Copper Concentration & Histopathologic Changes in Liver Biopsy in Participants With Wilson Disease Treated With ALXN1840

Liver biopsy samples were taken for the assessment of liver Cu concentration. Multiple imputation was used to impute missing data at Week 48 due to any reason based on Baseline values.

Fibrosis from histology was evaluated by NASH CRN Fibrosis Stage, which was scaled from 0 to 4 stages where Score 0: None; Score 1: Perisinusoidal or periportal - 1a - mild, zone 3, perisinusoidal; Score 1: Perisinusoidal or periportal - 1b - moderate, zone 3, perisinusoidal; Score 1: Perisinusoidal or periportal - 1c - portal/periportal; Score 2: Both perisinusoidal and portal/periportal; Score 3: Bridging fibrosis; and Score 4: Cirrhosis. Higher scores indicated greater fibrosis.

Fibrosis from histology was evaluated by Metavir Fibrosis Score, which was ranged from 0 to 4 where Score 0: No fibrosis; Score 1: Stellate enlargement of portal tract but without septa formation; Score 2: Enlargement of portal tract with rare septa formation; Score 3: Numerous septa without cirrhosis; and Score 4: Cirrhosis. Higher scores indicated greater fibrosis.

Fibrosis from histology was evaluated by Ishak Fibrosis Score, which was ranged from 0 to 6 where Score 0: No fibrosis; Score 1: Fibrous expansion of some portal areas, with or without short fibrous septa; Score 2: Fibrous expansion of most portal areas, with or without short fibrous septa; Score 3: Fibrous expansion of most portal areas with occasional portal to portal (P-P) bridging; and Score 4: Fibrous expansion of portal areas with marked bridging (P-P) as well as portal central (P-C); Score 5: Marked bridging (P-P and/or P-C) with occasional nodules (incomplete cirrhosis); and Score 6: Cirrhosis, probable or definite. Higher scores indicated greater fibrosis.

Fibrosis from histology was evaluated by morphometric quantification of hepatic collagen content.

Fibrosis from histology was evaluated by morphometric quantification of hepatic a-SMA content.

Steatosis from histology was evaluated by the steatosis component of the NAS, which was ranged from 0 to 3 where Score 0: < 5% (minimal); Score 1: 5 - 33% (mild); Score 2: 34 - 66% (moderate); and Score 3: > 66% (severe). Higher scores indicated greater steatosis.

Steatosis from histology was evaluated by morphometric quantification of hepatic fat content.

Inflammation was quantified by the NAS total score. The score is defined as the unweighted sum of the scores for steatosis (0 [minimal] to 3 [severe]), lobular inflammation (0 [none] to 3 [>4 foci / 200x field]), and hepatocellular ballooning (0 [none] to 2 [many]), thus ranging from 0 (no inflammation) to 8 (severe inflammation), with higher scores indicating more severe disease.

An adverse event (AE) was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. An SAE was an AE that met at least 1 of the following criteria: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization for the AE, persistent or significant disability/incapacity or substantial disruption of the ability to conduct normal life functions, congenital anomaly/birth defect (in the child of a participant who was exposed to the study drug), important medical event or reaction. The TEAEs were AEs with onset on or after the first study drug dose. A summary of all Serious Adverse Events and Other Adverse Events (nonserious) regardless of causality is located in the 'Reported Adverse Events' Section.

An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. An SAE was an AE that met at least 1 of the following criteria: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization for the AE, persistent or significant disability/incapacity or substantial disruption of the ability to conduct normal life functions, congenital anomaly/birth defect (in the child of a participant who was exposed to the study drug), important medical event or reaction. The TEAEs were AEs with onset on or after the first study drug dose. A summary of all Serious Adverse Events and Other Adverse Events (nonserious) regardless of causality is located in the 'Reported Adverse Events' Section.

The CGI-I is a 7-point scale clinician assessment where 1= very much improved; 2 = much improved; 3 = minimally improved; 4 = no change; 5 = minimally worse; 6 = much worse; or 7 = very much worse. Higher scores indicated worsening of disease.

The CGI-S is a 7-point scale clinician assessment. Participants were assessed on severity of illness at the time of rating/assessment as follows: 1 = normal, not at all ill; 2 = borderline ill; 3 = mildly ill; 4 = moderately ill; 5 = markedly ill; 6 = severely ill; or 7 = extremely ill. Higher scores indicated worsening of disease.