Modeyso is an oral protease activator approved for adults and children with recurrent H3 K27M-mutant diffuse midline glioma (DMG), a rare and aggressive brain tumor. By activating mitochondrial caseinolytic protease P (ClpP) and antagonizing dopamine D2 receptors, it induces stress-response pathways, apoptosis, and restoration of histone H3 trimethylation, ultimately slowing tumor growth. Taken once weekly on an empty stomach, Modeyso provides a systemic, non-invasive treatment option in an area where effective therapies have historically been limited.