Tenofovir monotherapy versus tenofovir and entecavir combination therapy in adefovir-resistant chronic hepatitis B patients with multiple drug failure: results of a randomised trial

Real-world study on the efficacy and safety of different treatment regimens in treatment-naïve CHB patients with high viral load

Evaluate the real-world effectiveness and safety of different treatment regimens for treatment-naïve high viral load chronic hepatitis B (CHB) patients. Between January 2021 and August 2022, CHB patients with HBV DNA ≥ 107 IU/mL were collected from four medical centers in Shenzhen. Patients treated with mono or combine antiviral therapy. The primary endpoint was the cumulative incidence of virological response at 48 weeks, and other endpoints included changes in HBsAg, HBeAg, ALT, and eGFR at 48 weeks. We used propensity score-based inverse probability of treatment weighting (IPTW) to balance the bias. Weighted logistics regression was used to estimate the factors affecting virological response. A total of 391 patients were included in the study, with 296 patients undergoing statistical analysis after IPTW. The patients were distributed into four groups: ETV (n = 62), TDF (n = 89), TAF (n = 36), TDF + LdT/ETV (n = 109). The 48-week cumulative incidence of virological response was significantly lower in ETV group (52.3%) compared to TDF (71.7%), TAF (74.2%), and TDF + LdT/ETV groups (77.9%) (P < 0.05). There were no significant differences in HBsAg loss among the four groups, but the HBeAg seroconversion rate was significantly higher in the TAF group. The ALT normalization rate was significantly higher in the TAF group (72.2%) compared to the others at 48 weeks (P < 0.05). In treatment-naïve CHB patients with high viral load, combination therapy was not superior to TDF or TAF monotherapy in virological response. Patients treated with TDF or TAF showed superior virological response compared to those treated with ETV. The TAF group demonstrated superiority in terms of ALT normalization and HBeAg seroconversion.

Are the New Nucleos(t)ide Analogs Better than the Old Nucleos(t)ide Analogs?

In treatment-naïve patients with chronic hepatitis B virus (HBV) infection, entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide have a minimal or no risk of drug-resistance. These 3 nucleos(t)ide analog agents are highly potent inducing high rate of virologic response (reducing serum HBV DNA to levels undetectable by polymerase chain reaction assays) in most treatment-naïve patients. Our randomized trials have demonstrated that monotherapy with TDF can provide a successful virological response in most of the heavily pretreated patients with multidrug resistance to ETV or adefovir.

Detecting Early Hepatocellular Carcinoma in Patients with Chronic Hepatitis B Using Longitudinal α-Fetoprotein Screening

BACKGROUND & AIMS

This study aimed to evaluate the parametric empirical Bayes (PEB) longitudinal α-fetoprotein (AFP) screening algorithm performance in patients with hepatitis B compared with AFP surveillance with a fixed threshold.

METHODS

The serum AFP of 588 patients was measured. Patients were screened at least once every 6 months with AFP and ultrasound or computed tomography/magnetic resonance imaging. Age, aspartate aminotransferase level, alanine aminotransferase level, platelet count, total bilirubin, prothrombin time, and hepatitis B virus DNA level were adjusted in the PEB algorithm. All variables were abstracted at the time of hepatocellular carcinoma (HCC) diagnosis for cases or last follow-up for controls and at months -6, -12, -18, -24, -30, -36, -42, -48, and -54, up to month -60.

RESULTS

Overall, 62 (10.5%) HCC cases developed during a median follow-up of 52.7 months. Moreover, 55 (88.7%) cases were detected at Barcelona Clinic Liver Cancer stage 0 or A. The area under the receiver-operating characteristic curve of the patient-level true positive rate against the screening-level false positive rate was significantly higher in the PEB algorithm than that in AFP alone (area under the receiver-operating characteristic curve: 0.94 vs 0.86; P < .0005). At 80% specificity, the PEB algorithm significantly improved the patient-level true positive rate within 2 years prior to HCC diagnosis compared with AFP alone (80.6% vs 67.7%, respectively; P = .0485; adjusted P = .1663). The PEB algorithm more effectively enabled first positive screening.

CONCLUSIONS

The longitudinal assessment of AFP by the PEB algorithm improved HCC screening performance compared to AFP alone in patients with hepatitis B. This algorithm may improve HCC screening without additional cost or inconvenience to patients.

Tenofovir Alafenamide for Drug-Resistant Hepatitis B: A Randomized Trial for Switching From Tenofovir Disoproxil Fumarate

BACKGROUND & AIMS

It remains unknown whether tenofovir alafenamide (TAF) could replace tenofovir disoproxil fumarate (TDF) in patients with drug-resistant hepatitis B virus (HBV).

METHODS

In this multicenter randomized non-inferiority trial, 174 patients with HBV resistant to multiple drugs (lamivudine, entecavir, and/or adefovir) under TDF monotherapy for ≥96 weeks were randomized 1:1 to switch to TAF (n = 87) or continue TDF (n = 87) for 48 weeks. The primary endpoint was proportion of patients with HBV DNA <60 IU/mL at week 48.

RESULTS

At baseline, 84 and 80 patients had HBV DNA <60 IU/mL in the TAF and TDF groups, respectively. At week 48, the proportion of patients with HBV DNA <60 IU/mL was 98.9% (86/87) in TAF group, showing non-inferiority to TDF group (97.7%, 85/87; difference, 1.1%; 95% confidence interval, -2.7% to 5.0%). Changes in median alanine aminotransferase at week 48 from baseline were statistically different between TAF and TDF groups (-3 IU/L vs +2 IU/L; P = .02). TAF group showed a statistically greater increase in bone mineral density at spine (+1.84% vs +0.08%; P = .01) and numerically higher increase in mean estimated glomerular filtration rate (+8.2% vs +4.5%; P = .06) compared with TDF group. Compared with TDF group, TAF group showed significantly greater increases in mean body weight (0.71 vs -0.37 kg; P = .01) and total, low-density lipoprotein, and high-density lipoprotein cholesterol levels (P < .001 for all) at week 48 from baseline.

CONCLUSIONS

TAF could be substituted for TDF in patients with multidrug-resistant HBV for improved bone and renal safety without a loss of efficacy. However, increases in body weight and cholesterol levels with TAF treatment would be a concern. ClinicalTrials.gov no.: NCT03241641.

[Ten years of the National Reference Center for hepatitis B viruses and hepatitis D viruses in Giessen, Germany: activities and experiences]

The National Reference Center (NRC) for hepatitis B viruses (HBV) and hepatitis D viruses (HDV) has been located at the Institute of Medical Virology of the Justus Liebig University (JLU) in Giessen, Germany, since its establishment in 2011. This paper describes the NRC's areas of activity and related experience.The NRC offers comprehensive consulting services on all diagnostic and clinical aspects of acute and chronic HBV and HDV infections for the Public Health Service (ÖGD), diagnostic laboratories, clinics, research institutes, and physicians in private practice. Uncertain diagnostic findings can be analyzed and interpreted and epidemiological correlations clarified with the HBV/HDV special diagnostics established at the NRC using state-of-the-art molecular, biochemical, and genetic laboratory tools. The NRC has access to a strain collection of many well-characterized and cloned HBV/HDV isolates, allowing comparative analysis and evaluation of antiviral resistance mutations and immune escape variants. Together with its national and international partner institutions, the NRC initiates and supervises, among other things, interlaboratory studies for the diagnosis of HBV resistance and immune escape for the establishment and validation of international World Health Organization (WHO) standards and for the improvement of quantitative HDV genome determination. The NRC actively participates in current recommendations and guidelines on HBV and HDV and the recommendations of medical societies. It also highlights current HBV/HDV-relevant aspects with contributions in the form of national and international lectures as well as original articles and comments in national and international journals.

Low-level viremia in nucleoside analog-treated chronic hepatitis B patients

ABSTRACT

Low-level viremia (LLV) was defined as persistent or intermittent episodes of detectable hepatitis B virus (HBV) DNA (<2000 IU/mL, detection limit of 10 IU/mL) after 48 weeks of antiviral treatment. Effective antiviral therapies for chronic hepatitis B (CHB) patients, such as entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF), have been shown to inhibit the replication of HBV DNA and prevent liver-related complications. However, even with long-term antiviral therapy, there are still a number of patients with persistent or intermittent LLV. At present, the research on LLV to address whether adversely affect the clinical outcome is limited, and the follow-up treatment for these patients is open to question. At the same time, the mechanism of LLV is not clear. In this review, we summarize the incidence of LLV, the association between LLV and long-term outcomes, possible mechanisms, and management strategies in these patient populations.

