Superiority of tenofovir alafenamide fumarate over entecavir for serum HBsAg level reduction in patients with chronic HBV infection: A 144-week outcome study after switching of the nucleos(t)ide analog

Chronic Hepatitis B in Which HBs Antigen Seroclearance Was Induced by Pegpegylated-interferonα-2a after Hepatocellular Carcinoma Treatment with Nucleos(t)ide Analogues: A Five-year Follow-up

We herein report a 40-year-old Japanese man with chronic hepatitis B genotype C (viral load 6.7 Log copies/mL) who developed hepatocellular carcinoma (HCC) despite achieving undetectable hepatitis B virus (HBV)-DNA levels with nucleos(t)ide analog (NA) treatment (entecavir). Notably, his hepatitis B surface antigen (HBsAg) level remained elevated at 388.4 IU/mL. Given the continued risk of carcinogenesis associated with HBsAg positivity, we initiated pegylated interferon (PEG-IFN) therapy one month after HCC surgery. Following three periods of PEG-IFN treatment, HBsAg seroclearance (HBsAg-negative state) was achieved.

Observational pilot study of switching from entecavir to tenofovir alafenamide in patients with chronic hepatitis B

This study evaluated the long-term efficacy and safety of the widely used drugs entecavir (ETV) and tenofovir alafenamide (TAF), as well as the incidence of HCC.A nonrandomized, prospective, observational analysis included 77 patients with chronic hepatitis B who were assigned to continue ETV or switch TAF. After 240 weeks, the mean changes in serum hepatitis B surface antigen (- 0.365 ± 0.069 log IU/mL vs. 0.301 ± 0.039 log IU/mL, p = 0.39) and hepatitis B core-related antigen (- 0.215 ± 0.092 log IU/mL vs. - 0.195 ± 0.056 log IU/mL) were not significantly different between the ETV and TAF groups. There were also no differences between the two groups in estimated glomerular filtration rate (- 5.407 ± 1.660 vs. - 2.666 ± 1.52, p = 0.240), urinary β2-microglobulin β/creatinine (ETV: 2.330 ± 0.374 at baseline and 2.335 ± 0.257 at 240 weeks; TAF: 2.720 ± 0.073 and 2.123 ± 0.310, p = 0.996 and 0.455, respectively) or urinary N-acetyl-β-D-glucosaminidase/creatinine (ETV: 0.040 ± 0.005 at baseline and 0.044 ± 0.004 at 240 weeks; TAF: 0.049 ± 0.005 and 0.053 ± 0.005, p = 0.642 and 0.684, respectively). Finally, no significant difference was found in the incidence of HCC between the ETV and TAF groups (log-rank test, p = 0.08). In conclusion, the long-term observation of this study demonstrated that ETV and TAF have comparable efficacy and safety.Clinical trial registration: UMIN000026465.

Decrease in HBsAg After TAF Switching from Entecavir During Long-Term Treatment of Chronic Hepatitis B Virus Infection

Achieving HBsAg seroclearance is a key goal in treating chronic hepatitis B virus (HBV) infection but remains difficult with nucleos(t)ide analogues (NAs). Tenofovir alafenamide fumarate (TAF), a recommended NA for managing chronic HBV infection (CHB), has uncertain effects on HBsAg levels and potential adverse events when used long-term after switching from entecavir (ETV). We retrospectively evaluated 77 CHB patients, including 47 who switched from ETV to TAF with a median follow-up of 40 months post-switch and a median of 60 months of HBsAg monitoring pre-switch. No significant change in HBsAg levels was observed in the overall cohort post-switch, consistent with the ETV continuation group. However, a significant decrease in HBsAg was noted in patients with HBsAg < 100 IU/mL at the time of switching. HBsAg loss occurred in three patients who switched to TAF. No adverse effects were observed, and TAF was well tolerated. The most significant factor associated with achieving HBsAg < 100 IU/mL was the Fib-4 index, a marker of liver fibrosis, at the time of switching. Switching from ETV to TAF is an effective strategy in CHB management, with hepatic inflammation potentially playing an essential role in achieving HBsAg decrease. Patients with increased Fib-4 index were significantly more likely to show decreased HBsAg. This finding suggests patients with mild to moderate fibrosis may respond better to TAF in terms of HBsAg reduction.

