Liver-First Drugs Redefine the Next Phase of the MASH Race

New 2025 data for Ionis ION224 highlight how liver-targeted drugs and GLP-1s may converge to reshape MASH care and deal-making

19 Dec 2025

Metabolic medicine is turning inward. After a decade defined by weight loss breakthroughs and diabetes blockbusters, attention is shifting to a smaller but decisive organ: the liver.

That change came into focus this summer with mid-stage results from Ionis Pharmaceuticals’ experimental therapy, ION224. Published on Aug. 23, 2025, in The Lancet, the study showed notable drops in liver fat and inflammation in patients with metabolic dysfunction-associated steatohepatitis, or MASH. Follow-up analyses and investor debate carried the signal into early fall. ION224 is not approved by the US Food and Drug Administration, but in a field known for late-stage disappointments, the data felt like a rare bright spot.

Researchers involved framed the work as a move away from treating the downstream effects of metabolic disease toward tackling its drivers inside the liver. That distinction matters. As pipelines fill with similar therapies, companies are searching for lasting benefits and clearer biological separation, not just another route to weight loss.

GLP-1 drugs still dominate the conversation. Treatments like Novo Nordisk’s Wegovy have already won approval for MASH, with others close behind. Their impact on weight and cardiometabolic health often improves liver measures as well. Increasingly, liver-first drugs are seen as potential partners rather than rivals, with combination approaches quietly taking shape, though they remain unproven.

Business moves echo the science. Roche’s 2025 purchase of 89bio underscored rising interest in therapies that directly target liver fat and inflammation. After the ION224 readout, RNA-based platforms and precision delivery tools drew renewed attention, alongside early academic support for new liver targets.

The challenges are substantial. Long-term safety must be shown. Manufacturing remains costly. Regulators will want proof that biomarker gains translate into real protection against cirrhosis and liver failure. In some trials, fibrosis gains have hovered around one-fifth of patients.

Even so, momentum is hard to ignore. With millions affected worldwide and liver-related costs climbing, urgency is shaping strategy. As trials advance and partnerships deepen, metabolic medicine appears ready for another reset, one that builds on the GLP-1 era while placing the liver firmly at center stage.