Results from a Phase II clinical trial observing possible treatment for progressive MS
Currently available therapies for multiple sclerosis are designed to target inflammation. This feature enables them to reduce the frequency relapses, which occur when waves of immune cells enter the central nervous system and cause damage to the protective myelin sheath. Although successful in treating relapsing forms of MS, this expanding list of therapies remain ineffective for progressive MS. The need for disease-modifying therapies for progressive MS is one that is recognized by the global MS scientific community, who have responded by launching research studies and clinical trials that will hopefully provide clearer answers about this advanced form of the disease.
This month a research team from the UK published a phase II clinical trial exploring the safety and efficacy (ability to produce a beneficial effect) of a cholesterol-lowering drug called simvastatin in people with secondary progressive MS. Statins are widely used in many countries to reduce the amount of ‘bad cholesterol’ produced in the body and lower risk of heart disease and stroke. Emerging research shows that statins can reduce inflammation and block immune cells from travelling into the central nervous system in mice. These abilities pose statins as an attractive candidate for treating MS.
Dr. Jeremy Chataway and colleagues from the University College London undertook a 2-year, phase II clinical trial involving 140 volunteers with secondary progressive MS across three neuroscience centres in the UK. They treated 70 people with high dose simvastatin (80mg/day), and the other 70 were given an inactive version of the drug called a ‘placebo’. The type of treatment administered was decided at random. The trial was blinded, meaning the person receiving treatment, the doctor giving the treatment, and the person analyzing the data were all unaware of who received simvastatin and who received a placebo. This is done to avoid bias in the results. The participants were observed over two years. Researchers looked at whether simvastatin had an effect on brain volume loss, known as ‘atrophy’, disability, and the immune system.
In the group of people with secondary progressive MS who were treated with simvastatin, there was a 43% reduction in the rate of atrophy in comparison to the group who received placebo. Researchers also found that the simvastatin group showed slower changes in EDSS and improved scores on the MSIS-29, a measure of the extent to which MS affects daily life. There was no different between groups in the Multiple Sclerosis Functional Composite (MSFC) score, which measures mobility, dexterity and cognition. The study also showed no differences between groups in levels of inflammation-associated molecules. The occurrence of serious adverse events was similar between groups, and simvastatin was well tolerated with no safety concerns.
Overall the results of the clinical trial demonstrate that simvastatin is safe and has a beneficial effect on brain atrophy and disability in people with secondary progressive MS. These results are encouraging and warrant phase III trials to determine the safety and efficacy of simvastatin on a larger group of people with MS as well as when taken over a longer term.
This study is another example of drug repurposing, a process in which a commercially available drug is evaluated for the treatment of a different condition. Drug repurposing is helpful in finding new treatment approaches, especially when time and resources are limited. With very little known about progressive MS, and no treatments available, researchers continue to look at current medications that may have nerve protective or repairing qualities.
Chataway J et al. Effect of high-dose simvastatin on brain atrophy and disability in secondary progressive multiple sclerosis (MS-STAT): a randomised, placebo-controlled, phase 2 trial. The Lancet 2014 Mar 19 [Epub ahead of print].