Alkermes Pushes Narcolepsy Program to Phase III With Highly Competitive Mid-Stage Data

Alkermes' investigational oral drug alixorexton, a selective orexin 2 receptor (OX2R) agonist, achieved statistically significant and clinically meaningful improvements in wakefulness and reduction in excessive sleepiness in adult patients with narcolepsy type 2 (NT2) during a Phase II trial1 4 8.

The Vibrance-2 Phase II study met its dual primary endpoints with improvements on the Maintenance of Wakefulness Test (MWT) and reductions in the Epworth Sleepiness Scale (ESS) scores at week eight compared to placebo; results were dose-dependent and meaningful across all dosing cohorts1 3 4.

A total of 93 adults with NT2 were randomized to receive one of three doses of alixorexton or placebo once daily for eight weeks3.

Alkermes' data support advancing alixorexton into global Phase III clinical trials, with the program targeting a start in the first quarter of 2026 after planned regulatory discussions with the FDA5 6 1.

The drug demonstrated a favorable safety and tolerability profile, with most adverse events reported as mild to moderate2 4.

Alixorexton is the first oral OX2R agonist with demonstrated efficacy in a large Phase II clinical trial in NT2, contributing to a highly competitive field for narcolepsy therapeutics4 1.

Competitors, such as Centessa, are also preparing for Phase III trials in the same space, highlighting the intensifying race for effective narcolepsy treatments1.