MINNEAPOLIS—An experimental drug may be an effective treatment for excessive daytime sleepiness and narcolepsy, according to research presented at the 28th Annual Meeting of the Associated Professional Sleep Societies. JZP-110 significantly reduces sleepiness and helps maintain wakefulness among patients with narcolepsy, compared with placebo. It has “a fairly robust and consistent effect” that improves alertness, said Jed Black, MD.
The mechanism of action of JZP-110 is distinct from that of other wake-promoting agents, added Dr. Black, Consulting Associate Professor of Psychiatry and Behavioral Science at the Stanford Center for Sleep Sciences and Medicine in California. Unlike traditional stimulants, JZP-110 does not cause a release of dopamine or norepinephrine. Furthermore, the drug does not appear to be associated with rebound hypersomnia.
A Randomized, 12-Week Study
Dr. Black and colleagues conducted a 12-week study of 93 individuals with narcolepsy. Forty-four participants were randomized to the treatment group, and 49 participants were randomized to placebo. Patients in the treatment group received 150 mg/day of JZP-110 for four weeks, followed by 300 mg/day of JZP-110 for eight weeks. The study’s primary outcome measures were the 40-minute Maintenance of Wakefulness Test (MWT) and the Clinical Global Impression-Change (CGIC). The secondary outcome measure was the Epworth Sleepiness Scale (ESS).
Eligible participants had ESS scores greater than 10 and less than 10 minutes of sleep latency on the 40-minute MWT. The cohort’s average age was approximately 40, and a greater number of females participated in the study than males. Average ESS score was approximately 17. The researchers did not observe significant differences between the two study groups.
Drug Increased Sleep Onset Latency
At four weeks, sleep onset latency on the 40-minute MWT was 9.5 minutes for the treatment group and 1.4 minutes for the placebo group. At 12 weeks, sleep onset latency on the 40-minute MWT was 12.8 minutes for the treatment group and 2.1 minutes for controls. This result was independent of cataplexy status, said Dr. Black.
At four weeks, 80% of participants in the treatment group reported on the CGIC that their symptoms were “much” or “very much” improved, compared with 51% of the placebo group. At 12 weeks, 86% of participants in the treatment group gave this response, compared with 38% of controls.
For the treatment group, ESS scores decreased by 5.6 points at four weeks and by 8.5 points at 12 weeks. For controls, ESS scores decreased by 2.4 points at four weeks and by 2.5 points at 12 weeks.
Adverse events associated with JZP-110 were similar to those associated with other wake-promoting agents. The drug had a dose-response effect on gastrointestinal symptoms, insomnia, anxiety, and irritability. Two serious adverse events, acute cholecystitis and conversion disorder, were reported.
—Erik Greb