Active SPG302 to be administered to adult participants with ALS who completed initial study. Dose to be administered to be dose received during previous study.

Open label SPG302 to be self-administered daily by eligible participants for 52 weeks.

Incidence, nature, and severity of treatment emergent adverse events (TEAEs) and serious adverse events (SAEs)

Prospective suicidality assessment is performed using the Columbia-Suicide Severity Rating Scale (C-SSRS), a questionnaire to evaluate suicidal ideation and behavior. Answer "yes" on item 4 or 5 of the Suicidal Ideation section or "yes" on any item of the Suicidal Behavior section is considered positive. The suicidal behavior lethality sub-scale evaluates the level of actual or potential medical damage

Questionnaire administered by a clinician that includes a series of questions about participants' ability to function in certain daily activities. Each type of function is scored from 4 (normal) to 0 (no ability), with a maximum total score of 48 and a minimum total score of 0. Patients with higher scores have more physical function. This outcome would evaluate these scores based on patient demographics including clinical presentation at outset of study, presence of ventilation assistance, and patient demographics. Results will be compared to matched historical controls