['secondary progressive multiple sclerosis']
['saline']

        Inclusion Criteria:

          1. A historical or current cranial MRI scan demonstrating T2-hyperintense lesions
             consistent with MS.

          2. Has SPMS as determined by the 2010 Update to the McDonald Criteria

          3. An Expanded Disability Status Scale (EDSS) of 3.0 to 6.5 at Screening.

          4. Has SPMS which, in the judgment of the investigator, has been clinically active and
             functionally progressive within the 2 years prior to Screening

          5. The absence of MS relapse for at least two years prior to Baseline.

          6. Neurologically stable for at least four weeks prior to Screening.

          7. Has the following laboratory values within three days prior to initiation of
             Investigational Product:

               -  Absolute neutrophil count (ANC) >= 1 x 109/L;

               -  Platelet count >= 100 x 109/L;

               -  Serum creatinine =< 1.5 mg/dL;

               -  Aspartate aminotransferase (AST) =<2 × upper limit of normal;

               -  Alanine aminotransferase (ALT) =< 2 × upper limit of normal.

          8. Provided written informed consent to participate.

        Exclusion Criteria:

          1. Has primary Progressive MS (PPMS), Relapsing Remitting (RRMS), or progressive
             relapsing MS as determined by the 2010 update to the McDonald Criteria.

          2. Has not completed the discontinuation period for approved and/or investigational
             multiple sclerosis disease modifying therapies prior to screening.

          3. Has had any other immunomodulatory drug therapy or immunosuppressive therapy within
             four weeks prior to Screening, or systemic corticosteroids within the eight weeks
             prior to Screening.

          4. Any previous exposure to investigational MS therapeutic vaccines.

          5. Any use of cell-depleting monoclonal antibodies including, but not limited to,
             Rituximab, or Ocrelizumab.

          6. A diagnosis or history of collagen vascular disease (including Sjögren's syndrome and
             systemic lupus erythematosus), anticardiolipin antibody syndrome, cerebral autosomal
             dominant arteriopathy with subcortical infarcts and leukoencephalopathy, sarcoidosis,
             vasculitis, Behcet's syndrome and/or Lyme disease.

          7. Contraindication to MRI (e.g., pacemaker or other contraindicated implanted metal
             device, allergy to gadolinium, or unmanageable claustrophobia).

          8. A history of alcohol or drug abuse (including cannabinoid use) within two years prior
             to Screening.

          9. Has had major surgery or radiation therapy within four weeks prior to Screening.

         10. Has an active infection requiring antibiotics within two weeks prior to Screening.

         11. Has had active malignancy within two years of Screening, with the exception of basal
             cell carcinoma and squamous cell carcinoma of the skin.

         12. Uncontrolled congestive heart failure, myocardial infarction, cerebrovascular
             accident, coronary/peripheral artery bypass graft surgery, or transient ischemic
             attack within twelve weeks prior to Screening.

         13. Has angina, other symptomatic coronary artery disease, or known cardiomyopathy.

         14. Has symptomatic cardiac dysrhythmias requiring treatment, or persistent prolongation
             of the QTcF (Fredericia) interval to > 450 msec for males or > 470 msec for females.
      