The FIB 4 score evaluates the degree of fibrosis in patients suspected of or already diagnosed with hepatic fibrosis. FIB-4 is calculated as (Age (years) * aspartate aminotransferase) / (platelets * √(ALT)).

The result provided from the above equation is interpreted according to 2 cut off values: FIB 4 <1.45 indicates absence of cirrhosis (with a negative predictive value of 90% for advanced fibrosis); FIB 4 between 1.45 - 3.25 are deemed inconclusive; FIB 4 >3.25 indicates cirrhosis (with a positive predictive value of 65% for advanced fibrosis).

The FIB 4 score evaluates the degree of fibrosis in patients suspected of or already diagnosed with hepatic fibrosis. FIB-4 is calculated as (Age (years) * aspartate aminotransferase) / (platelets * √(ALT)).

The result provided from the above equation is interpreted according to 2 cut off values: FIB 4 <1.45 indicates absence of cirrhosis (with a negative predictive value of 90% for advanced fibrosis); FIB 4 between 1.45 - 3.25 are deemed inconclusive; FIB 4 >3.25 indicates cirrhosis (with a positive predictive value of 65% for advanced fibrosis).

The APRI suggests the level of hepatic fibrosis and possible liver disease. APRI is calculated as 100*(aspartate aminotransferase/40) / platelets. Scores indicate the following: < 0.5 = fibrosis is ruled out; 0.5 - 0.7 = associated with some kind of liver damage; 0.7 - 1 = significant fibrosis; > 1 = associated with cirrhosis.

The APRI suggests the level of hepatic fibrosis and possible liver disease. APRI is calculated as 100*(aspartate aminotransferase/40) / platelets. Scores indicate the following: < 0.5 = fibrosis is ruled out; 0.5 - 0.7 = associated with some kind of liver damage; 0.7 - 1 = significant fibrosis; > 1 = associated with cirrhosis.

PRO-C3 may be a biomarker for the formation of fibrotic tissue in the liver. For serum, the normal range is 6.1 - 13.8 ng/mL (based on a study of human serum samples from healthy men and women). Due to ethnic, dietary and age variations, the reference limits given may not apply to all populations. A reduction in Pro-C3 over time may indicate a reduction in hepatic fibrogenesis.

PRO-C3 may be a biomarker for the formation of fibrotic tissue in the liver. For serum, the normal range is 6.1 - 13.8 ng/mL (based on a study of human serum samples from healthy men and women). Due to ethnic, dietary and age variations, the reference limits given may not apply to all populations. A reduction in Pro-C3 over time may indicate a reduction in hepatic fibrogenesis.

FibroScan is a type of liver elastography. Normal results are usually between 2 and 7 kilopascals (kPa), with results higher than the normal range if liver disease is present. The highest possible result is 75 kPa.

FibroScan is a type of liver elastography. Normal results are usually between 2 and 7 kilopascals (kPa), with results higher than the normal range if liver disease is present. The highest possible result is 75 kPa.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of portal inflammation, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of portal inflammation, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of interface hepatitis, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of interface hepatitis, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of lobular inflammation, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of lobular inflammation, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1- point worsening from the baseline category in the liver biopsy parameter of hepatocyte cell death. Hepatocyte Cell Death Score: 0 = No acidophil bodies; 1 = Few acidophil bodies; 2 = Many acidophil. Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of hepatocyte cell death. Hepatocyte Cell Death Score: 0 = No acidophil bodies; 1 = Few acidophil bodies; 2 = Many acidophil. Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1- point worsening from the baseline category in the METAVIR fibrosis stage score. The METAVIR scoring system is a system used to assess the extent of inflammation and fibrosis by histopathological evaluation in a liver biopsy of patients with hepatitis C. The stage represents the amount of fibrosis or scarring. Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

F0: no fibrosis F1: portal fibrosis without septa F2: portal fibrosis with few septa F3: numerous septa without cirrhosis F4: cirrhosis

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1- point worsening from the baseline category in the METAVIR fibrosis stage score. The METAVIR scoring system is a system used to assess the extent of inflammation and fibrosis by histopathological evaluation in a liver biopsy of patients with hepatitis C. The stage represents the amount of fibrosis or scarring. Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

F0: no fibrosis F1: portal fibrosis without septa F2: portal fibrosis with few septa F3: numerous septa without cirrhosis F4: cirrhosis

An Adverse Event (AE) is any untoward medical occurrence which does not necessarily have to have a causal relationship with this treatment. Serious Adverse Event (SAE) is an AE that results in death, is life-threatening, requires inpatient hospitalization or prolongation of an existing hospitalization, results in persistent or significant disability/incapacity, Is a congenital anomaly/birth defect, Is a medically important event or reaction. TEAEs are AEs with onset after administration of the study drug, or when a preexisting medical condition increases in severity or frequency after study drug administration. Not related events include those reported as 'Not Related' to study drug. Related events include those reported as 'Possibly Related' or 'Probably Related' to study drug.

