REPORT FROM THE 25th CONGRESS OF THE ECTRIMS Dusseldorf, Germany, September 9-12, 2009 Teriflunomide is an immunosuppressant currently being tested in four large phase III trials in clinically isolated syndrome (estimated enrollment 780), MS with relapses (TEMSO trial, estimated n=1080), relapsing-remitting MS (planned n=1110) and versus beta-interferon-1a in RRMS (TENERE trial, estimated n=300). The drug is the active metabolite of leflunomide that is used in the treatment of rheumatoid arthritis.