SOD1 and amyotrophic lateral sclerosis: Amyotrophic lateral sclerosis (ALS) is a progressiveneurodegenerativedisease that affects nerve cells in the brain and spinal cord.204 Ionis Pharmaceuticals in partnership with Biogenhas an ASO investigational drug, Tofersen, in phase III clinical trials(Table 6).151 Tofersen targets superoxide dismutase 1 (SOD1),the second most common and best understood genetic cause of ALS.