Phase 2 Vibrance-1 study extension shows sustained improvements in patient-reported disease severity, cognitive functioning, and fatigue.
Key takeaways:
- New data from the Vibrance-1 phase 2 study show alixorexton sustained improvements in patient-reported disease severity, cognitive functioning, and fatigue through a seven-week open-label extension.
- Alixorexton was generally well tolerated across all doses tested, with no serious treatment-emergent adverse events reported.
- The phase 3 Brilliance NT1 study evaluating alixorexton in patients with narcolepsy type 1 is currently ongoing.
Alkermes plc is presenting new data from the Vibrance-1 phase 2 study evaluating alixorexton in patients with narcolepsy type 1 (NT1) at the American Academy of Neurology (AAN) 2026 Annual Meeting today.
Alixorexton is an investigational, oral, selective orexin 2 receptor (OX2R) agonist in development for the treatment of NT1, narcolepsy type 2 (NT2), and idiopathic hypersomnia. Vibrance-1, a randomized, placebo-controlled, double-blind phase 2 study conducted in 92 patients with NT1, previously demonstrated clinically meaningful and statistically significant improvements from baseline compared to placebo in wakefulness, cognition, and fatigue during a six-week treatment period.
The new data to be presented at AAN augment these results, showing clinically meaningful improvements from pre-treatment baseline on established measures evaluating excessive daytime sleepiness and cataplexy. Furthermore, participant-reported outcomes, including narcolepsy symptom severity, cognitive functioning, and fatigue, were sustained through a seven-week open-label extension. More than 95% (n=88) of participants who entered Vibrance-1 completed treatment in both the six-week double-blind portion and the seven-week open-label extension for a total of 13 weeks.
“Improvements observed at week 6 across patient-reported measures of disease severity, cognitive functioning, and fatigue were sustained through the seven-week open-label extension, supporting the durability of alixorexton’s effects,” says neurologist Giuseppe Plazzi, MD, PhD, director of the Narcolepsy Center at the IRCCS of the Neurological Sciences of Bologna and professor of childhood neuropsychiatry at the University of Modena and Reggio Emilia, in a release. “These patient-reported outcomes highlight clinically relevant dimensions of narcolepsy that are often underrecognized, yet central to patients’ daily functioning, and demonstrate alixorexton’s potential to make a meaningful impact for people living with narcolepsy type 1.”
Exploratory patient-reported outcomes in Vibrance-1 included the Narcolepsy Severity Scale-Clinical Trials, British Columbia Cognitive Complaints Inventory, Patient Global Impression of Severity (PGI-S) for Cognition, PROMIS-Fatigue Short-form 6a, and PGI-S for Fatigue. Clinically meaningful improvements were seen across all measures at week 6 with alixorexton, with improvements sustained through weeks 12 to 13.
Alixorexton was generally well-tolerated across all doses tested throughout the 13-week period. No serious treatment-emergent adverse events were reported, and most were mild to moderate in severity.
“The breadth and depth of the data generated in the Vibrance-1 study provide strong evidence of alixorexton’s potential to meaningfully impact the lives of patients by addressing multiple elements across the spectrum of disease burden of narcolepsy type 1,” says Craig Hopkinson, MD, chief medical officer and executive vice president, research & development at Alkermes, in a release. “These data provide a strong foundation for our phase 3 program and reinforce our confidence as we enroll the recently initiated Brilliance Studies in narcolepsy type 1 and type 2.”
