Patients with progressive multiple sclerosis showed improvements in standard measures of disability after taking large doses of biotin in a phase III study, the product’s developer announced.

Paris-based MedDay SAS said the 154-patient, placebo-controlled trial met its primary endpoint — either a decrease in Expanded Disability Status Score (EDSS) of at least 1 point for baseline EDSS ≤5.5 and 0.5 points for EDSS ≥6, or an improvement in 25-foot walk time of at least 20% — but the firm did not indicate what proportion of patients achieved these outcomes.

The drug, called MD1003, delivers 300 mg/day of biotin — a massively greater dose than the usual recommendation of 30-100 mcg/day. Patients in the trial received the drug for 48 weeks. The primary endpoint was assessed at 9 months, with another assessment at 12 months.

According to the published abstract for the AAN presentation, biotin acts “as a coenzyme for carboxylases involved in key steps of energy metabolism and fatty acids synthesis. Among others, biotin activates acetylCoA carboxylase, a potentially key-enzyme in myelin synthesis.”

Demyelination and resulting neuronal dysfunction and death is thought to be the main basis for progressive MS. Consequently, agents that prompt new myelin synthesis are considered one way to slow, stop, or even reverse disability progression.

The abstract cited a 23-patient pilot study, in which open-label biotin doses of up to 600 mg/day “resulted in progressive and sustained improvement of disability in primary and secondary [progressive MS] patients.”

MedDay said the phase III trial design had been “discussed with U.S. and European regulators” and that it was “pleased” with the results. But the firm didn’t indicate whether it planned to seek marketing approvals on the basis of the trial findings. Aseparate trial is currently underway with visual endpoints in patients with MS-related optic neuritis. A third trial in the adult form of X-linked adrenoleukodystrophy has also launched, the company said.