UC San Diego team unveils new MASH drug: ION224 shows promise for reversing liver damage
Results from a clinical study at UC San Diego have put forward ION224, a potentially disease-modifying treatment for the millions of people affected by metabolic dysfunction-associated steatohepatitis (MASH). According to Science Daily, the drug, based on antisense oligonucleotide technology, blocks an enzyme in liver tissue, reducing fat accumulation and helping existing damage regress.
MASH itself is a silent global health problem. According to the latest report from the European Association for the Study of the Liver (EASL), about 115 million adults worldwide are affected by MASH; about 7 million of them are at risk of cirrhosis or liver cancer. The disease is seen as an extension of metabolic syndrome: type 2 diabetes, obesity and insulin resistance figure among the principal triggers of MASH. The only approved treatment to date, resmetirom (Rezdiffra), has shown limited efficacy; ION224 carries the potential to fill that gap.
How ION224 works is the cornerstone of the study. According to the details Science Daily carries, the drug blocks the mRNA molecule encoding the production of the DGAT2 (diacylglycerol O-acyltransferase 2) enzyme. DGAT2 is one of the central enzymes for triglyceride synthesis in the liver; blocking the enzyme reduces fat accumulation. UC San Diego lead investigator Dr Rohit Loomba told Science Daily: 'ION224 shuts down the liver's fat-storage programme at the root; this is an approach with the potential to physically change the natural course of the disease.'
According to Phase 2 trial details, 374 patients were followed for 18 months. In the treatment arm, 43 percent showed a 30 percent or larger reduction in steatosis (liver fat); in 22 percent of patients, liver biopsy showed that MASH had fully resolved. Those figures sit above the 29 percent improvement seen in a similar resmetirom study. The side-effect profile was relatively well tolerated: constipation (12 percent), liver enzyme increase (7 percent) and fatigue (9 percent) were the main side effects, with the serious adverse event rate limited to 3 percent.
The clinical results may carry significant economic impact. The global cost of MASH stands at about 110 billion dollars a year according to a 2024 Boston Consulting Group report, with roughly two-thirds of that coming from late-stage costs such as liver transplantation and cirrhosis treatment. If ION224 is approved and goes into broad use, a significant share of late-stage complications could be prevented. Annual treatment cost is projected at 14,000-18,000 dollars, materially below the roughly 50,000-dollar price band of Rezdiffra.
According to the drug's developer Ionis Pharmaceuticals, the Phase 3 study will begin in the last quarter of 2026 and will be conducted on 1,200 patients. An FDA submission is planned for 2028. Ionis CEO Brett Monia commented to Science Daily: 'this is the most concrete point we have reached for applying the success that antisense technologies have achieved in gene silencing in recent years to chronic liver disease.'
Other reactions from the scientific community are notable. Stanford University liver disease chair Dr Vladimir Nardi said: 'ION224 has a mechanism that current treatments do not offer; but to be sure that the Phase 3 results bring no surprise, we must wait until at least 2027.' Northwestern Medicine gastroenterology specialist Dr Anne Kotur added: 'many antisense drugs are now in clinical development; ION224 is seen as the candidate moving most quickly through this spectrum.'
The wider treatment landscape for MASH also shapes the context. Madrigal Pharmaceuticals's Rezdiffra received FDA approval in 2024 and is currently the only treatment on the market. Akero Therapeutics and 89bio are developing FGF21 mimetics; these drugs may receive approval within the next 18 months. The use of these drugs as combination therapy could shape ION224's long-term market share.
Financial market response also reflects: Ionis Pharmaceuticals shares rose 18 percent on Nasdaq after the news spread; analysts calculated the drug could have a potential annual market of 4-5 billion dollars. This article is not investment advice; the numerical data rest on the study report published by Science Daily and Bloomberg's market analysis.
This article is not medical advice; for personal health decisions on MASH or fatty liver disease please consult a gastroenterologist or hepatologist. If you are currently undergoing treatment for MASH, you are advised not to change your treatment because ION224 is not yet expected to be in broad use. Exercise, balanced diet and metabolic syndrome control are still recognised as the most reliable ways to manage MASH alongside clinical studies.