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

BACKGROUND

Few studies have demonstrated the potency of tenofovir alafenamide (TAF) in patients with poor response to other nucleos(t)ide analogs (NAs).

METHODS

We conducted a retrospective study comprising consecutive 40 patients exhibiting a poor response to other NAs, who subsequently received TAF-containing regimens. The primary outcome was the prevalence of virological response (VR) at each time and maintained virological response (MVR) under TAF-containing regimens until week 96.

RESULTS

In the entire cohort, the prevalence of MVR was 71.1% (27/38). Further, poor tenofovir disoproxil fumarate (TDF) response was significantly associated with a lower prevalence of MVR (p = 0.014). In TDF-naïve patients, the prevalence of MVR was 92.3% (12/13) and 62.5% (5/8) in patients with lamivudine resistance (LAM-r) and entecavir resistance (ETV-r), respectively. Further, viral load and HBeAg status at baseline were associated with a lower prevalence of MVR (p = 0.013). Among the seven patients with prior TDF exposure, 2 patients achieved MVR. Among them, one patient with development of viral breakthrough during TDF/LAM achieved MVR after switching to TAF/ETV. In contrast, one of the five patients with non-MVR had three substitutions (rtS106C, rtD134N/S, and rtL269I) of quadruple mutations in addition to ETV-r. Other patients with rtA181T + rtN236T also could not achieve MVR.

CONCLUSION

TAF exhibited high antiviral potency in patients with LAM-r and ETV-r. However, TAF potency was associated with previous TDF response, viral load, and HBeAg status at baseline. Additionally, a quadruple mutation may impact tenofovir resistance; however, further studies are needed to verify this.

Guidelines for Prevention and Treatment of Chronic Hepatitis B

To achieve the goal of the World Health Organization to eliminate viral hepatitis as a major public health threat by 2030, the Chinese Society of Infectious Diseases and the Chinese Society of Hepatology convened an expert panel in 2019 to update the guidelines for the prevention and treatment of chronic hepatitis B (CHB). The current guidelines cover recent advances in basic, clinical, and preventive studies of CHB infection and consider the actual situation in China. These guidelines are intended to provide support for the prevention, diagnosis, and treatment of CHB.

Tenofovir disoproxil fumarate on the risk of hepatocellular carcinoma in chronic hepatitis B patients with failure to preceding treatments: A nationwide cohort study

Tenofovir disoproxil fumarate (TDF) monotherapy is recommended for the treatment of chronic hepatitis B (CHB) patients who are refractory to other drugs. Yet, little data are available for the effectiveness of TDF monotherapy compared with TDF-based combination therapy on the risk of hepatocellular carcinoma (HCC) and death/transplantation. This nationwide population-based cohort study included 11,289 CHB patients who initiated TDF rescue therapy after failure of preceding treatments between 2012 and 2014 in Korea. The risks of HCC and death/transplantation were compared between TDF combotherapy (n = 2,499) and TDF monotherapy (n = 8,790) groups. The findings were validated in a hospital cohort of 1,163 CHB patients. In the nationwide cohort, during 44.2 months of overall treatment duration, 529 patients developed HCC and 190 died or received transplantation. In the 2,499 propensity score-matched pairs, compared with TDF combotherapy, TDF monotherapy showed no significantly different risks of HCC (1.11/100 person-year [PY] vs. 1.32/100 PY; HR 1.23, 95% CI 0.95-1.60, p = .12) and death/transplant (0.43/100 PY vs. 0.42/100 PY; HR 1.04, 95% CI 0.67-1.60, p = .87). However, in the 469 propensity score-matched pairs of cirrhosis subcohort, TDF monotherapy was associated with a higher risk of HCC than TDF combotherapy (HR 1.46, 95% CI 1.002-2.12, p = .049). In the validation hospital cohort, TDF monotherapy was not associated with significantly different risks of HCC and death/transplant in the entire cohort and cirrhosis subcohort. In CHB patients with failure to preceding treatments, TDF monotherapy showed no higher risks of HCC and death/transplantation compared with TDF combotherapy. However, the comparative effectiveness of rescue TDF monotherapy should be further clarified in cirrhotic patients since the findings were not consistent in the nationwide and hospital cohorts.

The Application of Dynamic Uncertain Causality Graph Based Diagnosis and Treatment Unification Model in the Intelligent Diagnosis and Treatment of Hepatitis B

Although hepatitis B is widespread, it is hard to cure. This paper presents a new and more accurate model for the diagnosis and treatment of hepatitis B. Based on previous research, the diagnosis and treatment modes were combined into one. By adding more influencing factors and risk factors, the overall diagnosis and treatment model will be further expanded, and a richer and more detailed overall diagnosis and treatment model will be constructed. Reverse logic gates are used in the model to improve the accuracy of the treatment planning. The new unified model is more accurate in subdividing diagnosis results, and it is more flexible and accurate in providing dynamic treatment plans. The prediction process and the static diagnosis process of the model are symmetric, and the related sub-graph is symmetric in structure. In addition, an algorithm for predicting the response probability of treatment scheme is developed, so as to predict the subsequent treatment effects of the current treatment scheme, such as the probability of drug resistance. The results show that this method is more accurate than other available systems, and it has encouraging diagnostic accuracy and effectiveness, which provides a promising help for doctors in diagnosing hepatitis B.

Distinctive HBV Replication Capacity and Susceptibility to Tenofovir Induced by a Polymerase Point Mutation in Hepatoma Cell Lines and Primary Human Hepatocytes

Tenofovir disoproxil fumarate (TDF) has been regarded as the most potent drug for treating patients with chronic hepatitis B (CHB). However recently, viral mutations associated with tenofovir have been reported. Here, we found a CHB patient with suboptimal response after more than 4 years of TDF treatment. Clonal analysis of hepatitis B virus (HBV) isolated from sequential sera of this patient identified the seven previously reported TDF-resistant mutations (CYELMVI). Interestingly, a threonine to alanine mutation at the 301 amino acid position of the reverse-transcriptase (RT) domain, (rtT301A), was commonly accompanied with CYELMVI at a high rate (72.7%). Since the rtT301A mutation has not been reported yet, we investigated the role of this naturally occurring mutation on the viral replication and susceptibility to tenofovir in various liver cells (hepatoma cells as well as primary human hepatocytes). A cell-based phenotypic assay revealed that the rtT301A mutation dramatically impaired the replication ability with meaningful reduction in sensitivity to tenofovir in hepatoma cell lines. However, attenuated viral replication by the rtT301A mutation was significantly restored in primary human hepatocytes (PHHs). Our findings suggest that the replication capability and drug sensitivity of HBV is different between hepatoma cell lines and PHHs. Therefore, our study emphasizes that validation studies should be performed not only in the liver cancer cell lines but also in the PHHs to understand the exact viral fitness under antiviral pressure in patients.

Characterization of Hepatitis B virus polymerase mutations A194T and CYEI and tenofovir disoproxil fumarate or tenofovir alafenamide resistance

Both the A194T and a quadruple mutation CYEI (S106C, H126Y, D134E and L269I) in hepatitis B virus (HBV) polymerase reverse transcriptase domain (pol/RT) are suggested to be associated with treatment failure with tenofovir disoproxil fumarate (TDF). To further evaluate this assertion, the prevalence of these mutations at baseline as well as their development and/or loss during TDF and tenofovir alafenamide (TAF) treatment was analysed in 3886 patients enrolled in Gilead HBV clinical studies. In total, six out of 3886 (0.2%) patients carried the rtA194T mutation, while only 1 patient carried a triple CYE and 2 patients carried a quadruple CYEI mutation at baseline. All the patients harbouring rtA194T or CYE/CYEI at baseline achieved viral suppression by week 96 after TDF or TAF treatment. No patients developed an rtA194T mutation or > 1 substitution of CYEI, and the number of patients losing any substitutions of CYEI (n = 17) was similar to the number who developed a single substitution of CYEI (n = 32) during treatment. Phenotypic evaluation of the site-directed mutant (SDM) panel containing these mutations with or without other resistance mutations did not demonstrate a significant shift in TFV and TAF potency in vitro. No evidence of rtA194T and CYEI conferring resistance to TDF or TAF was observed based on the treatment responses to TDF or TAF in patients with mutations at baseline, the lack of selection of mutations after starting TDF or TAF treatment and no change in susceptibility to TFV or TAF in vitro.

