The purpose of this study is to assess the effects of K-877 on the pharmacokinetics of digoxin in healthy adult volunteers.

Inclusion Criteria:

• Subject is a healthy adult male or female volunteer between the ages of 18 and 45 years, inclusive, at Screening.
• Subject has a body mass index of 18 to 30 kg/m2, inclusive, at Screening.
• Subject has hematology, serum chemistry, and urinalysis test results within the reference ranges or is showing no clinically relevant deviations, as judged by the investigator at Screening.

Exclusion Criteria:

• Subject has clinically relevant abnormalities in the screening or check in assessments.
• Subject has a blood pressure (as measured at Screening during the collection of vital signs) after resting supine for at least 5 minutes that is higher than 140 mm Hg systolic or 90 mm Hg diastolic, or lower than 90 mm Hg systolic or 60 mm Hg diastolic (for males) and 50 mm Hg diastolic (for females).
• Subject has a supine pulse rate (as measured at Screening during collection of vital signs) after resting for 5 minutes that is outside the range of 40 to 90 beats per minute.