A Phase 1, Single-Ascending-Dose, Safety, Tolerability, Pharmacokinetic(PK), and Pharmacodynamic(PD) Study of BIIB068 in Healthy Participants

Key Inclusion Criteria: * All male subjects must practice highly effective methods of contraception during the study and be willing and able to continue contraception and not donate sperm for at least 1 spermatogenic cycle (90 days) after administration of last dose of study treatment. * All female subjects of childbearing potential must practice highly effective methods of contraception during the study and be willing and able to continue contraception for at least 1ovulatory cycle (30 days) after their last dose of study treatment. * Must have a body mass index (BMI) between 18 and 32 kg/m2 * Must be in good health as determined by the Investigator, based on medical history and screening evaluations. Key Exclusion Criteria: * History of any clinically significant cardiac, endocrine, gastrointestinal (GI), hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, psychiatric, or renal disease, or other major disease, as determined by the Investigator. * History of severe allergic or anaphylactic reactions, or history of any allergic reactions that in the opinion of the Investigator is likely to be exacerbated by any component of the study treatment. * Clinically significant abnormal laboratory test values, as determined by the Investigator, at Screening or Day-1. NOTE: Other protocol-defined inclusion/exclusion criteria may apply.