RecruitingPhase 2Drug trialA Study to Evaluate the Efficacy and Safety of E2086 in Adults With NarcolepsyThe primary purpose of this study is to evaluate the optimal doses of E2086 compared to placebo in participants with narcolepsy for reduction of excessive daytime sleepiness (EDS) as assessed by Mean Sleep Latency (MSL) (measured from the first 4 maintenance of wakefulness tests \[MWTs\]).