A newly approved drug for Prader-Willi syndrome, a rare disease that causes an insatiable desire to eat, may be tied to a series of patient deaths, experts say.

A newly approved drug for Prader-Willi syndrome, a rare disease that causes an insatiable desire to eat, may be tied to a series of patient deaths, experts say.

When it comes to rare disease treatments, patients often confront a difficult risk-benefit calculus. Such is the case with a therapy from Neurocrine Biosciences.