A Single and Multiple Ascending Dose Study of CK-3773274 in Healthy Adult Subjects

Inclusion Criteria: 1. Males and females (of non-childbearing potential) between 18 and 55 years of age, inclusive 2. Body weight \> 55.0 kg and body mass index within 18.0 to 32.0 kg/m2, inclusive 3. Normal cardiac structure and function, or if abnormalities are present, they are deemed not clinically significant 4. Normal to high left ventricular ejection fraction. 5. Normal electrocardiogram (ECG) or, if abnormalities are present, they are deemed not clinically significant 6. Clinical laboratory findings within normal range 7. Negative hepatitis panel (including hepatitis B surface antigen and hepatitis C antibody), and negative human immunodeficiency virus antibody screens 8. Willing and able to refrain from strenuous exercise (eg, activity which could be expected to cause muscle soreness) 9. For Arms 5 and 6 only: Subject is a CYP2D6 poor metabolizer Exclusion Criteria: 1. History of any significant illness or disorder 2. History of stomach or intestinal surgery or resection (appendectomy, hernia repair, and/or cholecystectomy will be allowed) 3. A clinically significant illness within 4 weeks of Check-in 4. Inability to swallow capsules or tablets 5. History of or current substance abuse (drug or alcohol), known drug or alcohol dependence within the last 2 years prior to Screening, or positive test for drugs of abuse during the screening period 6. Use of any tobacco-containing or nicotine-containing products within 3 months prior to Check-in 7. Participation in any other investigational study drug trial in which receipt of an investigational study drug occurred within 30 days prior to Check-in 8. Any blood donation within 60 days of dosing, plasma donation within 30 days of dosing, or receipt of blood products within 2 months prior to Check-in