Study of NG01 Cell Therapy in Secondary Progressive Multiple Sclerosis

Inclusion Criteria: 1. Participants aged 18 to 65 years old. 2. Diagnosis of SPMS. 3. Documented EDSS worsening over the 2 years prior to study entry of ≥1 point for participants with EDSS \<6.0 at screening, and ≥0.5 point for participants with EDSS ≥6.0 at screening, or a documented worsening of at least 20% in the T25FW. If documented T25fW or EDSS is not available, a written summary of the clinical evidence of disability worsening over the previous 2 years and retrospective assessment of EDSS score from data up to 2 years prior to screening, must be submitted for central review by adjudication committee. 4. EDSS at the screening visit from 3.5 to 6.5 at screening. 5. T25FW at the screening visit of from 8.0 to 25 seconds. Exclusion Criteria: 1. Documented clinical relapse during the 24 months prior to enrollment and/or evidence of enhancing lesions on an MRI obtained at screening. 2. Pregnancy, breast feeding or women with childbearing potential without an acceptable form of contraception. 3. History of a general chronic handicapping/incapacitating disease other than MS. 4. Participants with clotting disorders 5. Participants unable to undergo an MRI scan. 6. Participants with uncontrolled hepatic disorders, renal or cardiovascular disease, or cancer. 7. Laboratory tests out of normal ranges considered by the investigator as clinically significant. 8. Participants with history or current alcohol abuse or drug addiction. 9. Untreated or uncontrolled psychiatric disorders, or positive suicidal risk assessed by Columbia-Suicide Severity Rating Scale (C-SSRS). 10. Participation in another research study involving an investigational product (IP) in the 90 days prior to inclusion, or planned use of another IP during the study duration. 11. Participants who have ever received NG01/MSCs treatment. 12. Participants who, in the opinion of the investigator, are unable to fully comprehend the consenting process or likely to be non-compliant with the study procedures or for whom long-term follow-up seems difficult to achieve. 13. Relapse occurring between screening and randomization. 14. Less than 6 months of the current disease-modifying therapy