Prospective Observational Long-term Safety Registry of Multiple Sclerosis Patients Who Have Participated in Cladribine Clinical Trials ClinicalTrials.gov, 22 Jul 2011 Accessed on 20 Feb 2012 from http://clinicaltrials.gov/ct2/show/NCT01013350?term=cladribine&rank=24. CommentRecommendBookmarkWatch