Study of Acthar® Gel (Acthar) for Amyotrophic Lateral Sclerosis (ALS)

About 213 people with ALS will participate in this study. There will be locations in North and South America. During the first part, participants will be randomly assigned to a group (like by flipping a coin). Out of every 3: * 2 will get the study drug * 1 will get a look-alike with no drug in it (placebo) During the second part, everyone will get the study drug. Participation will help doctors find out if Acthar can help or slow down the symptoms of ALS better than placebo.