This is a Phase 1, two-part, open-label study to evaluate the interaction of cyclosporine, probenecid, and rifampin as perpetrators with vadadustat (victim) in healthy male and female subjects.

This is a Phase 1, two-part, open-label study to evaluate the interaction of cyclosporine, probenecid, and rifampin as perpetrators with vadadustat (victim) in healthy male and female subjects. Part 1 consists of 2 arms (cyclosporine and probenecid) and Part 2 consists of 1 arm (rifampin). Twenty (20) unique subjects will be enrolled into each study arm. The PK and safety/tolerability data from Part 1 Arm 1 (cyclosporine) will determine if Part 2 (rifampin) will proceed. Subjects will be on study for up to 72 days, including a 28-day screening period, 6-10 day clinic period, and a 30-day follow-up period post last dose. Blood and/or urine samples for PK analysis will be collected at pre-defined timepoints throughout the study.

Inclusion Criteria:

• Healthy Male or female between 18 and 55 years of age, inclusive, at time of informed consent
• Body mass index between 18.0 and 30.0 kg/m2, with a minimum body weight of 45 kg for females and 50 kg for males, inclusive.

Exclusion Criteria:

• Current or past clinically significant history of cardiovascular, cerebrovascular, pulmonary, gastrointestinal, hematologic, renal, hepatic, immunologic, metabolic, urologic, neurologic, dermatologic, psychiatric, or other major disease. History of cancer (except treated non-melanoma skin cancer) or history of chemotherapy use within 5 years prior to Screening; History of latent or active tuberculosis (TB).
• Positive test results for human immunodeficiency virus (HIV) antibody; Positive test results of hepatitis B surface antigen (HBsAg), or positive hepatitis C virus antibody (HCVab) within 3 months prior to screening , or positive test results for human immunodeficiency virus antibody (HIVab) at Screening.
• Taking any prescription medication or over the counter multi-vitamin supplement, or any non-prescription products (including herbal-containing preparations but excluding acetaminophen) within 14 days prior to Day -1.