Praxis Precision Medicines Announces Positive Results from the EMBRAVE Part A Trial of Elsunersen in Patients with SCN2A Early-Onset Developmental and Epileptic Encephalopathy
Elsunersen demonstrated placebo-adjusted seizure reduction from baseline of 77% (p=0.015)
71% of elsunersen-treated patients achieved >50% seizure reduction by period 6, with sustained benefit observed in the open-label extension for up to one year
100% of elsunersen patients - and none on placebo - had additional improvements, including sleep, motor function, muscle tone and attention
No treatment-emergent or serious adverse events related to study drug reported
BOSTON, April 06, 2026 (GLOBE NEWSWIRE) -- , Inc. (NASDAQ: PRAX), a fully integrated, leading central nervous system (CNS) precision neuroscience biopharmaceutical company, today announced positive topline results from the EMBRAVE Part A trial of elsunersen in pediatric patients with early-seizure onset SCN2A developmental and epileptic encephalopathy (DEE).
“We are thrilled to see the remarkable, consistent results from EMBRAVE Part A, showing 77% reduction in monthly seizures and disease modifying improvements in children with SCN2A early-seizure onset DEE. We are well underway with our pivotal EMBRAVE3 study and look forward to sharing this placebo-controlled data from the EMBRAVE Part A study with all key stakeholders,” said Marcio Souza, president and chief executive officer.
EMBRAVE Part A is a randomized, placebo-controlled Phase 1/2 trial evaluating the safety and efficacy of ascending doses of elsunersen in patients with SCN2A DEE. Nine patients, aged 2-12 years old, were randomized 3:1 to receive either elsunersen or sham procedure every 4 weeks for 24 weeks, followed by an open-label extension (OLE); all 9 patients continued to the OLE. Patients received a starting dose of 1 mg with optional dose escalation based on observed seizure reduction and individual tolerability.
Key results from EMBRAVE Part A
Efficacy
- Elsunersen treatment led to a 77% placebo-adjusted seizure reduction from baseline (p=0.015, 95 CI [33,92]
- 57% of patients had at least a 28-day period of seizure freedom
- Efficacy was sustained in the OLE for up to one year
- 100% of elsunersen patients improved across sleep, motor function, muscle tone, attention or neuropsychomotor development compared to no improvements in placebo group
Safety
- Elsunersen was well-tolerated, with no drug-related SAEs, no discontinuations and no neuroinflammation signals at doses up to 8 mg
- Most treatment-emergent adverse events (TEAEs) were mild to moderate. TEAEs were consistent with the EMBRAVE Part 1 study
Additional results will be presented at upcoming scientific meetings.
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 about previous studies and publications about elsunersen please visit the . To learn more about the EMBRAVE3 study, please visit .
About Praxis
Praxis Precision Medicines is a fully integrated, leading central nervous system (CNS) precision neuroscience 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 movement disorders and epilepsy, with four late-stage product candidates. For more information, please visit and follow us on , and .
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Investor Contact: Praxis Precision Medicines 857-702-9452 Media Contact: Dan Ferry LifeSci Advisors 617-430-7576
