Teriflunomide


![Teriflunomide is the only active metabolite of leflunomide, completely responsible for its therapeutic actions. It results from the reaction of isoxazole ring opening, which occurs in vivo. Teriflunomide then can interconvert between the E and Z enolic forms (and the corresponding keto-amide), the Z-enol being the most stable and therefore most predominant form.[11][12]](/uploads/202502/15/Activation_of_leflunomide.svg1427.png)
Teriflunomide (trade name Aubagio, marketed by Sanofi) is the active metabolite of leflunomide. Teriflunomide was investigated in the Phase III clinical trial TEMSO as a medication for multiple sclerosis (MS). The study was completed in July 2010. 2-year results were positive. 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." The drug was approved by the FDA on September 13, 2012 and in the European Union on August 26, 2013.