A Clinical Study to Investigate the Safety and Tolerability of Efimosfermin Alfa Injection in Participants With Known or Suspected F2- or F3-stage MASH

This study will evaluate the safety and tolerability of Efimosfermin Alfa for participants with known or suspected MASH with fibrosis consistent with stage F2 or F3.

Inclusion Criteria: * Able and willing to understand and sign a written informed consent form (ICF) that must be obtained prior to the initiation of study procedures * Age \>=18 through \=5 × upper limit of normal (ULN) * Total bilirubin (BILI) \>=1.3 milligram per deciliter (mg/dL). Individuals with documented Gilbert's syndrome may be enrolled if they experienced an isolated increase in total BILI of \>=1.3 mg/dL and direct BILI is \=2 × ULN * Platelet (PLT) count \=1.5 mg/dL or creatinine clearance \=20 nanogram per milliliter (ng/mL) * HbA1c \>=9.0% * Model for End-Stage Liver Disease (MELD) 3.0 score \>=12 unless the score is elevated in the absence of liver dysfunction (eg, Gilbert's syndrome) * Phosphatidylethanol (PEth) \>=80 nanogram per milliliter (ng/mL) at Screening * Known co-infection with any of the following: a. Human immunodeficiency virus; b. Hepatitis B virus; c. Hepatitis C virus (HCV); d. Hepatitis D virus; or e. Hepatitis E virus. * Chronic liver disease from any other cause including, but not limited to, alcoholic liver disease; evidence of portal hypertension; viral hepatitis, or any history or evidence of cirrhosis; or decompensated liver disease such as clinical ascites, bleeding gastroesophageal varices, hepatorenal syndrome, or hepatic encephalopathy prior to Screening or Day 1. * Current or history of excessive alcohol intake for \>=3 months within the 12-month period prior to Screening