Neurocrine’s rare-disease drug approved but later linked to deaths and serious side effects

Neurocrine Biosciences received regulatory approval for a rare‑disease therapy after a small clinical trial showed modest efficacy and side effects that were considered manageable. The decision was based on the severe nature of the disease, which tipped the benefit‑risk balance in favor of treatment.

The approval was granted despite the limited data, reflecting regulators' willingness to address unmet medical needs in rare conditions.

In the months following launch, physicians began reporting a small number of patient deaths that had not occurred in the trial. At the same time, the incidence of serious adverse events rose sharply, with several cases requiring hospitalization.

These real‑world safety signals suggest the drug’s risk profile may be worse than initially thought, prompting renewed scrutiny of its use.