This is an optional open-label extension to participants that have completed the clinical trial CNMAu8.205.

A forty-eight (48) week optional open-label extension period (Open- Label Period), which may be extended by 12-week increments until discontinued by the Sponsor for participants that have completed protocol CNMAu8.205.

Inclusion Criteria:

1. Participants must have completed the randomized placebo-controlled Treatment Period without compliance issues.
2. Able to understand and give written informed consent to participate in the open-label extension.
3. If referred from a third party (neurologist or a State based ALS organisation), participant agrees to maintain transfer of care to a neurologist participating in the study.

Exclusion Criteria:

1. Lack of treatment compliance during the randomized placebo controlled Treatment Period.
2. Positive pregnancy test at the Week 36 visit, or, females who plan to get pregnant during the course of this extension or within 6 months of the end of this extension.
3. Based on the investigator's judgment, patients who may have difficulty complying with the protocol and/or any study procedures.
4. Patient with clinically significant abnormalities in haematology, blood chemistry, ECG, or physical examination identified during the W36 visit which according to Investigator may interfere with continued participation.
5. Patients with clinically significant hepatic or renal dysfunction or clinical laboratory findings that would limit the interpretability of change in liver or kidney function, or those with low platelet counts (< 150 x 10^9 per liter) or eosinophilia (absolute eosinophil count of ≥ 500 eosinophils per microliter) at the Week 36 visit.
6. Patient is considered a suicide risk in the opinion of the Investigator, has previously made a suicide attempt, or is currently demonstrating active suicidal ideation. Subjects with intermittent passive suicidal ideation are not necessarily excluded based on the assessment of the Investigator.