The concept that biotin, a water-soluble vitamin, could have a beneficial effect on the course of multiple sclerosis (MS) is biologically plausible. Biotin activates acetyl-CoA carboxylase, a potential rate-limiting enzyme in myelin synthesis, and has multiple other biochemical effects.
In a small consecutive pilot study in 2015 that was neither placebo-controlled, blinded, nor randomized, Sedel et al found a suggestion of high-dose biotin’s clinical efficacy in patients with progressive MS.
The follow-up study by Tourbah et al expanded and confirmed the clinical efficacy of high-dose biotin (in the form of MD1003) in progressive forms of MS. In contrast to the prior trial, this trial was a double-blind, placebo-controlled, randomized study of 154 patients treated with 300 mg of biotin or placebo daily for 48 weeks. The results indicated that 13.6% of 103 biotin-treated patients had improvement of disability, using change in Expanded Disability Status Scale score or Timed 25-Foot Walk from baseline, as compared with 51 placebo-treated patients. No serious side effects were reported.
Few, if any, studies have shown sustained clinical improvement in patients with progressive forms of MS to date. As is often the case, however, some patients with ostensibly progressive MS may have evidence of clinical relapses, as seen in the biotin trials, or subclinical MRI relapses, as seen by new T2 or enhancing lesions in other studies, that may respond transiently to corticosteroids or disease-modifying therapies.
The mechanism of action of biotin in progressive MS, if validated in other studies, is not well defined. Possibilities include remyelination, axonal regeneration, inhibition of free oxygen radicals, and other effects. Biotin’s efficacy probably is not due to immunosuppression, however.
The results of Dr. Tourbah’s study are consistent with previous animal and human data that indicate biotin’s excellent safety profile. For this reason, and in light of the lack of treatment efficacy in progressive MS, additional robust Phase III studies of biotin should be carried out in an attempt to corroborate and expand these findings. This effort should include a larger number of patients with a longer study duration and additional clinical, neuropsychologic, and MRI studies.
—Stuart D. Cook, MD
Ruth Dunietz Kushner and Michael Jay Serwitz
Professor of Neurology and Neurosciences
Rutgers, The State University of New Jersey
Newark, NJ