Single-Dose PK Study of GBT440 in Subjects With Renal Impairment

Inclusion Criteria: All subjects: * Males or females, 18 to 80 years old * Willing and able to give written informed consent Subjects with renal impairment: * Severe renal impairment (eGFR \< 30 mL/min/1.73m2, not on dialysis) * Moderate renal impairment (30 mL/min/1.73m2 = or \< eGFR \< 60 mL/min/1.73m2) * Mild renal impairment (60 mL/min/1.73m2 = or \< eGFR \< 90 mL/min/1.73m2) Healthy subjects: * Match in age, gender and body mass index with renal impaired subjects * Healthy and without clinically significant abnormalities in vital signs, ECGs, physical exam, clinical laboratory evaluations, medical and surgical history Exclusion Criteria: All subjects: * Participation in another clinical trial of an investigational drug (or medical device) within 30 days of the last dose of investigational drug or 5 half lives whichever is longer, prior to screening, or is currently participating in another trial of an investigational drug (or medical device) * Any signs or symptoms of acute illness at screening or Day -1 * History or presence of clinically significant allergic, hematological, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, or neurological disease Subjects with renal impairment: \- History of clinically significant hepatic disease e.g. hepatitis, cirrhosis and or liver enzymes (ALT, AST, GGT and total bilirubin) \> 5 times the upper limit of normal within the past year