SCN2A-DEEPhase 1/2NCT05737784
A Clinical Trial of PRAX-222 in Pediatric Participants With Early Onset SCN2A Developmental and Epileptic Encephalopathy
A Phase 1/2 study testing PRAX-222 - Initial Dose, PRAX-222 - Initial Ascending Doses and PRAX-222 - Optional Ascending Doses in people with SCN2A-DEE and Epilepsy, run by Praxis Precision Medicines at 3 sites in 2 countries.
Trial summary
The goal of this trial is to learn about the effect of PRAX-222 in pediatric participants with early onset SCN2A developmental and epileptic encephalopathy (DEE), aged 2 to 18 years. Read more about this study
- Who is it for?
- Ages 2 to 18 years
- What is being tested?
- PRAX-222 - Initial Dose, PRAX-222 - Initial Ascending Doses and PRAX-222 - Optional Ascending Doses
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 3 sitesin 2 countries
- Study dates
- 13 Apr 2023to Feb 2028
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
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 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Has onset of seizures prior to 3 months of age.
- Has a minimum weight of at least 10 kg at screening.
- Has a documented SCN2A variant through genetic testing obtained via a laboratory accredited per Clinical Laboratory Improvement Amendments (CLIA) or College of American Pathologists (CAP) or equivalent.
- Additional inclusion criteria apply and will be assessed by the study team
Who cannot join
- Has any clinically significant or known pathogenic genetic variant other than in the SCN2A gene, or a genetic variant that may explain or contribute to the participant's epilepsy and/or developmental disorder.
- Is taking more than 2 sodium channel blocking anti-seizure medications
- Additional exclusion criteria apply and will be assessed by the study team
Trial locations and contacts
3 sites in 2 countries.
3 sites in 2 countries
Brazil2 sites
Hospital de Clinicas de Porto Alegre
Porto Alegre, Rio Grande do Sul, 90035-003
Praxis Research Site
São Paulo, 05403-010
United States1 site
Le Bonheur Childrens Hospital
Memphis, Tennessee, 38103
About this study
Official title: A Seamless, Clinical Trial to Investigate the Safety and Efficacy of Multiple Doses of PRAX-222 in Pediatric Participants With Early Onset SCN2A Developmental and Epileptic Encephalopathy
The goal of this trial is to learn about the effect of PRAX-222 in pediatric participants with early onset SCN2A developmental and epileptic encephalopathy (DEE), aged 2 to 18 years.
- Being tested
- PRAX-222 - Initial Dose, PRAX-222 - Initial Ascending Doses, PRAX-222 - Optional Ascending Doses, PRAX-222 - Fixed Doses, Placebo
- Keywords
- Antisense Oligonucleotide, NaV1.2 Voltage-Gated Sodium Channel, Voltage-Gated Sodium Channel Blockers, SCN2A variant, Pediatric epilepsy, Developmental and Epileptic Encephalopathy, DEE
- Medical subject headings
- Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PRAX-222 - Initial DoseDrug
PRAX-222
PRAX-222 - Initial Ascending DosesDrug
Ascending doses of PRAX-222
PRAX-222 - Optional Ascending DosesDrug
Escalation of PRAX-222 dose(s)
PRAX-222 - Fixed DosesDrug
Fixed-dose(s) of PRAX-222 not to exceed the maximum tolerated dose of PRAX-222
PlaceboProcedure or surgery
Placebo procedure
| Study group | Role | What they receive |
|---|---|---|
| Preliminary Safety | Experimental | Open-label PRAX-222 Receives: Drug: PRAX-222 - Initial Dose |
| Dose Escalation - PRAX-222 | Experimental | Initial dose escalation consisting of double-blind ascending doses of PRAX-222 Receives: Drug: PRAX-222 - Initial Ascending Doses |
| Dose Escalation - Placebo | Placebo comparator | Double-blind placebo procedure Receives: Procedure: Placebo |
| Optional Dose Escalation - PRAX-222 | Experimental | Optional dose escalation consisting of double-blind ascending doses of PRAX-222 Receives: Drug: PRAX-222 - Optional Ascending Doses |
| Optional Dose Escalation - Placebo | Placebo comparator | Double-blind placebo procedure Receives: Procedure: Placebo |
| Confirmatory Dosing - PRAX-222 | Experimental | Double-blind fixed-dose PRAX-222 Receives: Drug: PRAX-222 - Fixed Doses |
| Confirmatory Dosing - Placebo | Experimental | Double-blind placebo procedure Receives: Procedure: Placebo |
| Open-label PRAX-222 | Experimental | Open-label PRAX-222 Receives: Drug: PRAX-222 - Fixed Doses |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with treatment-emergent adverse events (Preliminary Safety, Dose Escalation)
The number of participants with treatment-emergent adverse events will be reported by severity and preferred term.
