Phase II Cladribine Add-on to Interferon-beta (IFN-b) Therapy in MS Subjecs With Active Disease (ONWARD) ClinicalTrials.gov, 19 Jan 2012 Accessed on 20 Feb 2012 from http://clinicaltrials.gov/ct2/show/NCT00436826?term=cladribine+multiple+sclerosis&rank=2. CommentRecommendBookmarkWatch