight loss, compared to only 32% of the control group with sugar-filled balloons.

"The 5% total body weight loss threshold is important for this pivotal trial because it helps establish treatment efficacy as defined by the Food and Drug Administration. This study required that at least 35% of patients lost at least 5% total body weight and this trial achieved almost twice that requirement," Dr. Sullivan said.

Improvements in systolic blood pressure, fasting glucose, low-density lipoprotein cholesterol, and triglycerides were also seen in the active treatment arm but not in the control arm.

"While nine of 10 patients experienced some discomfort such as abdominal cramping and nausea, all of them rated the side effects as mild to moderate and most were resolved with no treatment or with homeopathic or over-the-counter treatments," Dr. Sullivan reported. "There was only one serious adverse event possibly related to the device."

"While patients in our study who used this balloon system had a nearly 7% total body weight loss, I believe that, once this system is used in the 'real world,' patients may experience more weight loss than that," Dr. Sullivan predicted. "This projection is based on the fact that we've seen other weight-loss interventions help people lose more weight than they lost during sham-controlled clinical trials," Dr. Sullivan said.

The researchers are following the patients in the gas-filled balloon arm to understand the long-term potential of this treatment after the balloons are removed.

Dr. Sullivan received funding from Obalon Therapeutics to conduct the study.