US-based Neurocrine Biosciences has started a Phase II clinical trial (T-Force GREEN) for NBI-98854 (valbenazine), a potential treatment for children and adolescents with Tourette syndrome.
NBI-98854 is a highly selective, small-molecule Vesicular Monoamine Transporter 2 (VMAT2) inhibitor.
VMAT2 is a protein concentrated in the brain. It re-packages and transports monoamines in pre-synaptic neurons.
The parallel group trial is designed to evaluate the safety, tolerability and efficacy of NBI-98854.
Around 90 children and adolescents will be given valbenazine once a day during a six-week treatment period.
The trial will be carried out at about 40 study centres in the US. It will evaluate two once-daily fixed doses of NBI-98854 against a placebo in a 1:1:1 randomisation.
Neurocrine Biosciences chief medical officer Dr Christopher O'Brien said: "Following the favourable results from our two-week T-Force study of valbenazine in paediatric Tourette patients, we are launching the T-Force GREEN study assessing children and adolescents over six weeks of continuous dosing.
"This study, coupled with the ongoing T-Forward study of adults with Tourette syndrome, will elucidate trial design, efficacy and safety outcomes for discussion with regulatory authorities on the utilisation of valbenazine in Tourette syndrome.
"Additionally, the ongoing Kinect studies of valbenazine in patients with tardive dyskinesia will support our anticipated NDA filing of valbenazine for tardive dyskinesia later this year."
The trial's primary endpoint is the change from baseline of the Yale global tic severity scale, which will be evaluated in placebo and active treatment groups at the end of week six.
The company noted that Tourette symptoms will also be evaluated via the rush video-based tic rating scale, the premonitory urge for tics scale, and clinical global impression scales.