Alkermes announces Vibrance-1 study meets primary endpoint

Alkermes (ALKS) announced topline results from the randomized double-blind treatment period of the Vibrance-1 phase 2 study evaluating alixorexton in patients with narcolepsy type 1. Alixorexton, formerly referred to as ALKS 2680, is the company’s investigational, oral orexin 2 receptor agonist in phase 2 development as a once-daily treatment for NT1, narcolepsy type 2 and idiopathic hypersomnia. In Vibrance-1, alixorexton met the primary endpoint across all doses tested, demonstrating statistically significant, clinically meaningful and dose-dependent improvements from baseline compared to placebo in wakefulness on the Maintenance of Wakefulness Test. In addition to achieving normative wakefulness across all dose groups on the MWT, once-daily alixorexton demonstrated robust and clinically meaningful improvements compared to placebo on patient-reported outcomes related to excessive daytime sleepiness and other key symptoms such as fatigue and cognition. Alixorexton was generally well tolerated at all doses tested. These data support rapid initiation of a global phase 3 program of alixorexton in patients with NT1. Across all doses tested, alixorexton demonstrated statistically significant, clinically meaningful and dose-dependent improvements from baseline in mean sleep latency compared to placebo at week six. At all doses tested, alixorexton drove statistically significant and clinically meaningful improvements from baseline in excessive daytime sleepiness compared to placebo on the Epworth Sleepiness Scale at week six. Alixorexton numerically improved weekly cataplexy rates across all doses compared to placebo at week six and achieved statistical significance at the 6 mg dose. Across all doses tested, alixorexton demonstrated clinically meaningful improvements from baseline in narcolepsy symptom severity as compared to placebo at week six. Across all doses tested, alixorexton demonstrated clinically meaningful improvements from baseline in cognitive complaints compared to placebo at week six. Across all doses tested, alixorexton demonstrated clinically meaningful improvements from baseline in fatigue as compared to placebo at week six. Alixorexton was generally well tolerated across all doses tested in the randomized double-blind period of the Vibrance-1 study. No treatment-emergent serious adverse events were reported. Most treatment-emergent adverse events were mild to moderate in severity and were generally consistent with the events observed across the alixorexton phase 1 program in healthy volunteers and patients with NT1, NT2 and IH. There were no treatment-related safety signals observed in hepatic and renal parameters, vital signs, or ophthalmic exams. More than 95% of patients who participated in the six-week double-blind portion of the trial entered into the seven-week open-label extension, which is ongoing. Alkermes plans to present detailed safety and efficacy results from the Vibrance-1 phase 2 study in an oral presentation at the upcoming World Sleep Congress, taking place Sept. 5-10 in Singapore. Vibrance-2 and Vibrance-3, phase 2 studies evaluating the safety and efficacy of alixorexton in adults with NT2, respectively, are ongoing.