By Adam FeuersteinAug. 12, 2026

Adam Feuerstein, a senior writer and biotech columnist, is the author of Adam’s Biotech Scorecard, a subscriber-only newsletter about the crossroads of drug development, business, Wall Street, and biotechnology.

Adam Feuerstein is a senior writer and biotech columnist, reporting on the crossroads of drug development, business, Wall Street, and biotechnology. He is also a co-host of the weekly biotech podcast The Readout Loud and author of the newsletter Adam’s Biotech Scorecard. You can reach Adam on Signal at stataf.54.A group of physicians and experts in Prader-Willi syndrome, a rare disease that causes an insatiable desire to eat, on Tuesday notified clinicians of a series of patient deaths and cases of severe side effects potentially associated with Vykat XR, a newly approved drug sold by Neurocrine Biosciences.

Vykat was approved by the Food and Drug Administration in March 2025 to curb the intense hunger sensation in children and adults with Prader-Willi syndrome, or PWS. But since its clearance, seven people prescribed the drug have died, according to the FDA’s Adverse Event Monitoring System. Additionally, more than 100 reports of serious adverse events, mostly cases of patients being hospitalized for swelling, respiratory, and heart complications, have been reported to the FDA.