Evaluate the Effect of Switching From Daily Injections of 20mg Glatiramer Acetate (GA) to 40mg GA Three Times a Week in Subjects With Relapsing-remitting Multiple Sclerosis

The primary aim of this study is to observe the effect of switching from daily injections of
20mg glatiramer acetate (GA) (20mg/daily) to GA 40mg three times a week (40mg x 3/weekly) on
thalamus pathology, as measured by changes in diffusion-tensor imaging (DTI) in patients
with relapsing-remitting multiple sclerosis (RRMS). We hypothesize that GA 40mg x 3/weekly
will exert similar, if not better effect on prevention of thalamic pathology, as compared to
GA 20mg/daily. The secondary objective of this study is to investigate the effect of
switching from GA 20mg/daily to GA 40mg x 3/weekly on evolution of microstructural changes
in normal appearing white matter (NAWM) and normal appearing gray matter (NAGM), as measured
by DTI.

Inclusion Criteria:

- MS patients diagnosed with MS according to the McDonald criteria

- MS patients having a relapsing disease course

- Being on GA monotherapy (20mg/daily sc) for at least 12 months prior to the standard
of care MRI at the time of switch to GA 40mg x 3/weekly

- Having standard of care 3T MRI scan while on GA 20mg/daily treatment for at least
12-18 months prior to the start day of the of the GA 40mg x 3/weekly and at the time
of switch to GA 40mg x 3/weekly Age over 18

- Pass MRI health screening (in case of EGFR <59, the contrast will not be applied)

- None of the exclusion criteria

Exclusion Criteria:

- Patients who had a relapse within 30 days prior to MRI scan date

- Patients who received steroid treatment within 30 days prior to the MRI scan date

- Women who are pregnant, lactating or of childbearing age who do not consent to
approved contraceptive use during the study

- MS patients who used other imunomodulatory or immunosuppressant treatment other than
GA during the 12 months prior to start of GA 40mg 3/weekly (e.g., IFN-β,
mitoxantrone, cyclophosphamide, cladribine, fludarabine, cyclosporine, total body,
azathioprine, methotrexate, IVIG, cellcept, natalizumab, etc.)