The maker of Hetlioz (tasimelteon) presented 4 abstracts at World Sleep 2017.

Vanda Pharmaceuticals, manufacturer of Hetlioz (tasimelteon), which became available in 2014 for the circadian sleep disorder Non-24, released a series of abstracts at World Sleep 2017. The abstracts offer preliminary insights into circadian aspects of linked disorders and hint at potential future uses of the circadian regulator drug.

In “Differences in the timing of melatonin secretion between African American and Caucasian patients with major depressive disorder,” Joseph Hull, PhD, and team found that melatonin secretion in patients who have major depressive disorder occurs earlier in African Americans than in Caucasians. “Circadian physiology has been hypothesized to play a role in the etiology of major depression and may affect symptom expression and response to treatment,” the authors wrote, adding that the role of their observation in the pathophysiology and treatment of major depressive disorder “would need to be further investigated.”

In “Tasimelteon improves symptoms of major depression in an African American population,” an analysis of the effects of Hetlioz 20 mg on the symptoms of those with major depression found the drug had a more significantly positive effect in African Americans. Of the 507 patients involved in the study, 32% were African American, with 78 of this subgroup receiving Hetlioz and 88 the placebo. The patients treated with the drug had a 9.9-point improvement according to the Hamilton Depression Scale as compared to the placebo group, which improved by 6.9 points. According to the study, led by Vanda co-founder Mihael Polymeropoulos, MD, this finding  suggests a circadian component is involved in the cause and treatment of the mood disorder.

In “Estimating burden of disease among blind individuals with non-24 hour sleep wake disorder,” also led by Polymeropoulos, the study concluded that the amount of daytime sleep free days (DSFD) is a good way to measure the burden of disease on Non-24 patients. The research team collected diary data on daytime sleep for 90 days in 178 blind patients who had trouble sleeping and analyzed it in 30 day segments. 121 participants had Non-24 and 57 did not. The results showed that Non-24 patients had daytime sleep episodes more frequently and also the episodes lasted longer than in those without the disorder. Patients with Non-24 also had fewer healthy days compared to the control group.

Finally, in “Tasimelteon improves sleep quality and behavior in individuals with Smith-Magenis syndrome (SMS) in an open-label study,” Hull and team found that Hetlioz improves sleep and behavior in those with the developmental disorder. They found that Hetlioz improved sleep and decreased self-injurious and aggressive behavior in children with SMS, which is caused by a deletion on chromosome 17. 12 participants with SMS aged 16 to 38 were assessed for 6 weeks followed by an open-label treatment phase of 9 to 36 weeks. “The associated nighttime sleep disturbances may be related to the observed inappropriate timing of the endogenous melatonin secretion during the daytime in this population,” the author wrote.

Via email, Vanda Pharmaceuticals stated it does not have any comments on these studies beyond what is included in the abstracts.

Dillon Stickle is associate editor of Sleep Review.