This is an open-label, single-sequence, 2-period crossover study in healthy subjects.

In this study, 20 subjects will be enrolled to allow at least 16 evaluable subjects.

Subjects will receive a single oral dose of 150 mg omaveloxolone (3 × 50 mg capsules) on Day 1 (Period 1) and on Day 29 (Period 2), and 600 mg efavirenz once a day from Days 15 through 42 (Period 2).

Inclusion Criteria:

• Healthy adult males and/or females, 18 to 55 years of age (inclusive) at the time of screening.
• BMI at screening between 18.0 and 32.0 kg/m2 (inclusive)
• Females will not be pregnant or lactating, and females of childbearing potential and males will agree to use contraception.
• 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).
• Use of any prescription medication before the first study drug administration (within 14 days before initial study drug administration or within 5 half-lives of the prescription medication, whichever is longer), and until after the last protocol-specified blood sample is prohibited, other than use of hormonal contraception.
• Clinically significant abnormal 12 lead ECGs
• Personal history of unexplained syncopal events, or family history of long QT syndrome or sudden unexplained death in a young person.
• Presence of any other condition (including surgery) known to interfere with the absorption, distribution, metabolism, or excretion of medicines.
• History of drug or alcohol abuse in the last 6 months
• Positive hepatitis panel and/or positive human immunodeficiency virus test.
• Presence of hypotension (diastolic blood pressure ≤50 mmHg, systolic blood pressure ≤90 mmHg) or hypertension (diastolic blood pressure ≥ 140 mmHg, systolic blood pressure ≥ 90 mmHg)
• Blood donation (excluding plasma donation) within 56 days prior to screening and plasma donation within 7 days before screening.
• Positive urine drug screen or positive alcohol breath test result or positive urine drug screen.

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