EPX-100 is a potential treatment being developed by Epygenix Therapeutics for Dravet syndrome patients.

How EPX-100 works

Dravet syndrome is a rare and severe form of epilepsy that causes prolonged seizures, often numerous times each day. It is known that the disease is caused by a mutation in the SCN1A gene, but it is not fully understood how this mutation leads to the development of seizures.

EPX-100 is a repurposed anti-histamine medication, originally known as clemizole, which was used to treat itchiness in the 1950s and ’60s. EPX-100 is thought to be able to suppress seizures through how it acts on serotonin signaling pathways, a mechanism that differs from its anti-histaminic properties.

Serotonin is a chemical messenger present in many parts of the brain. Scientists think that people with Dravet syndrome may have alterations in the serotonin signaling pathway, but exact problems are not known. Likewise, precisely how EPX-100 affects serotonin systems in the brain to improve seizures is still unclear.

Studies on EPX-100

EPX-100 was discovered in a study that tested over 3,000 approved medications in zebrafish models of Dravet’s syndrome. Among the medications tested, EPX-100 was found to be a powerful suppressor of seizures. The study, “Drug screening in Scn1a zebrafish mutant identifies clemizole as a potential Dravet syndrome treatment” was published in the journal Nature Communications in 2013.

Epygenix announced plans to initiate a Phase 1/2 clinical trial testing EPX-100 for Dravet’s syndrome in 2018.

Other details

EPX-100 was designated an orphan drug by the U.S. Food and Drug Administration (FDA) in April 2017. This program is designed to promote the development of new therapies for rare diseases.

Epygenix is currently preparing an investigational new drug application, an essential first step in launching a clinical trial. Among other things, it grants permission to manufacturers to ship experimental medication across the U.S. for such studies.

The company also announced its intentions to expand EPX-100’s development to include other forms of genetic epilepsy, such as infantile spasms, Lennox-Gastaut syndrome, and Ohtahara syndrome.


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