A Single-Dose, Pharmacokinetic/Pharmacodynamic (PK/PD), & Safety Study of BIIB017 in Participants With Renal Impairment & Healthy Volunteers

Key Inclusion Criteria: * Subjects must have stable renal disease (i.e., no change in disease status within the last month) as determined by the Investigator with laboratory and clinical findings that support the diagnosis of renal impairment. * Must have body mass index (BMI) between 18 and 35 kg/m2 inclusive. Key Exclusion Criteria: * History of any clinically unstable (in the past 6 months prior to screening) cardiac, endocrinologic, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, and psychiatric, or other major disease as determined by the Investigator. * Any evidence of clinically significant findings on screening evaluations, which, in the opinion of the Investigator would pose a safety risk, or would interfere with appropriate interpretation of safety or PK data, or other unspecified reasons that, in the opinion of the Investigator or Biogen Idec, make the subject unsuitable for enrollment NOTE: Other protocol defined Inclusion/Exclusion Criteria May Apply