Study to Learn About the Safety of Fazirsiran and if it Can Help People With Alpha-1 Antitrypsin Liver Disease With Mild Liver Scarring (Fibrosis)

DRUG

Fazirsiran Injection

Fazirsiran will be injected subcutaneously.

DRUG

Placebo

Fazirsiran matching placebo.

Number of Participants With Adverse Events (AEs) and Serious AEs (SAEs)

Time frame: From start of study drug administration up to End of study (EOS) (Week 124)

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of the study intervention, whether or not it is considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of the study intervention. An SAE is defined as any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, congenital anomaly/birth defect, suspected transmission of any infectious agent, an important medical event. AEs and SAEs including any pulmonary AEs or SAEs indicative of worsening pulmonary condition (example, pulmonary exacerbation, respiratory infection, significant pulmonary function test decline) will be reported.

Number of Participants With Clinically Significant Change From Baseline in Pulmonary Function Parameters

Time frame: From start of study drug administration up to EOS (Week 124)

Standard pulmonary function parameters will be used to study lung function. Clinical significance of pulmonary function parameters will be determined at the investigator's discretion.

Change From Baseline in Whole Lung 15th Percentile Density as Measured by Computed Tomography (CT) Lung Densitometry

Time frame: Baseline up to Week 100

Change from baseline in whole lung 15th percentile density as measured by CT lung densitometry will be assessed.

Number of Participants With Clinically Significant Changes in Vital Signs

Time frame: From start of study drug administration up to EOS (Week 124)

Vital signs include body temperature, respiratory rate, blood pressure (systolic and diastolic), pulse (beats per minute) and pulse oximetry. Clinical significance of vital signs will be determined at the investigator's discretion.

Number of Participants with Clinically Significant Changes in Electrocardiogram (ECG) Parameters

Time frame: From start of study drug administration up to EOS (Week 124)

12-lead ECG will be evaluated. Any clinically significant change in ECG assessments will be determined at the investigator's discretion.

Number of Participants With Clinically Significant Changes in Clinical Laboratory Parameters

Time frame: From start of study drug administration up to EOS (Week 124)

Laboratory parameters assessments include hematology, biochemistry including liver tests, coagulation, and urinalysis. Clinical significance of laboratory parameters will be determined at the investigator's discretion.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.