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

The ESS provides individuals with 8 different situations of daily life and asks them how likely they are to fall asleep in those situations (scored 0 to 3) and to try to imagine their likelihood of dozing even if they have not actually been in the identical situation; the scores are summed to give an overall score of 0 to 24. Higher scores indicate stronger subjective daytime sleepiness, and scores below 10 are considered to be within the normal range.

The MWT evaluates a participant's ability to remain awake under soporific conditions for a defined period. Because there is no biological measure of wakefulness, wakefulness is measured indirectly by the inability or delayed tendency to fall asleep. This tendency to fall asleep is measured via electroencephalography-derived sleep latency in the MWT. One MWT, that includes four 40-minute wake trials, will be done. Sleep latency in each wake trial will be recorded. Participants will be required to stay awake in between the 4 MWT wake trials.

The IHSS is a 14-item self-assessment questionnaire, to measure the severity, frequency and functional impact of the 3 key IH symptoms (during a recall period of "past 7 days"). The IHSS includes 2 items (1 and 2) on nighttime sleep duration and quality, 3 items (3, 4, and 5) on sleep inertia and sleep drunkenness after nighttime sleep and 1 (8) after daytime nap, and 3 items (6, 7, and 9) on diurnal symptoms (nap occurrence, daytime sleepiness). Items 10 to 14 assess daytime functioning alterations due to hypersomnolence. Six items (1,2,3,5,7,8) are scored with 4 ranged response options, with score from 0 to 3, and 8 items (4,6,9,10,11,12,13,14) with 5 ranged response options, with score from 0 to 4, with 1 additional response option for item 14. The total IHSS score is the sum of all item scores (range: 0 to 50); higher scores indicate more severe symptoms.

The NSS-CT is a 15-item self-administered questionnaire that assesses the severity and consequences of the 5 major narcolepsy symptoms such as daytime sleepiness, cataplexy, hallucinations, sleep paralysis, and disrupted nighttime sleep (DNS) with a total score range of 0 to 57 (sum of 8 items that assess symptoms severity [2 with 4 response options, 1 response with 6 options, and 5 items capturing event count], and 7 items that describe the symptom effect on daily life with 4 response options). The presence of narcolepsy symptoms is defined by EDS (score greater than or equal to [≥] 1 on at least one of items 1, 2, 3, 4, 5, 6, or 7), cataplexy (score ≥1 on at least one of items 8, 9, or 10), hallucinations (score ≥1 on at least one of items 11 and 12), sleep paralysis (score ≥1 on at least one of the items 13 and 14), and disrupted nighttime sleep by a score ≥1 on item 15. Higher scores indicate greater symptom severity or degree of impact.

The NSS-2-CT is a 12-item self-administered questionnaire that assesses the severity and consequences of major narcolepsy symptoms such as daytime sleepiness, hallucinations, sleep paralysis, and disrupted nighttime sleep, with higher scores indicating more severe narcolepsy symptoms and impacts. The total score ranges from 0-44(sum of 6 items that assess event symptom severity [including 2 items with 4 response options, 1 item with 6 response options, and 3 items capturing event count], and 6 items that describe symptom effect on daily life, with 4 response options), and differs from the NSS-CT in its omission of cataplexy-related items. The presence of narcolepsy symptoms is defined by EDS (score ≥1 on at least one of items 1, 2, 3, 4, 5, 6, or 7), hallucinations (score ≥1 on at least one of items 8 and 9), sleep paralysis (score ≥1 on at least one of the items 10 and 11), and disrupted nighttime sleep by a score ≥1 on item 12.

Participants will complete a patient-reported sleep diary to record self-reported narcolepsy symptoms. Participants will record episodes of cataplexy attacks in the diary. The total number of events averaged for a week will be reported.