A Double-blind, Placebo-Controlled, Randomized Withdrawal Trial to Evaluate the Efficacy and Safety of TAK-861 for the Treatment of Narcolepsy With Cataplexy (Narcolepsy Type 1)

The drug being tested in this study is called TAK-861. This study will look at how effective TAK-861 is for the treatment of narcolepsy type 1 and how well this effect is maintained over time. This study also evaluates how safe TAK-861 is and what adverse events may be associated with taking the drug and stopping the drug in participants with NT1. The study will enroll approximately 88 participants. All participants will take TAK-861 during the open-label (OL) treatment period. Participants who meet certain criteria at the end of the OL Treatment Period will be randomized to one of two treatm…