A Follow-up Study of Peginterferon Alfa-2b Combined With TDF in Patients With Chronic Hepatitis B

Inclusion criteria

• Participants who completion of the TB1901IFN study ("completion" is defined as completion of more than 80% of trial medications (including peginterferon alfa and tenofovir disoproxil fumarate), or meeting criteria for early discontinuation and completion of consolidation therapy, as well as completion of discontinuation follow-up and 24-week post-discontinuation visit);
• Voluntary enrollment, understand and sign the informed consent form.

For cohort 1 only; - Subjects who have achieved functional cure (defined as the disappearance of HBsAg at the completion of TB1901IFN, with or without the appearance of HBsAb);

For cohort 2 only:

• At the completion of TB1901IFN, the S antigen level has decreased by ≥1 log compared to the baseline, with an S antigen level of less than 100 IU/ml, or the S antigen level has decreased by ≥1.5 log compared to the baseline, with an S antigen level of less than 1500 IU/ml;
• Willing to accept the treatment of peginterferon combined with TAF;

For cohort 3 only:

• Participants who have not achieved functional cure upon completion of TB1901IFN (defined as HBsAg ≥ 0.05 IU/ml)；

Exclusion criteria

• Suspected or confirmed HCC patients.

For Cohort 2 only:

• Suspected or confirmed liver cirrhosis.
• Pregnant, breastfeeding women, or those who plan to conceive during the combined medication treatment period.
• Evidence of acute severe liver injury: e.g. ALT > 10 times of the upper limit of normal (ULN), or a significant increase in ALT accompanied by a significant increase in bilirubin;
• Evidence of decompensated liver disease: serum total bilirubin > 2ULN, serum albumin < 35 g/L, prothrombin time extended by more than 3 seconds beyond ULN, prothrombin activity < 60%; or a history of decompensated liver cirrhosis;
• Kidney disease: acute or chronic nephritis, renal insufficiency, nephrotic syndrome, etc., or serum creatinine > 1ULN;
• Neutrophil count < 1.5×10^9/L, platelet count < 90×10^9/L;
• Severe retinopathy or other severe ophthalmic diseases;
• Other conditions deemed by the investigator to be unsuitable for participation in the cohort 2.

For cohort 3 only:

• Participants who plan to enter Cohort 2.