As reported by Pharmaceutical Technology, Alkermes has announced that its investigational therapy alixorexton has received orphan drug designation from both US and European regulators, marking a significant regulatory milestone for the company’s sleep disorder program. The US Food and Drug Administration (FDA) granted the designation for idiopathic hypersomnia (IH), while the European Commission (EC) awarded orphan status for narcolepsy.
Orphan drug designation is intended to encourage development of treatments for rare diseases by offering regulatory and financial incentives. In the US, these include tax credits for qualifying clinical research, waiver of certain FDA fees, and seven years of market exclusivity if the product is approved. In the European Union, incentives include scientific and protocol assistance, reduced regulatory fees, and up to ten years of marketing exclusivity following approval.
Alixorexton is an oral orexin 2 receptor (OX2R) agonist designed to target the orexin system, which plays a central role in maintaining wakefulness. Dysfunction in this system is strongly linked to disorders of excessive daytime sleepiness, including narcolepsy and idiopathic hypersomnia. Unlike therapies that rely on residual orexin signaling, alixorexton is being studied for its potential benefit across hypersomnolence disorders regardless of orexin neuron loss.
The drug is currently being evaluated in the Phase III Brilliance clinical program for narcolepsy types 1 and 2 (NT1 and NT2) in adults. In parallel, Alkermes is conducting the Phase II Vibrance-3 study to assess alixorexton in patients with idiopathic hypersomnia. The FDA has previously granted breakthrough therapy designation to alixorexton for narcolepsy type 1, reflecting its potential to address unmet clinical needs in this population.
Narcolepsy is a chronic, rare neurological condition characterized by impaired regulation of the sleep–wake cycle. Excessive daytime sleepiness is the hallmark symptom, with classification into subtypes based on the presence of cataplexy and orexin neuron loss. Idiopathic hypersomnia is also a rare sleep disorder, marked by persistent daytime sleepiness despite adequate or prolonged nighttime sleep, often accompanied by sleep inertia, fatigue, and cognitive difficulties.
Commenting on the designations, Alkermes’ chief medical officer Craig Hopkinson said the recognitions highlight the therapeutic promise of alixorexton and its potential, if approved, to improve treatment options for patients with narcolepsy and idiopathic hypersomnia. He added that encouraging Phase II data in narcolepsy support continued advancement of the late-stage clinical program.
