Prospective Observational Long-term Safety Registry of Multiple Sclerosis Patients Who Have Participated in Cladribine Clinical Trials

Inclusion Criteria:

- Prior enrollment into selected oral cladribine clinical trials as of randomization to
either study drug or placebo, once participation in the clinical trial has ended

- Written informed consent was given

Exclusion Criteria:

- Subjects who cannot be reached by telephone

- Subjects unable to answer the registry questionnaires and who do not have a next of
kin or caregiver able to answer the registry questionnaires

- Subjects who - either during the lag interval or subsequently - enter an
interventional study