Progentos dosed first participant in Phase 1/2a trial of remyelination drug PRO-1562

What's the deal? Progentos Therapeutics, a Cambridge, Massachusetts-based biotech developing regenerative medicines for multiple sclerosis (MS), has dosed the first participant in a Phase 1/2a clinical trial of PRO-1562, an investigational oral small molecule designed to regenerate myelin — the protective sheath around nerve fibres that is damaged in MS. The company announced the milestone on 3 November 2026.

Why it matters: existing MS drugs reduce relapses by dampening inflammation, but none can repair myelin that is already lost, which is why many patients continue to accumulate neurological disability over time. PRO-1562 is a first-in-class approach: it prompts the brain's own precursor cells to mature into myelin-producing oligodendrocytes. In preclinical studies it increased myelination in both white and grey matter, and the company believes this could restore sensory, motor and cognitive function rather than merely slowing decline.

Trial details: the study (NCT07826689) begins with a Phase 1 single-ascending-dose portion in healthy adults at one site in Australia to characterise safety, tolerability and how well the drug reaches the central nervous system. The Phase 2a portion is a six-month, randomised, double-blind, placebo-controlled, dose-ranging study of once-monthly PRO-1562 in adults with relapsing MS and chronic optic neuropathy, measuring remyelination through electrophysiologic, MRI and clinical endpoints.

Read more: Progentos Therapeutics press release via BioSpace, Nov 2026