New Drug Landscape for Fatty Liver Disease in Type 2 Diabetes Patients

MASLD affects roughly 38% of the global population and is projected to reach 55% prevalence by 2040, tracking closely with rising rates of type 2 diabetes and obesity. Approximately two-thirds of people with T2D have MASLD, and up to one-third develop the more severe inflammatory form, MASH. Advanced fibrosis is the primary driver of mortality in this population, and T2D independently accelerates fibrosis progression. People with both T2D and compensated MASH cirrhosis face a four-fold increase in mortality over five years. MASLD also independently raises cardiovascular risk by approximately 45%, a risk that compounds with worsening fibrosis stage.

This review systematically evaluates every major glucose-lowering drug class for hepatic benefit. Metformin, DPP-4 inhibitors, sulfonylureas, and insulin show little to no meaningful histological improvement in liver disease and should not be selected for this purpose. Pioglitazone, a PPAR-γ agonist, consistently resolves MASH inflammation across multiple RCTs and is supported by meta-analyses, though its antifibrotic signal is weaker and its use is limited by fluid retention and heart failure risk.

GLP-1 receptor agonists represent the most transformative class. Semaglutide 2.4 mg weekly achieved MASH resolution in 62.9% of participants vs. 34.3% on placebo in the phase 3 ESSENCE trial, and improved fibrosis in 36.8% vs. 22.4%—results that earned FDA approval for non-cirrhotic MASH. Notably, mediation analyses suggest both weight-dependent and weight-independent mechanisms contribute to histological benefit. Liraglutide also demonstrated MASH resolution in a phase 2 trial. Tirzepatide, a dual GIP/GLP-1 agonist, showed dramatic liver fat reduction and MASH resolution signals in the SYNERGY-NASH trial. SGLT2 inhibitors, particularly dapagliflozin, show early antifibrotic signals in phase 2 data.

Beyond approved agents, the pipeline is advancing rapidly. Resmetirom, a thyroid hormone receptor-β agonist, is the only liver-specific approved therapy and demonstrated significant fibrosis improvement in the MAESTRO-NASH trial. Pan-PPAR agonists (lanifibranor), FGF21 analogues (pegbelfermin, efruxifermin), and triple GIP/GLP-1/glucagon agonists like retatrutide are all in phase 2–3 development, with retatrutide showing up to 80% relative liver fat reduction in early trials. Combination strategies targeting complementary pathways are also being explored.

The review concludes that therapeutic selection in T2D should now explicitly account for liver and cardiovascular risk alongside glycemic control. Semaglutide stands out as the preferred agent when MASH is present, while pioglitazone remains a viable option where cardiovascular concerns allow. The field is converging on a multi-target paradigm that simultaneously addresses metabolic, hepatic, and cardiovascular disease.