Five-year efficacy and safety of tenofovir-based salvage therapy for patients with chronic hepatitis B who previously failed LAM/ADV therapy

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.

Entecavir resistance mutations rtL180M/T184L/M204V combined with rtA200V lead to tenofovir resistance

BACKGROUND

Tenofovir disoproxil fumarate (TDF) imposes a high genetic barrier to drug resistance and potently inhibits replication of multidrug-resistant hepatitis B virus. Few clinical cases with confirmed TDF-resistance have been reported to date.

METHODS AND RESULTS

Here, we report viral rebound in a patient with chronic hepatitis B who underwent TDF monotherapy and harboured a quadruple mutant consisting of classic entecavir (ETV)-resistance mutations (rtL180M/T184L/M204V) together with an rtA200V mutation in the reverse transcriptase gene. Sequencing analysis revealed that this quadruple mutant emerged as a major viral population. In vitro phenotyping demonstrated that the rtL180M/T184L/A200V/M204V mutant had moderate resistance to TDF treatment, with a 4.52-fold higher half maximal effective concentration than that of wild-type virus. Importantly, this patient with TDF resistance achieved virological suppression after TDF/ETV combination rescue therapy.

CONCLUSION

An rtL180M/T184L/A200V/M204V mutant with moderate resistance to TDF monotherapy was selected during sequential nucleoside analogue (NA) treatment in a stepwise manner. ETV/TDF combination therapy effectively suppressed replication of this TDF-resistant mutant. Our studies provide novel insights into the treatment of NA-naïve patients as well as patients with TDF resistance.

Efficacy and safety of tenofovir disoproxil fumarate in Chinese patients with chronic hepatitis B virus infection: A 2-year prospective study

To date, a small number of studies concerning the effects and safety of tenofovir disoproxil fumarate (TDF) in Chinese individuals were conducted. In this study, we aimed to assess the antiviral effects and nephrotoxicity of TDF in Chinese patients with chronic hepatitis B virus (HBV) infection.Patients with chronic HBV infection were prospectively recruited and TDF treatment was given for 96 weeks. HBV serologic markers, HBV DNA, creatinine and phosphorus were collected.Fifty-seven treatment-naïve and 48 treatment-experienced patients were recruited. Irrespective of the prior treatment history, more than 95% of patients achieved virological response during 96 weeks treatment with TDF. Estimated glomerular filtration rate (eGFR) significantly declined in the first year of treatment in patients with chronic hepatitis B or younger age (<65 years old) (both P < .05), while that was not achieved in patients with liver cirrhosis or older age (≥65 years old) (both P > .05). For patients who were treatment-naïve or treated previously with adefovir dipivoxil, eGFR declined at the 48th week; however, eGFR was partially recovered at the 96th week. Furthermore, multivariable analysis showed that basal eGFR <90 mL/min/1.73 m (P = .001; odds ratio: 4.821; 95% confidence interval: 1.904-12.206) is the only independent risk factor for eGFR <90 mL/min/1.73 m at the 96th week.TDF has potent antiviral effect in both treatment-naïve and treatment-experienced patients.

Impact of antiretroviral therapy containing tenofovir disoproxil fumarate on the survival of patients with HBV and HIV coinfection

BACKGROUND

Tenofovir disoproxil fumarate (TDF) is active against both HBV and HIV. Whether the introduction of TDF-containing combination antiretroviral therapy (cART) has improved the outcome of HIV/HBV-coinfected patients remains unclear in areas of higher HBV endemicity.

METHODS

We retrospectively reviewed medical records of newly diagnosed antiretroviral-naïve HIV-infected patients between 2007 and 2015. Four groups of patients were defined, according to the HBV status and availability of TDF for HIV treatment in Taiwan in 2011. The primary outcome was all-cause mortality.

RESULTS

During the 9-year study period, 1,723 HIV-infected patients were included, with a median age of 31 years and baseline CD4 count of 273 cells per μL. The HBV seroprevalence had declined from 18.1% (125/692) in the pre-TDF era to 10.1% (104/1031) in the post-TDF era. The respective mortality rate for HIV/HBV-coinfected and HIV-monoinfected patients in the pre-TDF era was 23.2 (95% CI, 12.5-43.1) and 9.6 (95% CI, 6.1-15.0) deaths per 1000 person-years of follow-up [PYFU], and the respective mortality rate in the post-TDF era was 15.7 (95% CI, 7.0-34.8) and 8.0 (95% CI, 5.5-11.6) deaths per 1000 PYFU. The adjusted hazard ratio for mortality in multivariate Cox proportional-hazards regression analysis among HIV/HBV-coinfected patients compared to HIV-monoinfected patients was 2.79 (95% CI, 1.25-6.22) in pre-TDF era and 1.11 (95% CI, 0.45-2.72) in post-TDF era.

CONCLUSIONS

In this country of high HBV endemicity, the adverse impact of chronic HBV infection on the survival observed in the pre-TDF era has significantly diminished among HIV/HBV-coinfected patients compared to HIV-monoinfected patients in the era of TDF-containing cART.

