This study will assess in healthy male and female subjects the safety, tolerability and pharmacokinetics (PK) profiles of Immediate Release CTP-730 at steady state following 7 days of dosing. Three doses of Immediate Release (IR) CTP-730 capsules will be studied.

Inclusion Criteria:

• Healthy adult males and females between 18 and 50 years of age.
• Body weight ≥ 50 kg and BMI within the range of 18 to 30 kg/m2

Exclusion Criteria:

• Medical, psychiatric illness or history of depression that could, in the investigator's opinion, compromise the subject's safety
• Significant medical condition, laboratory abnormality, or psychiatric illness that would prevent the subject from participating in the study.
• History of clinically significant central nervous system (eg, seizures), cardiac, pulmonary, metabolic, renal, hepatic, or gastrointestinal (GI) conditions.
• PR interval ≥ 220 msec or QRS duration ≥ 120 msec or QTcB / QTcF interval > 450 msec obtained at screening visit or prior to the first dose of study drug.
• Liver function tests greater than the upper limit of normal.
• Positive blood screen for human immunodeficiency virus (HIV antibody), hepatitis B virus surface antigen, or hepatitis C virus antibody at screening.
• Urinalysis positive for protein or glucose.
• A positive screen for alcohol, drugs of abuse, or tobacco use.
• Inability to comply with food and beverage restrictions during study participation.
• Donation or blood collection or acute loss of blood prior to screening.