Efficacy and cost-effectiveness of antiviral regimens for entecavir-resistant hepatitis B: A systematic review and network meta-analysis

BACKGROUND

Chronic hepatitis B (CHB) patients who had exposed to lamivudine (LAM) and telbivudine (LdT) had high risk of developing entecavir (ETV)-resistance after long-term treatment. We aimed to conduct a systematic review and a network meta-analysis on the efficacy and cost-effectiveness on antiviral regimens in CHB patients with ETV-resistance.

DATA SOURCES

We searched PubMed, EMBASE and Web of Science for studies on nucleos(t)ide analogues (NAs) treatment [including tenofovir disoproxil fumarate (TDF)-based rescue therapies, adefovir (ADV)-based rescue therapies and double-dose ETV therapy] in CHB patients with ETV-resistance. The network meta-analysis was conducted for 1-year complete virological response (CVR) and biological response (BR) rates using GeMTC and ADDIS. A cost-effective analysis was conducted to select an economic and effective treatment regimen based on the 1-year CVR rate.

RESULTS

A total of 6 studies were finally included in this analysis. The antiviral efficacy was estimated. On network meta-analysis, the 1-year CVR rate in ETV-TDF [odds ratio (OR)  = 22.30; 95 % confidence interval (CI): 2.78-241.93], LAM-TDF (OR  = 70.67; 95 % CI: 5.16-1307.45) and TDF (OR  = 16.90; 95 % CI: 2.28-186.30) groups were significantly higher than that in the ETV double-dose group; the 1-year CVR rate in the LAM-TDF group (OR  = 14.82; 95 % CI: 1.03-220.31) was significantly higher than that in the LAM/LdT-ADV group. The 1-year BR rate of ETV-TDF (OR = 28.68; 95 % CI: 1.70-1505.08) and TDF (OR = 21.79; 95 % CI: 1.43-1070.09) therapies were significantly higher than that of ETV double-dose therapy. TDF-based therapies had the highest possibility to achieve the CVR and BR at 1 year, in which LAM-TDF combined therapy was the most effective regimen. The ratio of cost/effectiveness for 1-year treatment was 8 526, 17 649, 20 651 Yuan in the TDF group, TDF-ETV group, and ETV-ADV group, respectively.

CONCLUSIONS

TDF-based combined therapies such as ETV-TDF and LAM-TDF therapies were the first-line treatment if financial condition is allowed.

Tenofovir-based combination therapy or monotherapy for multidrug-resistant chronic hepatitis B: Long-term data from a multicenter cohort study

The treatment of multidrug-resistant (MDR) chronic hepatitis B (CHB) is challenging. Herein, we report a multicenter prospective cohort study for the evaluation of tenofovir disoproxil fumarate (TDF)-based therapy for MDR CHB in a real-life setting. The inclusion criteria comprised patients with resistance to more than two nucleos(t)ide analogue (NA) classes and hepatitis B virus (HBV) DNA level of ≥200 IU/mL. The primary end-point was virologic response (VR), defined as undetectable HBV DNA (<20 IU/mL) after 60 months. A total of 236 patients met the inclusion criteria. The mean HBV DNA level was 4.16 ± 1.44 log IU/mL; 26.7% of patients had liver cirrhosis. Before the initiation of TDF, 33.5%, 44.9% and 21.6% of patients had mutations resistant to L-NA + adefovir, L-NA + entecavir (ETV) and L-NA + adefovir + ETV, respectively. A total of 184 patients received TDF-based combination therapy [TDF + ETV (n = 178) or TDF + L-NA (n = 6)], and 52 patients received TDF monotherapy. In the entire cohort, the VR rates were 77.2%, 89.9% and 92.2% at 12, 36 and 60 months, respectively. The VR rates were not significantly different between the combination therapy and the monotherapy group after 12 (76.2% vs 80.4%, P = .533), 36 (89.8% vs 90.3%, P = 1.000) or 60 (92.9% vs 87.5%, P = .499) months. Also, there was no significant difference in the cumulative VR rates for 5 years between the treatment groups (P = .910). Newly developed antiviral resistance was not observed. TDF-based therapy was effective for the treatment of MDR CHB. The efficacy of TDF monotherapy was not different from that of the TDF-based combination therapy.

Japan Society of Hepatology Guidelines for the Management of Hepatitis B Virus Infection: 2019 update

The Drafting Committee for Hepatitis Management Guidelines established by the Japan Society of Hepatology published the first version of the Guidelines for the Management of Hepatitis B in 2013 (first English version in 2014), and has since been publishing updates to the Guidelines as new drugs become available, with the latest original Japanese version being Version 3.1. Herein, the Drafting Committee publishes the second English version that contains all the changes made since the first English version of the guidelines was published in 2014. This 2019 version covers: (i) the nucleos(t)ide analogs, tenofovir disoproxil fumarate and tenofovir alafenamide; (ii) updates to treatment recommendations and management of drug-resistant hepatitis B virus that reflect the new availability of these drugs; and (iii) new information about hepatitis B virus reactivation with each update. This latest update also contains information about treatment goals, indications for treatment and cessation of nucleos(t)ide analog therapy, most of which were covered by the first version.

Entecavir+tenofovir vs. lamivudine/telbivudine+adefovir in chronic hepatitis B patients with prior suboptimal response

Background/Aims

Suboptimal responses to lamivudine or telbivudine plus adefovir (LAM/LdT+ADV) rescue therapy are common in patients with LAM-resistant hepatitis B virus (HBV) infections. We compared patients switched to entecavir plus tenofovir (ETV+TDF) to those maintained on LAM/LdT+ADV.

Methods

This prospective randomized controlled trial examined 91 patients whose serum HBV DNA levels were greater than 60 IU/mL after at least 24 weeks of treatment with LAM/LdT+ADV for LAM-resistant HBV. Patients were randomized to receive a new treatment (ETV+TDF, n=45) or maintained on the same treatment (LAM/LdT+ADV, n=46) for 48 weeks. Patients with baseline ADV resistance were excluded.

Results

Compared to LAM/LdT+ADV group, ETV+TDF group had more patients with a virologic response (42/45 [93.33%] vs. 3/46 [6.52%], P<0.001) and had a greater mean reduction in serum HBV DNA level from baseline (-4.16 vs. -0.37 log₁₀ IU/mL, P<0.001). Multivariate analysis indicated that high baseline HBV DNA level (P=0.005) and LAM/LdT+ADV maintenance therapy (P=0.001) were negatively associated with virologic response. At week 48, additional ADV- or ETV-associated mutations were cleared in ETV+TDF group, but such mutations were present in 4.3% of patients in LAM/LdT+ADV group (P=0.106). The two groups had similar rates of adverse events.

Conclusions

ETV+TDF combination treatment led to a significantly higher rate of virologic response compared to LAM/LdT+ADV combination treatment in patients with LAM-resistant HBV who had suboptimal responses to LAM/LdT+ADV regardless of HBV genotypic resistance profile (NCT01597934).

Adverse events of nucleos(t)ide analogues for chronic hepatitis B: a systematic review

Nucleos(t)ide analogues (NAs) are the main drug category used in chronic hepatitis B (CHB) treatment. Despite the fact that NAs have a favourable safety profile, undesired adverse events (AEs) may occur during the treatment of CHB. Given the eminent number of patients currently receiving NAs, even a small risk of any of these toxicities can represent a major medical issue. The main objective of this review was to analyse information available on AEs associated with the use of NAs in published studies. We choose the following MesH terms for this systematic review: chronic hepatitis B, side effects and treatment. All articles published from 1 January 1990 up to 19 February 2018 in MEDLINE of PubMed, EMBASE, the Cochrane Library and LILACS databases were searched. A total of 120 articles were selected for analysis, comprising 6419 patients treated with lamivudine (LAM), 5947 with entecavir (ETV), 3566 with tenofovir disoproxil fumarate (TDF), 3096 with telbivudine (LdT), 1178 with adefovir dipivoxil (ADV) and 876 with tenofovir alafenamide (TAF). The most common AEs in all NAs assessed were abdominal pain/discomfort, nasopharyngitis/upper respiratory tract infections, fatigue, and headache. TAF displays the highest density of AEs per patient treated among NAs (1.14 AE/treated patient). In conclusion, treatment of CHB with NAs is safe, with a low incidence of AEs. Despite the general understanding TAF being safer than TDF, the number of patients treated with TAF still is too small in comparison to other NAs to consolidate an accurate safety profile. PROSPERO Registration No. CRD42018086471.