Switching from combination therapy with entecavir hydrate plus tenofovir alafenamide fumarate to tenofovir alafenamide fumarate monotherapy in patients with chronic hepatitis B based on nucleotide sequences of hepatitis B virus pregenome RNA

AIM

Patients with chronic hepatitis B virus (HBV) infection experiencing viral breakthrough (BTH) or partial response (PR) during lamivudine (LAM) or entecavir hydrate (ETV) administration often took ETV plus tenofovir alafenamide fumarate (TAF) due to the emergence of a drug-resistance mutation. However, in patients lacking drug-resistance mutation against TAF, sufficient antiviral effects may be achievable with TAF monotherapy. We assessed the drug-resistance profile through nucleotide sequences of HBV pregenome RNA, and subsequently changed to TAF monotherapy from ETV plus TAF.

METHODS

This prospective study included 25 patients with serum HBV-DNA below 20 IU/mL under ETV plus TAF administration. Pregenome RNA nucleotide sequences of HBV in the sera were analyzed using direct sequencing and deep sequencing. ETV was discontinued in patients without rtA194T and rtS106C + rtH126Y + rtD134E + rtL269I quadruple mutations in direct sequencing.

RESULTS

LAM-PR, LAM-BTH, ETV-PR, and ETV-BTH were observed in 1, 16, 7, and 1 patient(s), respectively. Pregenome RNA nucleotide sequences were analyzable in 20 patients. Among the 12 patients classified as LAM-BTH, six patients showed rtL180M + rtM204V/I in direct sequencing, and one patient showed minor clones containing rtL180M + rtM204V + A194T in deep sequencing at a frequency of 0.3%. In the six patients classified as ETV-PR, one patient harbored rtM204I. No clones showing rtS106C + rtH126Y + rtD134E + rtL269I quadruple mutation were detected in deep sequencing. Subsequently, ETV was discontinued, and serum HBV-DNA remained undetectable up to 48 weeks in all patients.

CONCLUSION

Patients receiving ETV plus TAF due to partial response or BTH during initial LAM or ETV administration were able to safely transition to TAF monotherapy based on nucleotide sequences of HBV pregenome RNA in the sera.

Impact of preS1 Evaluation in the Management of Chronic Hepatitis B Virus Infection

Background and Objectives: The measurement of hepatitis B surface antigen (HBsAg) is essential for managing chronic hepatitis B virus infection (CHB). HBsAg consists of three different surface envelope proteins: large, middle, and small HB surface proteins. However, in clinical practice, it is not common to evaluate each of these HB surface proteins separately. Materials and Methods: In this study, we investigated preS1 expression using seven monoclonal antibodies (mAbs) in 68 CHB patients, as well as examining their antigenicity. Results: Although the seven mAbs had been derived from genotype (Gt) C, they could recognize preS1 with Gts A to D. The epitopes were concentrated within the aa33-47 region of preS1, and their antigenicity was significantly reduced by an aa45F substitution. We found that preS1 expression remained consistent regardless of HBsAg levels and different Gts in CHB patients, in contrast to what was observed in SHBs. Conclusions: These results suggest that the antigenic epitope is preserved among different Gts and that the expression pattern of preS1 is altered during CHB, highlighting its vital role in the HBV infection cycle. Our present results suggest preS1 is a promising therapeutic target in CHB.

Comparison of Pegylated Interferon Alfa Therapy in Combination with Tenofovir Alafenamide Fumarate or Tenofovir Disoproxil Fumarate for Treatment of Chronic Hepatitis B Patients

Purpose

The study aims to evaluate the effectiveness of a tenofovir alafenamide fumarate (TAF) and pegylated interferon alfa (PegIFN-α) regimen compared to a tenofovir disoproxil fumarate (TDF) and PegIFN-α therapy in patients with chronic hepatitis B (CHB).

