The primary purpose of this study is to assess the single-dose bioavailability of AKB-6548 with ferrous sulfate relative to AKB-6548 in healthy volunteers.

Inclusion Criteria:

• Healthy male subjects 18 to 55 years of age with a body mass index between 18 and 30 kg/m2
• Participants and their partners must use a highly effective form of contraception during the study and for 1 month following discharge from the Clinical Research Unit (CRU)
• Subjects must discontinue all iron preparations for 14 days prior to study drug administration

Exclusion Criteria:

• Current or past history of cardiovascular, cerebrovascular, pulmonary, renal or liver disease
• Positive serology results for HBsAg, HCV, and HIV at Screening
• Renal impairment (estimated glomerular filtration rate (eGFR) of <65mL/min)
• Known active cancer (except non-melanoma skin cancer) or history of chemotherapy use within the previous 24 months
• Current or past history of gastric or duodenal ulcers or other diseases of the GI tract (including gastric bypass surgeries) that could interfere with absorption of study drug
• Subjects with a known history of smoking and/or have used nicotine or nicotine-containing products within the past 6 months