An experimental drug from Neurocrine Biosciences (NBIX) - Get Report failed to reduce the severity of tics experienced by adult patients with Tourette Syndrome compared to a placebo in a mid-stage clinical trial, the company said Tuesday evening.

The same Neurocrine drug, valbenazine, is currently under review at the FDA as a treatment for the movement disorder tardive dyskinesia.

Neurocrine shares fell 5% to $40.17 in regular Tuesday trading. The stock lost another 7% to $37.50 after the negative Tourette study results were announced.

The study enrolled 124 adults with moderate to severe Tourette syndrome, randomizing them to eight weeks of treatment with one of two doses of valbenazine or a placebo. Neurocrine used a relatively new method to measure reductions in tics -- the Yale Global Tic Severity Scale -- as the study's primary endpoint. There was no difference between valbenazine and placebo, Neurocrine said.

Valbenazine did show an improvement over placebo in overall symptoms of Tourette syndrome using a different efficacy measure, the company said.

A second, mid-stage study of valbenazine in children with Tourette syndrome is being conducted, with results expected in the second quarter.

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