Yamo Pharmaceuticals has concluded enrolment of patients in a Phase II study of its tyrosine hydroxylase inhibitor, L1-79, to treat the core symptoms of autism spectrum disorder (ASD).

The trial is designed to assess the therapy in young adults and adolescents with this condition.

Yamo plans to reveal top-line data from the trial in August next year.

By modulating the catecholaminergic pathways implicated in ASD, L1-79 enhances ASD’s core socialisation and communication symptoms.

After completing Phase II enrolment, Yamo has started a Phase III readiness programme for optimising the development timeline of L1-79.

The Phase II randomised, multi-centre and chronic-dosing study utilises a two-period placebo-controlled crossover design.

It aims to enrol at least 50 subjects and is being carried out at eight US clinical sites.

In this study, 58 participants aged between 12 and 21 will be randomly assigned in a 1:1 ratio to either the L1-79 200mg group or 300mg group.

After completing Period I, participants will undergo a washout period for six weeks, and then they switch to Period II. In this phase, those who initially got a placebo will receive L1-79, and vice versa two times a day for another 12 weeks.

Yamo Pharmaceuticals chief medical officer J Thomas Megerian said: “We would like to thank the families and their children for participation, as well as the research sites that have helped us get to this point.

“We are excited to share data from this study as it will provide further insights into the role of the catecholaminergic system in regulating social-communication function in autism.”

In 2018, the company obtained fast track designation from the US Food and Drug Administration (FDA).