A single center, Phase 1, open-label, fixed-sequence, drug-drug interaction study to evaluate the effect of multiple doses of Fluconazole, a CYP3A4 and CYP2C9 inhibitor, on the pharmacokinetics (PK) of CTP-543 in healthy subjects

Inclusion Criteria:

• Healthy, adult, male or female, aged 18-60 inclusive
• Non-smoker who has not used nicotine-containing products for at least 3 months prior to the first dosing
• Body mass index (BMI) ≥ 18.0 and ≤ 32.0 kg/m2 at screening
• If of reproductive age, willing and able to use a medically highly effective form of birth control 4 weeks 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 (ICF), 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 or presence of alcohol or drug abuse within the past 2 years
• History or presence of hypersensitivity or idiosyncratic reaction to the study drugs or related compounds
• Presence or history of significant gastrointestinal, liver or kidney disease, or any other condition that is known to interfere with drug absorption, distribution, metabolism or excretion, or known to potentiate or predispose to undesired effects
• History of prolonged QT syndrome or a QTc interval with Fridericia's correction (QTcF) > 450 msec for males or QTcF > 470 msec for females at Screening visit or prior to the first dosing
• Abnormal liver function at Screening
• 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 for coronavirus infection (COVID-19) at Screening or check-in
• Positive drug or alcohol results at Screening or check-in
• Positive results at Screening for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV)
• Vaccination with a live attenuated vaccine up to 6 weeks prior to dosing. Live vaccines include (but are not limited to) the measles, mumps, and rubella (MMR) vaccine; intranasal flu vaccine; and Zostavax for herpes zoster