Takeda has secured FDA approval for the first drug to treat the underlying cause of narcolepsy type 1, with the company forecasting peak annual sales of between $2bn and $3bn as it seeks further regulatory approvals. Known as Orzeyful (oveporexton), the therapy is an orexin receptor 2 agonist that restores a brain signal missing in people with narcolepsy type 1. Narcolepsy is a chronic neurological disorder characterised by excessive daytime sleepiness, sudden muscle weakness known as cataplexy, sleep paralysis and vivid hallucinations. For now, Orzeyful is approved only for adults with narcolepsy type 1 in the US. The company expects to launch Orzeyful in the US in November, subject to scheduling by the Drug Enforcement Administration.