The purpose of this research study is to assess the safety and efficacy of ALKS 2680 compared to placebo, including whether participants taking ALKS 2680 experience a greater decrease in sleepiness and a decrease in cataplexy ("sudden loss of muscle control"), compared to participants taking placebo alone.

Inclusion Criteria:

• 18-70 years of age

• Has a BMI ≥18 and ≤40 kg/m2

• Meets the diagnostic criteria of Narcolepsy type 1 according to ICSD-3-TR guidelines. Additionally, meets the following criteria:

  • Is HLA-DQB1*06:02-positive
  • Has residual excessive daytime sleepiness and cataplexy

• Is willing and able to discontinue any medications prescribed for the management of narcolepsy symptoms for at least 14 days and for the duration of study

• Is willing to adhere to additional protocol requirements

Exclusion Criteria:

• Significant comorbid medical conditions, including other sleep, cardiovascular, psychiatric, hepatic or other disorders may be exclusionary; eligibility will be determined on an individual basis by the study investigator
• Is currently pregnant, breastfeeding, or planning to become pregnant during the study
• Is currently enrolled in another clinical study (other than the parent study) or used any investigational drug or device within 30 days prior to Screening