A Study to Evaluate the Safety and Pharmacokinetics of Single and Multiple Doses of Prosetin in Healthy Volunteers and Participants With ALS

PRO-101, Parts A and B, were completed in healthy volunteers. PRO-101, Parts C and D are ongoing in participants with ALS. Key eligibility criteria are summarized below: Key Inclusion Criteria - Part C * Adults ≥18 years of age * Diagnosis of ALS based on the Gold Coast diagnostic criteria * Slow Vital Capacity (SVC) \>50% predicted * If being concomitantly treated with riluzole and/or locally approved standard of care treatments, the participant must be on a stable dose for at least 30 days prior to screening and throughout the study * In the opinion of the Investigator, participant is able to swallow liquid in order to ingest the study medication. Key Exclusion Criteria - Part C * Active dementia, neurologic diseases other than ALS, or psychiatric illness that in the opinion of the investigator would affect participation in the current study. * Significant history or clinical manifestation of comorbid disease in any organ system that currently requires active treatment or is likely to require treatment during the study. * Any episodes of vertigo in the previous 12 months prior to screening. * Any medical history of seizures, or any clinically significant EEG finding at Screening or at Day -1. * A diagnosis of cancer or evidence of continued disease within five years before screening. Protocol-specified exceptions may be considered with approval from the Sponsor's Medical Monitor. * Participation in any other investigational study drug trial in which receipt of an inves…