Alkermes announced the FDA granted Breakthrough Therapy designation to alixorexton, a novel, investigational, oral, selective orexin 2 receptor agonist, for the treatment of narcolepsy type 1, based on phase 1 and phase 2 clinical data.
About alixorexton
Alixorexton, formerly known as ALKS 2680, is a selective orexin 2 receptor agonist in development as a once-daily treatment for narcolepsy type 1, narcolepsy type 2, and idiopathic hypersomnia. By targeting the orexin pathway, the drug aims to address excessive daytime sleepiness across a range of hypersomnolence disorders.
The FDA’s Breakthrough Therapy designation is based on clinical data, including results from Vibrance-1, a large phase 2 study evaluating alixorexton in patients with narcolepsy type 1. In July 2025, Alkermes reported positive topline data from the study, noting that alixorexton met its primary endpoint across all tested doses. The drug demonstrated statistically significant, clinically meaningful, and dose-dependent improvements in wakefulness compared to placebo.
Participants across all dose groups achieved normative wakefulness on the Maintenance of Wakefulness Test, with a mean sleep latency greater than 20 minutes. Oncedaily alixorexton also showed meaningful improvements in patientreported measures of excessive daytime sleepiness, fatigue, cognition, and other key symptoms. The treatment was generally well tolerated at all tested doses.
According to the company, Alkermes plans to advance alixorexton into phase 3 development in the first quarter of 2026.
About narcolepsy
Narcolepsy, a lifelong neurological disorder, disrupts normal sleep-wake cycles, causing patients to feel overwhelmingly tired or experience sudden episodes of muscle weakness known as cataplexy. With a prevalence of about one in 2,000 people, this often-undiagnosed condition can significantly impact daily activities, such as eating, walking and driving, highlighting the importance of recognizing and managing its symptoms.
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