What does the drug do?

Tauroursodeoxycholic acid (TUDCA) is a substance naturally produced by the body and found in small trace amounts in bile. TUDCA works by camouflaging a stress chemical that triggers a chemical cascade that results in the death of a distressed or damaged cell. TUDCA is currently licensed to be used as a treatment in certain diseases of the liver in the USA. However, there is a growing body of evidence to suggest that TUDCA might be a potential therapeutic drug for a number of neurodegenerative diseases.

Trial Outcome

The Phase 3 clinical trial of TUDCA (TUDCA-ALS) investigated the safety and efficacy of the drug over 18 months. The trial did not meet its primary endpoint. A greater than 20% reduction in the slope of the ALSFRS-R score after 18 months was not observed, which indicates there wasn't a reduction in disease progression. Statistically significant differences in secondary endpoints, such as survival and a marker of nerve damage (neurofilament light chain) were also not observed. This data suggests that TUDCA is not beneficial for people with MND. You can read more in a press release

Clinical Trials

Phase 3 (TUDCA-ALS)

The Phase 3 clinical trial investigated the safety and efficacy of taking TUDCA in combination with riluzole over 18 months. The trial recruited 334 participants across 26 centres across Italy, Germany, UK, France, Belgium, the Netherlands and Ireland. The trial was randomised, double-blind and placebo-controlled, and participants were assessed over a 18 month period for both safety and potential effect of TUDCA on disease progression. After completing the trial, all participants were given the option to enter an open-label extension (OLE) study and receive the experimental treatment for up to 18 additional months. Find out more about this completed trial on clinicaltrials.gov.

Latest News


March 2024 - Topline data shows that the Phase 3 TUDCA-ALS trial did not meet its primary endpoint, as measured by ALSFRS-R. No statistically significant differences were observed in secondary endpoints, including survival. You can read more in a press release


October 2023 - The clinical trial has been completed. Data analysis will commence imminently, with top line results expected to be announced in early 2024. The open-label extension phase of the trial is still ongoing. 


Feb 2022 - The final participant was randomized into the trial. You can read more here

Last updated: 27/03/2024