Measured: Screening (-8 weeks) through up to 92 weeks
Seizure frequency (Confirmatory Phase)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following the 6th dose administration in the confirmatory phase.
Measured: 36 to 40 weeks
Secondary outcomes (21)
Seizure frequency (Preliminary Safety)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following the 4th dose administration in the preliminary safety phase.
Measured: 12 to 16 weeks
Seizure frequency (Preliminary Safety)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following each dose administration in the preliminary safety phase.
Measured: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks
Percent change in seizure frequency (Preliminary Safety)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following each dose administration in the preliminary safety phase. Percent change in seizure frequency will be calculated using a 4-week baseline observation period during Screening as the baseline measure.
Measured: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks
Number of participants with a treatment response (Preliminary Safety)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following each dose administration in the preliminary safety phase. Percent change in seizure frequency will be calculated using a 4-week baseline observation period during Screening as the baseline measure. Treatment response will be defined as a >=50% reduction in seizure frequency.
Measured: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks
Seizure frequency (Dose Escalation Phase)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following the 6th dose administration in the dose escalation phase.
Measured: 24 to 28 weeks (Group 1), 30 to 34 weeks (Group 2, optional)
Seizure frequency (Dose Escalation Phase)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following each dose administration in the dose escalation phase.
Measured: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks, 12 to 16 weeks, 18 to 22 weeks, 30 to 34 weeks (Group 1, optional), 36 to 40 weeks (Group 1, optional), 42 to 46 weeks (Group 1, optional), 48 to 52 weeks (Group 1, optional), 54 to 58 weeks (Group 1, optional)
Seizure frequency (Confirmatory Phase)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following each dose administration in the confirmatory phase.
Measured: 0 to 4 weeks, 6 to 10 weeks, 12 to 16 weeks, 18 to 22 weeks, 24 to 28 weeks
Percent change in seizure frequency (Dose Escalation Phase)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following each dose administration in the dose escalation phase. Percent change in seizure frequency will be calculated using a 4-week baseline observation period during Screening as the baseline measure.
Measured: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks, 12 to 16 weeks, 18 to 22 weeks, 30 to 34 weeks (optional), 36 to 40 weeks (optional), 42 to 46 weeks (optional), 48 to 52 weeks (optional), 54 to 58 weeks (optional)
Percent change in seizure frequency (Confirmatory Phase)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following each dose administration in the confirmatory phase. Percent change in seizure frequency will be calculated using a 4-week baseline observation period during Screening as the baseline measure.
Measured: 0 to 4 weeks, 6 to 10 weeks, 12 to 16 weeks, 18 to 22 weeks, 24 to 28 weeks
Number of participants with a treatment response (Dose Escalation Phase)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following each dose administration in the dose escalation phase. Percent change in seizure frequency will be calculated using a 4-week baseline observation period during Screening as the baseline measure. Treatment response will be defined as a >=50% reduction in seizure frequency.
Measured: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks, 12 to 16 weeks, 18 to 22 weeks, 30 to 34 weeks (optional), 36 to 40 weeks (optional), 42 to 46 weeks (optional), 48 to 52 weeks (optional), 54 to 58 weeks (optional)
Number of participants with a treatment response (Confirmatory Phase)
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following each dose administration in the confirmatory phase. Percent change in seizure frequency will be calculated using a 4-week baseline observation period during Screening as the baseline measure. Treatment response will be defined as a >=50% reduction in seizure frequency.
Measured: 0 to 4 weeks, 6 to 10 weeks, 12 to 16 weeks, 18 to 22 weeks, 24 to 28 weeks
Changes in EEG-based outcome measures (Confirmatory Phase)
A vEEG will be performed to record brainwave activity. Changes in mean vEEG measures (including, but not limited to, background frequency, slowing, epileptiform activity, sleep architecture, and seizures) will be calculated
Measured: Week 2, Week 42
Change from baseline in Clinical Global Impression-Severity (CGI-S) score (Confirmatory Phase)
The CGI-S assesses the clinician's impression of the participant's current epilepsy symptoms. The clinician should use his/her total clinical experience with this patient population and rate the current severity of the participant's symptoms on a 7-point scale from 1 (Normal, not at all affected) to 7 (Among the most extremely affected patients)
Measured: 6 weeks, 12 weeks, 18 weeks, 24 weeks, 36 weeks, 60 weeks
Change from baseline in Caregiver Global Impression-Severity (CgGI-S) score (Confirmatory Phase)
The CgGI-S assesses the caregiver's impression of the participant's current epilepsy symptoms. The caregiver will rate the current severity of the participant's symptoms on a 7-point scale from 1 (Normal, not at all affected) to 7 (Extremely affected)
Measured: 6 weeks, 12 weeks, 18 weeks, 24 weeks, 36 weeks, 60 weeks
Clinical Global Impression-Improvement (CGI-I) score (Confirmatory Phase)
The CGI-I assesses the participant's improvement (or worsening). The clinician is required to assess the participant's condition relative to Baseline (Day 1) on a 7-point scale from 1 (Very much improved) to 7 (Very much worse).
