Study to Check the Safety of Fazirsiran and Learn if Fazirsiran Can Help People With Liver Disease and Scarring (Fibrosis) Due to an Abnormal Version of Alpha-1 Antitrypsin Protein

Study Overview
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Brief Summary
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The main aim of this study is to learn if fazirsiran reduces liver scarring (fibrosis) compared to placebo. Other aims are to learn if fazirsiran slows down the disease worsening in the liver, to get information on how fazirsiran affects the body (called pharmacodynamics), to learn if fazirsiran reduces other liver injury (inflammation) and the abnormal Z-AAT protein in the liver, to get information on how the body processes fazirsiran (called pharmacokinetics), to test how well fazirsiran works compared with a placebo in improving measures of liver scarring including imaging and liver biomarkers (substances in the blood that the body normally makes and help show if liver function is improving, staying the same, or getting worse) as well as to check for side effects in participants treated with fazirsiran compared with those who received placebo. Participants will either receive fazirsiran or placebo. Liver biopsies, a way of collecting a small tissue sample from the liver, will be taken twice during this study.

Official Title
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A Randomized, Double-blind, Placebo-Controlled, Phase 3 Study to Evaluate the Efficacy and Safety of Fazirsiran in the Treatment of Alpha-1 Antitrypsin Deficiency-Associated Liver Disease With METAVIR Stage F2 to F4 Fibrosis

Conditions
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Alpha1-Antitrypsin Deficiency

Intervention / Treatment
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* Drug: Fazirsiran Injection
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: The participant must have a diagnosis of the Z allele homozygotes (PiZZ) genotype AATD. PiZZ diagnosis from source verifiable medical records is permitted. Otherwise, participants must undergo PiZZ confirmatory testing (genotyping for PiS and PiZ alleles) at screening. PiMZ or PiSZ genotypes are not permitted. The participant, of any sex, is aged 18 to 75 years, inclusive. The participant's liver biopsy core sample collected should meet the requirements of the protocol. The participant has evidence of METAVIR stage F2, F3, or F4 liver fibrosis, evaluated by a centrally read baseline liver biopsy during the screening period; or confirmed as meeting all the entry criteria by central reading of a previous biopsy conducted within 6 months before the estimated enrollment date using an adequate liver biopsy and slides as defined in the study laboratory manual. The participant has a pulmonary status meeting the protocol's requirements. It must be confirmed that the participant does not have HCC. Participants will be screened for HCC with alpha-fetoprotein (AFP) and abdominal ultrasound. If the participant has any of the following, they will be required to have contrast-enhanced CT or MRI imaging to exclude HCC before randomization. An adult participant must have a body mass index (BMI) between 18.0 and 39.0 kilograms per meter square (kg^m2), inclusive. The participant is a nonsmoker for at least 12 months before screening. Exclusion Criteria The participant has a history of liver decompensating events (overt hepatic encephalopathy [West Haven Grade >=2] documented by a physician, clinically significant ascites, spontaneous bacterial peritonitis, GI bleeding from varices, hepatopulmonary syndrome, hepatorenal syndrome, portal pulmonary hypertension, or portal gastropathy). The participant has a history of the presence of medium or large varices or varices with red wale signs based on a previous esophagogastroduodenoscopy (EGD) within 6 months before the estimated enrollment date. For certain participants, an EGD will be required at screening if there is no EGD available within 6 months before the estimated enrollment date. Presence of small varices with no red wale signs on EGD and no history of bleeding will be acceptable for study eligibility. The participant has evidence of other forms of chronic liver diseases, including viral hepatitis B or C, primary biliary