A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of RAG-17 in Subjects With Amyotrophic Lateral Sclerosis (ALS) With Superoxide Dismutase Type 1 (SOD1) Gene Mutation

Inclusion Criteria: 1. Voluntarily consents to participate in this study and provides written informed consent prior to the start of any study specific procedures. 2. ≥ 18 years of age at the time of informed consent. 3. Diagnosis of possible, laboratory supported probable, probable, or definite ALS according to the World Federation of Neurology El Escorial. 4. Documented SOD1 mutation. 5. Forced vital capacity (FVC) ≥50% of predicted value as adjusted for sex, age, and height (measured seated). 6. If taking riluzole or edaravone, subject must be on a stable dose or ≥30 days prior to Day 1 and expected to remain at that dose until the final study visit. Exclusion Criteria: 1. Documented p.F21C SOD1 mutation. 2. Treatment with another investigational drug, biological agent, or device within 1 month or 5 half-lives of study agent, whichever is longer. Specifically, no prior treatment with small interfering ribonucleic acid, stem cell therapy, or gene therapy is allowed. 3. Current enrollment in any other interventional study. 4. History of or positive test result for human immunodeficiency virus, hepatitis C virus antibody or hepatitis B virus. 5. Pregnant or currently breastfeeding.