Tau Aggregation Inhibitor Receives Orphan Drug Status for Treatment of Frontotemporal Dementia
Orphan drug designation has been granted to a tau aggregation inhibitor leucomethylthioninium (LMTX) (TauRx, Aberdeen, Scotland) being studied in phase 3 clinical trials for the treatment of frontotemporal dementia (FTD). This is a first-in-class drug as the first protein aggregation inhibitor to reach the stage of phase 3 clinical trials. The presumed mechanism of action is to slow the rate of formation of tau tangles and aggregates of TDP-43 protein, both of which are believed to be causative pathologies for FTD. It is hoped that treatment with tau aggregation inhibitor will slow the rate of disease and help to preserve patients’ neural function, cognition, and quality of life.
In unblinded post hoc analysis of data from a clinical trial that had not met primary outcomes, patients who took LMTX as monotherapy(4 mg twice daily, n = 79; 100 mg twice daily n = 76) had lower scores on the Alzheimer’s disease assessment scale cognitive subscore (ADAS-Cog) and less brain atrophy.
"The FDA orphan drug designation of LMTX is another positive step for patients, clinical researchers and care teams, and it reinforces our continuing research for a disease-modifying treatment for this poorly-addressed family of rare neurodegenerative conditions," said Prof. Claude Wischik, Executive Chairman of TauRx and Professor of Old Age Psychiatry at the University of Aberdeen.
The FDA orphan drug status is reserved for therapies intended to treat rare diseases that affect
fewer than 200,000 people in the US or for which a company is not expected to recover development and marketing expenses.