Mission Therapeutics Doses First Parkinson's Patient With Mitophagy Drug MTX325

A newly posted Phase 1b trial registration and a company disclosure show Mission Therapeutics has begun giving MTX325, an experimental drug designed to help brain cells clear damaged mitochondria, to patients with Parkinson's disease, a mechanism distinct from amyloid or alpha-synuclein-targeted drugs already in development.

Mission Therapeutics, a Cambridge, UK, biotechnology company, said on October 15, 2026, that the first Parkinson's disease patient had been dosed in a Phase 1b study of MTX325, an experimental oral drug that inhibits an enzyme called USP30. The dose was given at the Royal Liverpool University Hospital in the UK, according to the company's announcement. The trial is registered on ClinicalTrials.gov as NCT07630545, under the study code MTX325-101, and is listed as recruiting; it plans to enroll 36 patients with mild to moderate Parkinson's disease at sites in the UK, continental Europe and Australia, with the stated aim of measuring safety, tolerability and what the company calls proof-of-mechanism, not whether the drug relieves symptoms or slows the disease.

USP30 sits on the outer membrane of mitochondria, the structures that generate energy inside cells, where it normally interferes with mitophagy, the process cells use to tag and remove damaged mitochondria. By blocking USP30, MTX325 is designed, according to Mission, to let that cleanup proceed in dopamine-producing brain cells, the neurons that progressively die off in Parkinson's disease. The rationale comes chiefly from a mouse study published in Nature Communications in November 2023, in which researchers from Mission, Cambridge University and other institutions reported that deleting the Usp30 gene, or treating mice with MTX325, reduced loss of dopamine-producing neurons and reduced buildup of the protein alpha-synuclein after it had been triggered experimentally in the animals.

The patient dosing follows a completed Phase 1a study in healthy volunteers, in which the company says PET brain scans confirmed MTX325 reaches functional brain tissue, and a $13.3 million financing round Mission raised in October 2025 specifically to fund the Phase 1b patient study, on top of an earlier $5.2 million grant from the Michael J. Fox Foundation and Parkinson's UK. Company executives have said they expect initial proof-of-mechanism biomarker and imaging data from the new trial in the second half of 2027.

No treatment currently approved for Parkinson's disease is known to slow the underlying loss of brain cells; existing drugs manage symptoms such as tremor and slowness of movement. Whether MTX325 can do more than that will not be known until the Phase 1b trial reports findings the company has said it expects in the second half of 2027.