A Study of Long-Term Safety and Efficacy of Lanadelumab for Prevention of Acute Attacks of Non-histaminergic Angioedema With Normal C1-Inhibitor

Open to people ages 12 years and up

• Males and females, 12 years of age and older diagnosed with non-histaminergic normal C1-INH angioedema at the time of enrollment into the antecedent Study SHP643-303 (NCT04206605).
• Participants must have completed the treatment period (through Visit 26/Day 182) of Study SHP643-303 (NCT04206605) without reporting a clinically significant TEAE that would preclude subsequent exposure to lanadelumab.
• Agree to adhere to the protocol-defined schedule of treatments, assessments, and procedures.
• Males, or non-pregnant, non-lactating females who are of child-bearing potential and who agree to be abstinent or agree to comply with the applicable contraceptive requirements of this protocol for the duration of the study; or females of non-childbearing potential, defined as surgically sterile (status post hysterectomy, bilateral oophorectomy, or bilateral tubal ligation) or post-menopausal for at least 12 months.
• The participant (or the participant's parent/legal guardian, if applicable) has provided written informed consent approved by the institutional review board/research ethics board/ethics committee (IRB/REB/EC) at any time prior to study start. If the participant is a minor (i.e. lesser then (<) 18 years of age), have a parent/legal guardian who is informed of the nature of the study provide written informed consent (i.e. permission) for the minor to participate in the study before any study-specific procedures are performed. Assent will be obtained from minor participants.

• Discontinued from Study SHP643-303 (NCT04206605) after enrollment but before Visit 26 for any reason.
• Presence of important safety concerns identified in Study SHP643-303 (NCT04206605) that would preclude participation in this study.
• Dosing with an investigational product (IP, not including IP defined in antecedent Study SHP643-303 [NCT04206605]) or exposure to an investigational device within 4 weeks prior to Day 0.
• Use of any estrogen-containing medications with systemic absorption (such as oral contraceptives or hormone replacement therapy) within 6 months prior to Day 0.
• Use of long-term prophylactic therapy for angioedema attacks, eg, C1-INH, attenuated androgens (e.g. danazol, methyltestosterone, testosterone), or anti-fibrinolytics within 2 weeks prior to Day 0.
• Have any active infectious illness or fever defined as an oral temperature greater than (>) 38°celsius [C] (100.4°Fahrenheit [F]), tympanic > 38.5°C (101.3°F), or axillary > 38°C (100.4°F), within 24 hours prior to the first dose of study drug on Day 0.
• Any of the following liver function test abnormalities: alanine aminotransferase (ALT) > 3 × the upper limit of normal (ULN), or aspartate aminotransferase (AST) > 3 × ULN, or total bilirubin > 2 × ULN (unless the bilirubin elevation is a result of Gilbert's syndrome).
• Participants has a known hypersensitivity to the investigational product or its components.
• Have any condition (surgical or medical) that, in the opinion of the investigator or sponsor, may compromise their safety or compliance, preclude the successful conduct of the study, or interfere with interpretation of the results (e.g. significant pre-existing illness or other major comorbidities that the investigator considers may confound the interpretation of study results).