Trial to Evaluate ALN-CIDEB in Adults With Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Key Inclusion Criteria: 1. Has a clinical diagnosis of MASLD, as defined in the protocol 2. Has a liver stiffness measurement between 6 and 20 kilopascals (kPa), as measured by a FibroScan® scan during screening or within approximately 3 months of screening, as defined in the protocol Key Exclusion Criteria: 1. Has a known chronic liver disease other than MASLD, as determined by the investigator, as defined in the protocol 2. Has prior or current suspected or known drug-induced liver injury within approximately 1 year prior to screening 3. Has a history of liver transplantation, current placement on a liver transplant list, or Model for End-Stage Liver Disease (MELD) score \>12 4. Has a known history of alcohol or other substance abuse within the last year or at any time during screening based on investigator's discretion 5. Has prior, current, or planned future use (during the treatment period) of a GLP-1 receptor agonist-based therapy or any medication approved for the treatment of MASH (eg, resmetirom) unless used at a generally stable dose and regimen since at least 3 months prior to screening visit and throughout the screening period with no change to the dose or regimen anticipated during the treatment period, as defined in the protocol 6. Has evidence of uncontrolled human immunodeficiency virus (HIV) infection, hepatitis B virus (HBV) infection, or hepatitis C virus (HCV) infection during screening, as defined in the protocol NOTE: Other Protocol-defined Inclusion/Exclusion Criteria Apply