This study will assess the pharmacokinetics (PK), mass balance, metabolite profiles, and rates and routes of elimination of [14C] omaveloxolone and derived metabolites following administration as a single 150 mg (containing approximately 90 µCi) dose to healthy male subjects.

Inclusion Criteria:

• Subjects must satisfy all of the following criteria at the Screening Visit unless otherwise stated:
• Males, of any race, between 18 and 55 years of age, inclusive.
• Body mass index (BMI) between 18.0 and 32.0 kg/m2, inclusive, and a total body weight > 50 kg.
• Be surgically sterile or willing to agree to use contraception
• In good health, as assessed by the investigator (or designee).
• Able to comprehend and willing to sign an ICF and to abide by the study restrictions.

Exclusion Criteria:

• Significant history or clinical manifestation of any major system disorder, as determined by the investigator (or designee).
• History of significant hypersensitivity, intolerance, or allergy to any drug compound, food, or other substance, unless approved by the investigator (or designee).
• History of stomach or intestinal surgery or resection that would potentially alter absorption and/or excretion of orally administered drugs.
• Presence of any other condition, including surgery, known to interfere with the absorption, distribution, metabolism, or excretion of medicines.
• Abnormal laboratory values considered clinically significant by the investigator.
• Clinically significant abnormal 12-lead ECGs.
• History of alcoholism or drug/chemical abuse within 2 years prior to Check-in (Day-1).
• Alcohol consumption of > 21 units per week.
• Positive urine drug screen at Screening, or positive alcohol breath test result or positive urine drug screen at Check-in (Day -1).
• Positive hepatitis panel and/or positive human immunodeficiency virus test.
• Participation in a clinical study involving administration of an investigational drug (new chemical entity) in the past 30 days or 5 half-lives (if known) prior to dosing.
• Current enrollment in another clinical study.

In accordance with Biogen's Clinical Trial Transparency and Data Sharing Policy on https://www.biogentrialtransparency.com/