Donidalorsen Treatment in Children With Hereditary Angioedema
An Open-Label Study of Donidalorsen in Pediatric Patients Age 2 to Less Than 12 Years Old With Hereditary Angioedema
3 other identifiers
interventional
20
4 countries
6
Brief Summary
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).
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for phase_3
Started Jul 2026
Typical duration for phase_3
6 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
December 19, 2025
CompletedFirst Posted
Study publicly available on registry
December 23, 2025
CompletedStudy Start
First participant enrolled
July 1, 2026
ExpectedPrimary Completion
Last participant's last visit for primary outcome
June 1, 2029
Study Completion
Last participant's last visit for all outcomes
June 1, 2029
April 29, 2026
April 1, 2026
2.9 years
December 19, 2025
April 27, 2026
Conditions
Outcome Measures
Primary Outcomes (4)
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
over the period of approximately 17 months
Maximum Plasma Concentration (Cmax) of Donidalorsen
over the period of approximately 17 months
Maximum Time to Reach Cmax (Tmax) of Donidalorsen
over the period of approximately 17 months
Trough Plasma Concentration (Ctrough) of Donidalorsen
over the period of approximately 17 months
Secondary Outcomes (8)
Time-Normalized Number of Investigator-Confirmed HAE Attacks (per Month)
over the period of 12 months
Percentage of Investigator-Confirmed HAE Attack-free Participants
over the period of 12 months
Time-Normalized Number of Moderate or Severe Investigator-Confirmed HAE Attacks (per Month)
over the period of 12 months
Number of Participants with a Clinical Response Defined as a ≥ 50 Percent (%), ≥ 70% and ≥ 90% Reduction from Baseline in Investigator-Confirmed HAE Attack Rate
over the period of 12 months
Time-Normalized Number of Investigator-Confirmed HAE Attacks Requiring Rescue Treatment
over the period of 12 months
- +3 more secondary outcomes
Study Arms (3)
Donidalorsen: Group 1
EXPERIMENTALParticipant weighing 9 kilograms (kg) to less than (\<)26 kg, will be administered donidalorsen over the period of one year.
Donidalorsen: Group 2
EXPERIMENTALParticipant weighing greater than or equal to (≥)26 kg to \<41 kg, will be administered donidalorsen over the period of one year.
Donidalorsen: Group 3
EXPERIMENTALParticipant weighing ≥41kg, will receive donidalorsen over the period of one year.
Interventions
Donidalorsen will be administered by subcutaneous (SC) injection.
Eligibility Criteria
You may qualify if:
- Must be between the ages of 2 and less than 12 years, inclusive, at the time of informed consent and, as applicable, assent.
- Must weigh at least 9 kg at the time of informed consent and, as applicable, assent.
- Documented diagnosis of HAE-1/HAE-2 based upon both of the following:
- Documented clinical history consistent with HAE (SC or mucosal, non-pruritic swelling episodes without accompanying urticaria).
- Diagnostic testing results that confirm HAE-1/HAE-2: C1-inhibitor (C1-INH) functional level \<50% normal level AND complement factor C4 level below the lower limit of normal (LLN); OR a known pathogenic mutation in the SERPING1 gene.
You may not qualify if:
- Must not have been treated with another investigational drug, biological agent, or device within 1 month of Screening, or 5 half-lives of investigational agent, whichever is longer.
- Concurrent diagnosis of any other type of recurrent angioedema, including idiopathic angioedema or HAE with normal C1-INH (HAE-nC1-INH or Type III).
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (6)
Ionis Investigative Site
Santa Monica, California, 90404, United States
Ionis Investigative Site
St Louis, Missouri, 63141, United States
Ionis Investigative Site
Cincinnati, Ohio, 45236, United States
Ionis Investigative Site
Milan, 20157, Italy
Ionis Investigative Site
Warsaw, 04-501, Poland
Ionis Investigative Site
Barcelona, 08035, Spain
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 3
- Allocation
- NON RANDOMIZED
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
- Expanded Access
- Yes
Study Record Dates
First Submitted
December 19, 2025
First Posted
December 23, 2025
Study Start (Estimated)
July 1, 2026
Primary Completion (Estimated)
June 1, 2029
Study Completion (Estimated)
June 1, 2029
Last Updated
April 29, 2026
Record last verified: 2026-04
Data Sharing
- IPD Sharing
- Will share
Ionis may share anonymized individual participant data, aggregated clinical data, and other types of data that support the results in this study. Data requests from qualified researchers will be considered once all three of the following criteria are met: (1) 12 months from marketing approval of the study drug in both the United States and European Union; (2) 18 months from conclusion of the study; and (3) 6 months from publication of study article. Access would be via a secure environment and is contingent upon approval of a research proposal and entry into an appropriate data use agreement. Requests to access data can be submitted via the website https://vivli.org/ourmember/ionis/.