Primary Study Period (6-12 months): 200 mg dose of subcutaneous ARO-AAT for a minimum of 3 doses, with 2 optional treatment extension periods. Treatment Extension I (12 months): 200 mg dose of subcutaneous ARO-AAT Q12W. Treatment Extension II (up to 24 Months): 200 mg dose of subcutaneous ARO-AAT Q12W.

The maximum number of doses for participants completing the treatment extension periods was 15 doses.

Primary Study Period (6-12 months): 200 mg dose of subcutaneous ARO-AAT for a minimum of 5 doses, with optional treatment extension periods. Treatment Extension I (12 months): 200 mg dose of subcutaneous ARO-AAT Q12W. Treatment Extension II (up to 24 months): 200 mg dose of subcutaneous ARO-AAT Q12W.

The maximum number of doses for participants completing the treatment extension periods was 17 doses.

Total of all reporting groups

Primary Study Period (6-12 months): 200 mg dose of subcutaneous ARO-AAT for a minimum of 3 doses, with 2 optional treatment extension periods. Treatment Extension I (12 months): 200 mg dose of subcutaneous ARO-AAT Q12W. Treatment Extension II (up to 24 Months): 200 mg dose of subcutaneous ARO-AAT Q12W.

The maximum number of doses for participants completing the treatment extension periods was 15 doses.

Full Analysis Set: all participants who received at least one dose of study drug and had baseline and post-dose liver biopsy histology results available. Participants with an assessment at given time point.

Full Analysis Set: all participants who received at least one dose of study drug and had baseline and post-dose liver biopsy histology results available.

Full Analysis Set: all participants who received at least one dose of study drug and had baseline and post-dose liver biopsy histology results available.

Safety Analysis Set: all participants who received at least one dose of study drug. Participants with an assessment at given time point.

Safety Analysis Set: all participants who received at least one dose of study drug. Participants with an assessment at given time point.

Safety Analysis Set: all participants who received at least one dose of study drug; n=participants with an assessment at given time point. Participants with an assessment at given time point.

Safety Analysis Set: all participants who received at least one dose of study drug; n=participants with an assessment at given time point. Participants with an assessment at given time point.

The FIB 4 score evaluates the degree of fibrosis in patients suspected of or already diagnosed with hepatic fibrosis. FIB-4 is calculated as (Age (years) * aspartate aminotransferase) / (platelets * √(ALT)).

The result provided from the above equation is interpreted according to 2 cut off values: FIB 4 <1.45 indicates absence of cirrhosis (with a negative predictive value of 90% for advanced fibrosis); FIB 4 between 1.45 - 3.25 are deemed inconclusive; FIB 4 >3.25 indicates cirrhosis (with a positive predictive value of 65% for advanced fibrosis).

Safety Analysis Set: all participants who received at least one dose of study drug. Participants with an assessment at given time point.

The FIB 4 score evaluates the degree of fibrosis in patients suspected of or already diagnosed with hepatic fibrosis. FIB-4 is calculated as (Age (years) * aspartate aminotransferase) / (platelets * √(ALT)).

The result provided from the above equation is interpreted according to 2 cut off values: FIB 4 <1.45 indicates absence of cirrhosis (with a negative predictive value of 90% for advanced fibrosis); FIB 4 between 1.45 - 3.25 are deemed inconclusive; FIB 4 >3.25 indicates cirrhosis (with a positive predictive value of 65% for advanced fibrosis).

Safety Analysis Set: all participants who received at least one dose of study drug. Participants with an assessment at given time point.

The APRI suggests the level of hepatic fibrosis and possible liver disease. APRI is calculated as 100*(aspartate aminotransferase/40) / platelets. Scores indicate the following: < 0.5 = fibrosis is ruled out; 0.5 - 0.7 = associated with some kind of liver damage; 0.7 - 1 = significant fibrosis; > 1 = associated with cirrhosis.

Safety Analysis Set: all participants who received at least one dose of study drug. Participants with an assessment at given time point.

The APRI suggests the level of hepatic fibrosis and possible liver disease. APRI is calculated as 100*(aspartate aminotransferase/40) / platelets. Scores indicate the following: < 0.5 = fibrosis is ruled out; 0.5 - 0.7 = associated with some kind of liver damage; 0.7 - 1 = significant fibrosis; > 1 = associated with cirrhosis.

Safety Analysis Set: all participants who received at least one dose of study drug. Participants with an assessment at given time point.

PRO-C3 may be a biomarker for the formation of fibrotic tissue in the liver. For serum, the normal range is 6.1 - 13.8 ng/mL (based on a study of human serum samples from healthy men and women). Due to ethnic, dietary and age variations, the reference limits given may not apply to all populations. A reduction in Pro-C3 over time may indicate a reduction in hepatic fibrogenesis.

