研究单位：[1]Takeda[2]Xuanwu Hospital Capital Medical University Beijing,Beijing,China,100053[3]The First Affiliated Hospital of Jinan University Tianhe,Guangdong,China,510630[4]The First Hospital of Jilin University Changchun,Jilin,China,130021[5]Huashan Hospital,Fudan University Shanghai,Shanghai,China,200040[6]Fakultni nemocnice Hradec Kralove Hradec Kralove,Czechia,50333[7]Fakultni nemocnice Ostrava Ostrava,Czechia,708 52[8]Vseobecna fakultni nemocnice v Praze Praha 2,Czechia,128 21
研究目的：
The main aims of the study are:
To check for side effects from TAK-994 and check what dose of TAK-994 participants can tolerate.
To check what dose range provides adequate relief of narcolepsy symptoms.
To check how much TAK-994 stays in the blood of participants, over time.
The study will have 4 parts. Participants can only join 1 of the parts.
A. Participants with type 1 narcolepsy will take either TAK-994 or placebo tablets for 28 days. A placebo looks just like TAK-994 but will not have any medicine in it.
B. Participants with type 1 narcolepsy will take 1 of 3 doses of TAK-994 or placebo tablets for 56 days.
C. Participants with type 1 narcolepsy in China only will take TAK-994 or placebo tablets for 56 days.
D. Participants with type 2 narcolepsy will take either TAK-994 or placebo tablets for 28 days.
