The first-line NAs include entecavir (ETV), tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF). All the NAs mentioned above could achieve complete virologic response. NAs mentioned above are sufficient in inhibiting viral replication. However, there may exist difference in long-term prognosis such as HBsAg level decline, resistance development and HCC development. A prospective study performed by our team previously showed that TDF was better than ETV in HBsAg decline. A Korean research showed that TDF therapy was associated with a significantly lower risk of HCC than ETV therapy; the TDF group showed a distinct reduction in HBsAg level after one-year treatment. Also, a Japanese RCT study indicated that the reduction in HBsAg level was significantly greater in the TDF arm than the ETV arm at week 24. The mechanism of HBsAg decline induced by TDF has not been fully elucidated. Patients treated with nucleotide analogues (adefovir, tenofovir) had higher serum IFN-λ3 levels than those treated with nucleoside analogues (lamivudine, entecavir), according to results recently published in Gut. A team from Japan has found that nucleotide analogues inhibit LPS-mediated IL-10 production and induce IL-12p70 and TNF-α production. We speculated that, compared with entecavir, tenofovir could up-regulate IFN-λ3 and reduce the level of HBsAg more significantly.~As known as the second generation of TDF, TAF has a significantly longer half-life than TDF. A phase 3 study displayed that TAF 25 mg was non-inferior to TDF 300 mg in suppressing HBV replication, with a better performance in renal and bone safety. However, there is lack of study evaluating TAF in reducing HBsAg and induces IFN-λ3.The aim of this study was to investigate whether the TAF can achieve a better antiviral therapeutic endpoint, i.e. a greater reduction in HBsAg levels, or even meet the therapeutic expectation of stopping NAS in a larger number of treated patients.~The objective of this clinical study was to observe the changes of HBsAg levels after a sequential 48 weeks-treatment of TAF in ETV experienced CHB patients and to monitor the levels of cytokines such as IFN-λ3, IP-10, IL-12, IL-10, and IL-21.
The objective of this clinical study was to observe the changes of HBsAg levels after a sequential 48 weeks-treatment of TAF in ETV experienced CHB patients and to monitor the levels of cytokines such as IFN-λ3, IP-10, IL-12, IL-10, and IL-21.