Study to Evaluate Adverse Events and Change in Disease Activity in Adult and Adolescent Participants With Acute Hepatitis C Virus (HCV) Infection on Treatment With Oral Tablets of Glecaprevir (GLE)/Pibrentasvir (PIB)

Inclusion Criteria:

• Evidence of acute HCV infection prior to enrollment, defined as a physiciandiagnosis of acute HCV infection, quantifiable HCV ribonucleic Acid (RNA) atscreening, and at least 1 of the following:

• Negative anti-HCV antibody, HCV RNA and/or HCV core antigen followed by apositive HCV RNA or HCV core antigen all within an 8-month period prior toscreening; OR

• Negative anti-HCV antibody, HCV RNA and/or HCV core antigen followed by apositive HCV RNA or HCV core antigen all within an 11-month period prior toscreening; AND risk behavior for HCV infection within 6 months prior topositive HCV RNA or HCV core antigen; OR

• Clinical signs and symptoms compatible with acute hepatitis [alanineaminotransferase (ALT) > 5 × upper limit of normal (ULN) and/or jaundice] inthe absence of a history of chronic liver disease or other cause of acutehepatitis and positive HCV RNA or HCV core antigen all within an 8-month periodprior to screening; AND risk behavior for HCV infection within 6 months priorto positive HCV RNA or HCV core antigen; OR

• Negative anti-HCV antibody with a positive HCV RNA or HCV core antigen within a 5-month period prior to screening.

• Absence of hepatocellular carcinoma (HCC), for participants with cirrhosis, or withindeterminate cirrhosis status, as indicated by a negative ultrasound, computedtomography (CT) scan or magnetic resonance imaging (MRI) within 3 months prior toscreening or a negative ultrasound at screening. Participant who has a positiveultrasound result suspicious of HCC followed by a subsequent negative CT scan or MRIor biopsy result will be eligible for the study.

• Participants documented as having no cirrhosis or as having compensated cirrhosis.

Exclusion Criteria:

• Participants with prior treatment, including interferon for this HCV infection.

• History of liver decompensation.