 Approximately 250 participants will be recruited from multiple centers, in the US and Canada, that belong to the Northeast ALS Consortium NEALS and the Canadian ALS Clinical Trials and Research Network CALS. Enrollment will occur in stages. Initially 84 participants will be enrolled in the trial. An interim analysis using available data will occur after the 84th participant is enrolled. During this time, the Data and Safety Monitoring Board DSMB appointed by the National Institutes of Health NIH may decide to stop the trial for efficacy or futility reasons or to stop enrollment and request that follow-up continue with the 84 participants already enrolled in the trial, or the DSMB may decide to continue enrollment. 