Gastric On in Obesity Management: Evaluation of the Safety and Efficacy of the 6-Month Gastric Balloon (Prospective)

Background and Rationale

Obesity is a growing global public health problem associated with serious comorbidities, including type 2 diabetes, hypertension, cardiovascular disease and certain cancers, and it contributes substantially to morbidity and mortality. Conventional weight-loss strategies such as diet, exercise and behavioral modification often produce limited long-term success, particularly in individuals with moderate to severe obesity. For many patients, these conservative measures are insufficient, and more effective interventions are needed to achieve and maintain meaningful weight loss.

Intragastric balloons (IGBs) have emerged as a minimally invasive, temporary and reversible option for weight management in patients who do not respond adequately to lifestyle modification alone. IGBs occupy space within the stomach, promoting early satiety and reducing food intake. They have been shown to produce clinically meaningful short-term weight loss, may serve as a bridge to long-term weight-management strategies or bariatric surgery, and may improve obesity-related metabolic parameters. IGBs also provide an alternative for patients who are not candidates for, or do not wish to undergo, bariatric surgery.

Investigational Device

The GastricOn 6-Month Gastric Balloon (sponsor: Rigicon, Inc.) is a saline-filled intragastric balloon representing a new generation of IGB design. Compared with earlier-generation balloons, it features an optimized shape and expandable volume intended to improve positioning within the stomach, enhance patient comfort and reduce the incidence of adverse events. The balloon surface is treated with a specialized coating intended to minimize complications such as gastric ulceration and premature balloon deflation. The balloon is placed and removed endoscopically and is intended to remain in the stomach for approximately 6 months.

Although the device has shown promise in preliminary studies, safety and efficacy data in a larger population are needed. This study is designed to evaluate the GastricOn 6-Month Gastric Balloon in a real-world clinical setting.

Study Objectives

The primary objective is to evaluate the efficacy and safety of the GastricOn 6-Month Gastric Balloon in adults with obesity, measured by the percentage of total body weight loss (%TBWL) at 26 weeks and the incidence of device- and procedure-related serious adverse events (SAEs). The safety target is an SAE rate below 15%.

Secondary objectives are to evaluate changes in BMI; to calculate the percentage of excess weight loss (%EWL); to assess nutrition, appetite and patient satisfaction; to evaluate the effect of the balloon on longer-term weight loss; and to analyze the frequency of adverse events (AEs) and SAEs.

Hypotheses

The primary hypothesis is that the GastricOn 6-Month Gastric Balloon will produce a significant %TBWL at 26 weeks. Secondary hypotheses are that BMI and %EWL will decrease markedly; that appetite control and satiety will improve; that obesity-related metabolic parameters (e.g., blood glucose, cholesterol, blood pressure) will be favorably affected; that the rate of device- and procedure-related SAEs will be below 15%; and that patient satisfaction will be high.

Study Design

This is a prospective, multicenter, open-label, single-arm clinical investigation conducted at 3 hospitals in Türkiye. Approximately 70 adults aged 18 to 60 years with a BMI of 30 to 40 kg/m² and a history of obesity for at least 2 years will be enrolled. Participants will serve as their own controls. Because all participants receive the same intervention, no randomization or blinding will be used. The overall study duration is planned to be 12 months. Each participant's treatment period is approximately 6 months, followed by a post-removal follow-up visit at Week 26.

Participants will be recruited through announcements in hospitals and clinics, referrals from healthcare professionals, weight-loss volunteer pools, collaboration with dietitian and endocrinology clinics, and social media, online announcements and information sessions.

Study Procedures

Screening and enrollment: Eligibility will be assessed against the inclusion and exclusion criteria. Written informed consent will be obtained before any study procedure. Screening includes a medical history, physical examination, BMI measurement, laboratory tests and diagnostic endoscopy.

Balloon placement: The balloon will be placed endoscopically under mild sedation and filled with saline to a volume of 400 to 700 cc. It will then be released to float freely in the stomach. Participants will be observed for 1 to 2 hours after the procedure and then discharged. Participants will take a prescribed proton pump inhibitor for the duration of balloon placement and will take part in a supervised diet and behavioral modification program with regular medical follow-up.

Follow-up visits:

Day 7: assessment of adaptation to the balloon, side effects and adverse events Week 4: BMI measurement, weight loss, adverse events and dietary compliance Week 12: BMI change, nutritional status, appetite assessment and patient satisfaction questionnaire Week 24: endoscopic balloon removal under mild sedation, weight-loss assessment and evaluation of complications Week 26: final follow-up and assessment of late adverse events

Unscheduled visits will be performed as clinically indicated. Participants who miss scheduled visits will be followed up by telephone. A 24/7 advice line will be available throughout the study.

Safety Monitoring

Participant safety will be supported by strict eligibility criteria, a baseline medical and endoscopic evaluation, post-procedure observation after placement and removal, and systematic recording and evaluation of all AEs and SAEs at each visit. Participants who experience symptoms such as severe abdominal pain, gastrointestinal bleeding or signs of obstruction will receive immediate medical evaluation. An early balloon removal protocol will be applied if complications occur, and emergency surgical intervention may be required for serious complications such as bowel obstruction or gastric perforation.

Participants may be withdrawn from the study at their own request, if continued participation is judged unsafe because of an SAE or unexpected adverse effects, for non-compliance with protocol requirements, or if their health status changes significantly. Withdrawn participants will receive standard care appropriate to their condition, and reasons for withdrawal will be documented.

The study may be terminated early if the SAE rate exceeds 15%, if life-threatening complications increase markedly, if severe allergic reactions or intolerable side effects occur, if the study is unlikely to meet its scientific objectives, at the request of regulatory authorities or the Ethics Committee, or because of device-related technical, manufacturing or financial issues. In that case, all participants will be informed and their medical follow-up will be ensured.

Data Collection and Statistical Analysis

Data will be recorded on a Case Report Form (CRF) for each participant, including participants who withdraw. The primary endpoint (%TBWL at Week 26) will be analyzed using a paired t-test or analysis of covariance (ANCOVA), with a two-sided p-value below 0.05 considered statistically significant. Change in BMI will be analyzed using descriptive statistics and repeated-measures ANOVA. %EWL will be summarized as mean values and analyzed over time. AEs and SAEs will be reported using descriptive statistics. Appetite and patient satisfaction questionnaires will be evaluated using Likert scales. Missing data will be handled using the last observation carried forward (LOCF) method, supported by sensitivity analyses.

Ethics and Regulatory Compliance

The study will be conducted in accordance with the Declaration of Helsinki, ICH Good Clinical Practice, the EU Medical Device Regulation (2017/745) and the clinical research regulations of the Ministry of Health of the Republic of Türkiye. Ethics Committee approval will be obtained before study initiation and before any protocol amendment. Participant confidentiality will be maintained, and study records will be retained for at least 15 years after study completion. Study conduct will be overseen through periodic on-site monitoring visits covering participant safety, data integrity, protocol compliance and the informed consent process.