The purpose of this study is to assess the effect of gastric fundal mucosal ablation (GFMA) on weight trajectory following discontinuation of once-weekly semaglutide or tirzepatide in adults with obesity. In this study, GFMA will be performed on patients who have experienced \> 10% weight loss with GLP-1 therapy and who plan to discontinue use of GLP-1 medications for the duration of the study.

Obesity is a multifactorial, chronic, and progressive disease of pandemic proportions. Incretin mimetics , such as semaglutide and tirzepatide, induce weight loss in adults with obesity, while also improving weight-related medical conditions, such as cardiac and renal disease. The beneficial effects on weight and metabolism require the continued presence of these medications, which have a half-life of approximately five to seven days. This concept was substantially illustrated in the STEP4 and SURMOUNT4 randomized controlled trials. In the STEP4 trial, adults with obesity were treated with semaglutide for a 20-week run-in, losing 10.6% of body weight, thereafter randomized 2:1 to continued semaglutide use vs placebo. Over the subsequent 48 weeks, the semaglutide arm lost an additional 7.9% of original body weight, whereas the placebo arm saw two-thirds the lost weight return. In the SURMOUNT-4 trial, adults with obesity were treated with tirzepatide for a 36-week run-in period, losing 20.9% of body weight, thereafter, randomized 1:1 for continued treatment or placebo. Over the subsequent 52 weeks, the treatment arm lost an additional 5.5% of body weight, whereas the placebo arm saw a return of approximately half the weight that had been lost. These observations present challenges for long-term obesity management when confronted by multiple reports showing high rates of discontinuation of incretin mimetics soon after initiation. These observations present challenges for long-term obesity management when confronted by multiple reports showing high rates of discontinuation of incretin mimetics soon after initiation. Gastric fundal mucosal ablation (GFMA) is a novel endoscopic approach to control appetite which uses hybrid argon plasma coagulation (HybridAPC) to ablate the superficial tissue of the gastric fundus to induce cell death and fibrotic remodeling. In an early safety and feasibility study of ten adults with obesity, GFMA reduced circulating levels of the only known hunger hormone in humans, ghrelin. This led to a measured suppression of inter-meal hunger and cravings, as well as improved confidence in the ability to resist cravings. In addition to reducing ghrelin-producing cell population within the fundus, GFMA induced significant fundal fibrin deposition. This resulted in a stiffer, less compliant fundus, reducing maximum tolerated volume of a standardized nutrient drink test, enhancing intra-meal satiation. Given that GFMA induces appetite control through both visceroceptive and hormonal mechanism, much like incretin mimetics, we hypothesize that GFMA can prevent or limit weight recurrence in adults who have stopped these medications after successful obesity treatment.