A new era for MASH treatment: Semaglutide approved by FDA
In August 2025, the U.S. Food and Drug Administration (FDA) granted accelerated approval of semaglutide (Wegovy®), a peptide-based long-acting GLP-1 receptor (GLP1R) agonist, for patients with metabolic dysfunction-associated steatohepatitis (MASH) and moderate to advanced liver fibrosis. This conditional approval further acknowledges the high unmet need for effective pharmacological interventions in MASH.
The approval of semaglutide is based on part 1 of the ESSENCE phase 3 clinical trial, with full approval contingent on the confirmation of efficacy and safety outcomes from part 2 of the same study. The outcomes from Part 1 of the ESSENCE Phase 3 clinical trial were recently reported in detail by Sanyal et al. in The New England Journal of Medicine.
This regulatory pathway reflects a growing emphasis on expedited access to promising therapies for MASH. Beyond the U.S., regulatory submissions are currently underway in both the European Union and Japan, signaling the potential for global expansion of semaglutide as a MASH treatment.
What is semaglutide used for?
Semaglutide (Wegovy®, Ozempic®) is approved for the treatment of type 2 diabetes and obesity, based on the results from the SUSTAIN and STEP phase 3 clinical trial programs, respectively. While Wegovy® and Ozempic® are injectable formulations of semaglutide, an oral form of semaglutide (Rybelsus®), is also approved for type 2 diabetes, offering the first oral GLP1R agonist option.
Semaglutide lowers blood glucose primarily through enhanced insulin secretion and reduced glucagon levels in a glucose-dependent manner, while promoting weight loss through central appetite suppression and delayed gastric emptying.
It is noteworthy that semaglutide has also demonstrated significant benefits in reducing complications of metabolic disease, particularly cardiovascular and kidney outcomes.
Given the shared pathophysiology among type 2 diabetes, obesity, and MASH, the progression of GLP1R agonist development from diabetes to obesity and now to MASH represents a natural and logical evolution in therapeutic strategy with this important drug class. With the formal approval of semaglutide for MASH, the drug now stands at the forefront of pharmacological interventions in a field that has long been dominated by lifestyle modification and characterized by limited treatment options.
What will happen now? A race for MASH drug development
Resmetirom (Rezdiffra®), a liver-targeted THR-β receptor agonist, marked the first major milestone in drug development for MASH. It became the first FDA-approved treatment for patients with metabolic dysfunction-associated steatohepatitis (MASH) and moderate to advanced liver fibrosis in March 2024.
The FDA’s recent green light for semaglutide is expected to further accelerate the race among pharmaceutical companies to bring more effective MASH treatments to market. Key drug candidates currently under clinical evaluation for MASH with liver fibrosis include tirzepatide (dual GLP1R/GIPR agonist), survodutide (dual GLP1R/GCGR agonist), and retatrutide (triple GLP1R/GIPR/GCGR agonist), with early-phase clinical trials reporting promising results.
Beyond unimolecular dual and triple agonists, there is growing interest in combination therapies. This trend extends not only to injectable incretin-based agents and oral THR-β receptor agonists, but also to emerging investigational classes that are gaining momentum, such as injectable long-acting fibroblast growth factor 21 (FGF21) analogues (e.g., efruxifermin) and oral pan-peroxisome proliferator-activated receptor (PPAR) agonists (e.g., lanifibranor).
This momentum in drug development for MASH underscores a growing need for translatable preclinical models that accurately reflect human MASH pathology, support mechanistic insights, and predict treatment responses for streamlining the transition from preclinical to clinical development.
Gubra’s GAN DIO-MASH model: Advancing preclinical MASH research
At the heart of this shift is the need for robust and clinically relevant preclinical MASH models. Gubra’s biopsy-confirmed GAN DIO-MASH mouse model offers a powerful tool for studying MASH progression and therapeutic interventions. Built on a foundation of high-fat, high-sugar diets with added cholesterol, this model recapitulates the full histological spectrum of human MASH, including steatosis, inflammation, and fibrosis, along with metabolic hallmarks of obesity, hypercholesterolemia and insulin resistance. The LITMUS consortium has ranked Gubra’s GAN DIO-MASH mouse model as the number one preclinical model for its high human proximity score, indicating superior clinical translatability. At Gubra, we have validated the GAN DIO-MASH mouse model in an extensive series of studies published or presented at conferences since 2019. These include model phenotyping studies and the characterization of several MASH-targeted drug classes, such as GLP1R agonists (e.g., semaglutide), THR-β receptor agonists (e.g., resmetirom), PPAR agonists (e.g., lanifibranor), FGF21 analogues (e.g., efruxifermin), as well as various long-acting dual GLP1R-GIPR agonists (e.g., tirzepatide) and GLP1R-GCGR agonists (e.g., survodutide).
- Find all our reported GAN DIO-MASH mouse studies here.
For developers of novel MASH therapeutics, the biopsy-confirmed GAN DIO-MASH mouse model serves as a critical translational tool for preclinical efficacy validation. This model supports comprehensive analyses of treatment-induced changes in liver histopathology (pre-to-post histopathological scores and terminal quantitative histology), plasma/liver biochemistry, metabolic markers, and global hepatic transcriptional profiles, thereby facilitating both efficacy readouts and mechanistic characterization.
We also offer the GAN DIO-MASH-HCC mouse model for evaluating therapeutic interventions aimed at preventing progression to hepatocellular carcinoma (HCC) or assessing the efficacy of interventional treatments, thereby addressing a critical unmet need in MASH research. Notably, we have demonstrated that semaglutide treatment intervention reduces tumor burden in GAN DIO-MASH-HCC mice.
What’s coming: Semaglutide Benchmarking in the GAN DIO-MASH Mouse Model
Our research team is currently preparing a new publication demonstrating the reproducibility of semaglutide’s efficacy in the GAN DIO-MASH mouse model. The study further shows that extended treatment duration elicits robust anti-fibrotic effects, consistent with the primary outcomes of the ESSENCE Phase 3 clinical trial, and recapitulates circulating biomarker signatures observed in semaglutide-treated MASH patients.
Stay tuned for our data, which will deepen the understanding of semaglutide’s mechanism of action in MASH and further validate our model’s clinical translatability and relevance in preclinical drug development.
Explore the poster titled “Reproducible efficacy and clinical translatability of longer-term semaglutide treatment in the GAN diet-induced obese and biopsy-confirmed mouse model of MASH”
here.
Preclinical innovation driving clinical success
The FDA approval of Wegovy® for MASH is a monumental achievement, but it’s only the beginning. As the drug development landscape evolves, the need for reliable and translational preclinical models has never been greater.
At Gubra, we are proud to be at the forefront of preclinical MASH research, offering models that bridge the gap between bench and bedside. Whether you’re testing semaglutide, exploring novel pathways, or developing next-generation MASH therapies, our GAN DIO-MASH model is the trusted platform for discovery and innovation. Get in touch with our experts and contact us for more info.
