The purpose of this study is to assess the effect of multiple doses of isavuconazole on the pharmacokinetics (PK) of warfarin after single dose administration.

Subjects will receive a single dose of warfarin on Day 1 followed by a 15 day wash-out period (time from warfarin dosing to isavuconazole dosing).

On Days 16 and 17, isavuconazole will be dosed three times daily (TID). TID doses will be administered 8 hours apart. On Days 18 through 28, isavuconazole will be administered once daily (QD). All subjects will be administered a single dose of warfarin on Day 20. A follow up visit will occur approximately 7 days after the last dose of isavuconazole. Blood samples for pharmacokinetics will be collected throughout the study.

Inclusion Criteria:

• Subjects must have BMI of 18 to 32 kg/m2 and a body weight of at least 45 kg
• Subjects must have normal laboratory values especially for ALT, AST, protein C and S, and prothrombin time

Exclusion Criteria:

• The subject has a history of unexplained syncope, cardiac arrest, unexplained cardiac arrhythmia or torsade de pointes, structural heart disease, or family history of Long QT syndrome (suggested by sudden death of a close relative at a young age due to possible or probable cardiac causes)
• The subject has a positive result for hepatitis C antibodies or hepatitis B surface antigen at Screening or is known to be positive for human immunodeficiency virus (HIV)
• The subject has a known or suspected allergy to any of the components of the trial products or the azole class of compounds, or a history of multiple and/or severe allergies to drugs or foods (as judged by the investigator), or a history of severe anaphylactic reactions
• The subject is a smoker (any use of tobacco or nicotine containing products) within 6 months prior to Screening
• The subject has had treatment with prescription drugs or complementary and alternative medicines within 14 days prior to Day -1, or over-the-counter medications within 1 week prior to Day -1
• The subject has received an experimental agent within 30 days or 5 half-lives, whichever is longer prior to Day -1
• The subject has a recent history (within the last 2 years) of drug or alcohol abuse, as defined by the investigator, or a positive drug and/or alcohol screen