Neurizon Therapeutics (ASX: NUZ) said high levels of its drug candidate NUZ-001 and its major active Sulfone metabolite crossed the blood-brain barrier in a rodent preclinical pharmacokinetic study, according to a Friday Australian bourse filing.

They achieved brain concentrations consistent with those shown to reverse pathological transactive response DNA-binding protein 43 aggregation in patient-derived induced pluripotent stem cells.

The ability of therapeutics to access the central nervous system remains a major barrier in the treatment of neurodegenerative diseases such as amyotrophic lateral sclerosis. Transactive response DNA-binding protein 43 is a known driver of amyotrophic lateral sclerosis pathology.

NUZ-001 and its sulfone metabolite significantly prevented the aggregation of transactive response DNA-binding protein 43 in M337V motor neurons treated simultaneously with the proteasomal stressor at all concentrations tested.

The firm's shares fell 3% on market close.