This study will evaluate the long-term efficacy and safety of AXS-12 in narcoleptic subjects with cataplexy and excessive daytime sleepiness (EDS).

This study is a multi-center trial consisting of a 24-week open-label period, followed by a 4-week double-blind, placebo-controlled, randomized withdrawal period. At the Week 24 visit, subjects will be randomized in a 1:1 ratio either to continue to receive AXS-12 or to switch to placebo, for the next 4 weeks. Eligible subjects will have previously participated in the AXS-12-301 study.

Inclusion Criteria:

• Completed the treatment period of Study AXS-12-301
• Willing and able to comply with the study requirements

Exclusion Criteria:

• Significant change in medical history or concomitant medications since enrolling in the AXS-12-301 study which, in the opinion of the Investigator, would render the subject unsuitable to receive AXS-12