Neurocrine Biosciences will conduct a new study for the rare disease drug Vykat to explore dosing and safety in patients with Prader-Willi syndrome who have complex health issues.
Another patient has died after taking Neurocrine Biosciences’ Prader-Willi syndrome therapy Vykat, leading to analyst inquiries during the biotech’s third-quarter earnings call on Monday afternoon.
Clinicians and patient advocates have been sounding the alarm about serious safety events that have occurred in patients who took the product, which was approved for the rare disorder in 2025 and picked up by Neurocrine in April as part of the $2.9 billion acquisition of Soleno Therapeutics.
Neurocrine this week confirmed the newly reported death and reiterated confidence in the drug’s safety profile, urging appropriate monitoring and patient selection.
“We are confident in the benefit-risk profile of Vykat XR and believe the FDA-approved label provides clear guidance on how to use the medicine safely and effectively in the indicated patient population,” a spokesperson told BioSpace in a Monday evening statement.
Prader-Willi syndrome is a rare disease that causes an insatiable desire to eat plus a slow metabolism that together can lead to significant weight gain. The condition can also cause cognitive disabilities and behavioral challenges. Before Vykat was approved, patients had few options.
Neurocrine reported third-quarter earnings on Monday, with the investor call focusing on the safety profile of Vykat. Analysts wondered about the real-world safety reports and a recent letter from a clinician warning of safety risks associated with the drug.
“Neurocrine remains committed to the benefits of Vykat XR in the right patients with the right monitoring, and the franchise was resilient this quarter,” William Blair said in a Tuesday morning note.
Indeed, Vykat took home $107 million for the third quarter, helping Neurocrine to reach $1.1 billion in total revenue.
To help ease concerns, Neurocrine is planning a new study in 2027 to explore dosing and safety in patients with Prader-Willi who have complex health issues.
“We clarified on the call that this was not an FDA request, despite Neurocrine’s collaboration with the agency,” William Blair said. “There is no doubt that education and data is needed to extract value from the Soleno acquisition and return Vykat XR to a true rare disease growth product, but the cards are in place now and Neurocrine is not hiding.”
Clinicians have raised concerns in the Prader-Willi community, warning about seven deaths and more than 100 serious adverse events that have occurred in patients who received Vykat. Yesterday’s report would being the number of deaths to eight.
Most of the events were associated with edema, respiratory and cardiac complications. The most serious incidents occurred in patients who had complex medical issues, used other medications or had pre-existing obesity.
The events have not been definitively linked to Vykat, clinicians have noted, and patients with Prader-Willi have complex needs. The clinicians therefore warned prescribers of heightened risk among patients with obesity, severe breathing issues, underlying heart problems and other conditions.
The safety concerns have spurred BMO Capital Markets to temper expectations for Vykat growth.
“Recent concerns over product safety and patient deaths could lead to some increased patient discontinuations in 4Q26 and early 2027,” BMO said in a Monday evening note. “Over time, we expect Neurocrine will be able to further establish the safety and optimal dose titration of Vykat XR through additional studies, but until this time, we expect patient persistence to be somewhat negatively impacted.”
Neurocrine pledged to build the base of evidence that will give prescribers, patients and advocates confidence in the profile of Vykat. Executives on the earnings call insisted that the current label is sufficient to warn of the potential risks associated with the drug.
“We continue to closely monitor the safety of VYKAT XR, evaluate all available information, and work with the FDA as clinical and real-world experience with the medicine grows,” Neurocrine’s statement added.
