Developmental and Epileptic Encephalopathy 1Phase 3EMERALDNCT07010471
A Clinical Trial for Participants With DEE to Assess Efficacy, Safety, Tolerability, and PK of Relutrigine
A Phase 3 study testing 1.0mg/kg/day PRAX-562 and 1.5mg/kg/day PRAX-562 in people with Developmental and Epileptic Encephalopathy 1, run by Praxis Precision Medicines at 11 sites in 3 countries.
Trial summary
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 Followed by an Open-Label Extension Read more about this study
- Who is it for?
- Ages 2 to 65 years
- Conditions the study is for
- Developmental and Epileptic Encephalopathy 1
- What is being tested?
- 1.0mg/kg/day PRAX-562 and 1.5mg/kg/day PRAX-562
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 160 participants
- Where
- 11 sitesin 3 countries
- Study dates
- 9 Jul 2025to Nov 2027
- Phase
- Phase 3
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 2 to 65 years
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Has a documented diagnosis of a developmental and epileptic encephalopathy.
- Onset of seizures <12 years old.
- Has a weight >7 kg at the time of signing consent/assent.
Who cannot join
- Has a history of left bundle branch block, arrhythmias, Brugada syndrome, congenital heart disease, familial short QT syndrome, or family history of sudden death or ventricular arrhythmias, including idiopathic ventricular fibrillation.
- Had 2 or more episodes of convulsive status epilepticus requiring hospitalization and intubation in the 6 months prior to Screening.
- Has an abnormal ECG reading, including a QT interval corrected for heart rate using Bazett's method (QTcB) <350 and >450 ms (males), or <360 and >460 ms (females) at Screening and/or on Day 1.
- Any nerve stimulation must have been placed at least 3 months prior to Screening with at least 1 month of stable settings prior to Screening.
- Has received any other experimental or investigational drug, device, or other therapy within 30 days or 5 half-lives (whichever is longer) prior to Screening, including any prior use of gene therapy.
- Is currently pregnant or breastfeeding or is planning to become pregnant during the clinical trial or within 5 half-lives of the last study drug dose.
Trial locations and contacts
11 sites in 3 countries.
11 sites in 3 countries
United States6 sites
Praxis Research Site
Chevy Chase, Maryland, 20815
Praxis Research Site
Gulf Breeze, Florida, 32561
Praxis Research Site
Hackensack, New Jersey, 07601
Praxis Research Site
La Jolla, California, 92037
Praxis Research Site
Philadelphia, Pennsylvania, 19104
Praxis Research Site
Roseville, Minnesota, 55113
Brazil4 sites
Praxis Research Site
Paraná, 80250
Praxis Research Site
Rio de Janeiro, 20231
Praxis Research Site
Rio Grande, Do Sul, 90610
Praxis Research Site
São Paulo, 15090
About this study
Official title: 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 DEE Followed by an Open-Label Extension
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 Followed by an Open-Label Extension
- Being tested
- 1.0mg/kg/day PRAX-562, 1.5mg/kg/day PRAX-562, Placebo
- Keywords
- DEE, Developmental and Epileptic Encephalopathy, epilepsy
- Medical subject headings
- Infantile Epileptic-Dyskinetic Encephalopathy, Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
1.0mg/kg/day PRAX-562Drug
Also called relutrigine
Once daily orally or gastronomy/jejunostomy
1.5mg/kg/day PRAX-562Drug
Once daily orally or gastronomy/jejunostomy
PlaceboDrug
Once daily orally or gastronomy/jejunostomy
| Study group | Role | What they receive |
|---|---|---|
| Part A: Double-Blind Treatment Period | Experimental | Eligible participants will be randomly assigned in a double-blind manner and a 1:1 ratio to receive 1.0mg-1.5mg/kg relutrigine or placebo once daily orally or gastronomy/jejunostomy for 16 weeks Receives: Drug: 1.0mg/kg/day PRAX-562; Drug: 1.5mg/kg/day PRAX-562 |
| Part A: Double-Blind Treatment Period (Placebo) | Placebo comparator | Eligible participants will be randomly assigned in a double-blind manner and a 1:1 ratio to receive 1.0mg-1.5mg/kg relutrigine or placebo once daily orally or gastronomy/jejunostomy for 16 weeks Receives: Drug: Placebo |
| Part B: Open-Label Extension Treatment Period | Experimental | Participants from Part A will have the option to rollover to Part B to receive 1.0mg-1.5mg/kg of relutrigine once daily orally or gastronomy/jejunostomy for 32 weeks Receives: Drug: 1.0mg/kg/day PRAX-562; Drug: 1.5mg/kg/day PRAX-562 |
What is being measured
The primary outcome is the main question the study is designed to answer.
To assess the effect of relutrigine on seizure frequency in participants with DEEs compared to placebo
Change from baseline in monthly motor seizure frequency
Measured: 16 weeks
Secondary outcomes (14)
Achieve >50% reduction in monthly seizure frequency from baseline
Proportion of patients achieving >50% reduction in monthly seizure frequency from baseline
Measured: 16 weeks
Change in seizure-free days
Change in seizure-free days from baseline
Measured: 16 weeks
Clinical Global Impression-Severity questionnaire
CGI-S at baseline after 16 weeks
Measured: 16 weeks
Clinical Global Impression-Improvement questionnaire
CGI-I subdomains scores after 16 weeks
Measured: 16 weeks
Caregiver Global Impression-Severity questionnaire
CgGI-S at baseline after 16 weeks
Measured: 16 weeks
Caregiver Global Impression-Improvement questionnaire
CgGI-I subdomains scores after 16 weeks
Measured: 16 weeks
To evaluate the safety and tolerability of relutrigine in participants with DEEs
Incidence and severity of TEAEs
Measured: 16 weeks
Columbia-Suicide Severity Rating Scale questionnaire
Incidence of suicidal ideation or behavior as measured by the C-SSRS
Measured: 16 weeks
Evaluate the safety and tolerability of relutrigine in participants with DEEs
Incidence of clinically significant ECG abnormalities
Measured: 16 weeks
To evaluate the safety labs and tolerability of relutrigine in participants with DEEs
The principal investigator (PI) or sub investigator will review the laboratory report and document this review. Any clinically significant adverse changes occurring during the clinical trial will be documented as adverse events.
Measured: 16 weeks
To evaluate the change in respiratory rate and tolerability of relutrigine in participants with DEEs
Change in respiratory rate in breaths per minute
Measured: 16 weeks
To evaluate the change in blood pressure and tolerability of relutrigine in participants with DEEs
Change in blood pressure in mm/Hg
Measured: 16 weeks
To evaluate the change in pulse and tolerability of relutrigine in participants with DEEs
Change in heart rate in beats per minute
Measured: 16 weeks
To evaluate the change in body temperature and tolerability of relutrigine in participants with DEEs
Change in tympanic temperature in Celsius
Measured: 16 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jun 2025
- Study start9 Jul 2025
- Primary completionDec 2026 (estimated)
- Study completionNov 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Developmental and Epileptic Encephalopathy 1Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 160 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Praxis Precision Medicines
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Praxis Precision Medicines
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07010471
- Sponsor's protocol ID
- PRAX-562-311
- Acronym
- EMERALD
- Status last verified
- Jul 2026
- First submitted
- 30 May 2025
- Last updated
- 4 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No