Safety Analysis Set: all participants who received at least one dose of study drug.

PRO-C3 may be a biomarker for the formation of fibrotic tissue in the liver. For serum, the normal range is 6.1 - 13.8 ng/mL (based on a study of human serum samples from healthy men and women). Due to ethnic, dietary and age variations, the reference limits given may not apply to all populations. A reduction in Pro-C3 over time may indicate a reduction in hepatic fibrogenesis.

Safety Analysis Set: all participants who received at least one dose of study drug.

FibroScan is a type of liver elastography. Normal results are usually between 2 and 7 kilopascals (kPa), with results higher than the normal range if liver disease is present. The highest possible result is 75 kPa.

Safety Analysis Set: all participants who received at least one dose of study drug.

FibroScan is a type of liver elastography. Normal results are usually between 2 and 7 kilopascals (kPa), with results higher than the normal range if liver disease is present. The highest possible result is 75 kPa.

Safety Analysis Set: all participants who received at least one dose of study drug. Participants with an assessment at given time point.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of portal inflammation, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Safety Analysis Set: all participants who received at least one dose of study drug.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of portal inflammation, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Safety Analysis Set: all participants who received at least one dose of study drug.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of interface hepatitis, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Safety Analysis Set: all participants who received at least one dose of study drug.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of interface hepatitis, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Safety Analysis Set: all participants who received at least one dose of study drug.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of lobular inflammation, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Safety Analysis Set: all participants who received at least one dose of study drug.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of lobular inflammation, which was scored on a scale from 0 (none) to 3 (severe). Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Safety Analysis Set: all participants who received at least one dose of study drug.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1- point worsening from the baseline category in the liver biopsy parameter of hepatocyte cell death. Hepatocyte Cell Death Score: 0 = No acidophil bodies; 1 = Few acidophil bodies; 2 = Many acidophil. Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Safety Analysis Set: all participants who received at least one dose of study drug.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1-point worsening from the baseline category in the liver biopsy parameter of hepatocyte cell death. Hepatocyte Cell Death Score: 0 = No acidophil bodies; 1 = Few acidophil bodies; 2 = Many acidophil. Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

Safety Analysis Set: all participants who received at least one dose of study drug.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1- point worsening from the baseline category in the METAVIR fibrosis stage score. The METAVIR scoring system is a system used to assess the extent of inflammation and fibrosis by histopathological evaluation in a liver biopsy of patients with hepatitis C. The stage represents the amount of fibrosis or scarring. Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

F0: no fibrosis F1: portal fibrosis without septa F2: portal fibrosis with few septa F3: numerous septa without cirrhosis F4: cirrhosis

Safety Analysis Set: all participants who received at least one dose of study drug. Participants with an assessment at the given time point.

Percent of participants having ≥ 1-point improvement from baseline, no change from baseline, and ≥ 1- point worsening from the baseline category in the METAVIR fibrosis stage score. The METAVIR scoring system is a system used to assess the extent of inflammation and fibrosis by histopathological evaluation in a liver biopsy of patients with hepatitis C. The stage represents the amount of fibrosis or scarring. Participants with a baseline score of 0 were not included in any of the 3 categories for this analysis.

F0: no fibrosis F1: portal fibrosis without septa F2: portal fibrosis with few septa F3: numerous septa without cirrhosis F4: cirrhosis

Safety Analysis Set: all participants who received at least one dose of study drug.

An Adverse Event (AE) is any untoward medical occurrence which does not necessarily have to have a causal relationship with this treatment. Serious Adverse Event (SAE) is an AE that results in death, is life-threatening, requires inpatient hospitalization or prolongation of an existing hospitalization, results in persistent or significant disability/incapacity, Is a congenital anomaly/birth defect, Is a medically important event or reaction. TEAEs are AEs with onset after administration of the study drug, or when a preexisting medical condition increases in severity or frequency after study drug administration. Not related events include those reported as 'Not Related' to study drug. Related events include those reported as 'Possibly Related' or 'Probably Related' to study drug.

Safety Analysis Set: all participants who received at least one dose of study drug.

Primary Study Period (6-12 months): 200 mg dose of subcutaneous ARO-AAT for a minimum of 3 doses, with 2 optional treatment extension periods. Treatment Extension I (12 months): 200 mg dose of subcutaneous ARO-AAT Q12W. Treatment Extension II (up to 24 Months): 200 mg dose of subcutaneous ARO-AAT Q12W.

The maximum number of doses for participants completing the treatment extension periods was 15 doses.

Primary Study Period (6-12 months): 200 mg dose of subcutaneous ARO-AAT for a minimum of 5 doses, with optional treatment extension periods. Treatment Extension I (12 months): 200 mg dose of subcutaneous ARO-AAT Q12W. Treatment Extension II (up to 24 months): 200 mg dose of subcutaneous ARO-AAT Q12W.

The maximum number of doses for participants completing the treatment extension periods was 17 doses.