Transpyloric Shuttle Meets Endpoints for Obesity Treatment

Miriam E. Tucker

November 26, 2018

NASHVILLE, Tenn — A novel investigational weight-loss device called the TransPyloric Shuttle (TPS) system (BAROnova) was safe and effective in a 12-month phase 3 pivotal trial.  

Results from the nine-site ENDOBesity II study were presented November 14 here at Obesity Week 2018 by Richard Rothstein, MD, the Joseph M. Huber professor and chair of medicine, Geisel School of Medicine, Dartmouth University, Lebanon, New Hampshire. 

The device, made of silicone, is delivered endoscopically to the pylorus where it self-positions and alters gastric emptying without changing the patient's anatomy. It is designed to remain in place for a year, after which it is removed, again endoscopically.

Both delivery and retrieval procedures are performed as outpatient procedures and take about 15 minutes each, Rothstein said.

The study met both of its coprimary endpoints for mean total body weight loss compared with sham control and percentage of patients with 5% or more of total body weight loss at 12 months. The rate of device or procedure-related serious adverse events was lower than that seen for fluid-filled balloons and just slightly higher than for gas-filled balloons, Rothstein noted.

Asked to comment, Stephen R. Smith, MD, chief scientific officer of Florida Hospital Research Services, Orlando, told Medscape Medical News that it's difficult to compare event rates because the devices haven't been studied in head-to-head trials and the device isn't on the market yet.

But he said he categorizes this device in the same middle area as swallowable balloons and other weight loss devices, between medical and surgical obesity treatments.

"We will need some postmarket surveillance to ensure that there is safety [data] for rare events, and for when the device is outside the hands of expert endoscopists," Smith commented. "When you put [devices] into the community setting you often get different results," he said.

And he pointed out that while traditionally the US Food and Drug Administration (FDA) has required less data for devices than drugs, "increasingly the FDA is looking for more data on the device side."

Pivotal Trial Met Coprimary Endpoints

The study presented by Rothstein randomized 270 patients with a body mass index of 30 to 40 kg/m2 to TPS (n = 181) or sham device (n = 89), and another 32 patients received open-label TPS for additional safety analysis after a minor modification was made to the device's distal bulb. 

Patients were mostly in their mid-40s, were predominantly women, and had a mean BMI of 36 kg/m2

At 12 months, there was a significant 6.7% difference in total body weight loss between the two groups, averaging 9.5% with the TPS versus 2.8% for the sham device (P < .0001). Results of two intent-to-treat analyses were similar.    

The proportion of patients who lost 5% or more of total body weight was 67.0% with TPS versus 59.5% with sham device (P < .0001), and 39.5% versus 14.0% of patients, respectively, lost 10% or more of total body weight (P = .0001). 

Improvements in cardiometabolic risk factors were also seen with the TPS compared with the controls, including reduced blood pressure (P < .05) and improvements in insulin resistance and total and LDL-cholesterol (P < .05).

The TPS group also showed significantly greater improvement in quality of life scores in the areas of physical function, self-esteem, sexual life, and work, Rothstein said, adding that these results will be reported in greater detail in the future.

Few Serious Adverse Events

In the intent-to-treat population, 2.8% of patients experienced device- or procedure-related severe adverse events in the TPS group, compared with 1% of controls. These included one patient each with esophageal rupture, upper abdominal pain, gastric ulcer, vomiting, and gastric obstruction. All serious adverse events resolved.

By contrast, severe adverse events occurred in 7.5% to 10% of patients who received fluid-filled balloon devices and in around 0.3% of those who received gas-filled balloons, Rothstein noted. 

Gastric ulcers were observed endoscopically in 10.3% of TPS recipients. Most were asymptomatic, none developed bleeding or perforation, and all responded to medications with a mean healing time of 73 days.

Other adverse events reported by 10% or more of patients included nausea (64.5% TPS vs 39.3% controls), abdominal pain (63.1% vs 41.6%), and vomiting (62.1% vs 15.7%).

This isn't surprising, Rothstein noted, as overeating would be expected to cause those symptoms because of impaction of the device.

"Patients who were successful modified their behavior. If they over ate, they had discomfort."

However, just 14.8% of patients overall exited the study because of adverse events.

BAROnova submitted a pre-marketing approval application for the TPS for the treatment of obesity to the FDA on July 17, 2018.

The study was funded by BAROnova. Rothstein is on the corporate advisory board of Allurion.

Obesity Week 2018. Presented November 14, 2018.

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