Study of SPG302 in Healthy Volunteers and ALS Participants

Inclusion Criteria: * Age 18-55 * Must be in good health with no significant medical history * Clinical laboratory values within normal range or \< 1.2 times ULN * BMI 18-32 (inclusive) * Contraceptive use by men or women consistent with local regulations * Able and willing to provide written informed consent Exclusion Criteria: * Any physical or psychological condition that prohibits study completion * Known cardiac disease * Active or history of malignancy in the past 5 years * Serious infection within 1 month of screening * Acute illness within 30 days of Day 1 * Surgery, bone fracture, or major musculoskeletal injury in the past 3 months * History of suicidal behavior or suicidal ideation * Active cigarette smokers and users of nicotine-containing products * HIV, hepatitis B and hepatitis C positive * SBP \>140 or \<90 * DBP \>90 or \<40 * HR \<40 or \>100 * QTcF \>450ms, cardiac arrhythmia, or clinically significant abnormal ECG * Prescriptions, over-the-counter, or herbal medication within 7 days * Vaccines within 14 days * Other investigational products within 30 days * Blood donation within 30 days * Plasma donation within 7 days * Pregnant or breastfeeding * Otherwise unfit, on metabolic-altering lifestyle/diet, positive urine drug screen or intake of alcohol or caffeine-containing products ALS Cohort Inclusion Criteria: * Age 18-80 * ALS TRICALS risk score * Stable dose of standard of care treatment * Contraception use by men or women consistent with local regulations * Able and willing to provide written informed consent ALS Cohort Exclusion Criteria: * Underlying physical or psychological condition prohibiting study completion * Known cardiac disease * Active or history of malignancy in the past 5 years * Serious infection within 1 month of screening * Acute illness within 30 days of Day 1 * History of suicidal behavior or suicidal ideation * Active cigarette smokers and users of nicotine-containing products * Neurodegenerative disease * External respiratory support or supplemental oxygen requirement * HIV, hepatitis B and hepatitis C positive * SBP \>140 or \<90 * DBP \>90 or \<40 * HR \<40 or \>100 * QTcF \>450ms, cardiac arrhythmia, or clinically significant abnormal ECG * Vaccines within 14 days * Other investigational products within 30 days * Blood donation within 30 days * Plasma donation within 7 days * Pregnant or breastfeeding * Otherwise unfit