Harmony Biosciences to Present Dravet Syndrome Drug Data at 2026 AAN Meeting

The company will share open-label extension results for its investigational treatment EPX-100 at the neurology conference.

Apr. 16, 2026 at 12:05pm

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A highly detailed, translucent X-ray-style photograph revealing the intricate structure of the human brain, with glowing neural pathways and synapses, conceptually representing the complex neurological mechanisms underlying Dravet syndrome.An X-ray-like view into the intricate neural networks of the brain, highlighting the genetic and neurological complexities of Dravet syndrome.Chicago Today

Harmony Biosciences announced it will present encore open-label extension data from its Phase 3 ARGUS trial investigating EPX-100 (clemizole hydrochloride) as a treatment for Dravet syndrome at the 2026 American Academy of Neurology Annual Meeting in Chicago. EPX-100 is being developed to target serotonin receptors and modulate signaling in the central nervous system.

Why it matters

Dravet syndrome is a severe and progressive form of epilepsy that begins in infancy, causing high seizure frequency, intellectual disability, and risk of sudden death. Around 85% of cases are caused by genetic mutations, so new targeted treatments are needed to improve outcomes for patients.

The details

The ARGUS trial is currently enrolling participants to evaluate EPX-100 as an adjunctive (add-on) therapy for Dravet syndrome. The upcoming poster presentation will share preliminary results from the open-label extension phase of the study. EPX-100 is administered orally twice daily and was developed based on a zebrafish drug screening platform that models the genetic cause and symptoms of Dravet syndrome.

  • The 2026 American Academy of Neurology Annual Meeting will be held April 18-22 in Chicago.
  • The ARGUS trial of EPX-100 is currently enrolling participants.

The players

Harmony Biosciences

A pharmaceutical company dedicated to developing innovative therapies for patients with rare neurological diseases.

EPX-100 (clemizole hydrochloride)

An investigational drug being developed by Harmony Biosciences to treat Dravet syndrome by targeting serotonin receptors in the central nervous system.

Dravet Syndrome

A severe and progressive form of epilepsy that begins in infancy, characterized by high seizure frequency, intellectual disability, and risk of sudden death. Around 85% of cases are caused by genetic mutations in the SCN1A gene.

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What’s next

The ARGUS trial of EPX-100 is currently enrolling participants, and more information can be found at argustrial.com.

The takeaway

As a rare and difficult-to-treat form of epilepsy, Dravet syndrome represents a significant unmet medical need. Harmony Biosciences' investigational therapy EPX-100 aims to address this by targeting the underlying genetic causes and symptoms of the disease, offering hope for improved outcomes for patients.