Long-term Efficacy of Tenofovir Disoproxil Fumarate Monotherapy for Multidrug-Resistant Chronic HBV infection

BACKGROUND & AIMS

There are no globally agreed upon treatment guidelines for patients with chronic hepatitis B virus (HBV) with multidrug resistance (MDR). We conducted a multicenter, prospective, real-world cohort study of effects of tenofovir disoproxyl fumarate (TDF) monotherapy and TDF-based combination therapy, as rescue therapy, in patients with multidrug-resistant chronic HBV infections.

METHODS

We recruited patients with chronic HBV infection with resistance to antivirals from 8 tertiary hospitals in Korea. Patients (n=423) received rescue therapy with TDF monotherapy (n=174) or TDF-based combination therapy (n=249). The median follow-up period was 180 weeks. A virologic response was defined as a serum HBV DNA level of <20 IU/mL.

RESULTS

Cumulative rates of virologic response did not differ significantly between the groups that received TDF monotherapy vs combination therapy at 48 weeks (71.7% vs 68.9%), 96 weeks (85.1% vs 84.2%), 144 weeks (92.1% vs 92.7%), 192 weeks (93.4% vs 95.7%), or 240 weeks (97.7% vs 97.2%). Serum levels of HBV DNA below 4.0 log₁₀ IU/mL (odds ratio, 2.478; 95% CI 1.959-3.135; P < .001) and the absence of mutations associated with resistance to adefovir (odds ratio, 1.570; 95% CI 1.279-1.926; P < .001) were associated with virologic response in patients with MDR. There was no significant difference of virologic response among patients of different ages, sex, patients with vs without cirrhosis, positivity for hepatitis B e antigen, or renal function (all P > .05).

CONCLUSION

In a multicenter, real-world cohort study, long-term use of TDF monotherapy showed non-inferior antiviral efficacy compared with that of TDF-based combination therapy in patients with MDR.

Step-down strategy in antiviral resistant chronic hepatitis B patients who achieved viral suppression with rescue combination therapy

In the treatment of chronic hepatitis B (CHB) patients with drug resistance, rescue combination therapy leads to viral suppression in almost all patients. However, once it is achieved, lifelong maintenance especially, by using combination therapy is not always possible in a significant proportion of patients. At present, there is no consensus on whether it is possible to switch to monotherapy from combination therapy. However, there is robust evidence to support step-down therapy, which involves switching from combination therapy to monotherapy in antiviral resistant CHB patients who achieve complete viral response from combination therapy. We review the evidence in favor of switching to monotherapy in antiviral resistant CHB patients who achieve complete viral response by combination therapy.

Long-term safety and efficacy of nucleo(t)side analogue therapy in hepatitis B

Long-term treatment of chronic hepatitis B (CHB) with nucleos(t)ide analogues is often necessary to achieve durable viral suppression. Therefore, current guidelines recommend the most potent drugs with optimal resistance profiles. Entecavir (ETV), tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) are the first-line monotherapies for CHB. All of these drugs are highly effective in suppressing viral replication but with slightly different safety profiles. This review provides an overview of the long-term efficacy and safety data that have become available over the 10 years since ETV and TDF were first approved for the treatment of chronic hepatitis, and recent data on TAF in patients with CHB.

Hepatitis B infection among HIV infected individuals in Gabon: Occult hepatitis B enhances HBV DNA prevalence

In Gabon, a central African country, human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are endemic. In a recent study, conducted in a semi-urban area (Franceville, Gabon), HBV infection was found to be more prevalent among HIV infected individuals. This study aims to investigate the prevalence and genetic diversity of hepatitis B virus infection among HIV infected individuals, predominantly under antiretroviral therapy, living in fully urbanized area: Libreville, capital of Gabon. Serological and molecular tests were performed to detect HBV infection among patients living with HIV/AIDS (PLHA). We used Monolisa HBsAg ULTRA, Anti-HBc Plus and Anti-HBs Plus EIA kits for serological analyses. HBV DNA viral load (HBV DNA VL) was determined by real time PCR and molecular characterization of HBV strains was performed by sequencing and phylogenetic analysis of partial HBV surface and core genes. At all, 70.2% of patients were under antiretroviral therapy. The prevalence of HBsAg was 8.8% (43/487). Detectable HBV DNA was found in 69.7% (30/43) of HBsAg positive patients and in 17.5% (24/137) HBsAg negative patients. HBV DNA VL was significantly higher among patient with CD4 cell counts less than 200 cells/mm³ than those with CD4 cell counts greater than 500 cells/mm³ (p = 0.008). We confirmed the presence of HBV sub-genotypes QS-A3 (40%), and A4 (20%) and HBV-E genotype (40%). The percentage of resistance to Lamivudine was high (40%) and varied according to the M204V/I motif. Occult hepatitis B infection (OBI) was found in patients with isolated HBcAb and among patients who had completed their HBsAg seroconversion. We detected HBV DNA for one patient without any HBV serological marker. This study provides a new landmark for the comprehension of HBV infection in PLHA in urban areas. OBI enhances HBV DNA prevalence and should be investigated in all HBsAg negative individuals.