A Study to Evaluate Safety, and Efficacy of SUVN-G3031 (Samelisant) in Patients With Narcolepsy With and Without Cataplexy

A Phase 2, Double-blind, Placebo-controlled, Parallel-group, Multicenter Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Efficacy of 2 mg and 4 mg SUVN-G3031 Compared to Placebo in Patients With Narcolepsy With and Without Cataplexy

This study is of an investigational drug called SUVN-G3031 (Samelisant) as a possible treatment for narcolepsy with cataplexy or narcolepsy without cataplexy. The main purpose of this study is to learn how well the study drug works and how safe the study drug is compared to placebo.

This is a Phase 2, double-blind, placebo-controlled, parallel-group, multicenter study to evaluate the safety, tolerability, pharmacokinetics (PK), and efficacy of SUVN-G3031 compared to placebo in participants with narcolepsy with and without cataplexy. Participants will be randomized at a ratio of 1:1:1 to 2 mg SUVN-G3031, 4 mg SUVN-G3031, or placebo. Each participant will receive study drug once daily, in a tablet formulation, for 14 days.

Inclusion Criteria:

• Ages of 18 to 65 years (adult), inclusive.
• Have narcolepsy with or without cataplexy (Na-1 or Na-2) based on the International Classification of Sleep Disorders (3rd edition) criteria (new or previously diagnosed).
• Have undergone a multiple sleep latency test (MSLT) study showing an MSLT of ≤ 8 minutes.
• An Epworth Sleepiness Scale (ESS) score of ≥ 12; and mean Maintenance of Wakefulness Test (MWT) time of < 12 min.
• Body mass index ranging from 18 to < 45 kg/m2
• Negative urine drug screen.
• A woman must be either not of childbearing potential or of childbearing potential practicing highly effective methods of birth control.
• Willingness to complete the study protocol with full compliance with procedures and sign an informed consent form (ICF).

Exclusion Criteria:

• Habitual wake-up time after 8 AM as assessed by sleep diary, habitual sleep time of < 6 hours, and habitual bedtime past 1 AM as determined by sleep diary entries.
• Use of any investigational therapy within the 30-day period prior to enrollment.
• Excessive caffeine (defined as > 600 mg/per day) use at least 1 week prior to baseline assessments and during the course of the trial.
• Nicotine dependence that has an effect on sleep (eg, a patient who routinely awakens at night to smoke).
• Use of concurrent medications prescribed to treat narcolepsy as specified including stimulants, antidepressants and sodium oxybate.
• Current diagnosis of or past treatment for syndromes known to cause sleep disruption or any other cause of daytime sleepiness.
• Clinically significant ECG abnormalities.
• An occupation requiring variable shift work, night shifts, or frequent overnight travel which disrupts sleep patterns.