A Study of TAK-360 in Adults With Idiopathic Hypersomnia

Change from Baseline at Week 4 in Epworth Sleepiness Scale (ESS) Total Score

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.

Time frame: Baseline, Week 4

Change from Baseline at Week 4 in Idiopathic Hypersomnia Severity Scale (IHSS) Total Score

IHSS is a 14-item self-assessment questionnaire, to measure the severity, frequency and functional impact of the three key IH symptoms (during a recall period of "past 7 days"). The IHSS includes 14 items in total; two items (1 and 2) on nighttime sleep duration and quality, three items (3, 4 and 5) on sleep inertia and sleep drunkenness after nighttime sleep and one (8) after daytime nap, and three 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 are scored on a 3-point Likert scale and eight items on a 4-point Likert scale; the Likert scale is a point scale which is used to allow the individual to express how much they agree or disagree with a particular statement. The total IHSS score is the sum of all item scores (range: 0 to 50), and higher scores indicate more severe symptoms.

Time frame: Baseline, Week 4