P.021 Nonclinical studies of abuse potential with dual orexin-receptor antagonists: concordance with real-world use

Abstract

Background: Traditional insomnia drugs enhance gamma-aminobutyric acid and are associated with abuse/dependence. Dual orexin-receptor antagonists (DORAs) represent an alternate mechanism promoting wakefulness, rather than inhibition. Nonclinical studies indicate DORAs do not demonstrate abuse potential. Nonetheless, based on human abuse potential (HAP) studies and lack of postmarketing data at approval, DORAs are Schedule 4 controlled substances. However, HAP studies may not predict real-world abuse-potential risk. Methods: Adverse events with preferred terms (PTs) of drug-withdrawal-syndrome, drug-abuse, and drug-dependence were evaluated from Eisai’s ongoing global postmarketing safety surveillance system in the US, Canada, and Japan (20/Dec/2019–30/Sep/2023) and the FDA Adverse Event Reporting System (FAERS; 01/Jan/2015–30/Jun/2023). In FAERS, reports of those PTs from DORAs (lemborexant/suvorexant/daridorexant) were compared with zolpidem and with benzodiazepines approved for patients with insomnia (estazolam/temazepam/triazolam). Results: Since lemborexant’s approval, few of the 3 PTs were reported in Eisai’s surveillance system (~0.15 cases per million patient-days of global exposure). Reports in FAERS for PTs of drug-withdrawal-syndrome, drug-abuse, and drug-dependence for DORAs (10,202 reports) were <0.1%/<0.1%/0.1%, respectively. Reports for benzodiazepines (5534 reports) were 0.8%/12.9%/3.7%, respectively, and 1.0%/9.1%/5.3% for zolpidem (18,330 reports), respectively. Conclusions: Abuse potential may be better represented by nonclinical studies and national surveillance systems, suggesting DORAs may not pose meaningful abuse potential and related risks.