Axsome Therapeutics (NASDAQ:AXSM) said a long-term Phase 3 study of its drug AXS-12 for the treatment of narcolepsy with cataplexy has met its primary endpoint.

The study showed AXS-12 was able to statistically and significantly reduce the frequency of cataplexy attacks compared to placebo.

Axsome (AXSM) said that during the long-term, open label portion of the study, the data showed a 71% reduction from baseline in mean weekly cataplexy attacks at one month with AXS-12 treatment, with a 77% reduction at six months, according to a statement.

Cataplexy response, defined as ≥50% reduction from baseline in weekly cataplexy attacks, was achieved by 72% of patients at one month and 82% of patients at six months.

The study also showed a relatively high discontinuation rate, however, with 17.6% of patients discontinuing treatment due to adverse events over the six-month period. The most common adverse events were nausea and tachycardia.