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.