Tenofovir monotherapy versus tenofovir plus entecavir combination therapy in HBeAg-positive chronic hepatitis patients with partial virological response to entecavir

AIMS

The aim of this retrospective study was to compare the efficacy and safety of tenofovir disoproxil fumarate (TDF) monotherapy and TDF + entecavir (ETV) combination therapy for chronic hepatitis B (CHB) patients with the partial virological response (PVR) to ETV.

METHODS

CHB patients with PVR to ETV were switched to TDF monotherapy or TDF + ETV combination therapy. The primary efficacy outcome was a virological response (VR), and the secondary efficacy outcomes were hepatitis B e antigen (HBeAg) seroconversion and alanine aminotransferase (ALT) normalization. The primary safety outcomes were changes in serum creatinine and serum phosphorus levels.

RESULTS

A total of 143 patients were investigated, including 63 patients in the TDF monotherapy group and 80 patients in the TDF + ETV combination therapy group. Baseline demographics and clinical characteristics were comparable between groups. The median age of patients was 44.5 years, and 76.2% of them were male. The VR rate in TDF + ETV group was higher than that of the TDF group at 48 weeks (88.8% vs 71.4%; P = .009). At 48 weeks, the HBeAg seroconversion rate of TDF + ETV group was higher than that of the TDF group (30% vs 15.9%; P = .049). There was no significant difference in the proportion of patients with elevated ALT in the TDF group and TDF + ETV group at 48 weeks (9.5% vs 7.5%; P = .665). After adjusting the treatment regimen, serum creatinine levels increased slightly and serum phosphorus level decreased slightly in both groups.

CONCLUSIONS

TDF + ETV combination therapy for 48 weeks had a higher VR rate than TDF monotherapy in CHB patients with PVR to ETV.

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.

Monotherapy with tenofovir disoproxil fumarate for adefovir-resistant vs. entecavir-resistant chronic hepatitis B: A 5-year clinical trial

BACKGROUND & AIMS

Tenofovir disoproxil fumarate (TDF) monotherapy has displayed non-inferior efficacy to TDF plus entecavir (ETV) combination therapy in patients with hepatitis B virus (HBV) resistant to ETV and/or adefovir (ADV). Nonetheless, the virologic response rate was suboptimal in patients receiving up to 144 weeks of TDF monotherapy. We aimed to assess the efficacy and safety of TDF monotherapy given for up to 240 weeks.

METHODS

One trial enrolled patients with ETV resistance without ADV resistance (n = 90), and another trial included patients with ADV resistance (n = 102). Most patients (91.2%) also had lamivudine resistance. Patients were randomized 1:1 to receive TDF monotherapy or TDF + ETV combination therapy for 48 weeks, and then TDF monotherapy until week 240. We compared efficacy between the studies and safety in the pooled population at 240 weeks.

RESULTS

At week 240, the proportion of patients with serum HBV DNA <15 IU/ml was not significantly different between the ETV and ADV resistance groups in the full analysis set (84.4% vs. 73.5%; p = 0.07), which was significantly different by on-treatment analysis (92.7% vs. 79.8%; p = 0.02). Virologic blips associated with poor medication adherence occurred in 7 patients throughout the 240 weeks. None developed additional HBV resistance mutations. Among the 170 HBV e antigen (HBeAg)-positive patients at baseline, 12 (7.1%) achieved HBeAg seroconversion at week 240. None achieved HBV surface antigen seroclearance. Significant decreases from baseline were observed at week 240 in the estimated glomerular filtration rate (-3.21 ml/min/1.73 m² by the CKD-EPI equation, p <0.001) and bone mineral density (g/cm²) at the femur (-2.48%, p <0.001).

CONCLUSIONS

Up to 240 weeks of TDF monotherapy provided an increasing virologic response rate in heavily pretreated patients with HBV resistant to ETV and/or ADV. However, it was associated with poor serological responses and decreasing renal function and bone mineral density. (ClinicalTrials.gov No, NCT01639066 and NCT01639092).

LAY SUMMARY

In patients chronically infected with hepatitis B virus resistant to multiple drugs including lamivudine, entecavir, and/or adefovir, tenofovir disoproxil fumarate (TDF) monotherapy showed non-inferior efficacy compared with the combination therapy of TDF plus entecavir. Nonetheless, short-term TDF monotherapy was associated with suboptimal virologic response, and its long-term safety was uncertain. This study displayed that 240 weeks of TDF monotherapy provided a virologic response in most of those patients, but it was associated with poor serological responses and decreasing renal function and bone mineral density.

Identification of a quadruple mutation that confers tenofovir resistance in chronic hepatitis B patients

BACKGROUND & AIMS

Tenofovir disoproxil fumarate (TDF) is one the most potent nucleot(s)ide analogues for treating chronic hepatitis B virus (HBV) infection. Phenotypic resistance caused by genotypic resistance to TDF has not been reported. This study aimed to characterize HBV mutations that confer tenofovir resistance.

METHODS

Two patients with viral breakthrough during treatment with TDF-containing regimens were prospectively enrolled. The gene encoding HBV reverse transcriptase was sequenced. Eleven HBV clones harboring a series of mutations in the reverse transcriptase gene were constructed by site-directed mutagenesis. Drug susceptibility of each clone was determined by Southern blot analysis and real-time PCR. The relative frequency of mutants was evaluated by ultra-deep sequencing and clonal analysis.

RESULTS

Five mutations (rtS106C [C], rtH126Y [Y], rtD134E [E], rtM204I/V, and rtL269I [I]) were commonly found in viral isolates from 2 patients. The novel mutations C, Y, and E were associated with drug resistance. In assays for drug susceptibility, the IC₅₀ value for wild-type HBV was 3.8 ± 0.6 µM, whereas the IC₅₀ values for CYE and CYEI mutants were 14.1 ± 1.8 and 58.1 ± 0.9 µM, respectively. The IC₉₀ value for wild-type HBV was 30 ± 0.5 µM, whereas the IC₉₀ values for CYE and CYEI mutants were 185 ± 0.5 and 790 ± 0.2 µM, respectively. Both tenofovir-resistant mutants and wild-type HBV had similar susceptibility to the capsid assembly modulator NVR 3-778 (IC₅₀ <0.4 µM vs. IC₅₀ = 0.4 µM, respectively).

CONCLUSIONS

Our study reveals that the quadruple (CYEI) mutation increases the amount of tenofovir required to inhibit HBV by 15.3-fold in IC₅₀ and 26.3-fold in IC₉₀. These results demonstrate that tenofovir-resistant HBV mutants can emerge, although the genetic barrier is high.

LAY SUMMARY

Tenofovir is the most potent nucleotide analogue for the treatment of chronic hepatitis B virus infection and there has been no hepatitis B virus mutation that confers >10-fold resistance to tenofovir up to 8 years. Herein, we identified, for the first time, a quadruple mutation that conferred 15.3-fold (IC₅₀) and 26.3-fold (IC₉₀) resistance to tenofovir in 2 patients who experienced viral breakthrough during tenofovir treatment.

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.

Treatment Outcome and Renal Safety of 3-Year Tenofovir Disoproxil Fumarate Therapy in Chronic Hepatitis B Patients with Preserved Glomerular Filtration Rate

Background/Aims

To investigate the treatment efficacy and renal safety of long-term tenofovir disoproxil fumarate (TDF) therapy in chronic hepatitis B (CHB) patients with preserved renal function.

Methods

The medical records of 919 CHB patients who were treated with TDF therapy were reviewed. All patients had preserved renal function with an estimated glomerular filtration rate (eGFR) of at least 60 mL/min/1.73 m².

Results

A total of 426 patients (184 treatment-naïve and 242 treatment-experienced) were included for analysis. A virologic response (VR) was defined as achieving an undetectable serum hepatitis B virus (HBV) DNA level, and the overall VR was 74.9%, 86.7%, and 89.4% at the 1, 2, and 3-year follow-ups, respectively. Achieving a VR was not influenced by previous treatment experience, TDF combination therapy, or antiviral resistance. In a multivariate analysis, being hepatitis B e antigen positive at baseline and having a serum HBV DNA level ≥2,000 IU/mL at 12 months were associated with lower VR rates during the long-term TDF therapy. The overall renal impairment was 2.9%, 1.8%, and 1.7% at the 1, 2, and 3-year follow-ups, respectively. With regard to renal safety, underlying diabetes mellitus (DM) and an initial eGFR of 60 to 89 mL/min/1.73 m² were significant independent predictors of renal impairment.

Conclusions

TDF therapy appears to be an effective treatment option for CHB patients with a preserved GFR. However, patients with underlying DM and initial mild renal dysfunction (eGFR, 60 to 89 mL/min/1.73 m²) have an increased risk of renal impairment.

