ER-300m

ER-300m is an adeno-associated virus (AAV) gene therapy candidate developed by Life Biosciences for the treatment of metabolic dysfunction-associated steatohepatitis (MASH). The therapy delivers three Yamanaka factors—OCT4, SOX2, and KLF4 (collectively known as OSK)—under a constitutively active promoter to enable hepatic expression. ER-300m functions through partial epigenetic reprogramming, a process intended to improve cellular function and regenerative capacity by resetting the epigenetic clock while maintaining cellular identity and avoiding de-differentiation. Preclinical studies in mouse models of MASH have shown that ER-300m can significantly reduce liver injury biomarkers (ALT, AST), decrease hepatic steatosis, and improve overall histological scores.