Neurocrine Biosciences Inc.'s phase 2b trial assessing valbenazine did not meet its goal of reducing the tic symptoms of Tourette syndrome in children, such as facial grimacing and repeating words and phrases.
Tourette syndrome is a neurological disorder in which patients experience rapid motor and vocal tics, specifically facial grimacing, head jerks, extremity movements and other dystonic movements, grunting and throat clearing, according to Neurocrine's Dec. 12 press release.
San Diego-based Neurocrine was studying its medicine in a mid-stage trial to treat the disorder. Valbenazine previously failed an initial phase 2 trial for Tourette syndrome in 2017.
In the latest trial, the effects of valbenazine on Tourette syndrome were "less than we expected," Chief Medical Officer Eiry Roberts said on a Dec. 12 conference call addressing the topline data. The adverse events reported during the trial were consistent with previous valbenazine studies.
Valbenazine is approved by the U.S. Food and Drug Administration for the treatment of adults with tardive dyskinesia, a nervous system condition that results in repetitive, involuntary movements. The drug is marketed as Ingrezza in a once-daily capsule form and is believed to reduce the amount of dopamine released in the part of the brain responsible for motor function.
Tourette syndrome, which disregulates the dopaminergic system, similarly causes repetitive movements.
Following a complete analysis of the data, Neurocrine will decide how to proceed with valbenazine for Tourette syndrome, Roberts said.
Despite the ongoing data analysis, Neurocrine CEO Kevin Gorman advised analysts on the conference call to remove valbenazine for Tourette syndrome from their models. Gorman said the trial was well-designed and well-conducted, and valbenazine may simply not have the same effect on Tourette syndrome as it does on tardive dyskinesia.
"There is no need for Neurocrine to panic here in any situation," Gorman said. "It doesn't change our strategy and we're going to keep moving forward and that mission is to bring hope to patients."
Stifel analyst Paul Matteis followed Gorman's directive and changed his model in a note issued following the conference call. Matteis wrote that he was "disappointed by the data," however, the "blockbuster potential" of Ingrezza remains.
Valbenazine was granted orphan drug designation by the U.S. FDA in October 2017 for Tourette syndrome.
Shares of Neurocrine were down 13.9%, or $11.93, to $73.83 as of market close Dec. 12, according to data from S&P Global Market Intelligence.