A Single Dose Study of Oral Vadadustat in Subjects With Normal and Impaired Hepatic Function

This is an open label, parallel-group, single dose, Phase 1 study to evaluate the PK profile,
safety, and tolerability of a single oral 450 mg dose of vadadustat in subjects with hepatic
impairment relative to control subjects with normal hepatic function. The study will enroll
up to 24 subjects in 3 groups of 8 subjects at 2 study sites. Blood samples for vadadustat PK
and its metabolites will be collected pre-dose and at 0.5, 1, 1.5, 2, 3, 4, 6, 9, 12, 18, 24,
36, 48, 60, and 72 hours post-dose.

Inclusion Criteria (All groups):

- Male or female subjects between ≥18 years and ≤70 years of age

- Have a body weight ≥45 kg and body mass index (BMI) ≥18.5 kg/m2 to 40.0 kg/m2

Additional Group-Specific Inclusion Criteria:

- Group 1 (Moderate Hepatic Impairment Subjects):

- Presence of Moderate hepatic impairment (Child-Pugh Class B)

- Group 2 (Normal Hepatic Function Subjects):

- Normal hepatic function

- Group 3 (Mild Hepatic Impairment Subjects):

- Presence of mild hepatic impairment ( Child-Pugh Class A)

Exclusion Criteria (all groups):

- Renal impairment ≥ Stage 3 (estimated glomerular filtration rate [eGFR] <60
mL/min/1.73m2 using the Modification of Diet in Renal Disease (MDRD) study equation)

- Any history of active malignancy within 2 years prior to or during screening, except
for treated basal cell carcinoma of skin, curatively resected squamous cell carcinoma
of skin, or cervical carcinoma in situ; any history of tuberculosis and/or prophylaxis
for tuberculosis

- Positive test for human immunodeficiency virus (HIV) antibody at Screening.

- Hepatic or other organ or cell transplant

- Subjects with alcoholic cirrhosis must be sober for a minimum of 6 months