Open-label, long-term extension study available to participants who have completed CNMAu8.201.

This open-label, long-term extension study is only available to participants who have completed CNMAu8.201 (VISIONARY-MS). The Week 48/End-of-Study Visit for study CNMAu8.201 (VISIONARY-MS) will serve to establish the Baseline for electrophysiological, functional, morphological vision testing, as well as the neurological and outcome assessments. Participants will receive open-label CNM-Au8 throughout the study. All participants will receive a daily dose of 30 mg CNM-Au8 for the entire open-label, long-term extension study. The dose for participants may be adjusted once efficacy and safety data from study CNMAu8.201 becomes available, which may occur after participants have already started this study. Based upon a review of data and Sponsor or PI recommendation, this open-label, long-term extension study may be discontinued once each participant reaches her/his 48-week visit.

Inclusion Criteria:

• Participants must have completed study CNMAu8.201.
• Able to understand and give written informed consent.

Exclusion Criteria:

• Lack of treatment compliance during participation in the CNMAu8.201 (VISIONARY-MS) study.
• Positive pregnancy test.
• Any history of previous malignancy, with the exception of basal cell carcinoma of the skin or in situ carcinoma of the cervix, post documented full resections, with clean margins.
• Based on the Investigator's judgment, any concurrent chronic or acute illness or unstable medical condition that could confound the results of safety assessments, increase risk to the participant, or lead to difficulty complying with the protocol; any untreated or unstable psychiatric disease including depression, bipolar and psychosis.
• Participant is considered a suicide risk in the opinion of the Investigator, has previously made a suicide attempt, or is currently demonstrating active suicidal ideation.

Following clinical and serology sample analysis conducted at the end-of-study visit for CNMAu8.201 (VISIONARY-MS), participants may be removed from this long term extension study if any of the following criteria are met, at the discretion of the Medical Monitor and/or Sponsor's Medical Representative:

• Positive serology for viral hepatitis B and/or C and/or human immunodeficiency virus (HIV).
• Abnormal liver function tests (aspartate aminotransferase [ASAT] or alanine aminotransferase [ALAT] > 2x upper limit of normal range (ULN) or total bilirubin > 2x ULN or alkaline phosphatase (AP) > 3x ULN).
• Participants with clinically significant hepatic or renal dysfunction or clinical laboratory findings that would limit the interpretability of change in liver or kidney function (e.g., glomerular filtration rate < 40 mL/min [based on creatinine clearance according to Cockcroft-Gault equation]), or those with low platelet counts (<150 x 109 per liter) or eosinophilia (absolute eosinophil count of ≥500 eosinophils per microliter) at the EOS visit for CNMAu8.201 (Visionary-MS).

None, open-label.