NCT05818553

Brief Summary

A Clinical Trial of PRAX-562 in Subjects With Developmental and Epileptic Encephalopathies (DEE)

Trial Health

78
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
77

participants targeted

Target at P50-P75 for phase_2

Timeline
10mo left

Started Aug 2023

Typical duration for phase_2

Geographic Reach
4 countries

8 active sites

Status
active not recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress77%
Aug 2023Mar 2027

First Submitted

Initial submission to the registry

March 17, 2023

Completed
1 month until next milestone

First Posted

Study publicly available on registry

April 19, 2023

Completed
4 months until next milestone

Study Start

First participant enrolled

August 2, 2023

Completed
2.3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 12, 2025

Completed
1.3 years until next milestone

Study Completion

Last participant's last visit for all outcomes

March 1, 2027

Expected
Last Updated

January 29, 2026

Status Verified

January 1, 2025

Enrollment Period

2.3 years

First QC Date

March 17, 2023

Last Update Submit

January 27, 2026

Conditions

SCN2A EncephalopathySCN8A Encephalopathy

Keywords

Pediatric epilepsyNaV1.2 Voltage-Gated Sodium ChannelSCN2A variantSCN8A variantDevelopmental and epileptic encephalopathy

Outcome Measures

Primary Outcomes (2)

  • PART A (Cohorts 1 and 2) RDB: To evaluate the safety and tolerability of PRAX 562 in pediatric participants with SCN2A- and SCN8A- DEEs

    Changes from baseline in monthly (28-day) motor seizure frequency

    16 weeks

  • PART B (Cohorts 1 and 2) OLE: To evaluate the long-term safety and tolerability of PRAX-562 in pediatric participants with DEEs

    Incidence and severity of TEAEs

    48 weeks

Secondary Outcomes (5)

  • PART A (Cohorts 1 and 2) RDB: To assess the effect of PRAX-562 on the frequency of countable motor seizures in pediatric participants with DEEs

    16 weeks

  • Plasma concentrations of PRAX-562

    16 weeks

  • Seizure Frequency (OLE Extension)

    48 weeks

  • To assess the effect of PRAX-562 on the frequency of countable motor seizures in pediatric participants with DEEs

    16 weeks

  • Incidence of Treatment-Emergent Adverse Events (TEAEs) [Safety and Tolerability])

    16 weeks

Study Arms (4)

Part A: Randomized, Double-Blind 0.5mg/kg/day PRAX-562 or PRAX-562/Placebo

EXPERIMENTAL

Eligible participants from each cohort will be randomized in a 1:1 ratio to either 0.5 milligrams/kilograms/day (mg/kg/day) PRAX-562 for 16 weeks (PRAX-562 arm) or 0.5 mg/kg/day PRAX-562 for 12 weeks and matching placebo for 4 weeks (PRAX-562/placebo arm) administered orally or via gastrostomy tube (G-tube).

Drug: PRAX-562

Part B: Open-Label Extension Treatment 0.5mg/kg/day PRAX-562

EXPERIMENTAL

Eligible participants will receive 0.5mg/kg/day administered orally or via G-tube for up to 144 weeks.

Drug: PRAX-562

Part A: Randomized, Double-Blind 1.0 mg/kg/day PRAX-562 or PRAX-562/Placebo

EXPERIMENTAL

Eligible participants from each cohort will be randomized in a 1:1 ratio to either 1.0 milligrams/kilograms/day (mg/kg/day) PRAX-562 for 16 weeks (PRAX-562 arm) or 1.0 mg/kg/day PRAX-562 for 12 weeks and matching placebo for 4 weeks (PRAX-562/placebo arm) administered orally or via gastrostomy tube (G-tube).

Drug: PRAX-562

Open-Label Extension Treatment 1.0 mg/kg/day PRAX-562

EXPERIMENTAL

Eligible participants will receive 1.0 mg/kg/day administered orally or via G-tube for up to 144 weeks.

Drug: PRAX-562

Interventions

PRAX-562DRUG

Once daily oral or G-tube treatment.

Open-Label Extension Treatment 1.0 mg/kg/day PRAX-562Part A: Randomized, Double-Blind 0.5mg/kg/day PRAX-562 or PRAX-562/PlaceboPart A: Randomized, Double-Blind 1.0 mg/kg/day PRAX-562 or PRAX-562/PlaceboPart B: Open-Label Extension Treatment 0.5mg/kg/day PRAX-562

Eligibility Criteria

Age1 Year - 18 Years
Sexall
Healthy VolunteersNo
Age GroupsChild (0-17), Adult (18-64)

You may qualify if:

  • Has a documented variant in SCN2A with onset of seizures occurring in the first 3 months of life or has a diagnosis of SCN8A-DEE supported by both clinical and genetic findings.
  • Has a seizure frequency as follows:
  • At least 8 countable motor seizures in the 4 weeks immediately prior to Screening as reported by the parent/legal guardian or in the opinion of the investigator as documented in medical notes.
  • AND o At least 8 countable motor seizures during the 28 day Baseline Observation Period (during which seizure frequency is recorded in a daily seizure diary).

You may not qualify if:

  • Has any clinically significant or known pathogenic or likely pathogenic genetic variant other than in SCN2A and SCN8A or a genetic variant that may explain or contribute to the participant's epilepsy and/or developmental disorder.
  • Has a documented, functionally characterized loss-of-function (LoF) missense variant or a presumed LoF variant (nonsense or frameshift variant) based on genetic testing and/or clinical evidence that prior exposure to a sodium channel blocker (SCB) medication worsened seizures.
  • Has 2 or more episodes of convulsive status epilepticus requiring hospitalization and intubation in the 6 months prior to Screening.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (8)

Praxis Research Site

Atlanta, Georgia, 30329, United States

Location

Praxis Research Site

Chicago, Illinois, 60611, United States

Location

Praxis Research Site

Minneapolis, Minnesota, 55113, United States

Location

Praxis Research Site

Hackensack, New Jersey, 07601, United States

Location

Praxis Research Site

Tel Litwinsky, 52621, Israel

Location

Praxis Research Site

Madrid, 28034, Spain

Location

Praxis Research Site

Glasgow, G51 4TF, United Kingdom

Location

Praxis Research Site

London, WC1N 3BH, United Kingdom

Location

Study Officials

  • Medical Director

    Praxis Precision Medicines

    STUDY DIRECTOR

Study Design

Study Type
interventional
Phase
phase 2
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR
Masking Details
Double-blind
Purpose
TREATMENT
Intervention Model
PARALLEL
Model Details: Parallel group
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

March 17, 2023

First Posted

April 19, 2023

Study Start

August 2, 2023

Primary Completion

November 12, 2025

Study Completion (Estimated)

March 1, 2027

Last Updated

January 29, 2026

Record last verified: 2025-01

Locations

GB(2)US(4)ES(1)IL(1)