Efficacy of tenofovir in preventing perinatal transmission of HBV infection in pregnant women with high viral loads

Antivirals for prevention of hepatitis B virus mother-to-child transmission in human immunodeficiency virus positive pregnant women co-infected with hepatitis B virus

BACKGROUND

Hepatitis B virus (HBV)-human Immunodeficiency virus (HIV) co-infection promotes an aggressive disease course of HBV infection. In the only available non-Cochrane systematic review on antiviral therapy during pregnancy for prevention of mother-to-child transmission of HBV, none of the women studied had HBV-HIV co-infection but were either HBV- or HIV-seropositive. Treatment of HBV alone may develop HIV-strains that are resistant to non-nucleoside reverse transcriptase inhibitors. Accordingly, co-treatment of the HIV infection is recommended.

OBJECTIVES

To evaluate the benefits and harms of tenofovir-based antiviral combination regimens versus placebo, tenofovir alone, or non-tenofovir-based antiviral regimen either alone or in combination with HBV for the prevention of mother-to-child transmission of HBV in HIV-positive pregnant women co-infected with HBV.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials, MEDLINE Ovid, Embase Ovid, LILACS (Bireme), Science Citation Index Expanded (Web of Science), and Conference Proceedings Citation Index-Science (Web of Science) on 30 January 2023. We manually searched the reference lists of included trials, searched on-line trial registries, and contacted experts in the field and pharmaceutical companies for any further potential trials.

SELECTION CRITERIA

We aimed to include randomised clinical trials comparing tenofovir-based antiviral combination regimens (anti-HIV regimen with lopinavir-ritonavir therapy, or any other antiviral therapy, and two drugs with activity against HBV, specifically, tenofovir alafenamide (TAF) or tenofovir disoproxil fumarate (TDF), plus lamivudine or emtricitabine) with placebo alone, or tenofovir alone, or non-tenofovir-based antiviral regimen (zidovudine, lamivudine, telbivudine, emtricitabine, entecavir, lopinavir-ritonavir, or any other antiviral therapy) either alone or in combination with at least two other antivirals.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Primary outcomes included all-cause infant mortality, proportion of infants with serious adverse events, proportion of infants with HBV mother-to-child transmission, all-cause maternal mortality, and proportion of mothers with serious adverse events. Secondary outcomes included proportion of infants with adverse events not considered serious, proportion of mothers with detectable HBV DNA (deoxyribonucleic acid) (before delivery), maternal hepatitis B e antigen (HBeAg) to HBe-antibody seroconversion (before delivery) and maternal adverse events not considered serious. We used RevMan Web to carry out analyses and presented results, where feasible, using a random-effects model and risk ratios (RR) with 95% confidence intervals (CIs). We performed sensitivity analysis. We assessed risk of bias using predefined domains, assessed the certainty of the evidence using GRADE, controlled risk of random errors with Trial Sequential Analysis, and presented outcome results in a summary of findings table.

MAIN RESULTS

Five completed trials were included, of which four trials contributed data to one or more of the outcomes. They included a total of 533 participants randomised to tenofovir-based antiviral combination regimens (196 participants) versus control (337 participants). The control groups received non-tenofovir-based antiviral regimens either as zidovudine alone (three trials) or as a combination of zidovudine, lamivudine and lopinavir-ritonavir (five trials). None of the trials used placebo or tenofovir alone. All trials were at unclear risk of bias. Four trials used intention-to-treat analyses. In the remaining trial, two participants in the intervention group and two in the control group were lost to follow-up. However, the outcomes of these four participants were not described. Tenofovir-based antiviral combination regimen versus control We are very uncertain about the effect of a tenofovir-based antiviral combination regimen versus control on all-cause infant mortality (RR 2.24, 95% CI 0.72 to 6.96; participants = 132; trials = 1; very low-certainty evidence); proportion of infants with serious adverse events (RR 1.76, 95% CI 1.27 to 2.43; participants = 132; trials = 1; very low-certainty evidence), and proportion of mothers with serious adverse events (RR 0.90, 95% CI 0.62 to 1.32; participants = 262; trials = 2; very low-certainty evidence). No trial reported data on the proportion of infants with HBV mother-to-child transmission and all-cause maternal mortality. We are also very uncertain about the effect of tenofovir-based antiviral combination regimens versus control on the proportion of infants with adverse events not considered serious (RR 0.94, 95% CI 0.06 to 13.68; participants = 31; trials = 1; very low-certainty evidence), and proportion of mothers with detectable HBV DNA (before delivery) (RR 0.66, 95% CI 0.42 to 1.02; participants = 169; trials = 2; very low-certainty evidence). No trial reported data on maternal hepatitis B e antigen (HBeAg) to HBe-antibody seroconversion (before delivery) and maternal adverse events not considered serious. All trials received support from industry.