Longitudinal Assessment of Three Serum Biomarkers to Detect Very Early-Stage Hepatocellular Carcinoma

We aimed to determine the surveillance performance of alpha-fetoprotein (AFP), lectin-reactive AFP (AFP-L3), des-gamma-carboxy prothrombin (DCP), and their combinations for the early detection of hepatocellular carcinoma (HCC) by using prospectively collected longitudinal samples in patients at risk. Among 689 patients with cirrhosis and/or chronic hepatitis B who participated in four prospective studies, 42 HCC cases were diagnosed, selected, and matched with 168 controls for age, sex, etiology, cirrhosis, and duration of follow-up in a 1:4 ratio. Levels of AFP, AFP-L3, and DCP at the time of HCC diagnosis, month -6, and month -12 were compared between cases and controls. Of 42 HCC cases, 39 (93%) had cirrhosis, 36 (85.7%) had normal alanine aminotransferase levels, and 31 (73.8%) had very early-stage HCC (single <2 cm). AFP and AFP-L3 began to increase from 6 months before diagnosis of HCC in cases (P < 0.05), while they remained unchanged in controls. At HCC diagnosis, the area under the receiver operator characteristic curves (AUROCs) for AFP, AFP-L3, and DCP were 0.77, 0.73, and 0.71, respectively. Combining AFP and AFP-L3 showed a higher AUROC (0.83), while adding DCP did not further improve the AUROC (0.86). With the optimal cutoff values (AFP, 5 ng/mL; AFP-L3, 4%), the sensitivity and specificity of AFP and AFP-L3 combination were 79% and 87%, respectively. The sensitivity of ultrasonography was 48.6%, which was increased to 88.6% and 94.3% by adding AFP and AFP + AFP-L3, respectively. Conclusion: Among three biomarkers, AFP showed the best performance in discriminating HCC cases from controls; the AFP and AFP-L3 combination, adopting cutoff values (5 ng/mL and 4%, respectively), significantly improved the sensitivity for detecting HCC at a very early stage.

Okuda lecture: Challenges of hepatitis B in the era of antiviral therapy

Nucleos(t)ide analogs (NAs) are effective, safe, and convenient antiviral therapy to suppress replication of hepatitis B virus, which can be translated into improved long-term outcome of chronic hepatitis B patients. The current recommended first-line NAs, namely, entecavir and tenofovir, are largely free from problems of drug resistance. Nonetheless, there are still a few challenges in the era of NA. First, the risk of hepatocellular carcinoma can only be reduced but not eliminated, particularly among cirrhotic patients. For cirrhotic patients who have persistent low-level viremia on NA, that is, partial responders, the risk of hepatocellular carcinoma is higher than those with complete viral suppression. The best strategy to manage partial responders to entecavir or tenofovir is uncertain. Second, immune-tolerant patients are very difficult to treat with NA. A significant proportion of immune-tolerant patients will have detectable viremia despite a few years of continuous NA treatment, and the rate of hepatitis B e-antigen seroconversion is very low. Third, most patients need long-term treatment as NA cannot eliminate covalently closed circular DNA in the hepatocytes. Some patients can consider stop NA according to treatment guidelines, but viral and clinical relapses often occur after treatment cessation. There is no concrete consensus on when one should stop NA in a hepatitis B e-antigen-negative patient among different treatment guidelines. New biomarkers such as hepatitis B surface antigen level can be used to select patients to stop NA, but the data are still preliminary.

Is Combination Antiviral Therapy Mandatory for Maintenance Therapy in Fully Suppressed Multidrug-Resistant Hepatitis B Patients?

Aim

The efficacy of tenofovir disoproxil fumarate (TDF) monotherapy as maintenance therapy in multidrug-resistant (MDR) hepatitis B virus (HBV) patients after complete virologic suppression (CVS) has not been well evaluated. We evaluated the efficacy of maintenance TDF monotherapy compared with conventional TDF plus entecavir combination therapy after CVS of MDR HBV.

Methods

In this single-center retrospective study, patients with MDR HBV who were previously treated with entecavir plus TDF combination therapy and achieved CVS were included. Patients were either maintained on entecavir plus TDF combination therapy or switched to TDF monotherapy after CVS. The primary endpoint was the virologic breakthrough, and secondary outcomes were liver cirrhosis (LC) or hepatocellular carcinoma (HCC) development. To overcome immortal time bias, time-varying Cox proportional hazard regression analysis was performed.

Results

A total of 201 patients were included, and 153 patients were maintained on entecavir plus TDF combination therapy (combination group); 48 patients were converted from combination therapy to TDF monotherapy (single group) after CVS. Five patients experienced a virologic breakthrough, one patient in the single group owing to poor transient compliance and four patients in the combination group (P = 0.51). One new case of LC developed in the single group; five cases of LC developed in the combination group (P = 0.35). No new HCC development occurred in the single group, while seven cases of HCC developments were noted in the combination group. However, these results were not statistically significant (P = 0.54).

Conclusions

For patients with suppressed HBV DNA, the efficacy of TDF monotherapy as maintenance therapy is comparable to that of entecavir plus TDF combination therapy.

Taiwan consensus statement on the management of chronic hepatitis B

The experts of Taiwan Association for the Study of Liver (TASL) have actively participated and led the guidelines on hepatitis B virus (HBV) management by Asian Pacific Association for the Study of Liver (APASL) which is the first international association for the study of liver to publish the statement on HBV management before. However, there are more and more new data on the natural history and treatment of HBV infection in the past decade. These include new application of an old biomarker (quantitative HBsAg), clinical significance of HBV genotype and naturally occurring mutations, the role of non-invasive examination in evaluating severity of hepatic fibrosis, clinical significance of outcome calculators, new drug or new combination strategies towards more effective therapy and organ transplantation including liver and non-liver transplantation. It is time to publish the guidelines on HBV management of Taiwan. Hence, TASL have conducted an expert meeting to review, to discuss and to debate the relevant literatures, followed by draft the manuscript of HBV management guidelines and recommendations. The guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patient receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included.

Incident hepatocellular carcinoma developing during tenofovir alafenamide treatment as a rescue therapy for multi-drug resistant hepatitis B virus infection: A case report and review of the literature

Tenofovir disoproxil fumarate (TDF) is a potent nucleotide analogue with high barrier to resistance, which is recommended for multi-drug resistant hepatitis B virus (HBV) infection. However, nephrotoxicity has been reported during TDF treatment, and tenofovir alafenamide (TAF), which has comparable efficacy to TDF and improves bone and renal safety, can be used as a replacement strategy. Herein, we describe a clinical case concerning a 60-year-old individual suffering liver cirrhosis and renal dysfunction, and being infected with multidrug-resistant HBV. When failing treatment with TDF, he received TAF as a rescue therapy. TAF effectively inhibited HBV replication without worsening renal function or serum phosphorus abnormality. Furthermore, hepatocellular carcinoma (HCC) occurred during TAF treatment despite controlling the viral load. The risk of HCC could not be eliminated and should be monitored during TAF treatment.

Switching to tenofovir vs continuing entecavir for hepatitis B virus with partial virologic response to entecavir: a randomized controlled trial

Entecavir 0.5 mg (ETV) is widely used among treatment-naïve chronic hepatitis B (CHB) patients. However, 10%-30% of patients show partial virologic response (PVR) to the drug. If the hepatitis B virus (HBV) continues to replicate, the underlying liver disease may progress. Herein, we compared the efficacy of switching to tenofovir disoproxil fumarate (TDF) with that of continuing ETV in CHB patients with PVR to ETV. This was an open-label randomized controlled trial including CHB patients who had been receiving 0.5 mg of ETV for >12 months, but who still had detectable HBV DNA levels of >60 IU/mL without known resistance to ETV. Sixty patients were enrolled and 45 qualified for the study: Twenty-two patients were randomly assigned into the TDF group and 23 into the ETV group. After 12 months of treatment, the virologic response rate (HBV DNA <20 IU/mL) was significantly higher in the TDF group than in the ETV group, as measured using per-protocol analysis (55% vs 20%; P = .022) and intention-to-treat analysis (50% vs 17.4%; P = .020). The reduction in HBV DNA was greater (-1.13 vs -0.67 log₁₀ IU/mL; P = .024), and the mean HBV DNA level was lower (1.54 vs 2.01 log₁₀ IU/mL; P = .011) in the TDF group than in the ETV group. In conclusion, to achieve optimal response in CHB patients with PVR to ETV, switching to TDF would be a better strategy than continuing ETV. Appropriate modification of therapy would further improve the outcome of chronic HBV infection.

