This research study of fazirsiran (FAZ-i-sir-an; also called TAK-999 or the “study drug”) because you have alpha-1 antitrypsin deficiency-associated liver disease (AATD LD) with METAVIR stage F2 to F4 fibrosis (METAVIR is a system used to score the amount of inflammation and fibrosis seen in a liver biopsy).In AATD, abnormal (Z-AAT) proteins build up in liver cells, leading to varying amounts of liver problems. The goal of treatment with fazirsiran is to prevent and improve the build up of these abnormal proteins that cause liver injury and fibrosis

-The total amount of time you may be involved in the study is about 4 ½ years (230 weeks).-Screening Period of up to 70 days.-Treatment Period of 196 weeks or about 4 years. During the study, you will get the study drug or placebo at the study site.-Follow-up Period of 6 months. You will have visits 6, 12, and 24 weeks after your last injection of the study drug or placebo.-You will have lung function tests (PFT and DLCO) to check how your lungs are workingAt every visit during the treatment period you will have:-Your vital signs will be measured, this includes your heart rate, blood pressure, breathing rate, temperature, and amount of oxygen in your blood.-You will have a brief physical exam.-Your weight will be measured.-You will have an ECG.-Collect lab samplesDuring specific study visits during the treatment period the following tests will be performed:-An abdominal ultrasound-FibroScan-CT scansYou will complete questionnaires.