A Phase 3 interventional study of 1mg elsunersen and 0.5mg elsunersen in Epileptic Encephalopathy and SCN2A Encephalopathy, sponsored by Praxis Precision Medicines. Recruiting at 10 sites in 4 countries. Open to participants aged 1 Day to 18 Years. Per ClinicalTrials.gov, last updated 2026-08-03.
Sponsored by Praxis Precision Medicines · Phase 3, Interventional, and Treatment
A Multi-Center, Single-Arm Clinical Trial to Investigate the Efficacy and Safety of Elsunersen in Pediatric Participants with Early Onset SCN2A Developmental and Epileptic Encephalopathy
1,848 studies on the registry are indexed under Epilepsy; 422 are open to participants now.
This study's planned enrollment of 40 is below the median of 50 across 1,239 interventional studies indexed under Epilepsy.
Browse Epilepsy studies →Praxis Precision Medicines is the lead sponsor of 17 studies on the registry; 4 are open to participants now.
Of its 7 completed or terminated interventional studies of FDA-regulated products, 1 (14%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Open-label elsunersen
Drug: 1mg elsunersen
Open-label elsunersen
Drug: 1mg elsunersen
Open-label elsunersen
Drug: 0.5mg elsunersen
24 weeks every 4 weeks intrathecally
24 weeks every 4 weeks intrathecally
To assess the efficacy of elsunersen on seizure frequency in participants with early-onset SCN2A DEE
Median percent change in monthly (28 days) motor seizure frequency from baseline to treatment after 24 weeks
Time frame: 24 weeks
To assess secondary efficacy outcomes of elsunersen in participants with early-onset SCN2A DEE
Responder rate - defined as a ≥50% reduction in monthly seizure frequency from baseline compared to treatment after 24 weeks
Time frame: 24 weeks
To assess secondary efficacy outcomes of elsunersen in participants with early-onset SCN2A DEE
Change in motor seizure-free days from baseline
Time frame: 24 weeks
CGI-S change from baseline
CGI-S assesses the clinician's impression of the participant's current illness state. The clinician should use his/her total clinical experience with this patient population and rate the current severity on a 7-point scale from 1 (normal, not at all ill) to 7 (among the most extremely ill patients).
Time frame: 24 weeks
CGI subdomain scores at each postdose time point
Clinical Global Impression-Improvement (CGI-I) subdomains scores at each postdose time point
Time frame: 24 weeks
CgGI-S from baseline
Caregiver Global Impression-Severity (CgGI-S) at baseline compared to treatment after 24 weeks
Time frame: 24 weeks
CgGI-I subdomain scores at each postdose time point
Caregiver Global Impression-Improvement (CgGI I) subdomains scores at each postdose time point
Time frame: 24 weeks
Sleep assessment scores from baseline
Sleep assessment scores at baseline compared to each postdose time point
Time frame: 24 weeks
To evaluate the safety and tolerability of elsunersen in participants with early-onset SCN2A DEE
Incidence and severity of treatment-emergent adverse events (TEAEs)
Time frame: 24 weeks
Not enrolling at this site.
Not enrolling at this site.
Started Aug 2025 (actual). Primary completion is estimated for Dec 2026, 16 months after the start.
Of 66 industry-sponsored phase 3 interventional studies under Epilepsy, half reached primary completion within 48 months of starting (the median), counting those still running; a quarter within 30 and three quarters within 70. This study's planned 16 months is below that.
Counting every sponsor, half of 85 studies reached it within 48 months; a quarter within 29 and three quarters within 69.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Praxis Precision Medicines