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.

Real World Experience of Telbivudine Versus Entecavir in Patients with Chronic Hepatitis B, Including Long-Term Outcomes after Treatment Modification

PURPOSE

To estimate long-term outcomes after treatment modification in patients with chronic hepatitis B (CHB) treated with entecavir (ETV) and telbivudine (LdT).

MATERIALS AND METHODS

The study enrolled 131 nucleos(t)ide analogue (NA)-naïve CHB patients treated with ETV or LdT. During the 3-year study, NA treatment history including the incidence, the type of treatment modification, reasons for the modification, and overall complete virologic response (CVR) rate were retrospectively evaluated using the patients' medical records.

RESULTS

Among the 131 patients, 84 and 47 were initially treated with ETV and LdT, respectively. During the course of 3-year study, 82 patients in the ETV group (97.6%) maintained initial treatment whereas only 19 in the LdT group (40.4%). In the LdT group, 26 patients (92.9%) switched to another NA and another NA was added in 2 (7.1%) patients. An assessment of the CVR rate at 3 years, including treatment modification, showed that 89.3% and 95.7% of patients in the ETV and LdT groups, respectively, had undetectable serum hepatitis B virus DNA levels (p=0.329). Among LdT patients with treatment modification, the cumulative incidence rate of a CVR for rescue therapy was significantly higher in the tenofovir than in the ETV group (p=0.009).

CONCLUSION

During the 3-year study, there were no significant differences in the CVR between the ETV and LdT groups if appropriate rescue therapy was considered.

Chronic Hepatitis B Infection: A Review

IMPORTANCE

More than 240 million individuals worldwide are infected with chronic hepatitis B virus (HBV). Among individuals with chronic HBV infection who are untreated, 15% to 40% progress to cirrhosis, which may lead to liver failure and liver cancer.

OBSERVATIONS

Pegylated interferon and nucleos(t)ide analogues (lamivudine, adefovir, entecavir, tenofovir disoproxil, and tenofovir alafenamide) suppress HBV DNA replication and improve liver inflammation and fibrosis. Long-term viral suppression is associated with regression of liver fibrosis and reduced risk of hepatocellular carcinoma in cohort studies. The cure (defined as hepatitis B surface antigen loss with undetectable HBV DNA) rates after treatment remain low (3%-7% with pegylated interferon and 1%-12% with nucleos[t]ide analogue therapy). Pegylated interferon therapy can be completed in 48 weeks and is not associated with the development of resistance; however, its use is limited by poor tolerability and adverse effects such as bone marrow suppression and exacerbation of existing neuropsychiatric symptoms such as depression. Newer agents (entecavir, tenofovir disoproxil, and tenofovir alafenamide) may be associated with a significantly reduced risk of drug resistance compared with older agents (lamivudine and adefovir) and should be considered as the first-line treatment.

CONCLUSIONS AND RELEVANCE

Antiviral treatment with either pegylated interferon or a nucleos(t)ide analogue (lamivudine, adefovir, entecavir, tenofovir disoproxil, or tenofovir alafenamide) should be offered to patients with chronic HBV infection and liver inflammation in an effort to reduce progression of liver disease. Nucleos(t)ide analogues should be considered as first-line therapy. Because cure rates are low, most patients will require therapy indefinitely.

Evaluating the efficacy of switching from lamivudine plus adefovir to tenofovir disoproxil fumarate monotherapy in lamivudine-resistant stable hepatitis B patients

BACKGROUND

The efficacy of switching to tenofovir disoproxil fumarate (TDF) monotherapy from lamivudine (LAM) plus adefovir dipivoxil (ADV) combination therapy (stable switching) in patients with LAM-resistant chronic hepatitis B (CHB) and undetectable hepatitis B virus (HBV) DNA is not clear.

METHODS

In this non-inferiority trial, patients with LAM-resistant CHB and undetectable serum HBV DNA (<20 IU/mL) for >6 months after initiating LAM+ADV combination therapy were randomized (1:2) either to continue the combination therapy (LAM+ADV group, n = 58) or switched to TDF monotherapy (TDF group, n = 111). They were followed-up with serum biochemistry tests and HBV DNA measurement at 12-week intervals for 96 weeks. The primary endpoint of this study was the proportion of patients with viral reactivation at week 96.

RESULTS

Patients with CHB enrolled in this study (n = 169) included 74 patients with compensated liver cirrhosis. In total, 9 patients (4 in the LAM+ADV group and 5 in the TDF group) dropped-out from the study. After a mean follow-up period of 96 weeks, the proportion of HBV reactivation observed was 6.8% (4/58) in the LAM+ADV group and 4.5% (5/111) in the TDF group by using intention-to-treat analysis (difference, -2.3%; 95% CI, -9.84-5.24%). None of the subjects in either group experienced viral reactivation based on per protocol analysis. No serious adverse reactions were observed. In the subgroup analysis for estimated glomerular filtration rate (eGFR) before and after treatment, decreased eGFR was observed only in the TDF group with cirrhosis (85.22 vs. 79.83 mL/min/1.73 m2, p = 0.000).

CONCLUSIONS

Stable switching to TDF monotherapy yielded non-inferior results at 96 weeks compared to the results obtained with LAM+ADV combination therapy in patients with LAM-resistant CHB and undetectable HBV DNA. However, TDF monotherapy in patients with cirrhosis requires close attention with respect to renal function.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01732367.

Effects of antiviral therapy in patients with chronic hepatitis B and cirrhosis

Hepatitis B virus (HBV) infection is the major cause of cirrhosis worldwide. The ultimate goal of current antiviral treatments for chronic hepatitis B (nucleos(t)ide analogs and interferon-α) is to prevent the development of end-stage liver diseases. Areas covered: We present a review of the current literature on antiviral therapy in patients with chronic hepatitis B and cirrhosis. Medline search was performed to identify relevant literature from 1993 through January of 2017. Expert commentary: One randomized controlled trial and a number of observational studies have shown that nucleos(t)ide analogs can decrease the incidence of hepatocellular carcinoma (HCC) in chronic hepatitis B patients with advanced fibrosis. Data from clinical trials of entecavir and tenofovir have shown that histological improvement and regression of fibrosis can be achieved in the majority of patients with chronic hepatitis B by successful viral suppression. Entecavir and tenofovir are the preferred antiviral agents for treatment of chronic hepatitis B in patients with cirrhosis due to their high antiviral potency and high genetic barrier to resistance. Pegylated interferon-α is another therapeutic option for chronic hepatitis B patients with well-compensated cirrhosis. However, interferon therapy is contraindicated in patients with decompensated cirrhosis, and evidence for reduced HCC is currently insufficient.

Switching from tenofovir and nucleoside analogue therapy to tenofovir monotherapy in virologically suppressed chronic hepatitis B patients with antiviral resistance

It is unclear whether chronic hepatitis B (CHB) patients with antiviral resistance, who achieve a complete virologic response (CVR) with tenofovir disoproxil fumarate (TDF) and nucleoside analogue (NUC) combination therapy, maintain CVR if switched to TDF monotherapy. We investigated the persistence of CVR after cessation of NUC in virologically suppressed antiviral resistant CHB patients using TDF+NUC combination therapy. This study recruited 76 antiviral-resistant CHB patients showing CVR on TDF+entecavir (ETV) (n = 52), TDF+lamivudine (LAM; n = 14), and TDF+telbivudine (LdT; n = 10) combination therapy, who were switched to TDF monotherapy as step-down therapy. At baseline, 47 patients were male and the median age was 53.0 years (range: 30-78 years); 72.3% cases were hepatitis B e antigen-positive (HBeAg+) and 23.7% were of liver cirrhosis. The median duration of TDF+NUC combination therapy was 20.8 months (range: 3-46 months). At a median follow-up of 24.7 months (range: 12-48 months) after switching to TDF monotherapy, all 76 patients maintained CVR, regardless of the duration of combination therapy and the type of prior NUC and antiviral resistance. Renal dysfunction was not observed during the treatment period. The step-down strategy of switching from TDF+NUC combination therapy to TDF monotherapy in virologically suppressed CHB patients with antiviral resistance should be considered.

Tenofovir vs lamivudine plus adefovir in chronic hepatitis B: TENOSIMP-B study

AIM

To demonstrate the non-inferiority (15% non-inferiority limit) of monotherapy with tenofovir disoproxil fumarate (TDF) vs the combination of lamivudine (LAM) plus adefovir dipivoxil (ADV) in the maintenance of virologic response in patients with chronic hepatitis B (CHB) and prior failure with LAM.

