PTC Therapeutics is a US pharmaceutical company focused on the development of orally administered small molecule drugs and gene therapy which regulate gene expression by targeting post-transcriptional control mechanisms in orphan diseases. In September 2009, PTC entered into an agreement with Roche for the development of orally bioavailable small molecules for central nervous system diseases. In 2020, PTC announced the FDA approval of Evrysdi™ for the treatment of spinal muscular atrophy in adults and children 2 months and older, in partnership with the SMA Foundation and Roche. PTC acquired the Bio-e platform in 2019. The Bio-e platform utilizes expertise in electron-transfer chemistry to modulate key biological processes beyond the reach of current drug development approaches. The lead compounds from the Bio-e platform, PTC743 and PTC857, target the enzyme 15-lipoxygenase – a key enzymatic hub that regulates the inflammation and oxidative stress that underpin mitochondrial disease and CNS pathology. Two pivotal studies will investigate the safety and efficacy of PTC743: a Phase 2/3 trial in refractory mitochondrial epilepsy and a Phase 3 trial in Friedreich’s ataxia.