Teriflunomide, sold under the brand name Aubagio, is the active metabolite of leflunomide.[4] Teriflunomide was investigated in the Phase III clinical trial TEMSO as a medication for multiple sclerosis (MS). The study was completed in July 2010.[5] 2-year results were positive.[6] However, the subsequent TENERE head-to-head comparison trial reported that "although permanent discontinuations [of therapy] were substantially less common among MS patients who received teriflunomide compared with interferon beta-1a, relapses were more common with teriflunomide."[7] The drug was approved for use in the United States in September 2012[8][9] and for use in the European Union in August 2013.[10]