Axial Therapeutics has concluded the enrolment of 156 children and adolescents in the Phase IIb TAPESTRY Autism Study of AB-2004 to treat irritability associated with autism spectrum disorder.

The international, placebo-controlled, double-blind, randomised study is being carried out at several clinical trial centres in Australia, New Zealand and the US.

It will assess the tolerability, safety and efficacy of the oral gut-targeted small molecule therapeutic AB-2004 in children aged five to 17 years diagnosed with autism and suffering with increased irritability.

They will be given either AB-2004 or placebo three times a day along with food.

The study’s primary efficacy endpoint is the mean change in the Aberrant Behavior Checklist Irritability subscale (ABC-I) from baseline to week eight.

The mean change in the Clinical Global Impression-Severity (CGI-S) and the number of participants reporting treatment emergent adverse events from baseline to week eight are the key secondary outcome measures of the study.

Tapestry Autism Study principal investigator and Yale School of Medicine child psychiatrist Roger Jou said: “AB-2004 leverages the gut-brain connection; it works in the gut by trapping bacterial by products and removing them in the stool, which reduces their absorption into the body and ultimately their negative effect on the brain.

“I eagerly anticipate the results of the Phase II clinical trial of AB-2004 to assess the possibility this novel approach reduces irritability associated with autism.”

Topline clinical data from this trial is expected in the first quarter of next year.

The company is also expanding a pipeline of small-molecule drug candidates for treating Parkinson’s disease.