A Phase IIa Study of Vitamin D3 Tolerogenic Dendritic Cells (tolDC) for Multiple Sclerosis

Inclusion Criteria: * Patient is ≥ 18 years old, and ≤65 years of age, at time of screening visit * Diagnosis of MS according to the 2017 McDonald Criteria or more recent criteria * Progressive MS by 2014 Lublin MS phenotypic criteria * EDSS 2,0 - ≤7,5 * No clinical evidence of relapses in the past 2 years * Ability to understand and the willingness to sign a written informed consent document. Patients must have signed informed consent to participate in the trial. * Appropriate venous access * Use of adequate contraceptive measures or not of childbearing potential Exclusion Criteria: * Previous treatment with alemtuzumab, autologous hematopoietic stem cell transplantation or cladribine in the past 3 years. * Prior treatment with any investigational agent within 3 months, or 5 half-lives, whichever is longer. * Current and ongoing treatment with an approved DMT for MS * Treatment with S1P receptor modulators, natalizumab, dimethylfumarate, teriflunomide within the last 3 months prior to study enrolment; last treatment with B cell depleting monoclonal antibodies at least 6 months prior to enrollment and normal CD19 B cell counts at time of enrollment * Pregnancy or planning pregnancy in the next 12 months and breast feeding * Drug or alcohol abuse * Inability to undergo MRI assessments * History of or actual signs of immunodeficiency or malignancies (with the exception of treated basal cell carcinoma) * Concurrent clinically relevant cardiac, immunological, pulmonary, neurol…