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

Purpose

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

Conditions

  • SCN2A Encephalopathy
  • SCN8A Encephalopathy

Eligibility

Eligible Ages
Between 1 Year and 18 Years
Eligible Sex
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  • 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). • Additional inclusion criteria apply and will be assessed by the study team.

Exclusion Criteria

  • 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. - Additional exclusion criteria apply and will be assessed by the study team.

Study Design

Phase
Phase 2/Phase 3
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Intervention Model Description
Parallel group
Primary Purpose
Treatment
Masking
Triple (Participant, Care Provider, Investigator)
Masking Description
Double-blind

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Part A: Randomized, Double-Blind 0.5mg/kg/day PRAX-562 or PRAX-562/Placebo
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
    Once daily oral or G-tube treatment.
Experimental
Part B: Open-Label Extension Treatment 0.5mg/kg/day PRAX-562
Eligible participants will receive 0.5mg/kg/day administered orally or via G-tube for up to 144 weeks.
  • Drug: PRAX-562
    Once daily oral or G-tube treatment.
Experimental
Part A: Randomized, Double-Blind 1.0 mg/kg/day PRAX-562 or PRAX-562/Placebo
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
    Once daily oral or G-tube treatment.
Experimental
Open-Label Extension Treatment 1.0 mg/kg/day PRAX-562
Eligible participants will receive 1.0 mg/kg/day administered orally or via G-tube for up to 144 weeks.
  • Drug: PRAX-562
    Once daily oral or G-tube treatment.

Recruiting Locations

More Details

NCT ID
NCT05818553
Status
Active, not recruiting
Sponsor
Praxis Precision Medicines

Detailed Description

A Phase 2, double-blind, randomized clinical trial to evaluate the safety and tolerability of PRAX 562 in pediatric participants with SCN2A- and SCN8A- DEEs.