This is a Phase 3, multicenter, randomized, double-blind, parallel-group, placebo-controlled clinical study to assess the efficacy and safety of HBS-301 in adult participants (ages ≥18 years) with idiopathic hypersomnia (IH).
Has a current documented diagnosis of IH per the International Classification of Sleep Disorders, Third Edition (ICSD-3) or Text Revision (ICSD-3-TR) criteria with confirmatory polysomnogram (PSG) with multiple sleep latency test (MSLT; and if applicable, a 24-hour PSG report or an actigraphy report with sleep log) on file that led to the diagnosis and was completed within the last 10 years.
Has EDS.
Has moderate to very severe symptoms of IH.
If taking a permitted chronic concomitant medication or supplement, including nonprohibited antidepressants or wake-promoting agents, must be on a stable dose for at least 3 months prior to Screening and agree to continue at that stable dose for the Double-blind Treatment Period of the study. As-needed use of any treatment that could affect daytime sleepiness (including but not limited to stimulants, modafinil, and armodafinil) used on an as-needed basis is not permitted.
Has hypersomnia due to another medical disorder.
Has a history of pitolisant use within 5 half-lives prior to Screening.
Has a primary diagnosis of psychiatric illness, including depression, that is not well controlled.
Has a history of moderate or severe hepatic impairment.