Measured: 6 weeks, 12 weeks, 18 weeks, 24 weeks, 36 weeks, 60 weeks
Caregiver Global Impression-Improvement (CgGI-I) score (Confirmatory Phase)
The CgGI-I assesses the participant's improvement (or worsening). The caregiver is required to assess the participant's condition relative to Baseline (Day 1) on a 7-point scale from 1 (Very much improved) to 7 (Very much worse).
Measured: 6 weeks, 12 weeks, 18 weeks, 24 weeks, 36 weeks, 60 weeks
Developmental milestones (Confirmatory Phase)
Developmental milestones will be assessed using the Bayley Scales of Infant Development - Fourth Edition (Bayley-4) domain and subtest scores or the Wechsler Preschool and Primary Scales of Intelligence - Fourth Edition (WPPSI-IV). The Bayley-4 is a standardized neurodevelopmental assessment measure used by clinicians to evaluate key domains in early childhood development for individuals between 16 days and 42 months after birth. Each domain includes a variable number of items for assessing development. Each item is scored as a 0, 1, or 2 based on the child's response to the rater's prompt or instruction. Higher scores on the Bayley-4 indicate more advanced development. The WPPSI-IV is a comprehensive test used to assess cognitive function in children from the age of 2 years 6 months to 7 years 7 months. Higher scores on the WPPSI-IV indicate more advanced development.
Measured: 36 weeks
Quality of life as assessed by Quality of Life Inventory-Disability (Confirmatory Phase)
The QI-Disability is a parent-report measure for children with intellectual disabilities. Parents report on engagement in and enjoyment of activities and behaviors related to health and well-being, feelings and emotions, family and friends, activities and the outdoors, and daily life. 32 items are rated on a 5-point scale from 0 (Never) to 4 (Very often). Higher scores on the QI-Disability indicate more frequent and more enjoyable behavior and activity.
Measured: 36 weeks
Behavior as assessed by Vineland Adaptive Behavior Scale-3rd edition (Vineland-3; Confirmatory Phase)
The Vineland-3 is a clinician-assessed measure of adaptive behavior in individuals with intellectual disabilities using information obtained via interview of a caregiver or parent. Individuals are assessed on frequency of adaptive behaviors in the following domains: communication, daily living skills, socialization, and motor skills. Each domain has a variable number of items. Each item is scored on a 2 or 3-point scale from 0 (Never) to 2 (Usually). Higher scores indicate more frequent behaviors.
Measured: 36 weeks
Behavior as assessed by Aberrant Behaviors Checklist-2nd edition (ABC-2; Confirmatory Phase)
The ABC-2 is a clinician-assessed rating scale consisting of 58 items that measure the severity of a range of problem behaviors commonly observed in individuals with intellectual disabilities, including irritability, social withdrawal, stereotypic behavior, hyperactivity, and inappropriate speech. Items are rated on a 4-point scale from 0 (not at all a problem) to 3 (the problem is severe in degree). Higher scores indicate more aberrant behaviors.
Measured: 36 weeks
Sleep as assessed by Sleep Disturbance Scale for Children (Confirmatory Phase)
The parent-reported Sleep Disturbance Scale for Children (SDSC) is a 26-item scale designed to categorize sleep disorders in children. In addition to an overall score, the instrument provides 5 sub-scores for the following: disorders of initiating and maintaining sleep, sleep breathing disorders, disorders of arousal or sleep-wake transition disorders, disorders of excessive somnolence, and sleep hyperhidrosis. Most items are scored on a 5-point scale from 1 (Never) to 5 (Always). The amount of time spent asleep and the length of time taken to fall asleep is also used in calculating the score. Higher scores on the SDSC indicate more sleep disturbances.
