New Remyelination Drug for Relapsing MS Starts Human Trials
Progentos Therapeutics, a Cambridge, Massachusetts biotech, has started the first human trial of PRO-1562 for multiple sclerosis (AllSci, October 1, 2026, by Robert McTiernan). PRO-1562 is an oral pill meant to repair the nerve insulation (myelin) that MS damages, rather than only calming the immune attack as current MS drugs do. It works by prompting the brain's own repair cells to make new myelin-producing cells. Progentos hasn't disclosed the drug's exact target and pitches it as potentially the first remyelination therapy of its kind.
The trial (NCT07826689):
- Phase I: single doses in healthy adults, with doses increasing step by step and placebo-controlled.
- Phase IIa: a six-month study in adults aged 18–65 with relapsing MS and lasting optic nerve damage. They stay on their usual MS medication and add PRO-1562 or a placebo once a month by mouth.
- Size: 160 participants in total.
- Main measure: how much faster signals travel along the optic nerve, a sign of repaired myelin. A secondary measure is myelin content on MRI.
- Timing: recruiting since late September 2026, with the main results expected by December 2028.
- Location: the only registered site so far is in Adelaide, Australia.
Background: Progentos launched in 2024 with $65 million in funding led by Forbion. It acquired the program from Frequency Therapeutics, which built on research from Robert Langer's lab at MIT and from Jeffrey Karp's Harvard-affiliated work.
Context: earlier remyelination candidates, such as clemastine and bexarotene, showed measurable signs of nerve repair, but none has been proven to slow long-term disability, and no remyelination drug is approved. Myrobalan Therapeutics is a competitor, with MRO-002 aimed at progressive MS.
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