Alkermes Soars 10.25% on Positive Narcolepsy Drug Trial Results

On September 8, 2025, Alkermes' stock surged by 10.25% in pre-market trading, driven by positive news from its narcolepsy drug trial.

Alkermes announced encouraging results from the Vibrance-1 phase 2 study of alixorexton in narcolepsy type 1 patients. The study showed significant improvements in wakefulness, cognition, and fatigue across all tested doses. Notably, all dose groups achieved normative wakefulness with a mean sleep latency of 24-28 minutes, and over 40% of patients at higher doses experienced complete cataplexy reduction. The drug was well-tolerated with no serious adverse events reported.

Based on these findings, Alkermes plans to initiate a global phase 3 program in the first quarter of 2026. Additional phase 2 studies for narcolepsy type 2 and idiopathic hypersomnia are also ongoing. The positive results from the Vibrance-1 study position alixorexton as a potential first-in-class once-daily oral OX2R agonist, addressing multiple hypersomnolence disorders and significantly enhancing Alkermes' neuroscience portfolio.