Praxis Medicines to Present at 36th International Epilepsy Congress 2025 in Lisbon, Showcasing Latest RADIANT Study Data and Leading Precision Epilepsy Pipeline

Praxis Precision Medicines, Inc. (NASDAQ: PRAX), a clinical-stage biopharmaceutical company focused on developing therapies for central nervous system (CNS) disorders, today announced its participation in the upcoming International Epilepsy Congress (IEC), taking place August 30–September 3, 2025, in Lisbon, Portugal.

In addition to showcasing recent topline results from the RADIANT study in focal onset seizures (FOS), Praxis will share the latest preclinical and clinical data and progress on trials across its precision epilepsy pipeline over twelve presentations at the event:

• Vormatrigine: Showcasing positive topline RADIANT results in FOS, updates from the first-in-human Phase 1 study, and further preclinical and clinical data supporting the accelerated advancement of the POWER1 pivotal study and the wider ENERGY program, poised to transform the epilepsy landscape.
• Relutrigine: Sharing the latest from the EMBOLD study in SCN2A- and SCN8A-DEE, the EMERALD registrational study in broad DEEs, as well as preclinical data emphasizing the promising potential of relutrigine to address significant unmet needs across the spectrum of DEEs.
• Elsunersen: Highlighting the ongoing EMBRAVE3 registrational study, alongside updates from the global emergency use cases demonstrating potential for long-term benefits, consistent safety and tolerability, and potential for further enhancement by precision sodium channel modulation in patients with early onset SCN2A gain-of-function DEE.
  
  

"IEC is an important moment to showcase how our science is translating into meaningful potential for people living with epilepsy," said Steven Petrou, chief scientific officer and co-founder of Praxis. "We look forward to engaging with the clinical and advocacy communities in Lisbon to share progress and highlight the strength of our patient-centered approach to epilepsy. This includes the latest from the RADIANT study in FOS, further validating the differentiation of our precision epilepsy platform, as well as updates on our rapidly enrolling studies. These advancements offer exciting insights into the therapeutic potential of our pipeline and reinforce our commitment to developing transformative treatments for people with epilepsy."

Praxis will be present at Booth #435 and adjoining scientific exhibit , where attendees can connect with the team and explore the company's broader work in epilepsy and commitment to delivering meaningful, patient-centered outcomes through its proprietary small molecule and ASO platforms.

Throughout the conference, Praxis will participate in scientific presentations including a platform presentation and poster presentations. Additional details are available here :

• Sunday, August 31, 2025

Platform Presentation | 15:15 – 16:15 PM (CET)

• Aud V (Pavilion 1) : Establishing the Predictive Validity of Preclinical Seizure Models in Generalized Epilepsies: An Extension of the Praxis Analysis of Concordance Framework
  

In-Person Poster Presentations | 13:45 – 15:15PM (CET)

• P196 (Pavilion 3) :​ Vormatrigine Rapidly Reduces Seizures in Adults with Treatment-Resistant Epilepsy: Results from the RADIANT Open Label Phase 2 Study​
• P157 (Pavilion 3) ​: Relutrigine Demonstrates Robust Seizure Reduction and Seizure Freedom in DEEs: Results from the EMBOLD Study​
• P158 (Pavilion 3) ​: Emergency Use Case of Relutrigine, a Functional State Sodium Channel Modulator, in an Infant with SCN2A-DEE and Refractory Status Epilepticus​
• P504 (Pavilion 4) ​: Complementary Antisense Oligonucleotide Treatment and Precision Sodium Channel Modulation for Early Onset SCN2A Developmental and Epileptic Encephalopathy: Emergency Use Cases in a Preterm Infant with Refractory Status Epilepticus​
• P505 (Pavilion 4) ​: EMERALD: A Phase 3, Randomized, Multi-Center, Double-Blind, Placebo-Controlled Clinical Trial to Evaluate the Efficacy, Safety, Tolerability, and Pharmacokinetics of Relutrigine in Participants with Developmental and Epileptic Encephalopathies ​
• P635 (Pavilion 5) ​: Epilepsy Monitoring of Prospective Seizure Observations with Electronic Records (EMPOWER): A Novel, Prospective, Large-scale, Observational Study Designed to Better Understand the Patient Journey​

Poster Tour S2 | 14:00 – 14:30 PM (CET)

• P157 (Pavilion 3) ​: Relutrigine Demonstrates Robust Seizure Reduction and Seizure Freedom in DEEs: Results from the EMBOLD Study​
• P249 (Pavilion 3) ​: Clinical Updates from the Elsunersen Emergency Use Program: A Novel ASO for Treatment of Early Onset SCN2A Developmental and Epileptic Encephalopathy​
  
  

• Monday, September 1, 2025

In-Person Poster Presentations | 13:45 – 15:15 PM (CET)

