The purpose of this version is to correct minor clerical errors for consistency and edits for clarification throughout the protocol in addition to the following: - Modify and clarify eligibility criteria: - Total bilirubin parameter was removed as an eligibility criterion. - Addition of cholestatic liver disease such as primary biliary cholangitis and primary sclerosing cholangitis to list of examples of causes for liver disease. - Added an allowance for retesting for hemoglobin or calculated creatinine clearance if initial test is exclusionary. - Appendix D Activity Schedule – activity visits after Baseline are indicated only by week for clarity. - Section 6.1 - Clarified procedure for reporting pregnancy in a study subject. - The following modifications were made due to the COVID-19 pandemic: - Section 2.2 – noted the re-evaluation of the benefit and risks to subjects participating in the study. - Section 5.1 – added rescreening criteria for subjects who had a SARS-CoV-2 infection. - Section 5.4 – added COVID-19 pandemic-related vaccination guidance. - Section 5.5 – added information on COVID-19 pandemic-related mitigation strategies for discontinuation of subjects from the study. - Section 5.7 – included instructions that in the event the subject cannot pick up study drug onsite, refer to the Operations Manual for DTP shipment as needed and permitted by local regulations. - Section 5.9 – clarified that protocol deviations may include modifications due to COVID-19. - Section 8.2 – added information that AbbVie should be notified if any urgent safety measures are taken. - Section 9 – noted that remote monitoring may be employed as needed.

(continued) - Appendix F - Operations Manual updated to include details on how to perform specific activities/procedures due to the COVID-19 pandemic, including use of phone/virtual visits, visits at alternative locations, or changes in frequency or timing of study procedures, DTP shipment of study drug and other study supplies as allowed, and supplemental eCRFs required in the event of a COVID-19 related SAE.

The purpose of this version is to incorporate the following: - Modify eligibility criteria: - Contraception language was modified to widen the criteria in Section 5.2. - Modify clinical laboratory tests required: - Estimated glomerular filtration rate (Modification of Diet in Renal Disease equation) was added to the table of clinical laboratory tests in the Operations Manual (Appendix F).

The purpose of this version is to correct minor clerical errors for consistency throughout the protocol in addition to the following: - Section 5.1: Removed weight restriction from eligibility criteria for adolescents 12 years and older. - Section 5.1: Modified text regarding who should undergo viral testing to rule out SARS-CoV-2 infection. - Section 5.1: Modified text for eligibility criteria regarding subjects who are enrolled in another clinical study. - Section 5.2: Clarified contraception requirements for males. - Operations Manual (Appendix F): Added text describing pregnancy testing. - Operations Manual (Appendix F): Replaced clinical laboratory name of Covance CLS with Labcorp Central Laboratory Services Limited Partnership. - Section 5.2: Clarified contraception requirements for females. - Section 6.1 and Operations Manual (Appendix F): Added text to define methods/contact information for reporting product complaints. - Operations Manual (Appendix F): Added text regarding storage of study drug. - Update information as per Administrative Change 1 dated 01 June 2021: - Modified text in the diagram in Section 4.1 of the Operations Manual (Appendix F). - Added a footnote to Table 1 in the Operations Manual (Appendix F).

The purpose of this version is to correct minor clerical errors for consistency throughout the protocol in addition to the following: - Title page: Added Sponsor name for EU countries. - Section 5.1: Added text to Eligibility Criterion 5 to indicate that subjects must have quantifiable HCV RNA at Screening. - Section 5.1: Added bictegravir to Eligibility Criterion 9 as a permitted ART. - Section 5.1: Added instructions to Eligibility Criterion 11 for determining absence of decompensated cirrhosis. - Section 5.1: Added text to Eligibility Criterion 12 to indicate that subjects with indeterminate cirrhosis status must demonstrate absence of HCC. - Section 5.1: Edited text in Eligibility Criterion 23 to update the length of time that subjects must not have been treated with any investigational drug prior to the first dose of study drug. - Section 5.3: Added text to describe timing of discontinuation of prohibited medications and to indicate that concomitant use of certain medications is not allowed. - Section 5.7: Added text to describe handling of study drug upon completion or discontinuation from study treatment. - Section 5.7 and Section 6.1: Added text and table to define study drugs. - Section 6.1: Added text to describe collection of SAEs after 30 days following last dose of study drug or completion of study treatment. - Section 7.4: Added subgroups to the list for analysis of efficacy. -Section 11: Added definition of study start and updated definition of end-of-study. - Appendix B: Added text describing reporting responsibilities of the investigator. - Appendix C and Appendix F: Modified the list of protocol signatories. - Appendix F: Removed collection of respiratory rate. - Appendix F: Updated Section 1 contact information. - Appendix F: Added text to describe testing procedures for subjects with indeterminate cirrhosis status.