Amiloride, Ibudilast, Riluzole
The Multiple Sclerosis-Secondary Progressive Multi-Arm Randomisation Trial ( MS-SMART) is a UK based initiative aimed at examining the efficacy of three drugs in treating progressive MS. The three drugs under study are currently used for treating other conditions and their investigation in treating progressive MS is an example of drug repurposing. Phase II clinical trials are planned but not yet recruiting.
Amiloride (Midamor): Currently used as a drug to treat high blood pressure and heart disease. It is suggested that Amiloride may exert neuroprotective effects in MS by reducing the levels of sodium and calcium that are able to pass through the neuronal membrane and cause damage to axons. A pilot study of 14 people revealed promising findings. Participants administered Amiloride showed a reduction in brain shrinkage compared to what was experienced prior to treatment. However, definitive conclusions cannot be drawn from such a small experimental group.
Ibudilast (MN-166): Currently used as a drug for treatment of asthma. Ibudilast has shown promise as an anti-inflammatory drug, reducing levels of immune cells associated with damage in MS. A pilot study revealed participants administered Ibudilast showed a reduction in disability progression and evidence of neuroprotective effects. Further clinical trials are required to determine Ibudilasts safety and efficacy in the treatment of progressive MS.
Riluzole (Rilutek): Currently used as a drug for treating motor neurone disease. Riluzole is a glutamate receptor blocker. Excessive glutamate release can damage neurons. Inhibiting glutamate release could help prevent damage in MS. A small pilot study of 16 people investigated the neuroprotective effect of Riluzole. Results were inconclusive. Future studies are planned.
“The MS-SMART trial is independent research awarded by the NIHR Efficacy and Mechanism Evaluation Programme (EME) and funded by the Medical Research Council (MRC) and the Multiple Sclerosis Society (MS Society) and managed by the National Institute for Health Research (NIHR) on behalf of the MRC-NIHR partnership.”