A Study of Experimental ALXN1840 in Participants With Wilson Disease

Open to people ages 18 years and up

1. Diagnosis of WD by Leipzig Criteria ≥ 4 or by historical test results.
2. Continuous treatment for WD with penicillamine, trientine or zinc for at least 1 year prior to screening.
3. Body mass index < 30 kilograms/meter squared.
4. Able to cooperate with a percutaneous liver biopsy.
5. Willing and able to follow protocol-specified contraception requirements.
6. Capable of giving signed informed consent.

1. Decompensated cirrhosis or Model for End Stage Liver Disease score > 13.
2. Modified Nazer score > 7.
3. Clinically significant gastrointestinal bleed within past 3 months.
4. Alanine aminotransferase > 2 × upper limit of normal.
5. History of bleeding abnormality or known coagulopathy, including platelet count < 100,000, and international normalized ratio for prothrombin time ≥ 1.5.
6. Participant unwilling to accept blood products, if required.
7. Marked neurological disease requiring either nasogastric feeding tube or intensive inpatient medical care.
8. Hemoglobin less than lower limit of the reference range for age and sex.
9. Participants in renal failure, defined as in end-stage renal disease on dialysis (chronic kidney disease 5) or creatinine clearance < 30 milliliters/minute.
10. Lymphoma, leukemia, or any malignancy within the past 5 years.
11. Current or chronic history of liver disease not associated with WD.