Alkermes plc said its investigational narcolepsy drug alixorexton met primary endpoints in a mid-stage trial, demonstrating statistically significant improvements in excessive daytime sleepiness compared with placebo.
The phase 2 Vibrance-1 study enrolled 92 adults with narcolepsy type 1 and evaluated once-daily doses of 4 mg, 6 mg, or 8 mg of alixorexton against a placebo over six weeks. All dose groups achieved mean sleep latency values of at least 20 minutes on the Maintenance of Wakefulness Test and Epworth Sleepiness Scale scores of 10 or below by week six, placing results within normative ranges.
The 6 mg dose group also showed a reduction in weekly cataplexy rates versus placebo. Patient-reported outcomes assessed disease severity, fatigue, cognition, and health-related quality of life, though these were exploratory measures. The drug was generally well tolerated, with most adverse events reported as mild to moderate and no serious events recorded.
Alkermes has initiated the Brilliance phase 3 program, which will evaluate once-daily and split-dose regimens of alixorexton in adults with narcolepsy type 1 and type 2. The U.S. Food and Drug Administration previously granted breakthrough therapy designation for narcolepsy type 1 and orphan drug designation for idiopathic hypersomnia.
Alixorexton is also under investigation for narcolepsy type 2. Alkermes markets treatments for alcohol dependence, opioid dependence, schizophrenia, bipolar I disorder, and narcolepsy.
