A Study to Assess the Long-Term Safety and Efficacy of Donidalorsen in the Prophylactic Treatment of Hereditary Angioedema (HAE)

Exclusion Criteria

• •Open-Label Extension Participants:
• •1. Have any new condition or worsening of an existing condition or change or anticipated change in medication.
• •New (not previously on donidalorsen) Participants ONLY:
• •2. Concurrent diagnosis of any other type of recurrent angioedema, including acquired, idiopathic angioedema or HAE with normal C1-INH (also known as HAE Type III).
• •3. Anticipated change in the use of concurrent androgen or tranexamic acid prophylaxis used to prevent angioedema attacks.
• •4. Any clinically-significant abnormalities in screening laboratory values.
• •5. Malignancy within 5 years of Screening, except for non-melanoma skin cancers, cervical in situ carcinoma, breast ductal carcinoma in situ, or stage 1 prostate carcinoma that has been successfully treated.
• •6. Hypersensitivity to the active substance (donidalorsen) or to any of the excipients.
• •7. Treatment with another investigational drug (non-oligonucleotide) or biological agent within 1 month of Screening or 5 half-lives of investigational agent, whichever is longer.
• •8. Recent history of, or current drug or alcohol abuse.
• •9. Participated in a prior donidalorsen study.
• •10. Exposure to any of the following medications:
• •1. Angiotensin-converting enzyme (ACE) inhibitors or any estrogen containing medications with systemic absorption.
• •2. Oligonucleotides (including small interfering ribonucleic acid \[siRNA\]) within 4 months of Screening if single dose received, or within 12 months of Screening if multiple doses received. This exclusion does not apply to vaccines.