Patient Satisfaction Study of Single-Use Autoinjector for the Delivery of Pre-Filled Avonex Syringe

Inclusion Criteria: * Must be using liquid AVONEX® to treat MS. In addition, the subject must be on liquid AVONEX® for 12 weeks prior to the Screening Visit. * Must have a BMI of 19 to 28 kg/m², inclusive, and a minimum body weight of 50 kg at Screening. * Must be able to physically demonstrate use of the device and be able to self-administer all injections. * Must be English speaking. * Must be able to understand and comply with the protocol. Exclusion Criteria: * Abnormal screening or screening blood tests determined to be clinically significant by the investigator for: white blood count (WBC) or differential, platelet count, hemoglobin, serum creatinine, bilirubin, alanine transaminase (ALT) aspartate transaminase (AST), prothrombin time (PT). * Known sensitivity to dry natural rubber. * Treatment with other agents to treat MS symptoms or underlying disease as specified in the protocol. * History of severe allergic or anaphylactic reactions. * History of intolerance to acetaminophen (paracetamol), ibuprofen, naproxen, and aspirin that would preclude the use of at least one of these during the study. * Serious local infection Other inclusion and exclusion criteria apply as per Biogen Idec Protocol