In October 2021, the FDA approved the Spatz3, the first adjustable intragastric balloon (aIGB) available in the U.S. It’s indicated for temporary use—up to eight months—for weight loss in adults with obesity who have failed to achieve and maintain weight loss through a supervised weight control program.
IGBs are placed endoscopically into the stomach to alter appetite and facilitate rapid initial weight loss. The novel feature of the Spatz3 is that its volume can be endoscopically adjusted in response to the patient’s individual needs—upward to augment weight loss or downward to mitigate intolerance.
In The Lancet, Christopher C. Thompson, MD, the director of Endoscopy in the Division of Gastroenterology at Brigham and Women’s Hospital and co-director of the Center for Weight Management and Wellness, Barham K Abu Dayyeh, MD, of the Mayo Clinic, and colleagues report on the manufacturer-sponsored trial that informed the FDA approval.
288 patients were enrolled in the open-label trial at seven U.S. sites between August 9, 2016, and December 7, 2018, and were randomly assigned 2:1 to receive the aIGB plus dietary and exercise counseling, or dietary and exercise counseling alone for 32 weeks.
The initial balloon volume was based on patient height and history of gastroesophageal reflux disease. The volume could be increased by 250 mL if the patient did not respond within two weeks and could be decreased by 100–150 mL (to a minimum of 300 mL) for symptoms of intolerance.
At 18 weeks (±4 weeks), patients meeting certain criteria could have the volume increased (to a maximum of 1,000 mL) to induce greater weight loss. At the end of 32 weeks, the aIGB was removed and patients were followed for 24 more weeks.
Prespecified definitions of clinical success were met on all endpoints:
- Percentage total weight loss (co-primary endpoint), with clinical success in the aIGB group defined as loss >4.5% of the mean loss of the control group at 32 weeks—The results were 15.0% in the aIGB group vs. 3.3% in the control group (P<0.0001); the difference of 11.7% exceeded the prespecified margin
- Clinical response (co-primary endpoint), defined as ≥5% total weight loss at 32 weeks, with success specified as a clinical response rate >50% in the aIGB group—the rate in the aIGB group was 92%
- Short-term weight loss maintenance, defined as maintenance of 40% of total weight loss six months after device removal, with success specified as weight loss maintenance in ≥50% of the aIGB group—74% of the aIGB group maintained their weight loss
- Excess weight loss, with success specified as excess weight loss ≥25% at 32 weeks—84% of the aIGB group met that performance criterion (using BMI of 25 kg/m2 as ideal)
70% of the aIGB group underwent upward adjustments at week 18 that resulted in an additional mean of 5% of total weight loss. At week 32, total weight loss was 3% greater in those who had upward adjustments than in those who did not.
The decision to increase aIGB volume should be balanced against the presence and degree of ulcers and esophagitis. Decreases in volume to address symptoms were effective for avoiding premature extraction, but downward volume adjustment must be accompanied by a thorough risk stratification and severity assessment.
There were no deaths, balloon deflations with migration into the small intestine, obstructions, pancreatitis or esophageal or gastric perforations.
The most commonly reported non-serious adverse events were nausea, dyspepsia, vomiting and abdominal pain. Most occurred during the first few days after balloon placement and were manageable with medication or downward adjustment.
24 separate device-related serious adverse events were observed in seven patients in the aIGB group (4%). The most common were nausea, vomiting, metabolic or nutritional disorders, dehydration, abdominal pain and diarrhea. All resolved with no long-term consequences.
The FDA specifies that the Spatz3 is to be used in conjunction with a long-term supervised diet and behavior modification program. The agency has issued a warning about potential risks with other liquid-filled intragastric balloons, and clinicians should inform themselves of the contraindications to Spatz3 use as listed in its Summary of Safety and Effectiveness Data.