Measured: 36 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Feb 2023
- Study start13 Apr 2023
- Primary completion1 Apr 2026
- Study completionFeb 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SCN2A-DEEStudies 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 1/2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Seamless study design with sequential study parts, including an open-label safety part; a double-blind, randomized dose-escalation part; a double-blind, randomized confirmatory part; and an open-label extension part.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 60 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
- NCT05737784
- Sponsor's protocol ID
- PRAX-222-111
- Status last verified
- Jul 2026
- First submitted
- 10 Feb 2023
- Last updated
- 3 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Seamless, Clinical Trial to Investigate the Safety and Efficacy of Multiple Doses of PRAX-222 in Pediatric Participants With Early Onset SCN2A Developmental and Epileptic Encephalopathy
- ClinicalTrials.gov ID
- NCT05737784
- Acronym / sponsor ID
- PRAX-222-111
- Keywords
- Antisense Oligonucleotide, NaV1.2 Voltage-Gated Sodium Channel, Voltage-Gated Sodium Channel Blockers, SCN2A variant, Pediatric epilepsy, Developmental and Epileptic Encephalopathy, DEE
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Praxis Precision MedicinesIndustry (pharma, biotech, devices)
- Study start
- 13 Apr 2023 (actual)
- Primary completion
- 1 Apr 2026 (actual)
- Study completion
- Feb 2028 (estimated)
- First posted
- 21 Feb 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this trial is to learn about the effect of PRAX-222 in pediatric participants with early onset SCN2A developmental and epileptic encephalopathy (DEE), aged 2 to 18 years.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 8
- Model description
- Seamless study design with sequential study parts, including an open-label safety part; a double-blind, randomized dose-escalation part; a double-blind, randomized confirmatory part; and an open-label extension part.
| Arm | Type | Receives |
|---|---|---|
| Preliminary Safety | Experimental | Drug: PRAX-222 - Initial DoseOpen-label PRAX-222 |
| Dose Escalation - PRAX-222 | Experimental | Drug: PRAX-222 - Initial Ascending DosesInitial dose escalation consisting of double-blind ascending doses of PRAX-222 |
| Dose Escalation - Placebo | Placebo comparator | Procedure: PlaceboDouble-blind placebo procedure |
| Optional Dose Escalation - PRAX-222 | Experimental | Drug: PRAX-222 - Optional Ascending DosesOptional dose escalation consisting of double-blind ascending doses of PRAX-222 |
| Optional Dose Escalation - Placebo | Placebo comparator | Procedure: PlaceboDouble-blind placebo procedure |
| Confirmatory Dosing - PRAX-222 | Experimental | Drug: PRAX-222 - Fixed DosesDouble-blind fixed-dose PRAX-222 |
| Confirmatory Dosing - Placebo | Experimental | Procedure: PlaceboDouble-blind placebo procedure |
| Open-label PRAX-222 | Experimental | Drug: PRAX-222 - Fixed DosesOpen-label PRAX-222 |
Who may qualify
- Ages
- 2 to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (4 listed)
- Has onset of seizures prior to 3 months of age.
- Has a minimum weight of at least 10 kg at screening.
- Has a documented SCN2A variant through genetic testing obtained via a laboratory accredited per Clinical Laboratory Improvement Amendments (CLIA) or College of American Pathologists (CAP) or equivalent.
- Additional inclusion criteria apply and will be assessed by the study team
Key exclusion criteria (3 listed)
- Has any clinically significant or known pathogenic genetic variant other than in the SCN2A gene, or a genetic variant that may explain or contribute to the participant's epilepsy and/or developmental disorder.
- Is taking more than 2 sodium channel blocking anti-seizure medications
- Additional exclusion criteria apply and will be assessed by the study team
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PRAX-222 - Initial DosePRAX-222 | Drug | Preliminary Safety |
| PRAX-222 - Initial Ascending DosesAscending doses of PRAX-222 | Drug | Dose Escalation - PRAX-222 |
| PRAX-222 - Optional Ascending DosesEscalation of PRAX-222 dose(s) | Drug | Optional Dose Escalation - PRAX-222 |
| PRAX-222 - Fixed DosesFixed-dose(s) of PRAX-222 not to exceed the maximum tolerated dose of PRAX-222 | Drug | Confirmatory Dosing - PRAX-222, Open-label PRAX-222 |
| PlaceboPlacebo procedure | Procedure or surgery | Confirmatory Dosing - Placebo, Dose Escalation - Placebo, Optional Dose Escalation - Placebo |
Primary outcome
Number of participants with treatment-emergent adverse events (Preliminary Safety, Dose Escalation)
Time frame: Screening (-8 weeks) through up to 92 weeks
The number of participants with treatment-emergent adverse events will be reported by severity and preferred term.
