Improvement across doses
Results showed that, compared with placebo, improvement in disturbed nocturnal sleep from baseline was significantly greater for the active treatment at 6 g at week 3 (mean between-group difference, –11; P < .001), at 7.5 g at week 8 (mean difference, –17.7; P < .001), and at 9 g at week 13 (mean difference, –22.6; P < .001).
The mean difference between the three doses and placebo for reduction in number of arousals was –11.3 (P < .05), –19.4 (P < .001), and –23.7 (P < .001), respectively. And the 6 g at week 3, 7.5 g at week 8, and 9 g at week 13 doses showed significant (P < .001) improvements versus placebo on the ESS (mean difference, –2.1, –3.2, and –3.9, respectively).
All three doses also showed significant improvement in sleep quality and refreshing nature of sleep (P < .001 for all comparisons), as well as improvement of sleep paralysis (P = .04, P = .02, and P = .04, respectively).
There were no significant differences between FT218 and placebo for improvement in hypnagogic hallucinations. Dr. Thorpy noted that the number of patients with baseline hallucinations “was relatively small,” which may have led to this finding. “Had there been a much larger population with hallucinations, I suspect that we would have seen a statistically significant improvement there as well,” he said.
Generally well tolerated
The investigators noted that FT218 was “generally well tolerated, and the most common adverse reactions were well-known and established sodium oxybate adverse reactions.”
Treatment-related AEs that occurred in more than 2% of the patients receiving FT218 included nausea, dizziness, enuresis, headache, decreased appetite, and vomiting.
Seven serious AEs were reported, including five in those assigned to the active treatment. This included one case each of diabetes inadequate control, paresthesia, perirectal abscess, hypertension, and suicidal ideation. Only the case of suicidal ideation was considered to be a treatment-related AE.
The investigators noted that, although they have not yet delved into subgroup analysis to look for differences among sex, age, or race, they plan to do so in the future.
Overall, the results indicate that “FT218 is an effective agent not only for the major symptoms of sleepiness and cataplexy, but also the quality of sleep at night,” said Dr. Thorpy.
Asked whether he thinks the FDA will approve the drug, he said that it should be “straightforward” because it’s just a different formulation of an already-approved agent. “I very much expect there will not be any problems in this medication being approved,” Dr. Thorpy said.
Benefits ‘sleep architecture’
Commenting on the findings, Logan Schneider, MD, codirector of the Stanford/VA Alzheimer’s Center and clinical assistant professor at the Stanford Sleep Center, Redwood City, Calif., said that the investigators’ focus on these secondary outcomes “was really worthwhile.”
Dr. Schneider, who was not involved in the research, noted that, because the study only included patients with narcolepsy, the results can’t be extrapolated to groups who have other sleep disorders.
Still, “it is worthwhile now to expand beyond the two primary symptoms that are, in my consideration, life threatening: daytime sleepiness and cataplexy. We should also address more of the quality of life and other aspects of narcolepsy, including disturbed nocturnal sleep and sleep quality issues related to that,” he said.
“Being able to address those aspects and say, ‘I have a therapy that clearly helps the multidimensionality of our patients’ is very vindicating,” Dr. Schneider noted.
He was also impressed with the various measures the researchers used, rather than relying just on patient reports, “which are subject to recollection difficulties. This was a nice way to quantify possibly as a diagnostic marker the underlying disruption of sleep, as well as a possible treatment marker to show how well a therapy works.”
“It actually shows a beneficial effect on sleep architecture,” Dr. Schneider said.
The study was funded by Avadel Pharmaceuticals. Dr. Thorpy is a consultant/advisory board member for Avadel, Axsome, Balance Therapeutics, Eisai, Harmony Biosciences, Jazz Pharmaceuticals, NLS Pharmaceuticals, Suven Life Sciences, and Takeda Pharmaceutical. Dr. Schneider reports being an adviser and/or on the speakers’ bureau for similar drugs by Jazz Pharmaceuticals and Harmony Biosciences.
A version of this article first appeared on Medscape.com.