Exploring the Use of GLP-1-Based Interventions for Obesity: A Qualitative Analysis of ClinicalTrials.gov Data.
This registry-based cross-sectional qualitative analysis examined the landscape of completed clinical trials investigating GLP-1 receptor agonists (GLP-1 RAs) for obesity, using data retrieved from ClinicalTrials.gov in October 2025. The authors identified 227 completed interventional studies and analyzed their design characteristics, research themes, and outcome domains. Liraglutide was the most studied agent (n = 86), followed by semaglutide and tirzepatide (n = 18 each) and exenatide (n = 15). Phase 3 and 4 trials predominated, though most studies enrolled fewer than 200 participants, suggesting relatively modest individual sample sizes. The authors reported a notable surge in completed trials after 2018, coinciding with the emergence of newer GLP-1 analogues. Primary outcomes were predominantly weight-related, but the synthesis identified a growing research focus on hepatic, cardiometabolic, and inflammatory endpoints. The study's key limitation is its registry-based, qualitative design — it does not synthesize individual-level patient outcome data or conduct meta-analysis, and therefore cannot draw conclusions about comparative efficacy or safety. Rather, it maps the structural and thematic evolution of the GLP-1 obesity research field. The authors conclude that the field is maturing beyond glycaemic and weight outcomes toward broader organ-specific endpoints.
Why this grade: This is a registry-based qualitative synthesis of trial metadata rather than a study generating or pooling direct clinical outcome data, making it a descriptive landscape review that cannot independently establish efficacy or safety in humans.
Background Glucagon-like peptide-1 (GLP-1) receptor agonists are a key pharmacological target in obesity management, associated with sustained weight loss and broader metabolic benefits beyond glycaemic control. Objective To analyse the characteristics, design trends, and research themes of completed clinical trials investigating GLP-1-based interventions for obesity registered in ClinicalTrials.gov. Methods A registry-based cross-sectional qualitative analysis was conducted using ClinicalTrials.gov data retrieved on October 18, 2025. Completed interventional trials evaluating GLP-1 receptor agonists, including liraglutide, semaglutide, tirzepatide, exenatide, dulaglutide, and lixisenatide, were identified. Extracted variables included study phase, intervention type, enrolment, primary outcomes, and completion year. Descriptive statistics were used to summarize quantitative data, and qualitative thematic synthesis was applied to categorize outcome domains and research focus. Results A total of 227 completed interventional studies were identified. Liraglutide was the most frequently investigated agent (n = 86), followed by semaglutide (n = 18), tirzepatide (n = 18), exenatide (n = 15), and other GLP-1 analogues. Phase 3 and 4 trials predominated, with most studies enrolling fewer than 200 participants. Primary outcomes were mainly weight-related, with increasing attention to hepatic, cardiometabolic, and inflammatory endpoints. A marked rise in completed trials was observed after 2018, corresponding with the introduction of newer GLP-1 analogues. Conclusion Completed GLP-1 obesity trials demonstrate an expanding research focus from weight and glycaemic control toward broader metabolic and organ-specific outcomes. This registry-based qualitative analysis provides a novel overview of research maturity and evolving priorities in GLP-1-based obesity pharmacotherapy.
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