Alkermes (ALKS) said Tuesday a late-stage trial evaluating its investigational Lumryz oral suspension in adults with idiopathic hypersomnia, a rare condition in which patients require excessive sleep, met all primary and key secondary endpoints.

The medication demonstrated statistically significant reductions in excessive daytime sleepiness alongside improvements in patient-reported disease severity when compared to a placebo, the company said.

Participants who were switched to a placebo during the withdrawal phase experienced significant symptom worsening compared to subjects who continued treatment, Alkermes said.

The company plans to submit a supplemental new drug application to the US Food and Drug Administration by the end of the year, it said.

Shares of the company were up 1.3% in Tuesday premarket activity.