The primary objective of this dose-finding study is to evaluate the safety, tolerability and pharmacodynamics of single dose of INS1202 via IT administration in participants ≥ 18 to \<80 years of age with ALS who carry superoxide dismutase type 1 (SOD1) mutations or harbor no known ALS-related genetic mutation.
Participant with body mass index (BMI) ≥18 kilograms per square meter (kg/m²).
Participant with symptomatic ALS as diagnosed by Gold Coast diagnostic criteria.
Sporadic ALS cohorts: Negative testing for known monogenic mutations associated with familial ALS.
SOD1-ALS (Cohorts 2 and 3 only): Confirmed pathogenic SOD1 mutation, with negative testing for other genetic mutations associated with familial ALS.
Previous treatment for ALS with cellular or gene therapies.
Any investigational medication or treatment (for ALS or other condition).