People with **Narcolepsy Type 2 (NT2)**, a condition that causes extreme sleepiness during the day, are being asked to join a study. The study will test a medicine called **ALKS 2680** to see if it helps reduce sleepiness. A **placebo**, a tablet with no medicine, will also be used to compare results. Participants must be 18-70 years old and have a body mass index (BMI) between 18 and 40. They must also have NT2, still feel sleepy during the day, and be willing to stop any current narcolepsy treatments for at least 14 days. People with other serious health problems or those who are pregnant cannot join. This study requires participants to follow specific rules and stop certain medications.

• Study involves stopping current narcolepsy medications for at least 14 days.
• Participants should not have other significant health issues.
• Being pregnant or planning to become pregnant during the study disqualifies candidates.