The condition and the treatment
Multiple sclerosis is a disease in which areas of the brain and spinal cord become damaged by the body's own immune system. There are different types of the condition. One type is relapsing–remitting multiple sclerosis, in which people have flare-ups of symptoms (relapses) followed by a period of recovery (remission). Active relapsing–remitting multiple sclerosis is when there have been 2 clinically significant relapses in the previous 2 years. Highly active or rapidly evolving severe relapsing–remitting multiple sclerosis is when the condition is even more active and severe.
Teriflunomide (also known as Aubagio) is a drug that works by modifying the body's immune system to stop it attacking the brain and spinal cord.
NHS Choices (www.nhs.uk) may be a good place to find out more.