Neurocrine Biosciences (NASDAQ:NBIX) shares dropped 5.8% following reports of patient deaths and serious adverse events potentially associated with Vykat, a treatment for Prader-Willi syndrome.
According to Stat News, physicians and experts specialising in the rare condition alerted clinicians to several deaths and severe side effects reported among patients who had been prescribed the drug. Prader-Willi syndrome is a rare disorder that can cause persistent and excessive hunger.
Since Vykat received approval from the U.S. Food and Drug Administration, seven patients prescribed the treatment have died, while more than 100 serious adverse events had been reported to the FDA’s adverse event monitoring system as of July 31.
No definitive link established between Vykat and deaths
The physicians and experts who spoke with Stat News said none of the reported deaths or serious adverse events had been definitively attributed to Vykat.
The group also stopped short of recommending that the treatment be removed from the market.
“We don’t see a relationship between the deaths and Vykat XR,” Neurocrine CEO Kyle Gano told Stat News.
Gano added that potential revisions to Vykat’s prescribing label or updated guidance for physicians remain “on the table,” according to the report.
The uncertainty surrounding the reported adverse events weighed on Neurocrine shares as investors assessed the potential regulatory and commercial implications for the treatment.
INGREZZA Phase 4 study shows patient improvements
Separately, Neurocrine announced the publication of results from its KINECT-PRO Phase 4 study evaluating INGREZZA as a treatment for tardive dyskinesia.
The study found improvements in patient-reported quality of life and functionality alongside reductions in movement severity after 24 weeks of treatment.
A total of 59 patients participated in the trial and received once-daily INGREZZA for up to 24 weeks.
Mean improvements measured using the Tardive Dyskinesia Impact Scale and assessments of movement severity exceeded established thresholds for clinically meaningful change at Week 24.
Around 58% of patients reach symptomatic remission threshold
Approximately 58% of patients met the threshold for symptomatic remission at Week 24 based on clinicians’ assessments of movement severity.
Neurocrine said INGREZZA’s safety and tolerability results were consistent with the treatment’s established profile, with no new safety concerns identified during the study.
While the KINECT-PRO findings provided positive clinical evidence for INGREZZA, investor attention remained focused on the reports surrounding Vykat and the possibility of changes to its prescribing information or physician guidance.
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