The rise in the prevalence of metabolic dysfunction-associated steatohepatitis (MASH) is attributed significantly to dysregulated lipid metabolism. This study discovered that the enedioic acid ATP-citrate lyase (ACLY) inhibitor 326E, an investigational new drug in a phase 2a study for hypercholesterolemia, markedly reduces hepatic lipid accumulation and alleviates MASH in mouse models of MASH. Mechanistic studies demonstrated that 326E exerts these effects not only by inhibiting ACLY to reduce de novo lipogenesis (DNL) but also as a peroxisome proliferator-activated receptor α (PPARα) allosteric regulator to increase hepatic fatty acid oxidation (FAO). The efficacy of activated PPARα for MASH is enhanced by suppressed recycling of FAO products to lipid accumulation as a result of ACLY inhibition. Subsequent studies in cynomolgus monkeys (Macaca fascicularis) confirmed the effectiveness of 326E for MASH in primate species. In a randomized phase 1b/2a clinical trial in patients with MASH (NCT06491576), 326E was well tolerated and reduced circulating gamma-glutamyl transferase (γ-GGT). Taken together, our results indicate the therapeutic potential of 326E for MASH via distinctive dual mechanisms of inhibiting ACLY while activating PPARα.
Keywords: 326E; ACLY; PPARα; fatty acid β-oxidation; lipogenesis; metabolic dysfunction-associated steatohepatitis; phase 1b/2a clinical trial.
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