Effectiveness of tenofovir alafenamide for chronic hepatitis B patients with a poor response to the previously used nucleos(t)ide analogs

A systematic review and meta-analysis of the risk of hepatitis B virus (HBV) resistance in people treated with entecavir or tenofovir

BACKGROUND

As nucleos/tide analogue (NA) therapy (e.g. entecavir and tenofovir) for chronic Hepatitis B virus (HBV) infection becomes more widely indicated and available, understanding drug resistance is essential. A systematic review to quantify resistance to these agents has not previously been undertaken.

METHODS

We performed a systematic review and random-effects meta-analysis to estimate the risk of HBV resistance to entecavir and tenofovir. We searched nine databases up to 29-Aug-23. We included studies of HBV infection featuring >10 individuals, written in English, reporting treatment ≥48 weeks, with assessment of HBV resistance based on viral sequence data. Data were analysed according to prior exposure history to NA, and choice of NA agent. Analyses were performed in R.

FINDINGS

62 studies involving a total of 12,358 participants were included. For entecavir, in treatment-naive individuals (22 studies; 4326 individuals), resistance increased over time to 0.9 % at ≥5 years (95 %CI 0.1-2.3 %), and resistance was increased in NA-experienced individuals (18 studies; 1112 individuals), to 20.1 % (95 %CI 1.6-50.1 %) at ≥5 years. For tenofovir, pooled resistance risk was 0.0 % at all time points, whether previously NA naive (11 studies; 3778 individuals) or experienced (19 studies; 2059 individuals). There was a lack of consistent definitions, poor global representation and insufficient metadata to support subgroup analysis.

INTERPRETATION

We have generated the first pooled estimates of HBV entecavir and tenofovir resistance over time. HBV resistance to entecavir in treatment-experienced groups in particular may represent a clinical and public health challenge. To date, tenofovir appears to have an excellent resistance profile, but due to data gaps, we caution that existing studies under-estimate the true real-world risk of resistance. Robust prospective data collection is crucial to reduce health inequities and reduce blind-spots in surveillance as treatment is rolled out more widely.

Body weight increase and metabolic derangements after tenofovir disoproxil fumarate switch to tenofovir alafenamide in patients with chronic hepatitis B

BACKGROUND

Lipid-lowering effect was observed during treatment with tenofovir disoproxil fumarate (TDF) for chronic hepatitis B (CHB). However, the metabolic features in patients switching from TDF to tenofovir alafenamide (TAF) remain unclear.

AIMS

To compare the impacts of switching from TDF to TAF or from entecavir to TAF on body weight and metabolic features in patients with CHB.

METHODS

This was a multi-centre, prospective, observational study in patients with CHB on TDF or entecavir who switched to TAF. Baseline characteristics, lipid profile and sugar profile were determined. This study received IRB approval from each hospital.

RESULTS

We enrolled 177 patients on TDF (99) or entecavir (78) and followed them for 48 weeks after the switch to TAF. At baseline, TDF-experienced patients had lower serum triglyceride, total cholesterol, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol than entecavir-experienced patients. The switch from TDF to TAF significantly increased body weight, triglyceride, total cholesterol, HDL, LDL, fasting glucose, glycaemic haemoglobin, insulin and insulin resistance. The switch from entecavir to TAF did not affect these measures. There was no significant difference in atherosclerotic cardiovascular disease risk scores between groups.

CONCLUSIONS

The switch from TDF to TAF was associated with weight gain, derangements of lipid profile, and increased insulin resistance in patients with CHB. Long-term effects on these metabolic features need further investigation.

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.