The objective of this study is to evaluate the long-term safety and tolerability of oral edaravone in subjects with Amyotrophic Lateral Sclerosis (ALS) over 24 and 48 weeks.

Inclusion Criteria:

• Subjects will be male or female, ≥ 18 to 75 years of age at the time the ICF is signed
• Subjects will be diagnosed with Definite ALS, Probable ALS, Probable laboratory-supported ALS, or Possible ALS according to the El Escorial revised criteria for the diagnosis of ALS.
• Subjects will be living and functioning independently (eg, able to eat, excrete, ambulate independently without assistance of others). The use of supportive tools and adaptive utensil is allowed
• Subjects will have a baseline forced vital capacity percentage (%FVC) ≥ 70%.
• Subjects whose first symptom of ALS occurred within 3 years of the time of providing written informed consent.

Exclusion Criteria:

• Subjects who have the presence or history of any clinically significant disease (except ALS) that could interfere with the objectives of the study (the assessment of safety and efficacy) or the safety of the subject, as judged by the Investigator.
• Subjects of childbearing potential unwilling to use acceptable method of contraception from the screening visit until 3 months after the last dose of study medication. Subjects who are sexually active who do not agree to use contraception during the study period.
• Subjects who are female and pregnant (a positive pregnancy test) or lactating at the screening visit (Visit 1).
• Subjects who have a significant risk of suicidality. Subjects with any suicidal behavior or suicidal ideation of type 4 (active suicidal ideation with some intent to act, without a specific plan) or type 5 (active suicidal ideation with specific plan and intent) based on the Columbia-Suicide Severity Rating Scale (C-SSRS) within the 3 months before the screening visit.
• Subjects who have ALT or AST elevations greater than 2 times the ULN at screening.
• Subjects with a Glomerular Filtration Rate (GFR) <30 mL/Min Per 1.73 m2.
• Subjects with history of hypersensitivity to edaravone, any of the additives or inactive ingredients of edaravone, or sulfites.
• Subjects with hereditary fructose intolerance.
• Subjects who participated in another study and were administered an investigational product within 1 month or 5 half-lives of the investigational agent, whichever is longer before providing informed consent for the present study.
• Subjects who are unable to take their medications orally.