This is a Phase 2a multi-center, randomized, double-blind, placebo-controlled parallel-group, 2-arm study with a long-term, open-label treatment phase in patients with C9ORF72 ALS and/or FTD. This study includes a 6-week Screening Period, a 24-week Double-blind Treatment Period, a 24-week Open-label Treatment Period, and a Follow-up Visit 4 weeks post-treatment.