Seizure frequency (Confirmatory Phase)
Time frame: 36 to 40 weeks
Seizure frequency will be captured by a seizure diary and outcomes will be measured by summing the seizure frequency over a 28-day time period following the 6th dose administration in the confirmatory phase.
21 secondary outcomes
Seizure frequency (Preliminary Safety)
Time frame: 12 to 16 weeks
Seizure frequency (Preliminary Safety)
Time frame: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks
Percent change in seizure frequency (Preliminary Safety)
Time frame: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks
Number of participants with a treatment response (Preliminary Safety)
Time frame: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks
Seizure frequency (Dose Escalation Phase)
Time frame: 24 to 28 weeks (Group 1), 30 to 34 weeks (Group 2, optional)
Seizure frequency (Dose Escalation Phase)
Time frame: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks, 12 to 16 weeks, 18 to 22 weeks, 30 to 34 weeks (Group 1, optional), 36 to 40 weeks (Group 1, optional), 42 to 46 weeks (Group 1, optional), 48 to 52 weeks (Group 1, optional), 54 to 58 weeks (Group 1, optional)
Seizure frequency (Confirmatory Phase)
Time frame: 0 to 4 weeks, 6 to 10 weeks, 12 to 16 weeks, 18 to 22 weeks, 24 to 28 weeks
Percent change in seizure frequency (Dose Escalation Phase)
Time frame: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks, 12 to 16 weeks, 18 to 22 weeks, 30 to 34 weeks (optional), 36 to 40 weeks (optional), 42 to 46 weeks (optional), 48 to 52 weeks (optional), 54 to 58 weeks (optional)
Percent change in seizure frequency (Confirmatory Phase)
Time frame: 0 to 4 weeks, 6 to 10 weeks, 12 to 16 weeks, 18 to 22 weeks, 24 to 28 weeks
Number of participants with a treatment response (Dose Escalation Phase)
Time frame: 0 to 4 weeks, 4 to 8 weeks, 8 to 12 weeks, 12 to 16 weeks, 18 to 22 weeks, 30 to 34 weeks (optional), 36 to 40 weeks (optional), 42 to 46 weeks (optional), 48 to 52 weeks (optional), 54 to 58 weeks (optional)
Number of participants with a treatment response (Confirmatory Phase)
Time frame: 0 to 4 weeks, 6 to 10 weeks, 12 to 16 weeks, 18 to 22 weeks, 24 to 28 weeks
Changes in EEG-based outcome measures (Confirmatory Phase)
Time frame: Week 2, Week 42
Change from baseline in Clinical Global Impression-Severity (CGI-S) score (Confirmatory Phase)
Time frame: 6 weeks, 12 weeks, 18 weeks, 24 weeks, 36 weeks, 60 weeks
Change from baseline in Caregiver Global Impression-Severity (CgGI-S) score (Confirmatory Phase)
Time frame: 6 weeks, 12 weeks, 18 weeks, 24 weeks, 36 weeks, 60 weeks
Clinical Global Impression-Improvement (CGI-I) score (Confirmatory Phase)
Time frame: 6 weeks, 12 weeks, 18 weeks, 24 weeks, 36 weeks, 60 weeks
Caregiver Global Impression-Improvement (CgGI-I) score (Confirmatory Phase)
Time frame: 6 weeks, 12 weeks, 18 weeks, 24 weeks, 36 weeks, 60 weeks
Developmental milestones (Confirmatory Phase)
Time frame: 36 weeks
Quality of life as assessed by Quality of Life Inventory-Disability (Confirmatory Phase)
Time frame: 36 weeks
Behavior as assessed by Vineland Adaptive Behavior Scale-3rd edition (Vineland-3; Confirmatory Phase)
Time frame: 36 weeks
Behavior as assessed by Aberrant Behaviors Checklist-2nd edition (ABC-2; Confirmatory Phase)
Time frame: 36 weeks
Sleep as assessed by Sleep Disturbance Scale for Children (Confirmatory Phase)
Time frame: 36 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Aug 2026.
- Related InfoLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Medical Director study director
Praxis Precision Medicines
3 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing PRAX-222 - Initial Dose, PRAX-222 - Initial Ascending Doses and PRAX-222 - Optional Ascending Doses in people with SCN2A-DEE and Epilepsy, run by Praxis Precision Medicines at 3 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 3 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Brazil, United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants with treatment-emergent adverse events (Preliminary Safety, Dose Escalation) (time frame: Screening (-8 weeks) through up to 92 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Aug 2026.