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

SCN2A Encephalopathy Clinical Trial

— EMBOLD  

Official title:

A Phase 2,Double-Blind,Randomized Clinical Trial to Explore the Safety,Tolerability,Efficacy, and Pharmacokinetics of PRAX-562 in Pediatric Participants With Developmental and Epileptic Encephalopathies Followed by Open-Label Extension(OLE)

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05818553
• Other study ID #: PRAX-562-221
• Status: Recruiting
• Phase: Phase 2
• Start date: August 2, 2023
• Est. completion date: June 30, 2025

Study information

• Verified date: January 2024
• Source: Praxis Precision Medicines
• Contact: Head of Pharmacovigilance
• Phone: 617-300-8460
• Email: clinicaltrials[@]praxismedicines.com
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This is a Phase 2, double-blind, randomized clinical trial to explore the safety, tolerability, efficacy, and pharmacokinetics of PRAX-562 in pediatric participants who have seizures associated with early-onset SCN2A-DEE and SCN8A-DEE.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 20
• Est. completion date: June 30, 2025
• Est. primary completion date: June 30, 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 2 Years to 18 Years

Eligibility

Inclusion Criteria:

• Has a documented rare missense variant in SCN2A with onset of seizures occurring in the first three months of life or has a documented de novo (not observed in either parent) missense variant in SCN8A with onset of seizures occurring in the first six months of life.

• 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 AND

• 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.

Related Conditions & MeSH terms

• Brain Diseases
• Epilepsy
• SCN2A Encephalopathy
• SCN8A Encephalopathy

Intervention

Drug:
• Part A: 0.5mg/kg/day PRAX-562 for 16 Weeks
Once daily oral or G-tube treatment.
• Part A: 0.5mg/kg/day PRAX-562 for 12 Weeks and Matching Placebo for 4 Weeks
Once daily oral or G-tube treatment with PRAX-562 for 12 weeks and matching placebo for 4 weeks.
• Part B: 0.5mg/kg/day PRAX-562
Once daily oral or G-tube treatment.

Locations

Country	Name	City	State
Spain	Praxis Research Site	Madrid
United States	Praxis Research Site	Atlanta	Georgia
United States	Praxis Research Site	Boston	Massachusetts
United States	Praxis Research Site	Chicago	Illinois
United States	Praxis Research Site	Tacoma	Washington

Sponsors (1)

Lead Sponsor	Collaborator
Praxis Precision Medicines

Countries where clinical trial is conducted

United States,  Spain, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Incidence of Treatment-Emergent Adverse Events (TAEs) [Safety and Tolerability])	The number of participants with treatment-emergent adverse events will be reported by severity and preferred term.	16 weeks
Primary	To evaluate the long-term safety and tolerability of PRAX-562 in pediatric participants with DEEs	Incidence and severity of TEAEs	48 weeks
Secondary	To assess the effect of PRAX-562 on the frequency of countable motor seizures in pediatric participants with DEEs	Changes from baseline in monthly (28-day) motor seizure frequency	16 weeks
Secondary	Plasma concentrations of PRAX-562	Sparse pharmacokinetic (PK) sampling will be used to calculate mean concentrations at baseline, and at Weeks 2, 4, 6, 8,10, 12 and 16.	16 weeks
Secondary	Seizure Frequency (OLE Extension)	Efficacy assessments (seizure diary) will be collected daily and reviewed at timepoints Day 1, Week 16, Week 32, and Week 48.	48 weeks