Research Says Allergy Medications Can Fight Multiple Sclerosis

A large focus in research regarding multiple sclerosis is how to protect from inflammation-mediated damage to the myelin sheath that acts as a barrier for the neuronal axons. Therefore, it is important to find effective remyelinating agents.

Recently, one has been discovered in an unexpected form - clemastine fumarate, an over-the-counter antihistamine.

The recent research

Jonah R. Chan, PhD is the vice chief of the Division of Neuroinflammation and Glial Biology and a Debbie and Andy Rachleff Distinguished Professor of Neurology. He is the senior author of the study, and the first to suggest clemastine fumarate, a drug that has been available to treat allergies for over twenty years, might be a method of treatment for multiple sclerosis.

A crossover study was conducted by UC San Francisco scientists that analyzed fifty patients who were experiencing relapsing multiple sclerosis. All patients remained on their preexisting immunomodulatory therapy, but one group was randomly chosen to take clemastine fumarate, while the other was given a placebo for three months, followed by two months of treatment. Both the researchers and patients were unaware throughout the duration of the study of which group had the placebo and which was actively taking the drug. Even after the switch, neither was aware. This form of control was especially effective, increasing the study's statistical relevance and power.

Chan explains the initial reaction to the study: "People thought we were absolutely crazy to launch this trial, because they thought that only in newly diagnosed cases could a drug like this be effective - intuitively, if myelin damage is new, the chance of repair is strong. In the patients in our trial the disease had gone on for years, but we still saw strong evidence of repair."

For more information, the results of the Phase II trial have been published in The Lancet, and are available online. The study was supported generously by the Rachleff family.

Importance of myelin

Myelin acts as a catalyst to electrical signals in the nervous system, making its strength instrumental in the health of those with the condition. MS affects around 2.5 million people internationally, and occurs when one's immune system assaults myelin, which is many layers of fatty membrane that sits surrounding nerve fibers.

Myelin damage tends to progress throughout patients' experiences with the disease, which results in neurons losing their transmission capabilities regarding electrical signals. This directly affects the patient by harming vision, balance, strength, mobility, and coordination.

The study showed profound results

The researchers showed that clemastine fumarate offers the first-ever proven drug-induced myelin repair in multiple sclerosis - or any chronic neurodegenerative condition for that matter.

Other treatments have attempted to protect the immune system from the progression of the destruction, but have not been able to actively repair the myelin. Restoring nervous system function impacts those with multiple sclerosis tremendously, and should offer relief to many.

Read on to learn more about these surprisingly positive results, and what they mean for the future of multiple sclerosis care and clinical research.