FUSION: A Study to Evaluate the Efficacy, Safety, Pharmacokinetics and Pharmacodynamics of ION363 in Amyotrophic Lateral Sclerosis Participants With Fused in Sarcoma Mutations (FUS-ALS)

Inclusion criteria

• . Participants must be ≥10 years of age at the time of informed consent and have signs or symptoms consistent with an ALS disease (in the opinion of the Investigator).
• . Genetic mutation in FUS confirmed by a testing laboratory that is Clinical Laboratory Improvement Amendments (CLIA) certified and European Conformity (CE)-marked, or equivalent. Mutations must be reviewed and approved by a variant classification committee.
• . Upright (sitting position) slow vital capacity (SVC) is ≥ 50% of predicted value (as adjusted for sex, age, and height) OR if SVC is \< 50% of predicted value, must be 10 to 30 years of age (inclusive) at the time of informed consent AND had ALS symptom onset within 12 months before the time of informed consent.
• . Participants taking edaravone, riluzole, Relyvrio (sodium phenylbutyrate/taurursodiol combination, called Albrioza in Canada), sodium phenylbutyrate, or tauroursodeoxycholic acid (TUDCA, also known as taurursodiol or urosodiol) must be on a stable dose for ≥ 28 days prior to Day 1, and willing to continue on that dose throughout the duration of the study, unless the Investigator determines that it should be discontinued for medical reasons, in which case it may not be restarted during the study.