Inclusion Criteria:
1. Males and females ≥18 years of age at the time of informed consent.
2. Diagnosed within the previous 1 year with laboratory-supported probable, clinically probable or definite ALS according to the World Federation of Neurology Revised El Escorial criteria.
3. Must have familial or sporadic ALS.
4. First ALS symptoms occurred no more than two (2) years prior to screening visit ALS disease duration from diagnosis no longer than 12 months at the Screening visit.
5. If treated with riluzole, edaravone or any other approved ALS medication, treated with a stable dose for at least 4 weeks prior to Day 1.
6. If documented, patient with an ALSFRS-R score progression between onset of the disease and Screening of \> 0.3 per month, confirmed with an ALSFRS-R score progression of ≥ 1 point during a 12 week prior to randomisation.
7. Has a score of at least 26 overall, including a score of at least 3 on item #3 and at least 2 on each of the 12 ALSFRS-R individual component items at Screening and at least 2 on each of the 12 ALSFRS-R individual component items at randomisation.
8. Seated slow vital capacity (SVC) ≥ 50% of predicted value for gender, height, and age at screening.
9. Must be willing and able to comply with the requirements of the protocol and must be available to complete the study.
10. Must provide written informed consent to participate in the study.
Exclusion Criteria:
1. Has dementia or significant neurological, psychiatric, systemic, or organic disease, uncontrolled or that may interfere with the conduct of the trial or its results.
2. Pregnant or nursing females.
3. History of drug/chemical/substance/alcohol abuse within the past 2 years prior to Screening, including cannabinoid therapies.
4. Significant symptomatic, viral, bacterial (including upper respiratory infection), or fungal (non-cutaneous) infection within the past 2 weeks prior to study medication administration (at the discretion of the Investigator).
5. Mechanical ventilation via tracheostomy or dependence on non-invasive ventilation, (\> 16 hours / day). (Lesser intermittent use of non-invasive ventilation eg, continuous positive airway pressure, non-invasive bi-level positive airway pressure or non-invasive volume ventilation is not an exclusion).
6. Patients positive for human immunodeficiency virus (HIV) antibody, hepatitis C antibody, or for hepatitis B virus surface antigen (HBsAg).
7. Sexually active females of childbearing potential and male subjects who are not practicing at least one method of hormonal or mechanical birth control with their partner during the study and for 90 days after the last dose of the study medication. Males and females who are not heterosexually active or who practice true abstinence are exempt from contraceptive requirements.
8. Experimental agent within 30 days or 5 half-lives, whichever is longer, prior to study drug administration (Part 1 only).
9. Any other condition which, in the opinion of the Investigator, precludes participation in the study.
10. Dependents of the Sponsor or Investigator.
11. Known allergy to the study drug and/or its constituents.