METHODS

This study was a Phase IV prospective, randomized, open, controlled study with 2 parallel groups (TDF and LAM+ADV) of adult patients with hepatitis B e antigen (HBeAg)-negative CHB, prior failure with LAM, on treatment with LAM+ADV for at least 6 mo, without prior resistance to ADV and with an undetectable viral load at the start of the study, in 14 Spanish hospitals. The follow-up time for each patient was 48 wk after randomization, with quarterly visits in which the viral load, biochemical and serological parameters, adverse effects, adherence to treatment and consumption of hospital resources were analysed.

RESULTS

Forty-six patients were evaluated [median age: 55.4 years (30.2-75.2); 84.8% male], including 22 patients with TDF and 24 with LAM+ADV. During study development, hepatitis B virus DNA (HBV-DNA) remained undetectable, all patients remained HBeAg negative, and hepatitis B surface antigen (HBsAg) positive. Alanine aminotransferase (ALT) values at the end of the study were similar in the 2 groups (25.1 ± 7.65, TDF vs 24.22 ± 8.38, LAM+ADV, P = 0.646). No significant changes were observed in creatinine or serum phosphorus values in either group. No significant differences between the 2 groups were noted in the identification of adverse effects (AEs) (53.8%, TDF vs 37.5%, LAM+ADV, P = 0.170), and none of the AEs which occurred were serious. Treatment adherence was 95.5% and 83.3% in the TDF and the LAM+ADV groups, respectively (P = 0.488). The costs associated with hospital resource consumption were significantly lower with the TDF treatment than the LAM+ADV treatment (€4943 ± 1059 vs €5811 ± 1538, respectively, P < 0.001).

CONCLUSION

TDF monotherapy proved to be safe and not inferior to the LAM+ADV combination therapy in maintaining virologic response in patients with CHB and previous LAM failure. In addition, the use of TDF generated a significant savings in hospital costs.

Renal safety of tenofovir and/or entecavir in patients with chronic HBV monoinfection

Background

Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) are recommended as the first-line therapy for chronic hepatitis B (CHB) due to their genetic barrier to resistance and effectiveness of virological suppression. TDF and ETV may cause renal toxicity through various mechanisms such as renal tubular injury, apoptosis, and mitochondrial toxicity. The aims of the current review were to assess the potential renal toxicity associated with the use of TDF and ETV in patients infected with chronic hepatitis B virus (HBV) and to provide clinical perspectives on these two agents in the treatment of CHB.

Methods

A literature search of clinical studies published in PubMed and posted on ClinicalTrials.gov website was implemented to find studies evaluating the potential renal toxicity of TDF and ETV.

Results

Twenty-one studies were examined in this review. The TDF dose used in the studies was 245 or 300 mg/day and that of ETV was 0.5 or 1 mg/day. Based on the markers of renal function, patients treated with TDF were not more likely to show changes in renal function than those treated with ETV; however, the estimated glomerular filtration rates (eGFRs) of patients receiving TDF tended to be more clearly reduced than those of patients receiving ETV. The eGFRs of patients treated with TDF decreased in a time-dependent manner, whereas those of patients treated with ETV increased or decreased across various time points.

Conclusion

The data shown in this study suggest that use of TDF and ETV could be at least associated with reductions in renal function in patients with chronic HBV infection. However, various risk factors, such as pre-existing renal failure and comorbidities, are also associated with decreased renal function during the treatment of TDF and ETV. Thus, studies of management strategies for HBV-infected patients with these risk factors are necessary in the near future.

Efficacy and safety of tenofovir disoproxil fumarate rescue therapy for chronic hepatitis B patients who failed other nucleos(t)ide analogs

AIM

Acquisition of nucleos(t)ide analog (NA) inhibitor resistance is critical in successful chronic hepatitis B treatment. As the pattern of tenofovir disoproxil fumarate (TDF) resistance mutations differs from that of other antiviral drugs, we sought to clarify the salvaging potential of TDF in patients with hepatitis B virus (HBV) infection who are poor responders or resistant to other NAs.

METHODS

A prospective, multicenter, single-arm, open-label study was carried out from December 2011 to October 2014. Poor responders defined as subjects with serum HBV-DNA levels >4 log₁₀  copies/mL were enrolled. Subjects receiving lamivudine (LAM) + adefovir pivoxil (ADV) before the initiation of the study were switched to LAM + TDF. Subjects on entecavir hydrate (ETV) with or without ADV were switched to ETV + TDF. The primary efficacy end-point was the proportion of subjects achieving HBV-DNA <2.1 log₁₀  copies/mL (LLQ) at week 24. The secondary efficacy end-points were the proportion of subjects with LLQ at weeks 48 and 96, serum alanine aminotransferase normalization, hepatitis B envelope antigen/antibody and hepatitis B surface antigen/antibody seroconversion.

RESULTS

Thirty-four subjects were enrolled, 21 subjects were switched to ETV + TDF, and 13 subjects were switched to LAM + TDF. Drug resistance mutations were determined in 85% of the subjects at the time of the enrolment. The proportion of subjects who achieved LLQ was 59%, 62%, and 71% at weeks 24, 48, and 96, respectively. No serious adverse event related to TDF was reported.

CONCLUSION

Our study clearly showed that TDF containing regimens were effective in salvaging poor responders and/or those who are drug-resistant to other NAs. This study is registered with ClinicalTrials.gov (NCT01475851) and the GSK Clinical Study Register (GSK LOC115912).

Monotherapy with tenofovir disoproxil fumarate for multiple drug-resistant chronic hepatitis B: 3-year trial

Combination therapy has been recommended for the treatment of patients harboring multiple drug-resistant hepatitis B virus (HBV). However, we recently demonstrated that monotherapy with tenofovir disoproxil fumarate (TDF) for 48 weeks displayed noninferior efficacy to TDF plus entecavir (ETV) combination therapy in patients with HBV resistant to multiple drugs, including ETV and adefovir. Nonetheless, whether prolonged TDF monotherapy would be safe and increase the virologic response rate in these patients was unclear. Among 192 patients with HBV-resistance mutations to ETV and/or adefovir, who were randomized to receive TDF monotherapy (n = 95) or TDF/ETV combination therapy (n = 97) for 48 weeks, 189 agreed to continue TDF monotherapy (TDF-TDF group) or to switch to TDF monotherapy (TDF/ETV-TDF group) and 180 (93.8%) completed the 144-week study. Serum HBV DNA <15 IU/mL at week 48, the primary efficacy endpoint, was achieved in 66.3% in the TDF-TDF group and 68.0% in the TDF/ETV-TDF group (P = 0.80). At week 144, the proportion with HBV DNA <15 IU/mL increased to 74.5%, which was significantly higher compared with that at week 48 (P = 0.03), without a significant difference between groups (P = 0.46). By on-treatment analysis, a total of 79.4% had HBV DNA <15 IU/mL at week 144. Transient virologic breakthrough occurred in 6 patients, which was due to poor drug adherence. At week 144, 19 patients who had HBV DNA levels >60 IU/mL qualified for genotypic resistance analysis, and 6 retained some of their baseline resistance mutations of HBV. No patients developed additional resistance mutations throughout the study period.

CONCLUSION

TDF monotherapy was efficacious and safe for up to 144 weeks, providing an increasing rate of virologic response in heavily pretreated patients with multidrug-resistant HBV. (Hepatology 2017;66:772-783).

Management of Clevudine-Resistant Chronic Hepatitis B: A Multicenter Cohort Study

Background/Aims

Data are lacking regarding the management of chronic hepatitis B (CHB) with resistance to clevudine (CLV). This study evaluated the efficacy of different rescue therapies for CLV-resistant CHB.

Methods

Patients with CLV-resistant CHB were enrolled in the cohort, and all patients developed virologic breakthrough during CLV therapy and had confirmed-genotypic resistance to CLV (rtM204I mutation) before enrollment.

Results

Of the 107 patients, 12 received adefovir (ADV), 21 received a CLV plus ADV combination (CLV+ADV), 34 received a lamivudine plus ADV combination (LAM+ADV), and 40 received entecavir (ETV) therapy for 48 weeks. The CLV+ADV group had the lowest hepatitis B virus (HBV) DNA level (p<0.0001) and showed the greatest reduction of HBV DNA levels from baseline compared to all other groups (p=0.004) at week 48. HBV DNA was undetectable (<70 IU/mL) in 0%, 57.1%, 21.2%, and 27.5% (p=0.003) of the patients in each group, respectively, at week 48. At the end of the study, the mean alanine transaminase (ALT) level, rate of ALT normalization, and rate of hepatitis B envelope antigen loss or seroconversion did not differ between groups.

