Massachusetts General Hospital (MGH) is seeking individuals to participate in a research study enrolling under the direction of Nazem Atassi, MD, MMSc. We are doing this research study to find out about the safety and tolerability of the study drug BIIB067. The study is funded by Biogen MA Inc. This study has two parts: Part A is a single dose of the study drug BIIB067. Part B will include repeated doses of BIIB067 over a specified timeframe. Part A is recruiting participants with Amyotrophic Lateral Sclerosis (ALS) with a forced vital capacity greater than or equal to 50% of predicted value. Part B is recruiting SOD1-ALS patients, also with a forced vital capacity greater than or equal to 50% of predicted value. Participation in Part A of the study will last for approximately 12 weeks and will include an overnight stay at MGH in addition to in person visits. Participation in Part B of the study will last for approximately 31 weeks and will include an overnight stay at MGH in addition to in person visits. The study team can provide additional information on the number of required visits during your initial visit. There are additional inclusion/exclusion criteria that the study team will review with you in more detail if you are interested in participating. For more information regarding this trial, or to further discuss how to participate, please contact Mark Levine-Weinberg at 617-643-6252 or firstname.lastname@example.org.