SEARCHING FOR THERAPIES FOR PROGRESSIVE MS
There are now 11 medications, FDA approved, for relapsing and remitting MS. Other than Novantrone, which is no longer used because of safety issues that were worse than initially predicted, no medication has been approved for progressive MS.
The current thrust of research is neuroprotection rather than anti-inflammatory effects. Below is the summary of studies presented at the 2015 CMSC Annual Meeting.
Lamotrigine (Lamictal) is a sodium channel blocker, widely used to treat epilepsy. The point is to block the sodium channels on the axon and on cells in the brain termed microglia. This technique has proven effective in animal models but so far not consistently in human trials. In one study at 2 years of patients with secondary progressive MS, patients who received the medication had more brain atrophy than controls, though this recovered partly after treatment was stopped. Despite this, there was improvement in the timed 25-foot walk and a reduction in serum neurofilament levels. These levels correlate with brain tissue loss and disability.
Phenytoin (Dilantin), another antiepileptic drug which affects sodium channels, was tested in acute optic neuritis. Patients on the medication had 30% less atrophy in the retinal nerve fiber layer.
Biotin is a coenzyme and widely used for hair thinning and to improve nail growth. Surprisingly, it was found effective in patients with primary and secondary progressive MS, improving the disability scale and the timed 25-foot timed walk. Very high doses were used, and patients would need to take 30 pills daily at the currently available over-the-counter doses. More research is planned.
Amiloride is a medication that treats blood pressure. It also affects an ion channel within axons and within certain brain cells called oligodendrocytes. In one study, it reduced the rates of brain atrophy and damage to the white and grey matter in patients with primary progressive MS.
Riluzole is the only medication approved by the FDA to treat ALS (Lou Gehrig’s disease). In a small study, it seemed to reduce the rate of atrophy in the cervical spinal cord and decrease the development of T1 lesions in the brain in MS patients. These lesions are a marker of atrophy and disability.
Fluoxetine (Prozac) is a widely used antidepressant in the SSRI class. In fact, it was the first in that class approved by the FDA. In some studies, it protects against loss of axons in the brain. A large clinical trial termed MS-SMART is currently recruiting patients to test this further.
Finally, a trial termed SPRINT-MS will test whether the medication called ibudilast can reduce brain atrophy in patients with secondary and primary progressive MS.
To locate clinical trials, go to ClinicalTrials.gov. That site contains every trial registered in the US.