Alkermes’ investigational drug helped people with a type of narcolepsy stay awake during the day in a mid-stage trial, results that boost the company’s potential to compete in what’s predicted to be a multibillion-dollar market.

The company did not release specific data, but said Monday that patients with narcolepsy type 1 taking all doses tested of the daily pill, called alixorexton, experienced statistically significant improvements in wakefulness, reaching normal levels, as well as statistically significant decreases in daytime sleepiness over six weeks.

Only patients on the middle dose tested, however, had a statistically significant decrease in the frequency of sudden loss of muscle control, or cataplexy, a symptom of the disease. CEO Richard Pops said those results were likely due to methodological limitations, as patients self-report cases of cataplexy based on their memory. The company plans to refine the method in future trials.