Narcolepsy is a condition that makes people feel very sleepy during the day. This study is testing a new medicine called HBS-301 to see if it helps with narcolepsy. The study is called a "Phase 3" study, which means it is in the later stages of testing. The study is "double-blind," meaning that neither the participants nor the doctors will know who is getting the real medicine or a placebo (a fake medicine that looks the same). This is done to make sure the results are fair.

The study will have different parts. First, there will be a Screening/Baseline Period that can last up to 28 days. Then, there is an 8-week treatment period where participants will take the medicine. After that, there is an optional 1-year extension where everyone can take the real medicine, and a final check-up 30 days later.

• The study will last for over a year if you join the extension.
• You will need to stop certain other medicines during the study.
• It's important to have stable health conditions to join.