Safety of Engensis in Participants With Amyotrophic Lateral Sclerosis

Inclusion Criteria: 1. Clinically definite or probable Amyotrophic Lateral Sclerosis or laboratory-supported probable Amyotrophic Lateral Sclerosis as defined in the revised El Escorial/Airlie House diagnostic criteria 2. The site of onset of Amyotrophic Lateral Sclerosis symptoms is a limb and experiencing symptoms of lower motor dysfunction (e.g., weakness, atrophy, cramps, poor circulation, etc.) with upper motor neuron symptoms (e.g., weakness, brisk reflexes, spasticity) 3. Onset of Amyotrophic Lateral Sclerosis symptoms ≤ 4 years 4. Slow Vital Capacity ≥ 50% of predicted value at Screening 5. Not taking riluzole, or on a stable dose (defined as no noted toxicities) for at least 30 days prior to Screening and throughout the study 6. Not taking edaravone or on a maintenance cycle for at least 30 days prior to Screening and throughout the study 7. For females of childbearing potential, a negative urine pregnancy test at Screening and on Day 0 8. Male Participants and their female partners must agree to use double-barrier contraception during the study or provide proof of postmenopausal state (minimum 1 year) or surgical sterility 9. Male Participants must not donate sperm during the study 10. Female Participants must be nonpregnant, nonlactating, and either postmenopausal for at least 1 year, or surgically sterile for at least 3 months, or agree to use double-barrier contraception from 28 days prior to randomization (Day 0) and/or their last confirmed menstrual period prior to study randomization (whichever is longer) until the end of the study 11. Capable of complying and willing to comply with the requirements and restrictions in the informed consent form and this protocol 12. Willing to forgo new experimental Amyotrophic Lateral Sclerosis treatments for at least 6 months following randomization Exclusion Criteria: 1. Progressive or degenerative neurological disorder such as Alzheimer's disease, Parkinson's disease, vascular dementia, multiple sclerosis, and other neurological or vascular disorders felt by the Investigator to preclude participation 2. Requires tracheotomy ventilation or noninvasive ventilation related to bulbar function 3. Evidence by physical examination, history, or laboratory evaluation of significant concomitant disease with a life expectancy of \< 6 months at Screening 4. International Normalized Ratio values \>2.0 5. Platelet count \<100,000/µL 6. Inflammatory disorder of the blood vessels (inflammatory angiopathy or vasculitis, such as Buerger's disease) 7. Active infection (chronic infection or severe active infection that may compromise the Participant's wellbeing or participation in the study in the Investigator's judgment) 8. Chronic inflammatory disease (e.g., Crohn's disease, rheumatoid arthritis) 9. Positive human immunodeficiency virus or human T-cell lymphotrophic virus I/II test at Screening 10. Active acute or chronic hepatitis B 11. Active hepatitis C 12. Immunosuppression due to underlying disease (e.g., rheumatoid arthritis, systemic lupus erythematosus) or to currently receiving immunosuppressive drugs, (e.g., chemotherapy, corticosteroids) or to radiation therapy 13. Stroke or myocardial infarction within 3 months prior to Screening 14. Active deep vein thrombosis 15. Recent history (\< 3 years) or presence of cancer except basal cell carcinoma or squamous cell carcinoma of the skin that was excised and has shown no evidence of recurrence for at least 1 year 16. Major psychiatric disorder diagnosed in the past 6 months that has not been stabilized or in the Investigator's opinion would not allow the patient to participate in the scheduled procedures 17. Use of an investigational drug for the treatment of Amyotrophic Lateral Sclerosis in the past 30 days or 5 half-lives (if available), whichever is longer, or previous participation in a clinical study with Engensis 18. Stem cell administration for investigational treatment of Amyotrophic Lateral Sclerosis or other conditions in the 6 months prior to Screening