cirrhosis, primary sclerosing cholangitis, Wilson disease, alcoholic hepatitis, hemochromatosis, liver cancer, history of biliary diversion, or autoimmune hepatitis. The participant has alanine transaminase (ALT) or aspartate transaminase (AST) levels >250 units per liter (U/L). The participant has a platelet count <60,000 per cubic millimeter (mm^3) (<60 × 10^9 per liter [10^9/L]). The participant has albumin <=2.8 gram per deciliter (g/dL) (28 grams per deciliter [g/L]). The participant has international normalized ratio (INR) >=1.7. The participant is expected to have severe and unavoidable high-level exposure to inhaled pulmonary toxins during the study such as may occur with occupational exposure to mineral dusts or metals. The participant has a history of drug abuse (such as cocaine, phencyclidine) within 1 year before the screening visit or has a positive urine drug screen at screening. The participant has previously been treated with fazirsiran or any other RNAi for AATD-LD. The participant has portal vein thrombosis. The participant has a prior transjugular portosystemic shunt procedure. The participant has a history of malignancy within the last 5 years, except for adequately treated basal cell carcinoma, squamous cell skin cancer, superficial bladder tumors, or in situ cervical cancer. Participants with other curatively treated malignancies who have no evidence of metastatic disease and a greater than 1-year disease-free interval may be entered after approval by the medical monitor.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Fazirsiran<br>Participants will receive fazirsiran 200 milligram per milliliter (mg/ml) subcutaneous (SC) injection on Day 1, at Week 4, and then every 12 weeks (Q12 W) thereafter up to Week 196. | Drug: Fazirsiran Injection<br>* Participants will receive fazirsiran 200 mg/ml SC injection on Day 1, at Week 4, and Q12 W thereafter up to Week 196.<br>* Other names: TAK-999, ARO-AAT, ADS-001;|
| Placebo Comparator: Placebo<br>Participants will receive placebo on Day 1, at Week 4, and Q12 W thereafter up to Week 196. | Other: Placebo<br>* Participants will receive placebo (sterile normal saline [0.9% NaCl]) SC injection on Day 1, at Week 4, and Q12 W thereafter up to Week 196.<br>* Other names: Sodium chloride;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduction From Baseline of at Least 1 Stage of Histologic Fibrosis (METAVIR Staging) in the Centrally Read Liver Biopsy at Week 106 in AATD-LD With METAVIR Stage F2 and F3 Fibrosis | Reduction from baseline of at least 1 stage of histologic fibrosis METAVIR staging in the centrally read liver biopsy at Week 106 in AATD-LD with METAVIR stage F2 and F3 fibrosis will be assessed. | Baseline, Week 106 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent Change from Baseline in Intrahepatic Z-AAT Protein in Alpha-1 Antitrypsin Deficiency-Associated Liver Disease (AATD-LD) with METAVIR Stage F2 to F3 Fibrosis at Week 106 | Percent change from baseline in intrahepatic Z-AAT protein in AATD-LD with METAVIR stage F2 to F3 fibrosis will be assessed. | Baseline, Week 106 | 
| Reduction From Baseline of at Least 1 Stage of Histologic Fibrosis (METAVIR Staging) in the Centrally Read Liver Biopsy | Reduction from baseline of at least 1 stage of histologic fibrosis (METAVIR Staging) in the centrally read liver biopsy in participants with AATD-LD with METAVIR stage fibrosis will be assessed. | Baseline, Week 106 and Week 202 | 
| Number of Participants With Liver Related Clinical Events up to Week 202 | Number of participants with any qualifying liver-related clinical events up to Week 202 in AATD-LD with METAVIR stage F2 to F4 fibrosis will be assessed. | Baseline up to Week 202 | 
| Change From Baseline in Serum Z-Alpha-1 Antitrypsin (Z-AAT) Protein | Change from baseline in serum Z-AAT protein in participants with AATD-LD with METAVIR stage fibrosis will be assessed. | Baseline, Week 106, Week 202 | 
| Change From Baseline in Intrahepatic Z-AAT Protein Polymer Burden Assessed by Periodic Acid Schiff Plus Diastase (PAS+D) Staining | Change from baseline in intrahepatic Z-AAT protein polymer burden assessed by PAS+D staining liver biopsy in participants with AATD-LD with METAVIR stage fibrosis will be assessed. | Baseline, Week 106, Week 202 | 
