The Centaur Open Label Extension Study (CENTAUR-OLE) is an extension study for patients with ALS who participated in the CENTAUR study (Study AMX3500). During the OLE, all participants received active treatment (AMX0035), and the investigators, evaluators, and participants remained blinded to the randomized treatment assigned at the beginning of the double-blind main study. The study was designed to assess the longer term safety and therapeutic potential of AMX0035.