iWAIST Trial: ERCG (Endoscopic Radial Compression Gastroplasty) vs Optimized Lifestyle Intervention for Weight Loss

Official title

iWAIST Trial: A Multicenter, Single-Blind, Randomized, Sham-Controlled Trial of Endoscopic Radial Compression Gastroplasty (ERCG) Plus Optimized Lifestyle Intervention for Weight Management in Chinese Adults With Overweight or Mild-to-Moderate Obesity

Overview

Obesity and overweight are rising in Chinese populations, where metabolic risks begin at lower BMI thresholds than in Western cohorts. Many individuals with overweight or mild-to-moderate obesity are ineligible or unwilling to undergo bariatric surgery due to invasiveness and risk. Endoscopic bariatric and metabolic therapies offer minimally invasive alternatives but vary in complexity, cost, and safety profiles. Investigators developed a sutureless endoscopic procedure, Endoscopic Radial Compression Gastroplasty (ERCG), which reduces gastric volume by apposing gastric walls using a clip-and-loop system. This randomized controlled trial evaluates the efficacy and safety of ERCG versus an optimized lifestyle intervention in Asian adults with BMI 24.0-37.4 kg/m² who have not succeeded with conservative measures. Preliminary studies suggest ERCG can achieve approximately 12% total body weight loss (TBWL) at 3 months. The primary endpoint is percent TBWL at 3 months; secondary outcomes include changes in BMI, metabolic parameters, quality of life, and adverse events. Results are expected to inform the role of ERCG as a safe, effective, and scalable option between conservative care and bariatric surgery.

Detailed description

The prevalence of obesity and overweight continues to increase worldwide, and Chinese populations are particularly vulnerable due to lower thresholds for metabolic risk compared with Western populations. Individuals with overweight or mild-to-moderate obesity (BMI 24.0-37.4 kg/m²) often fail conservative measures but are ineligible or unwilling to undergo bariatric surgery because of its invasiveness, risk, and costs. This creates an unmet need for minimally invasive, effective, and scalable interventions.

Endoscopic bariatric and metabolic therapies (EBMTs) have emerged as alternatives, but many existing procedures involve technically complex endoscopic suturing, high costs, or device-related risks. Investigators developed ERCG, a novel endoscopic procedure that reduces gastric volume by apposing the gastric walls using a newly designed clip-and-loop system. Preliminary studies demonstrated that ERCG can induce rapid weight loss, with mean percent total body weight loss (TBWL) of approximately 12% at 3 months, while maintaining a favorable safety profile.

This randomized controlled trial aims to evaluate the efficacy and safety of ERCG compared with an optimized lifestyle intervention (OLI) in Chinese adults with overweight and mild-to-moderate obesity who have failed conservative weight reduction efforts. Eligible participants will be randomized 1:1 into two groups. The experimental group will undergo ERCG under general anesthesia or deep sedation, following a standardized perioperative protocol, then receive structured OLI. The control group will receive structured OLI consisting of individualized dietary counseling, caloric restriction, exercise prescription, and behavioral support. Follow-up visits are scheduled at 1 month, 2 month, 3 month and 6 month after enrollment.

The primary endpoint is percent TBWL at 3 months, assessed using standardized weight measurement protocols. Secondary endpoints include %EBWL at 3 and 6 months, changes in BMI, metabolic parameters (fasting plasma glucose, HbA1c, insulin resistance indices, lipid profile), quality of life assessed by validated questionnaires (IWQOL-Lite), and the incidence of adverse events classified according to international standards.

Randomization will be computer-generated with concealed allocation, and outcome assessors will be blinded to treatment assignment. Analyses will follow the intention-to-treat principle with appropriate methods for handling missing data.

The study is expected to generate high-quality evidence regarding the short-term and medium-term efficacy of ERCG, to clarify its safety profile, and to determine whether ERCG can serve as a safe and scalable option bridging the therapeutic gap between conservative lifestyle approaches and bariatric surgery for overweight and mildly to moderately obese Chinese populations.

Interventions

• Procedure Endoscopic Radial Compression Gastroplasty
  Sutureless endoscopic gastric volume reduction using a novel clip-and-endoloop apposition system; performed under general anesthesia or deep sedation; standard perioperative care.
• Behavioral Optimized Lifestyle Intervention (OLI)
  Structured nutrition counseling, calorie deficit plan, physical activity prescription per regional guidelines, and behavioral support; visit frequency matched to the ERCG arm.

