A Study to Evaluate the Efficacy, Safety and Tolerability of ALKS 2680 in Adults With Narcolepsy Type 1 (Brilliance NT1 - 304)

May 13, 2026 updated by: Alkermes, Inc.

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of ALKS 2680 in Adults With Narcolepsy Type 1 (Brilliance NT1 Study 304)

The purpose of this study is to measure decreases in daytime sleepiness, cataplexy (sudden loss of muscle tone), and disease symptoms in participants with NT1 when taking ALKS 2680 tablets compared with placebo tablets.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

150

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Georgia
      • Atlanta, Georgia, United States, 30328
        • Recruiting
        • Alkermes Investigational Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Meets the diagnostic criteria of NT1 according to ICSD-3-TR guidelines, confirmed by diagnostic evaluations (either PSG/MSLT* or CSF hypocretin-1 level)

Exclusion Criteria:

  • Has another comorbid sleep disorder or condition that may influence the sleep-wake cycle.
  • Has a history or presence at Visit 1 of other clinically significant (treated or untreated) illness, disease, abnormality, or surgical procedure that, in the opinion of the Investigator, might compromise participant safety, interfere with any study assessment, or affect the participant's ability to complete the study.
  • Is currently enrolled in another interventional clinical trial or has received any investigational drug or used any interventional investigational device within 30 days prior to Visit 1. Participants previously enrolled in Study ALKS 2680-201 are not eligible for enrollment.
  • Is currently pregnant, breastfeeding, or is planning to become pregnant during the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
Drug: Placebo
Participants will receive placebo tablets, daily, orally for 12 weeks
Experimental: ALKS 2680 Dose 1
Drug: ALKS 2680 Dose 1
Participants will receive ALKS 2680 tablets, daily, orally, for 12 weeks
Other Names:
  • Alixorexton
Experimental: ALKS 2680 Dose 2
Drug: ALKS 2680 Dose 2
Participants will receive ALKS 2680 tablets, daily, orally, for 12 weeks
Other Names:
  • Alixorexton

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Change in mean sleep latency (MSL) on Maintenance of Wakefulness Test (MWT) from baseline to Week 12 by dose level
Time Frame: Baseline to Week 12
Baseline to Week 12

Secondary Outcome Measures

Outcome Measure
Time Frame
Change in Epworth Sleepiness Scale (ESS) from baseline to Week 12 by dose level
Time Frame: Baseline to Week 12
Baseline to Week 12
Weekly cataplexy rate (WCR) at Week 12 by dose level
Time Frame: Week 12
Week 12
Change in British Columbia Cognitive Complaints Inventory (BC-CCI) from baseline to Week 12 by dose level
Time Frame: Baseline to Week 12
Baseline to Week 12
Change in number of lapses on Psychomotor Vigilance Task (PVT) from baseline to Week 12 by dose level
Time Frame: Baseline to Week 12
Baseline to Week 12
Percentage of participants who achieve a status of "normal, not ill at all", "borderline ill", or "mildly ill" on Clinical Global Impression-Severity (CGI-S) (general disease) at Week 12 by dose level
Time Frame: Week 12
Week 12
Change in Narcolepsy Severity Scale for Clinical Trials (NSS-CT) from baseline to Week 12 by dose level
Time Frame: Baseline to Week 12
Baseline to Week 12
Percentage of participants who achieve a status of "none" or "mild" on Patient Global Impression- Severity (PGI-S) scale(general disease) at Week 12 by dose level
Time Frame: Week 12
Week 12
Change in Patient-Reported Outcomes Measurement Information System - Fatigue 6a (PROMIS Fatigue 6a) from baselineto Week 12 by dose level
Time Frame: Baseline to Week 12
Baseline to Week 12
Incidence of treatment emergent adverse events
Time Frame: Baseline to Week 14
Baseline to Week 14

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Alkermes, Inc.

Investigators

  • Study Director: Medical Director, MD, Alkermes, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

May 1, 2026

Primary Completion (Estimated)

June 1, 2027

Study Completion (Estimated)

July 1, 2027

Study Registration Dates

First Submitted

April 15, 2026

First Submitted That Met QC Criteria

April 15, 2026

First Posted (Actual)

April 21, 2026

Study Record Updates

Last Update Posted (Actual)

May 15, 2026

Last Update Submitted That Met QC Criteria

May 13, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ALKS 2680-304

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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