• P202 (Pavilion 3) ​: Vormatrigine Demonstrates Potent Antiseizure Activity Across Three Acute Models with Highest Predictive Validity for Focal Onset Seizures​
• P212 (Pavilion 3) ​: Preclinical Findings of Relutrigine, a Precision Sodium Channel Modulator, Point to Anticonvulsant Potential in Dravet Syndrome​
• P225 (Pav 3) ​: POWER1 – A Double-Blind, Randomized, Multicenter Phase 2/3 Study Evaluating the Efficacy and Safety of Vormatrigine in Adults with Focal Onset Seizures ​
• P248 (Pav 3) ​: Updates from the First-in-human Phase 1 Clinical Trial Evaluating the Safety, Tolerability, Pharmacokinetics and Food Effect of Vormatrigine in Healthy Participants​
• P249 (Pav 3) ​: Clinical Updates from the Elsunersen Emergency Use Program: A Novel ASO for Treatment of Early Onset SCN2A Developmental and Epileptic Encephalopathy​
  
  

• Tuesday, September 2, 2025

Poster Tour T2 | 14:00 – 14:30 PM (CET)

• P635 (Pav 5) ​: Epilepsy Monitoring of Prospective Seizure Observations with Electronic Records (EMPOWER): A Novel, Prospective, Large-scale, Observational Study Designed to Better Understand the Patient Journey​
  

For more information on Praxis's presence at IEC 2025, visit http://praxismedicines.com/iec2025meeting .

Materials will be made available on this page and on the Resources page of the Praxis website following presentation at IES 2025.

About Vormatrigine (PRAX-628)

Vormatrigine is a functionally selective small molecule targeting the hyperexcitable state of sodium-channels in the brain that is currently being developed as a once daily, oral treatment for adult focal onset seizures and generalized epilepsy. Preclinical data demonstrates vormatrigine is differentiated from standard of care, with the potential to be best-in-class for focal epilepsy. In vitro, vormatrigine has demonstrated superior selectivity for disease-state NaV channel hyperexcitability. In vivo studies of vormatrigine have demonstrated unprecedented potency in the maximal electroshock seizure (MES) model, a highly predictive translational model for efficacy in focal epilepsy. Data from the first cohort of patients with focal onset seizures in the RADIANT study demonstrated robust seizure reduction and a generally safe and well tolerated profile. To learn more about the POWER1 study, please visit POWER1 study .

About Relutrigine (PRAX-562)

Relutrigine is a first-in-class small molecule in development for the treatment of developmental and epileptic encephalopathies (DEEs) as a preferential inhibitor of persistent sodium current, shown to be a key driver of seizure symptoms in severe DEEs. Relutrigine's mechanism of precision sodium channel (NaV) modulation is consistent with superior selectivity for disease-state NaV channel hyperexcitability. In vivo studies of relutrigine have demonstrated dose-dependent inhibition of seizures up to complete control of seizure activity in SCN2A, SCN8A and other DEE mouse models. Relutrigine has been generally well-tolerated in three Phase 1 studies and has demonstrated biomarker changes indicative of NaV channel modulation. Data from cohort 1 of the Phase 2 EMBOLD study demonstrated a well-tolerated, robust, short- and long-term improvement in motor seizures in a heavily pre-treated population, alongside maintained seizure freedom in some patients with SCN2A- and SCN8A-DEE. Relutrigine has received Orphan Drug Designation (ODD) and Rare Pediatric Disease Designation from the FDA for the treatment of SCN2A-DEE, SCN8A-DEE and Dravet syndrome; as well as Breakthrough Therapy Designation (BTD), and ODD from the European Medicines Agency for the treatment of SCN2A-DEE and SCN8A-DEE. To learn more about the EMERALD and EMBOLD studies, please visit ResilienceStudies.com .

About Elsunersen (PRAX-222)

Elsunersen is an antisense oligonucleotide (ASO) designed to selectively decrease SCN2A gene expression, directly targeting the underlying cause of early-seizure-onset SCN2A-DEE to treat seizures and other symptoms in patients with gain-of-function SCN2A mutations. In vitro studies of elsunersen have demonstrated reduction in both SCN2A gene expression and protein levels. In vivo, elsunersen has demonstrated significant, dose-dependent reduction in seizures, improvement in behavioral and locomotor activity and increased survival in SCN2A mouse models, with potential to be the first disease-modifying treatment for SCN2A-DEE. Elsunersen has received ODD and RPDD from the FDA, and ODD and PRIME designations from the European Medicines Agency for the treatment of SCN2A-DEE. The elsunersen program is ongoing under a collaboration with Ionis Pharmaceuticals, Inc., and RogCon, Inc. To learn more about the EMBRAVE study, please visit ResilienceStudies.com/embrave .

About Praxis

Praxis Precision Medicines is a clinical-stage biopharmaceutical company translating insights from genetic epilepsies into the development of therapies for CNS disorders characterized by neuronal excitation-inhibition imbalance. Praxis is applying genetic insights to the discovery and development of therapies for rare and more prevalent neurological disorders through our proprietary small molecule platform, Cerebrum™, and antisense oligonucleotide (ASO) platform, Solidus™, using our understanding of shared biological targets and circuits in the brain. Praxis has established a diversified, multimodal CNS portfolio including multiple programs across epilepsy and movement disorders, with four clinical-stage product candidates. For more information, please visit www.praxismedicines.com and follow us on Facebook , LinkedIn and Twitter/X .

Investor Contact:  Praxis Precision Medicines  investors@praxismedicines.com  857-702-9452    Media Contact: Dan Ferry Life Science Advisors Daniel@lifesciadvisors.com 617-430-7576