Table 1 Inclusion Criteria

Patients must meet all of the following criteria to be eligible for further study participation:

1. Signed informed consent form (ICF)

2. Age 18 to 55 years old (inclusive) as of the date the ICF is signed

3. Diagnosis of MS according to the McDonald criteria 2010 and cranial MRI scan demonstrating white matter lesions attributable to MS within 10 years before screening

4. Onset of MS symptoms (as determined by a neurologist, either at present or retrospectively) within 10 years of the date the ICF is signed

5. EDSS score 0.0 to 5.0 (inclusive) at Screening

6. Patients with (highly) active RRMS disease course indicated to receive alemtuzumab according to the following conditions (at least 1 out of 3 conditions has to be fulfilled):

 1. ≥2 MS relapses within 24 months

 2. Clinical (≥1 relapse) or MRI (new gadolinium enhancing lesions) disease activity under therapy with other disease-modifying therapies

 3. Severe relapse with high disease activity (≥9 T2 hyperintense Lesions and ≥1 gadolinium enhancing lesion) on MRI.

7. Completion of all vaccinations required by the applicable immunization guidelines published by “ständige Impfkommission” (STIKO)

8. History of chickenpox or positive test for antibodies against varizella zoster virus (VZV)