Donidalorsen for children with hereditary angioedema

An Open-Label Study of Donidalorsen in Pediatric Patients Age 2 to Less Than 12 Years Old With Hereditary Angioedema

This trial tests if donidalorsen is safe and how it is processed in the body for children aged 2 to under 12 with hereditary angioedema types I or II.

Quick facts

• Phase: Phase 3
• Study type: Interventional
• Enrollment: 20 (estimated)
• Ages: 2 Years to 11 Years
• Sex: All
• Sponsor: Ionis Pharmaceuticals, Inc. (Industry-sponsored)
• Locations: 6 sites (Santa Monica, California and 5 other locations)
• Trial ID: NCT07298447 on ClinicalTrials.gov

What this trial studies

This open-label Phase 3 trial gives donidalorsen to pediatric participants aged 2 to less than 12 years with HAE type I or II and follows them for safety, efficacy, pharmacokinetics, and pharmacodynamics. The protocol includes a 3-month screening period, a one-year treatment period, and a 3-month post-treatment follow-up. Eligibility requires confirmed HAE by low C1‑INH functional level and low C4 (or a known SERPING1 mutation) and a minimum weight of 9 kg. Dosing and monitoring visits occur at Ionis investigational sites in Santa Monica, CA; St. Louis, MO; and Cincinnati, OH.

Who should consider this trial

Good fit: Children aged 2 to under 12 years who weigh at least 9 kg and have confirmed HAE type I or II by low C1‑INH function and low C4 (or a pathogenic SERPING1 mutation) are ideal candidates.

Not a fit: Children outside the age or weight limits, those without confirmed HAE-1/2, those with clinically significant screening laboratory abnormalities, or those recently treated with other investigational agents may not benefit or be eligible.

Why it matters

Potential benefit: If successful, donidalorsen could provide a safe preventive option that lowers attack frequency and treatment burden for young children with HAE.

How similar studies have performed: Other approved HAE therapies and kallikrein-pathway approaches have shown benefit in older patients, but donidalorsen's use in young children is relatively novel.

Eligibility criteria

Key Inclusion Criteria:

1. Must be between the ages of 2 and less than 12 years, inclusive, at the time of informed consent and, as applicable, assent.
2. Must weigh at least 9 kg at the time of informed consent and, as applicable, assent.
3. Documented diagnosis of HAE-1/HAE-2 based upon both of the following:

   1. Documented clinical history consistent with HAE (SC or mucosal, non-pruritic swelling episodes without accompanying urticaria).
   2. 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.

Key Exclusion Criteria:

1. Must not have any screening laboratory abnormalities or any other clinically significant abnormalities during screening that would render a participant unsuitable for inclusion.
2. 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.
3. Concurrent diagnosis of any other type of recurrent angioedema, including idiopathic angioedema or HAE with normal C1-INH (HAE-nC1-INH or Type III).

Note: Other protocol-specified inclusion/exclusion criteria may apply.

Where this trial is running

Santa Monica, California and 5 other locations

• Ionis Investigative Site — Santa Monica, California, United States (Recruiting)
• Ionis Investigative Site — St Louis, Missouri, United States (Recruiting)
• Ionis Investigative Site — Cincinnati, Ohio, United States (Recruiting)
• Ionis Investigative Site — Milan, Italy (Recruiting)
• Ionis Investigative Site — Warsaw, Poland (Recruiting)
• Ionis Investigative Site — Barcelona, Spain (Recruiting)

Study contacts

• Study coordinator: Ionis Pharmaceuticals, Inc.

Conditions Hereditary Angioedema