Patients and Methods

Patients who were treated with PegIFN-α in combination with TAF or TDF were retrospectively enrolled. The primary outcome measured was the HBsAg loss rate. The rates of virological response, serological response for HBeAg, and normalization of alanine aminotransferase (ALT) were also calculated. The cumulative incidences of response rates were compared between the two groups using Kaplan-Meier analysis.

Results

A total of 114 patients were retrospectively enrolled in the study, with 33 receiving TAF plus PegIFN-α treatment and 81 receiving TDF plus PegIFN-α treatment. The HBsAg loss rate for the TAF plus PegIFN-α group was 15.2% at 24 weeks and 21.2% at 48 weeks, while the TDF plus PegIFN-α group had rates of 7.4% at 24 weeks and 12.3% at 48 weeks (P=0.204 at 24 weeks, P=0.228 at 48 weeks). In subgroup analysis of HBeAg positive patients, the TAF group had a higher HBsAg loss rate of 25% at week 48, compared to 3.8% in the TDF group (P=0.033). According to Kaplan-Meier analysis, the TAF plus PegIFN-α group achieved virological response more quickly than the TDF plus PegIFN-α group (p=0.013). There was no statistical difference in HBeAg serological rate or ALT normalization rate.

Conclusion

There was no significant difference in the HBsAg loss between the two groups. However, subgroup analysis revealed that TAF plus PegIFN-α treatment had a higher HBsAg loss rate than TDF plus PegIFN-α treatment in HBeAg-positive patients. Additionally, TAF plus PegIFN-α treatment demonstrated better virological suppression for CHB patients. Therefore, TAF plus PegIFN-α treatment regimen is recommended for CHB patients who aim to achieve functional cure.

Switching to Tenofovir Alafenamide Fumarate in Chronic Hepatitis B Patients Who Had Detectable HBV DNA during Treatment with Entecavir

Nucleos(t)ide analogues (NAs) suppress hepatitis B virus (HBV) replication, but the risk of hepatocellular carcinoma still remains. The presence of detectable HBV DNA in the serum during NA therapies for chronic hepatitis B patients has been reported to be associated with the risk of hepatocellular carcinoma. In this study, we investigated the antiviral effect of switching from entecavir (ETV) to tenofovir alafenamide fumarate (TAF) in chronic hepatitis B patients who had detectable HBV DNA in the serum at least once within a year. Among a total of 77 cases in 7 hospitals that switched NAs from ETV to TAF, 23 patients with detectable HBV DNA in a year before switching were analyzed. When the detection frequencies of HBV DNA in the 1st and 2nd years after switching to TAF were analyzed, they were significantly lower than those in the year before switching (68.8% vs. 34.1% for the 1st year and 21.3% for the 2nd year, P < 0.001 for both). The HBsAg decline tended to be larger after switching than before (-2.5% vs. -3.0% for 1st year and -3.1% for 2nd year), but the difference was not significant. One patient died of a cardiovascular event 11 months after the treatment switch, but no adverse effects due to TAF including renal function were observed. In conclusion, it was suggested that switching from ETV to TAF might be effective to suppress the HBV DNA level further in patients whose HBV DNA is detectable, even if at a very low level.

SEB genotyping: SmartAmp-Eprimer binary code genotyping for complex, highly variable targets applied to HBV

Background

SmartAmp-Eprimer Binary code (SEB) Genotyping is a novel isothermal amplification method for rapid genotyping of any variable target of interest.

Methods

After in silico alignment of a large number of sequences and computational analysis to determine the smallest number of regions to be targeted by SEB Genotyping, SmartAmp primer sets were designed to obtain a binary code of On/Off fluorescence signals, each code corresponding to a unique genotype.

Results

Applied to HBV, we selected 4 targets for which fluorescence amplification signals produce a specific binary code unique to each of the 8 main genotypes (A–H) found in patients worldwide.

Conclusions

We present here the proof of concept of a new genotyping method specifically designed for complex and highly variable targets. Applied here to HBV, SEB Genotyping can be adapted to any other pathogen or disease carrying multiple known mutations. Using simple preparation steps, SEB Genotyping provides accurate results quickly and will enable physicians to choose the best adapted treatment for each of their patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07458-4.