GLP-1 Receptor Agonists Post-Bariatric Surgery (GRABS) Trial: Rationale, Design and Baseline Characteristics

Why clinicians should know about it

• Picked for Bariatric and Metabolic Surgery (paper of the day, 10 September 2026): Randomized trial of tirzepatide after RYGB for persistent obesity

Abstract

AIMS: No studies have investigated the synergistic effectiveness of Glucagon-Like Peptide 1 Receptor Agonists (GLP1RAs) in patients with persistent obesity following bariatric surgery. The GLP-1 Receptor Agonists Post-Bariatric Surgery (GRABS) Trial aims to investigate the effectiveness of tirzepatide (TRZ) versus standard of care (SOC) after Roux-en-Y gastric bypass (RYGB) in patients with persistent obesity (body mass index [BMI] ≥ 30 kg/m2). MATERIALS AND METHODS: This randomized, open-label proof-of-concept trial compares 24 weeks of TRZ with SOC versus SOC alone after RYGB. The primary outcome is total percent weight change from baseline to 24 weeks after trial initiation. Patients aged 25-65 with BMI ≥ 30 kg/m2 enroled 12 months after RYGB are randomized 1:1 to 24 weeks of TRZ or SOC. Exclusion criteria include: type 1 diabetes, type 2 diabetes treatment other than metformin, conversion to RYGB from prior bariatric surgery, and GLP1RA use in the past 3 months. RESULTS: The study enroled 33 patients, with 5 withdrawals prior to completing a baseline visit, resulting in a final sample of 28 patients. The final cohort is 82% female, 75% white, median age 42.0 years, pre-surgery BMI of 48.3 kg/m2, baseline BMI at randomization of 36.0 kg/m2 and baseline weight of 95.6 kg. CONCLUSIONS: GRABS is the first randomized trial to investigate GLP1RA effectiveness in patients with persistent obesity following RYGB, with the potential to inform synergistic adjuvant strategies to enhance surgical weight loss. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT06162715.

Abstract as published, via PubMed.