Sequential PEG-IFN for HBV After Ending RNA-targeted Regimens

The goal of this clinical trial is to compare sequential PEG-IFNα therapy strategies in chronic hepatitis B (CHB) patients previously treated with ASO/siRNA. The main questions it aims to answer are:

1. Does sequential PEG-IFNα therapy (vs. deferred/no treatment) improve HBsAg clearance rates? 2. What are the HBsAg clearance and relapse rates after 24 weeks of PEG-IFNα therapy? 3. Is intermittent PEG-IFNα therapy as effective and safe as continuous therapy?

Researchers will compare:

• Group A (immediate 24-week PEG-IFNα + 24-week follow-up) vs. Group B (24-week observation + 24-week PEG-IFNα) in Phase 1 to see if sequential PEG-IFNα therapy will improve HBsAg loss rate .

Researchers will describe:

* The response rate of IFN treatment in non-responders (HBsAg-positive) in Phase 2. * The relaspe rate of responders (HBsAg-negative).

Participants will:

Phase 1 (0-48 weeks):

* Group A: Receive PEG-IFNα for 24 weeks, followed by 24-week treatment-free follow-up. * Group B: Undergo 24-week observation, then receive PEG-IFNα for 24 weeks.

Phase 2 (48-96 weeks):

* HBsAg-positive at week 48 patients either from group A or group B : Receive 24-week PEG-IFNα therapy, followed by 24-week follow-up. * HBsAg-negative at week 48 patients either from group A or group B: Enter 24-week follow-up without treatment.

All participants will undergo:

• HBsAg quantification, HBV DNA, liver function, and safety monitoring (every 12 weeks).