How does it work?

Teriflunomide affects the immune system by blocking the action of a specific set of immune cells called T cells, which are thought to be responsible for causing damage to the brain and spinal cord in people with MS. Other immune functions are thought to be left intact, affording people with MS some immune protection against pathogens.  

How is it administered?

Teriflunomide is taken as a tablet once a day 

To what type of MS is it targeted?

Relapsing remitting MS or people with secondary progressive MS who are still experiencing relapses 

Most recent trial results

Recent phase II trial results were published in 2006 involving two different doses of Teriflunomide over 36 weeks in a trial involving 179 people with relapsing remitting MS, 157 people with secondary progressive MS who still experience relapses and 22 who received placebo. MRI brain scans were performed every 6 weeks.

Both doses of drug tested in the study were associated with reduced numbers of active MRI lesions. Fewer people receiving the higher dose of Teriflunomide demonstrated disability increase compared to placebo. No effect on relapse rate was observed.
 

Current situation

Sanofi-Aventis began one phase III study called TEMSO involving 870 people with MS, assessing if Teriflunomide is able to reduce the frequency of relapses and the accumulation of disability. The study began in Sept 2004 and was completed in June 07. The results have not yet been published. (ClinicalTrials.gov Identifier: NCT00134563)

Another is a world-wide study involving 780 people with MS to try to assess if teriflunomide is able to reduce the number of people who go on to develop clinically definite MS after having their first symptoms, compared to placebo. This began in February 2008. (ClinicalTrials.gov Identifier: NCT00622700)

Other phase II studies are assessing the effects of teriflunomide in conjunction with beta interferon therapies.
 

Side effects

Treatment was well tolerated. More side effects were reported for the higher dose taken on the trial. Side effects included nausea, headaches, diarrhoea, and limb pain.