In March 2022, Biogen and Ionis Pharmaceuticals announced that BIIB078, an investigational ASO for C9orf72-associated ALS that degrades G4C2 expansion-containing mRNA, did not show clinical benefit in their phase 1 clinical trial (NCT03626012), which has since been discontinued. Here, C9orf72 is linked to amyotrophic lateral sclerosis.