Fragile X case study

Fragile X case study

The Project

The aim was to identify and validate approved drugs that may be able to treat the inherited disease fragile X syndrome, accelerating delivery of drugs to patients and reducing the costs of the development process. FRAXA Research Foundation approached Healx to apply artificial intelligence (AI) and pharmacological expertise to the problem.

Project timeline


The Challenge

Fragile X is the most common inherited cause of autism and learning disabilities, affecting 1 in 4,000 males and 1 in 8,000 females. It is caused by the expansion of a DNA repeat in the FMR1 gene located on the X chromosome. Despite extensive research, including the application of other drug repurposing approaches, there are currently no effective treatments for this devastating disease.


Eight repurposing candidates were identified in silico to treat fragile X within 6 months

Healx combined their drug matching technology and expert pharmacological review to prioritise eight repurposing candidates that may have benefits for treating aspects of fragile X syndrome. The compounds identified by Healx had not been previously linked to fragile X syndrome. In addition, this project identified new potential targets involved in the disease.

Several candidates clearly demonstrated efficacy in vivo and one candidate is progressing to phase 2a trial.

The three prime candidates were tested and all had beneficial effects on fragile X behaviours in the mice. Out of these three, the most promising candidate which showed positive results in all four behavioural assays tested, was chosen to progress to Phase 2a trials.

FRAXA DVI, a partner of the FRAXA Research Foundation, were responsible for testing the candidates in a validated genetic mouse model of fragile X syndrome.

In vivo experiments by the FRAXA Research Foundation’s Drug Validation Initiative. Example data showing that one of Healx’s repurposing candidates significantly improved the outcomes of the mice in three behavioural tests: exploration in open field to analyse hyperactivity, nesting, a freezing response as a measure of fear conditioning.

Next Steps

An open label Phase 2a trial is being planned to test the most promising compound in patients. Healx's work allowed the drug discovery process to be accelerated, resulting in a timeline of 18 months from project start to Phase 2a clinical trial. Healx and FRAXA Research Foundation are also collaborating on two further projects to identify drug combinations and biomarkers for fragile X syndrome.


This work was supported by the FRAXA Research Foundation and the FRAXA Research Foundation's Drug Validation Initiative.

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