A Safety and Tolerability Study of an Investigational Drug, ALN-TTRSC02, in Healthy Subjects

Inclusion Criteria: * Male and female subjects, age 18 to 65 years, inclusive. * Body mass index (BMI) ≥18.0 kg/m2 and ≤30 kg/m2 assessed at Screening. * No clinically significant health concerns, as determined by medical history and physical examination, in the opinion of the Investigator. * Women of child bearing potential must have a negative pregnancy test, cannot be breastfeeding, and must be willing to use contraception, willing and able to comply with the study requirements and to provide written informed consent. * For Japanese cohorts, subjects of Japanese descent are defined as people carrying a Japanese passport, descendants of 4 Japanese grandparents, and have not been outside Japan for more than 5 years. Exclusion Criteria: * Clinically relevant history or presence of respiratory, gastrointestinal, renal, cardiovascular, hepatic, hematological, lymphatic, neurological, psychiatric, musculoskeletal, genitourinary, immunological, and other inflammatory diseases, or dermatological or connective tissue diseases or disorders. * Active serious mental illness or psychiatric disorder. * Clinically significant ECG abnormalities. Abnormal for AST/ALT and any other clinical safety laboratory result considered clinically significant. * Known history of allergic reaction to an oligonucleotide or GalNAc. * History of intolerance to subcutaneous injection.