Neurodegeneration is the main cause of permanent disability in MS and there are few treatment options. A new study from the University of Oxford has investigated whether amiloride, a drug that is already available for other conditions, might be able to limit neurodegeneration in people with primary progressive MS.
Amiloride works by blocking a potassium channel known as ASIC1, and is currently licenced for hypertension and congestive heart failure. The first stage of the study used post-mortem brain tissue taken from six people with primary progressive MS and compared this with brain tissue taken from people without the disease.
The researchers wanted to determine the level of activity of the potassium channel in the brain and specifically within chronic inactive MS lesions. They found that the potassium channel was more active in nerve fibres and myelin producing cells from people with MS. This meant that blocking the channels with amiloride might prevent damage in the brain.
Amiloride was given to 12 people with primary progressive MS over one year in the form of a single daily 10mg oral dose. The participants were tracked using magnetic resonance imaging that incorporated scans taken during the year before the treatment period began and throughout the treatment phase. The MRIs were analysed to see if markers of neurodegeneration, such as brain volume and tissue damage, were improved on amiloride.
The MRI scans showed that the rates of neurodegeneration and tissue damage were reduced during the amiloride treatment phase when compared to the year prior to treatment. The participants also showed higher rates of disability change on the expanded disability severity score, in the period before treatment when compared with the treatment phase – although since the trial only included a very small group this finding will have to be confirmed.
Even though the trial was small, these are encouraging results and further clinical trials are warranted. ‘This is the first translational study on neuroprotection to target ASIC1,’ said the authors, ‘and supports future randomised controlled trials measuring neuroprotection with amiloride in patients with MS’. Since amiloride has already been approved for other conditions, the clinical trial process may be shortened, and provide a much needed treatment option for disability in MS.
To read the abstract please click here http://www.ncbi.nlm.nih.gov/pubmed?term=23365093
Source: Multiple Sclerosis Research Australia © 2013 Multiple Sclerosis Research Australia (MSRA ABN: 34 008 581 431) (08/02/13)