STAT+: Neurocrine Biosciences rare disease drug possibly tied to safety issues, experts say

A group of physicians and experts in Prader-Willi syndrome (PWS) have notified clinicians of a series of patient deaths and cases of severe side effects potentially associated with Vykat XR, a newly approved drug by Neurocrine Biosciences. Vykat XR was cleared by the FDA in March 2025 to curb the intense hunger sensation in children and adults with PWS. Since its clearance, seven people prescribed the drug have died, according to the FDA's Adverse Event Monitoring System, and more than 100 reports of serious adverse events—mostly hospitalizations for swelling, respiratory, and heart complications—have been filed.

The experts said their statement is meant to increase awareness of the risks for people with PWS when starting Vykat XR, while noting that neither the deaths nor the severe side effects have been definitively linked to the drug.