Conclusions

CLV+ADV combination therapy in patients with CLV-resistant CHB more effectively suppresses HBV replication than ETV, ADV, or LAM+ADV therapy.

EASL 2017 Clinical Practice Guidelines on the management of hepatitis B virus infection

Hepatitis B virus (HBV) infection remains a global public health problem with changing epidemiology due to several factors including vaccination policies and migration. This Clinical Practice Guideline presents updated recommendations for the optimal management of HBV infection. Chronic HBV infection can be classified into five phases: (I) HBeAg-positive chronic infection, (II) HBeAg-positive chronic hepatitis, (III) HBeAg-negative chronic infection, (IV) HBeAg-negative chronic hepatitis and (V) HBsAg-negative phase. All patients with chronic HBV infection are at increased risk of progression to cirrhosis and hepatocellular carcinoma (HCC), depending on host and viral factors. The main goal of therapy is to improve survival and quality of life by preventing disease progression, and consequently HCC development. The induction of long-term suppression of HBV replication represents the main endpoint of current treatment strategies, while HBsAg loss is an optimal endpoint. The typical indication for treatment requires HBV DNA >2,000IU/ml, elevated ALT and/or at least moderate histological lesions, while all cirrhotic patients with detectable HBV DNA should be treated. Additional indications include the prevention of mother to child transmission in pregnant women with high viremia and prevention of HBV reactivation in patients requiring immunosuppression or chemotherapy. The long-term administration of a potent nucleos(t)ide analogue with high barrier to resistance, i.e., entecavir, tenofovir disoproxil or tenofovir alafenamide, represents the treatment of choice. Pegylated interferon-alfa treatment can also be considered in mild to moderate chronic hepatitis B patients. Combination therapies are not generally recommended. All patients should be monitored for risk of disease progression and HCC. Treated patients should be monitored for therapy response and adherence. HCC remains the major concern for treated chronic hepatitis B patients. Several subgroups of patients with HBV infection require specific focus. Future treatment strategies to achieve 'cure' of disease and new biomarkers are discussed.

Efficacy of long-term tenofovir-based rescue therapy in patients with chronic hepatitis B refractory to nucleoside/nucleotide analogs

BACKGROUND

Few studies have investigated the efficacy of long-term tenofovir disoproxil fumarate (TDF)-based rescue therapy in patients with chronic hepatitis B refractory to nucleoside/nucleotide analogs.

METHODS

We retrospectively analyzed 40 Japanese patients with chronic hepatitis B refractory to nucleoside/nucleotide analogs who received TDF-based rescue therapy [TDF monotherapy, TDF plus lamivudine (LAM) combination therapy, or TDF plus entecavir (ETV) combination therapy] followed up for a median of 45 months (range 14-99 months). Viral response, changes in hepatitis B surface antigen levels from the baseline, and viral breakthrough during therapy were analyzed.

RESULTS

The proportion of patients with undetectable serum hepatitis B virus (HBV) DNA levels (less than 2.1 log copies per milliliter) (viral response) during TDF-based rescue therapy was 68, 78, 85, 88, 83, 81, 88, and 100 % at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, and 4 years respectively. There were no differences in the viral response rate between the TDF plus LAM group and the TDF plus ETV group. The mean reduction from the baseline in hepatitis B surface antigen levels in patients with LAM-resistant HBV was greater than the reductions in patients with adefovir dipivoxil (ADV)-resistant or ETV-resistant HBV at 2 and 3 years (P = 0.024, and P = 0.025 respectively). However, two patients with ADV- or ETV-resistant HBV at the baseline developed viral breakthrough during TDF-based rescue therapy.

CONCLUSIONS

Long-term therapy with a TDF-based rescue regimen demonstrated high viral suppression in patients in whom LAM plus ADV combination therapy, ETV plus ADV combination therapy, or ETV monotherapy had failed. However, patients with ADV- or ETV-resistant HBV at the baseline may develop viral breakthrough and resistance, and careful follow-up is advised.

Management of Antiviral Resistance in Chronic Hepatitis B

The primary goal of therapy for chronic hepatitis B (CHB) is to prevent liver disease progression. Hepatitis B surface antigen (HBsAg) seroclearance or seroconversion is regarded as an optimal endpoint to discontinue treatment. However, HBsAg seroclearance occurs very rarely with nucleos(t)ide analog (NUC) treatment, and long-term, almost indefinite, NUC treatment is required for the majority of patients. In patients with drug-resistant hepatitis B virus (HBV), a combination of tenofovir disoproxil fumarate (TDF) and entecavir (ETV), which is currently regarded as the strongest combination therapy against HBV, would be potentially safe to prevent the emergence of additional HBV resistance mutations. However, long-term tolerance data are lacking, and cost may be an issue for combination therapies. Several recent, well-designed, randomized controlled trials have shown that TDF monotherapy provides similar antiviral efficacy compared with the combination of TDF and ETV. Furthermore, no additional HBV resistance mutations emerged during TDF monotherapy for up to 96 weeks. Considering a comparable antiviral efficacy, extremely low risk of TDF-resistance, lower cost, and better safety potential, TDF monotherapy would be a reasonable choice for the treatment of drug-resistant patients with CHB.

Tenofovir has inferior efficacy in adefovir-experienced chronic hepatitis B patients compared to nucleos(t)ide-naïve patients

Background/Aims

A recent study reported that entecavir had inferior efficacy in nucleos(t)ide analogue (NA)-experienced chronic hepatitis B (CHB) patients compared to NA-naïve patients. We sought to compare the efficacy of tenofovir disoproxil fumarate (TDF) in NA-experienced and NA-naïve CHB patients.

Methods

We retrospectively enrolled 252 consecutive patients who had a serum hepatitis B virus (HBV) DNA level greater than 2,000 IU/mL at the initiation of TDF treatment and who received TDF for at least 6 months. Complete virologic suppression (CVS) was defined as undetectable serum HBV DNA. We generated a multivariate Cox proportional-hazard model to examine predictive factors that were independently associated with time to CVS.

Results

The mean age of patients was 48.2 years, and the cohort included 181 NA-naïve patients and 71 NA-experienced patients. The median duration of TDF treatment was 14.4 (interquartile range, 9.5-17.8) months. A total of 167 (92.3%) of 181 NA-naïve patients achieved CVS, and 60 (84.5%) of 71 NA-exposed patients achieved CVS. Forty-nine (89.1%) of 55 patients who previously took an NA aside from adefovir and 11 (68.8%) of 16 adefovir-experienced patients achieved CVS. In multivariable analysis, previous adefovir exposure significantly influenced time to CVS (hazard ratio, 0.37; 95% confidence interval, 0.19-0.72; P=0.003), after adjusting for HBeAg positivity, baseline HBV DNA level and cirrhosis.

Conclusions

Tenofovir had inferior efficacy in adefovir-experienced CHB patients compared to NA-naïve patients. The response of patients with previous adefovir exposure to TDF monotherapy should be monitored closely.

Tenofovir versus tenofovir plus entecavir for chronic hepatitis B with lamivudine resistance and entecavir resistance

We compared the viral suppressive efficacy of tenofovir disoproxil fumarate (TDF) mono-rescue therapy (TDF group) and TDF plus entecavir (ETV) combination-rescue therapy (TDF + ETV group) in chronic hepatitis B (CHB) patients with lamivudine resistance and entecavir resistance. One hundred and thirty-three CHB patients with lamivudine and entecavir resistance were investigated. Ninety-six patients were treated with TDF and 37 with TDF + ETV for at least 6 months. We compared the virologic response rate (HBV DNA level <20 IU/mL) between the two groups and identified the predictive factors of treatment outcome. There were no significant differences between the two groups in demographic characteristics. Up to 24 months [median: 18 (range 6-24) months], 85.4% and 89.2% of the TDF group and TDF + ETV group, respectively, achieved a virologic response (P=.068). Only the HBV DNA level at baseline was significantly associated with a virologic response in the multivariate analysis. In a subanalysis of patients with HBV DNA levels ≥4 log (IU/mL) at baseline, a higher proportion of patients in the TDF + ETV group than the TDF group achieved a virologic response (92.9% vs 68.3%; P<.001), while 90% of patients with HBV DNA (IU/mL) levels <4 log in all both TDF and TDF + ETV groups achieved a virologic response. TDF mono-rescue therapy is a reasonable option in patients with lamivudine resistance and entecavir resistance. However, the combination strategy should be considered in patients with high baseline HBV DNA levels.