An allergy drug showed promise for MS, but could they prove it? (Yes, inexpensive clemastine repairs myelin)

Medical Xpress / University of California, San Francisco / The Lancet ^ | Feb. 16, 2024 | Suzanne Leigh / Jonah Chan, Ph.D. et al

[ConservativeMind]

What if an over-the-counter allergy medicine could help halt and even reverse multiple sclerosis? And if it did, could patients return to their full capacity? Those were some of the questions posed by Jonah Chan, Ph.D., and Ari Green, MD.

The two had discovered in the lab that the medication clemastine—originally approved as an antihistamine—could repair myelin, the protective insulation around nerve fibers that is damaged in MS.

That early discovery in Chan's lab, in which clemastine was shown to stimulate the differentiation of myelin-making stem cells, led to clinical trials to test the therapy in people.

Surprisingly, these were patients with long-term damage from chronic MS, not just recent damage, said Green.

So together with Chan, they zeroed in on myelin-rich areas of the brain using MRIs from participants in their earlier trial.

The trial had split the patients into two groups: one set received clemastine in the first portion of the study and the other received clemastine in the second portion. The researchers found that the myelin content of the targeted areas they evaluated in the brain increased in group No. 1 during the first portion of the study and continued to increase in the second portion after clemastine was stopped. In group No. 2, myelin dropped in the first portion of the study and rebounded in the second portion. They had their proof.

The 2022 findings were accompanied and preceded by studies that reinforced that clemastine acted directly on myelin and proved the importance of myelin for keeping nerve fibers healthy. Meanwhile, labs around the world have confirmed Chan's initial findings. Data also linked MS patients' vision improvements to increases in myelin around the optic nerve.

Collectively, this work may herald a sea change in prognosis for patients with MS.

[Rockingham]

Ah, yes, until withdrawn, phenylpropanolamine was my decongestant of choice for many years. I never had any trouble and it keep me working by alleviating otherwise chronically swollen sinuses. Critics said the stroke risk was so statistically slight as to raise suspicion that the FDA was clearing the path for a new decongestant from a politically favored drug company.