A Randomized Study to Evaluate the Effects of CTP-543 on the QT/QTc Intervals in Health Volunteers

Inclusion Criteria: * Healthy, non-smoking, adult males or females aged 18-60 * Body mass index of 18 to 32 mg/m2 at Screening * Medically healthy with no clinically significant medical history, physical examination, laboratory profiles, vital signs or Electrocardiograms (ECGs) * If of reproductive age, willing and able to use a medically highly effective form of birth control 30 days prior to first dose, during the study and for 30 days following last dose of study medication * Understands the study procedures in the informed consent form and be willing and able to comply with the protocol Exclusion Criteria: * History or presence of clinically significant medical or psychiatric condition or disease * History of any illness that might confound the results of the study or poses an additional risk to the subject by their participation in the study * History or presence of alcohol or drug abuse within the past 2 years prior to the first dosing * History of prolonged QT syndrome or a Corrected QT-interval (QTc) with Fridericia's correction (QTcF) \> 450 msec for males or QTcF \> 470 msec for females obtained at Screening visit or prior to the first dosing * Females who are nursing, pregnant, or planning to become pregnant while in the study, and for 30 days after last dose of study drug * Positive results at Screening for human immunodeficiency virus, hepatitis B surface antigen or hepatitis C virus * A positive test or history of incompletely treated or untreated tuberculosis