Status: Recruiting

A Study of Olezarsen for the Treatment of Familial Chylomicronemia Syndrome (FCS) in Pediatric Participants

The primary purpose of the study is to evaluate the efficacy of olezarsen administered by subcutaneous injection to pediatric participants with FCS.

Participants needed: 12

Trial details

Phase: Phase 3Age: 2-17Biological sex: AllType: InterventionalSponsor: Ionis Pharmaceuticals, Inc.Updated: Oct 8, 2026Locations: 5

Eligibility criteria

Parental or legally authorized representative consent must be obtained, and the... [+5]

Newly diagnosed within 12 weeks prior to screening or during the screening perio... [+9]

Status: Recruiting

ATTUNE: A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Intrathecally-Administered ION440 in Participants With Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome (MDS)

The primary purpose of this study is to evaluate the safety and tolerability of ION440.

Participants needed: 48

Trial details

Phase: Phase 1, Phase 2Age: 2-65Biological sex: MaleType: InterventionalSponsor: Ionis Pharmaceuticals, Inc.Updated: Oct 8, 2026Locations: 12

Eligibility criteria

Males aged ≥ 2 to ≤ 65 years, depending on specific cohort and group, at the tim... [+6]

Documented diagnosis of severe MECP2 duplications including terminal duplication... [+11]

Status: Recruiting

Rocket Study: A Study to Characterize Biomarkers and Disease Progression in Participants With Pelizaeus-Merzbacher Disease

The purpose of the study is to prospectively assess longitudinal changes in proteolipid protein 1 (PLP1) protein, disease-related biomarkers in cerebral spinal fluid (CSF) and blood, neuroimaging parameters relevant to Pelizaeus-Merzbacher disease (PMD) and longitudinal changes in performance on clinical, participant, and caregiver-reported outcome assessments to inform the development of therapies for PMD.

Participants needed: 32

Trial details

Age: 6-17Biological sex: MaleType: ObservationalSponsor: Ionis Pharmaceuticals, Inc.Updated: Oct 2, 2026Locations: 10

Eligibility criteria

Participant has a parent or caregiver capable of providing informed consent (sig... [+3]

Clinically significant abnormalities in medical history or physical examination [+2]

Status: Recruiting

CHAMPION: A Study to Evaluate the Efficacy and Safety of Obudanersen (ION582) in Children and Adults With Angelman Syndrome (AS)

The primary purpose of the study is to evaluate efficacy of obudanersen in participants with AS due to uniparental disomy or imprinting defects (UPD/ID) as measured through expressive communication.

Participants needed: 30

Trial details

Phase: Phase 3Age: 2-50Biological sex: AllType: InterventionalSponsor: Ionis Pharmaceuticals, Inc.Updated: Sep 28, 2026Locations: 1

Eligibility criteria

Clinical diagnosis of AS with molecular result indicating either paternal UPD of... [+5]

Participant has a clinical diagnosis of AS with molecular confirmation of a UBE3... [+4]

Status: Recruiting

A Study to Assess the Safety, Tolerability and Efficacy of ION775

The main objective of this study is to evaluate the effect of ION775 on fasting triglyceride (TG) levels in participants with hypertriglyceridemia (HTG) and severe hypertriglyceridemia (sHTG).

Participants needed: 72

Trial details

Phase: Phase 2Age: 18+Biological sex: AllType: InterventionalSponsor: Ionis Pharmaceuticals, Inc.Updated: Sep 3, 2026Locations: 17

Eligibility criteria

Adult males and females with HTG (fasting TG more than or equal to (≥) 350 milli... [+1]

Hemoglobin A1c (HbA1c) ≥ 8.5% at Screening. [+3]

Status: Recruiting

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

The primary purpose of this study is to evaluate the safety and tolerability of ION337 in participants with Dravet syndrome (DS).

Participants needed: 32

Trial details

Phase: Phase 1, Phase 2Age: 2-12Biological sex: AllType: InterventionalSponsor: Ionis Pharmaceuticals, Inc.Updated: Sep 3, 2026Locations: 6

Eligibility criteria

Participant is aged ≥ 2 to ≤ 12 years old at the time of informed consent. [+6]

Known brain or spinal disease that would interfere with the LP procedure or CSF... [+5]

Status: Recruiting

Donidalorsen Treatment in Children With Hereditary Angioedema

The purpose of this study is to evaluate the safety, tolerability and pharmacokinetics of donidalorsen in pediatric participants with hereditary angioedema (HAE) Type I (HAE-1) or Type II (HAE-2).

Participants needed: 20

Trial details

Phase: Phase 3Age: 2-11Biological sex: AllType: InterventionalSponsor: Ionis Pharmaceuticals, Inc.Updated: Sep 2, 2026Locations: 16

Eligibility criteria

Must be between the ages of 2 and less than 12 years, inclusive, at the time of... [+3]

Must not have any screening laboratory abnormalities or any other clinically sig... [+2]

Status: Recruiting

Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of ION464 Administered to Adults With Multiple System Atrophy (HORIZON)

The primary objectives are to evaluate the safety and tolerability of multiple doses of ION464 administered via intrathecal (IT) injection (Part 1) and to evaluate the long-term safety and tolerability of ION464 (Part 2) in participants with multiple system atrophy (MSA). The secondary objectives are to evaluate the pharmacodynamic (PD) effect of ION464 on the level of a potential biomarker of target engagement (Parts 1 and 2) and to evaluate the pharmacokinetic (PK) profile of ION464 in serum (Part 1).

Participants needed: 40

Trial details

Phase: Phase 1Age: 40-70Biological sex: AllType: InterventionalSponsor: Ionis Pharmaceuticals, Inc.Updated: Apr 27, 2026Locations: 15

Eligibility criteria

Screening single-photon emission computed tomography (SPECT) with DaTscan™ (iofl... [+2]

Presence of cognitive dysfunction (defined as Montreal Cognitive Assessment (MoC... [+1]

Status: Recruiting

Orbit Study: A Study to Evaluate the Safety, Pharmacokinetics, and Pharmacodynamics of Intrathecally Administered ION356 in Participants With Pelizaeus Merzbacher Disease (PMD)

The primary purpose of this study is to evaluate the safety and tolerability of ION356.

Participants needed: 24

Trial details

Phase: Phase 1Age: 2-17Biological sex: MaleType: InterventionalSponsor: Ionis Pharmaceuticals, Inc.Updated: Dec 12, 2025Locations: 7

Eligibility criteria

Participant's parent or legally accepted representative can provide informed con... [+4]

Clinically significant abnormalities in medical history, laboratory tests or phy... [+9]

Clinical trials

A Study of Olezarsen for the Treatment of Familial Chylomicronemia Syndrome (FCS) in Pediatric Participants

ATTUNE: A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Intrathecally-Administered ION440 in Participants With Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome (MDS)

Rocket Study: A Study to Characterize Biomarkers and Disease Progression in Participants With Pelizaeus-Merzbacher Disease

CHAMPION: A Study to Evaluate the Efficacy and Safety of Obudanersen (ION582) in Children and Adults With Angelman Syndrome (AS)

A Study to Assess the Safety, Tolerability and Efficacy of ION775

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

Donidalorsen Treatment in Children With Hereditary Angioedema

Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of ION464 Administered to Adults With Multiple System Atrophy (HORIZON)

Orbit Study: A Study to Evaluate the Safety, Pharmacokinetics, and Pharmacodynamics of Intrathecally Administered ION356 in Participants With Pelizaeus Merzbacher Disease (PMD)