A cheap cholesterol-lowering drug might be a potential new treatment for those with secondary progressive and untreatable multiple sclerosis, according to a study published in the journal Lancet.

Researchers in the United Kingdom tested Simvastatin, a generic pill known as a "statin," in 140 patients with secondary progressive MS.

No current drugs work on this type of MS, which is marked by steadily worsening symptoms and disability.

Over two years of study, the researchers found those on daily doses of the cholesterol-lowering drug had a 43 per cent lower rate of brain shrinkage than those on placebo.

Over a typical year, the brain shrinks by about .6 per cent in those with secondary progressive MS.

Those on the Simvastatin had a brain atrophy rate of .3 per cent a year, according to Dr. Jeremy Chataway of University College London Hospitals.

"We feel that atrophy is very important in driving neurological disability," Dr. Chataway wrote in an email to CTV News.

Doctors also say the saw small improvements in disability tests, and added that the drug was safe and well tolerated.

But the statins didn’t affect brain lesions or relapse rates.

Professor John Greenwood at the UCL Institute of Ophthalmology, who has been involved in this area of research, admits scientists don’t know how a drug that removes cholesterol from the body might be slowing brain atrophy.

In fact patients on the drug didn’t have significant changes in cholesterol levels.

In an email to CTV News, Dr. Greenwood wrote: "This raises the possibility that it is due to other effects such as a direct effect on the brain microvasculature (e.g. increasing blood flow)."

Researchers say they are hoping to launch a larger study to see if this statin drug increases quality of life and slow.

"We're really excited by this significant finding in an untreatable stage of the disease," Dr. Chataway said.