Actively Recruiting

Phase 1
Phase 2
Age: 2Years - 12Years
All Genders
ID07531745

Phase 1-2 Open-Label Study to Evaluate Safety, Tolerability, and Pharmacokinetics of Intrathecal ION337 in Children With Dravet Syndrome

Led by Ionis Pharmaceuticals, Inc. · Updated on 2026-05-20

32

Participants Needed

3

Research Sites

N/A

Total Duration

On this page

AI-Summary

What this Trial Is About

Researchers are evaluating the safety and tolerability of ION337 in children with Dravet syndrome (DS) aged 2 to 12 years. Dravet syndrome is a severe form of epilepsy, and this open-label study aims to understand how well participants tolerate this investigational treatment and monitor its safety over time. The study is divided into two parts. In Part 1, participants receive a single intrathecal bolus injection of ION337 and are observed for 6 months in a single ascending dose phase. Participants who complete Part 1 may enter Part 2, where they receive multiple doses of ION337 over 24 months in a multiple ascending dose phase, followed by a 7-month safety follow-up period. All doses are administered intrathecally. Participants will be closely monitored throughout the study with assessments including physical and neurological exams, vital signs, ECGs, laboratory tests, and tracking of treatment-emergent adverse events. Researchers will also measure seizure frequency and analyze drug levels in blood and cerebrospinal fluid. The total study duration for participants can be up to 31 months, including treatment and follow-up.

CONDITIONS

Brief Title

ASCEND: Safety and Tolerability of ION337 for the Treatment of Dravet Syndrome

Who Can Participate

Age: 2Years - 12Years
All Genders

Eligibility Criteria

Eligible

You may qualify if you...

  • Participant is aged 2 to 12 years at the time of informed consent
  • Has at least one parent or caregiver aged 18 or older willing to provide consent and attend all study visits
  • Diagnosed with Dravet syndrome according to agreed criteria
  • Has a confirmed pathogenic or likely pathogenic SCN1A genetic variant
  • Currently receiving at least one anti-seizure medication at a stable dose for at least 4 weeks before consent
  • Other epilepsy treatments and medications, including ketogenic diet or vagus nerve stimulation, stable for at least 4 weeks before consent
  • Experiences the required number of major motor seizures during screening period
Not Eligible

You will not qualify if you...

  • Known brain or spinal disease that would affect lumbar puncture safety or cerebrospinal fluid circulation
  • Has a pathogenic variant in another gene causing epilepsy
  • Previously treated with or currently enrolled in gene therapy or antisense oligonucleotide trials for Dravet syndrome
  • Treated with or enrolled in other investigational drug or device trials within 30 days or 5 half-lives of that agent
  • Currently receiving anti-seizure medications that act primarily as sodium channel blockers for maintenance
  • Prior brain surgeries such as corpus callosotomy, deep brain stimulation device implantation, or other palliative brain surgeries intended to reduce seizures

AI-Screening

AI-Powered Screening

Complete this quick 3-step screening to check your eligibility

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Your Study Journey

Screening

Duration - 2 to 4 weeks

Participants are screened for eligibility to participate in the trial.

1 visit (in-person)

Part 1: Single Ascending Dose (SAD) Treatment

Duration - Up to 6 months

Participants receive a single intrathecal bolus injection of ION337 and are monitored for safety and tolerability.

Multiple visits over 6 months for safety monitoring

Part 2: Multiple Ascending Dose (MAD) Treatment

Duration - Up to 24 months

Participants who complete Part 1 receive multiple doses of ION337 at the same dose level as in Part 1, with ongoing safety and tolerability assessments.

Regular visits for dosing and assessments over 24 months

Safety Follow-up

Duration - 7 months

Participants are monitored for safety for 7 months after completing multiple dose treatment.

Several follow-up visits during the 7-month safety monitoring period

Trial Site Locations

Total: 3 locations

1

University of Michigan Health System

Ann Arbor, Michigan, United States, 48109

Actively Recruiting

2

Mayo Clinic

Rochester, Minnesota, United States, 55905

Actively Recruiting

3

Le Bonheur Children's Hospital

Memphis, Tennessee, United States, 38103

Actively Recruiting

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Research Team

I

Ionis Pharmaceuticals, Inc.

How is the study designed?

Study Type

INTERVENTIONAL

Masking

NONE

Allocation

NON_RANDOMIZED

Model

SEQUENTIAL

Primary Purpose

TREATMENT

Number of Arms

5

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