Epygenix Therapeutics: New Treatments for Rare Epilepsy

Epygenix Therapeutics is a clinical-stage biopharmaceutical company dedicated to developing treatments for severe and uncommon neurological disorders. The company’s mission is to find solutions for genetic epilepsies that begin in childhood and often resist current medications. Epygenix was recently acquired by Harmony Biosciences, a move intended to accelerate the development of its central nervous system therapies. This acquisition integrates Epygenix’s epilepsy-focused pipeline into a broader portfolio aimed at addressing unmet needs in complex brain disorders.

Targeting Severe and Rare Epilepsies

Epygenix concentrates its efforts on developing therapies for rare and severe forms of epilepsy, including Dravet syndrome and Lennox-Gastaut syndrome (LGS). Dravet syndrome is a severe form of intractable epilepsy that starts in the first year of life and is often caused by a genetic mutation in the SCN1A gene. This condition leads to frequent, severe seizures, developmental delays, and places a significant burden on patients and their families.

Lennox-Gastaut syndrome is another severe epileptic encephalopathy characterized by multiple types of seizures, intellectual disability, and abnormal brain wave patterns. The company also investigates treatments for other developmental epileptic encephalopathies, such as Ohtahara syndrome, which is a life-threatening condition with an onset in the first few weeks of life.

Epygenix’s Approach to Epilepsy Treatment

The company’s therapeutic strategy is rooted in a precision medicine approach, using a specialized zebrafish model for drug discovery. This model replicates the genetic mutations found in patients, such as the scn1a mutation in Dravet syndrome, and mimics the human pathology, allowing for high-throughput screening of potential drug compounds. This method led to the identification of several promising candidates by testing repurposed, previously FDA-approved drugs.

Epygenix’s lead candidate, EPX-100 (clemizole hydrochloride), is a repurposed antihistamine that functions as a serotonin 5HT2 receptor agonist. It is designed to modulate serotonin signaling in the brain to control seizure activity. Another candidate, EPX-200, is a potent 5HT2C agonist that was previously approved as a weight management drug. A third compound, EPX-300 (trazodone), was identified as a potential treatment for sleep disorders.

Clinical Trial Progress and Milestones

The drug candidates from Epygenix have been advancing through various stages of clinical development, supported by regulatory designations. EPX-100 is currently in a Phase 2 trial as an add-on therapy for Dravet syndrome, with top-line data anticipated in 2026. There are also plans to initiate a Phase 3 trial for EPX-100 in patients with Lennox-Gastaut syndrome.

The U.S. Food & Drug Administration (FDA) has granted multiple designations to Epygenix’s candidates. EPX-100, EPX-200, and EPX-300 have all received Orphan Drug Designation, a status that provides incentives for the development of drugs for rare diseases. Furthermore, EPX-100 and EPX-200 have received Rare Pediatric Disease Designation for Dravet syndrome and LGS, and EPX-100 also has this designation for Ohtahara syndrome. These designations can help expedite the review and approval process for bringing these therapies to patients.