Primary outcome measures

• Percent Total Body Weight Loss (%TBWL) [Time frame: 1-6 months post-intervention]
• Clinical Responder Rate (CRR) [Time frame: 3 month, 6 month]

Secondary outcome measures (11)

• Body Weight (kg) [Time frame: Baseline, 1 month, 2 month, 3 month, 6month]
• Body Height (m) [Time frame: Baseline]
• Percent Excess Body Weight Loss (%EBWL) [Time frame: 1-6 months post-intervention]
• Change in BMI (kg/m²) [Time frame: Baseling, 1 month, 2 months, 3 months and 6 months]
• Glycated Hemoglobin (HbA1c) [Time frame: Baseline, 3 months]
• Adverse Events (AEs/SAEs) Related to Procedure [Time frame: 3, 6, 12 months]
• GERD-Q Total Score [Time frame: Baseline, 3, and 6 months]
• Postoperative Pain (VAS/NRS) [Time frame: 6 hours, 24 hours, and 7 days]
• Postoperative Nausea Score [Time frame: 6 hours, 24 hours, and 7 days]
• Total Cholesterol [Time frame: Baseline, 3 months]
• Low-Density Lipoprotein Cholesterol (LDL-C) [Time frame: Baseline, 3 months]

Eligibility criteria

Inclusion criteria

• Asian adults aged 18-65 years.
• BMI 24.0-37.4kg/m²(Chinese standard)。
• Failed prior conservative weight loss attempts ≥2 months。
• Willingness to comply with follow-up.
• Provided written informed consent.

Exclusion criteria

• Prior gastrointestinal surgery with clinically relevant sequelae.
• Active or clinically significant gastrointestinal disease, including inflammatory conditions (e.g., esophagitis, Barrett's esophagus, Crohn's disease), peptic ulcer disease (gastric/duodenal ulcer), or neoplastic lesions.
• Any condition associated with an increased risk of upper gastrointestinal bleeding.
• Hiatal hernia >2 cm or severe/refractory gastroesophageal reflux disease (GERD); acid reflux requiring ≥2 medications for symptom control.
• Esophageal/pharyngeal structural abnormalities that may impede endoscope passage (e.g., stricture, diverticulum).
• Achalasia or other severe esophageal motility disorder.
• Severe coagulopathy.
• Insulin-dependent diabetes mellitus.
• Chronic abdominal pain.
• Gastrointestinal motility disorder (e.g., gastroparesis).
• Hepatic impairment or cirrhosis.
• Severe or uncontrolled psychiatric illness.
• Alcohol abuse or substance dependence.
• Unwilling to participate in a physician-supervised diet/behavior modification program and/or unwilling to comply with routine follow-up.
• Daily regular use of NSAIDs, anticoagulants, or other gastric-irritating medications.
• Unable or unwilling to take proton pump inhibitor (PPI) therapy as prescribed during the treatment period.
• Known or suspected hypersensitivity to any material/component of the study system.
• Pregnant or breastfeeding.
• Severe cardiopulmonary disease or other serious systemic/organic disease.
• Positive Helicobacter pylori (H. pylori) test.
• Use of time-critical medications potentially affected by altered gastric emptying (e.g., antiepileptics, antiarrhythmics).
• Current systemic corticosteroids, immunosuppressants, or opioid analgesics.
• Use of any weight-loss medication within the past 3 months or current use.
• Prior use of any intragastric device.
• Participation in a weight-affecting clinical trial within the past 6 months.
• Symptomatic congestive heart failure, clinically significant arrhythmia, or unstable coronary artery disease.
• Clinically significant respiratory disease.
• Autoimmune connective tissue disease.
• Life expectancy <1 year or severe renal/hepatic/pulmonary or other serious medical illness.
• Known genetic or endocrine cause of obesity (e.g., hypothyroidism, Prader-Willi syndrome) or other endocrine disease known to affect body weight.
• Eating disorder (e.g., night eating syndrome, bulimia nervosa, binge eating disorder, compulsive eating).

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

China · 2 centers

• The fifth Medical Center of Chinese PLA General Hospital, Beijing — Beijing
• The fifth Medical Center of Chinese PLA General Hospital, Beijing — Beijing

Identifiers

NCT: NCT07237750 · 307-2026-iWAIST-RCT

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