EPX-200, a compound similar to an approved weight management medicine, is in early testing by Epygenix Therapeutics as a potential treatment for Dravet syndrome, a severe form of epilepsy. This compound works on serotonin signaling pathways linked to epilepsy.

The oral medication is known as lorcaserin (brand name, Belviq) when it is used to treat obese and overweight patients.

How EPX-200 works

Using a zebrafish model of Dravet syndrome, researchers screened more than 3,000 compounds to identify ones that suppressed neurological symptoms associated with the disease. EPX-200 was one of the compounds identified and found to be effective in reducing seizures and convulsive behaviors in the animals.

EPX-200 is a serotonin-receptor agonist that works by modifying serotonin signaling pathways. Preclinical studies suggest that the activation of serotonin receptors called HTR2A and HTR2C have anti-epileptic effects. EPX-200 specifically activates HTR2C, suggesting this may be its mechanism of action.

Studies of EPX-200

EPX-200 has been tested off-label in five children with severe Dravet syndrome under the FDA’s compassionate use program. These children were resistant to at least five different anti-epileptic medicines and had mutations in the SCN1A gene.

All five had fewer seizures while taking the medication, according to a study published in the journal Brain in 2017. One child with previous seizures daily went seizure-free for two weeks while taking EPX-200. After a few months, the child’s seizure activity increased but remained less frequent than before starting EPX-200 treatment. No severe side effects were reported in any of the children taking EPX-200 and the medication — which can decrease appetite — was well-tolerated.

Epygenix is still evaluating EPX-200 in preclinical studies as a possible Dravet therapy.

Other information

EPX-200 was granted orphan drug status by the U.S. Food and Drug Administration as a potential treatment for Dravet syndrome in 2017. The orphan drug program promotes the development of new treatments for rare diseases.


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