A Study of TAK-360 in People With Narcolepsy or Idiopathic Hypersomnia

Central hypersomnia conditions are a group of sleeping disorders where the brain has trouble keeping a person awake during the day (called excessive daytime sleepiness or EDS). These conditions usually include narcolepsy (type 1 and 2) and idiopathic hypersomnia (IH). Narcolepsy type 1 (NT1) includes sudden muscle weakness while you stay awake, called cataplexy, often triggered by strong emotions. Narcolepsy type 2 (NT2) does not include cataplexy. People with narcolepsy typically feel refreshed by short naps. People with IH feel extremely sleepy during the day, and do not feel refreshed by sleep. Waking up from sleep is difficult. This is common in the morning and also when waking up from long naps.

The study wants to learn about TAK-360 when taken over a long time period; this is called a long-term extension or LTE study. The main aim of this LTE study is to find out how well participants with NT1, NT2, and IH tolerate TAK-360 over a longer period (long-term tolerability) and to learn how safe TAK-360 is when given over a longer period of time (long-term safety).

Participants who completed one of the TAK-360 parent studies can join this study if they meet the study rules. Parent studies include TAK-360-2001(NCT06952699), TAK-360-2002 (NCT06812078), or other TAK-360 studies that evaluate the TAK-360 medicine. All participants will receive TAK-360 in this study. They will either receive the same dose as they did in the parent study, or the closest dose available in this LTE study. Participants who received placebo (the placebo looks just like TAK-360 but does not have any medicine in it) in their parent study will receive one of the TAK-360 doses available in this study. Placebo will only be used to not reveal the dose of TAK-360 from parent studies to investigator, participants, and sponsor. Sponsor, investigators and participants will not know which TAK-360 dose was used in the LTE study as long as the parent study is ongoing.

The participants will have to visit the clinic multiple times during this study.