RSO-021

RSO-021 is a first-in-class small molecule inhibitor of peroxiredoxin 3 (PRX3), a critical antioxidant enzyme located in the mitochondrial matrix. Developed by RS Oncology LLC, it is a novel formulation of thiostrepton, a naturally occurring cyclic oligopeptide antibiotic of the thiopeptide class. RSO-021 is specifically designed for the treatment of malignant pleural effusion (MPE) resulting from mesothelioma and other advanced solid tumors. Its mechanism of action involves covalently and irreversibly binding to PRX3, which leads to an accumulation of mitochondrial reactive oxygen species (ROS) and increased oxidative stress. This selectively induces apoptosis in tumor cells, which are more dependent on PRX3 for survival than normal cells. The drug is administered weekly via intrapleural infusion directly into the pleural space following drainage of the effusion.

Other names

thiostrepton