Efficacy and Safety of ALXN1840 Administered for 48 Weeks Versus Standard of Care in Participants With Wilson Disease

Key Inclusion Criteria: * Established diagnosis of WD by Leipzig-Score ≥ 4 * Female participants of childbearing potential, if heterosexually active, must be willing to follow protocol-specified guidance for highly effective contraception starting at least 6 weeks before the Day 1 visit and continuing through 28 days after the last dose of either ALXN1840 or SoC * Male participants, if heterosexually active, must be willing to follow protocol-specified guidance for highly effective contraception beginning at Day 1 visit and continuing through 90 days after last dose of either ALXN1840 or SoC Key Exclusion Criteria: * Decompensated hepatic cirrhosis * MELD score \> 13 * Modified Nazer score \> 7 * Clinically significant gastrointestinal bleed within past 3 months * Alanine aminotransferase \> 2 X upper limit of normal (ULN) for participants treated for \> 28 days with WD therapy (Cohort 1) * Alanine aminotransferase \> 5 X ULN for treatment-naïve participants or participants who have been treated for ≤ 28 days (Cohort 2) * Marked neurological disease requiring either nasogastric feeding or intensive inpatient medical care * Hemoglobin \< 9 grams/deciliter * History of seizure activity within 6 months prior to informed consent * Pregnant (or women who are planning to become pregnant) or breastfeeding women * Active infection with hepatitis B virus (positive hepatitis B surface antigen) or C virus or seropositivity for human immunodeficiency virus (HIV) * Previous treatment w…