| Change From Baseline in Intrahepatic Portal Inflammation | Change from baseline in intrahepatic portal inflammation liver biopsy in participants with AATD-LD with METAVIR stage fibrosis will be assessed. | Baseline, Week 106, Week 202 | 
| Change From Baseline in Vibration-Controlled Transient Elastography (VCTE)/Magnetic Resonance Elastography (MRE)-derived Liver Stiffness | Change from baseline in VCTE/MRE-derived liver stiffness in participants with AATD-LD with METAVIR stage fibrosis will be assessed. | Baseline, Week 106, Week 196 and Week 202 | 
| Change From Baseline in Model of End-Stage Liver Disease (MELD) Score | The MELD scoring system is used to assess the severity of chronic liver disease. The MELD score is derived from the participant's serum total bilirubin, serum creatinine, and prothrombin international normalized ratio (INR): 3.78*log e serum bilirubin (milligram per deciliter [mg/dL]) + 11.20* log e INR + 9.57* log e serum creatinine (mg/dL) + 6.43 (constant for liver disease etiology). The MELD score ranges from 6 to 40 with higher scores indicating more severe liver disease and a worse outcome. Change from baseline in MELD score in participants with AATD-LD with METAVIR stage fibrosis will be assessed. | Baseline, Week 106, and Week 202 | 
| Change From Baseline in Liver Injury | Change from baseline in liver injury in participants with AATD-LD with METAVIR stage fibrosis will be assessed. | Baseline, Week 106 and Week 202 | 
| Percent Change from Baseline in Intrahepatic Z-AAT Protein in AATD-LD With METAVIR Stage F2 to F4 Fibrosis | Percent change from baseline in intrahepatic Z-AAT protein in AATD-LD with METAVIR stage F2 to F4 fibrosis will be assessed. | Baseline, Week 106 and Week 202 | 
| Observed Plasma Concentrations of Fazirsiran | Observed Plasma Concentrations of Fazirsiran will be assessed. | Pre-dose up to Week 196 | 
| Number of Participants with Treatment-emergent adverse event (TEAE) and Serious TEAEs | An AE is any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this investigational product (IP) or medicinal product. An SAE is any untoward medical occurrence that at any dose met one, more of the following criteria: results in death, life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent, significant disability/incapacity, a congenital abnormality/birth defect, an important medical event. A TEAE is any event emerging or manifesting at or after the initiation of treatment with an IP or medicinal product or any existing event that worsens in either intensity or frequency following exposure to the IP or medicinal product. Number of participants with TEAEs and serious TEAEs will be assessed. | From start of study drug administration up to end of the study (EOS) (Week 220) | 
| Number of Participants with Clinically Significant Declines in Lung Function Parameters | Standard pulmonary function parameters measured will be used to study lung function. | From start of study drug administration up to EOS (Week 220) | 
| Change From Baseline in Whole Lung PD15 (15th percentile point) Measured by CT lung Densitometry | Change from baseline in whole lung PD15 (15th percentile point) as measured by CT lung densitometry will be assessed. | Baseline up to EOS (Week 220) | 
| Number of Participants with Clinically Significant Change in Vital Signs | Vital signs will include body temperature, respiratory rate, blood pressure, pulse and amount of oxygen in the blood. Any change in vital signs which are deemed clinically significant by the investigator will be reported as AE. | From start of study drug administration up to EOS (Week 220) | 
| Number of Participants with Clinically Significant Changes in Electrocardiogram (ECG) Parameters | 12-lead ECG will be evaluated. Any change in ECG assessments which are deemed clinically significant by the investigator will be reported as AE. | From start of study drug administration up to EOS (Week 220) | 
| Number of Participants with Clinically Significant Changes in Clinical Laboratory Assessments | Clinical laboratory assessments include hematology, serum chemistry, coagulation, and urinalysis. Changes in laboratory values may be considered as AE if they were judged to be clinically significant. | From start of study drug administration up to EOS (Week 220) |