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

Inclusion Criteria:

• Able and willing to understand and sign a written informed consent form (ICF) thatmust be obtained prior to the initiation of study procedures

• Age >=18 through <=75 years at enrolment

• History or presence of 2 or more of the 5 components of metabolic syndrome perAmerican Heart Association definition

• History or presence of known or suspected MASH with evidence of fibrosis

Exclusion Criteria:

• ALT or AST >=5 × upper limit of normal (ULN)

• Total bilirubin (BILI) >=1.3 milligram per deciliter (mg/dL). Individuals withdocumented Gilbert's syndrome may be enrolled if they experienced an isolatedincrease in total BILI of >=1.3 mg/dL and direct BILI is <=20% of total BILI;otherwise, the individual will be excluded.

• Serum albumin <=3.5 grams per deciliter (g/dL)

• International normalized ratio (INR) >=1.3 not due to therapeutic anticoagulation.Individuals receiving chronic anticoagulant treatment with higher INR values may beenrolled at the discretion of the Investigator and Study Medical Monitor.

• Alkaline phosphatase (ALP) >=2 × ULN

• Platelet (PLT) count <140 000 per (/) cubic millimeter (mm^3); individuals with aPLT count between 110,000/mm^3 and 140,000/mm^3 may be enrolled after discussionwith the Study Medical Monitor

• Serum creatinine >=1.5 mg/dL or creatinine clearance <=60 milliliter (mL)/minute (min)/1.73 square meter by Chronic Kidney Disease Epidemiology Collaborationequation.

• Alpha-fetoprotein >=20 nanogram per milliliter (ng/mL)

• HbA1c >=9.0%

• Model for End-Stage Liver Disease (MELD) 3.0 score >=12 unless the score is elevatedin 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. HepatitisE virus.

• Chronic liver disease from any other cause including, but not limited to, alcoholicliver disease; evidence of portal hypertension; viral hepatitis, or any history orevidence of cirrhosis; or decompensated liver disease such as clinical ascites,bleeding gastroesophageal varices, hepatorenal syndrome, or hepatic encephalopathyprior to Screening or Day 1.

• Current or history of excessive alcohol intake for >=3 months within the 12-monthperiod prior to Screening