AUTHORS' CONCLUSIONS

We do not know what the effects of tenofovir-based antiviral combination regimens are on all-cause infant mortality, proportion of infants with serious adverse events and proportion of mothers with serious adverse events, proportion of infants with adverse events not considered serious, and proportion of mothers with detectable HBV DNA before delivery because the certainty of evidence was very low. Only one or two trials, with insufficient power, contributed data for analyses. We lack randomised clinical trials at low risk of systematic and random errors, and fully reporting all-cause infant mortality, serious adverse events and reporting on clinical and laboratory outcomes, such as infants with HBV mother-to-child transmission, all-cause maternal mortality, maternal hepatitis B e antigen (HBeAg) to HBe-antibody seroconversion before delivery and maternal adverse events not considered serious.

Efficacy and Long-term Safety of Telbivudine Usage During Second or Third Trimester in Hepatitis B Surface Antigen Positive Mothers With High Viral Load: A 10-year Prospective Study

GOALS

The study is to evaluate the efficacy and long-term safety of telbivudine (LdT) usage for hepatitis B surface antigen (HBsAg) positive pregnant women with high viral load.

BACKGROUND

The efficacy and safety of LdT during pregnancy were not assessed from a long-term perspective.

STUDY

HBsAg-positive pregnant women were enrolled and grouped according to antiviral initiation time. Group A (n=100) and group B (n=100) were treated with LdT initiated in the second or third trimester. Group C (n=90) received no antiviral treatment. The efficacy and safety of LdT treatment were compared and infants were followed-up at 1, 5, and 10 years. Denver developmental screening test was conducted at 5 years.

RESULTS

Viral loads before delivery in LdT-treated groups were lower than that in group C and group A was lower than that in group B ( P <0.001). No infants in LdT-treated groups were infected whereas 8.8% (8/90) infants in group C had positive HBsAg (χ 2 =23.20, P <0.001). All LdT-treated mothers were well tolerated and no LdT-related adverse events in infants were reported. Part of the physical growth index of infants was higher than Chinese standard values (SV) and showed significant differences. In groups A and B, the developmental screening test qualified rate of 100% (48/48) and 97.96% (48/49) showed no significant difference compared with 92% in normal Chinese children (χ 2 =5.72, P =0.06).

CONCLUSIONS

Treatment initiated during the second trimester could strengthen the success of mother-to-child transmission blockage. LdT treatment during pregnancy is safe for both mothers and infants in the long term.

Low levels of tenofovir in breast milk support breastfeeding in HBV-infected mothers treated with tenofovir disoproxil fumarate

OBJECTIVE

Tenofovir disoproxil fumarate (TDF) is recommended for the prevention of mother-to-infant transmission of the hepatitis B virus (HBV). This study investigated the safety of infants whose mothers continued to receive TDF while breastfeeding.

PATIENTS AND METHOD

Thirty women taking TDF daily from the second or third trimester of pregnancy to three months postpartum were enrolled. Tenofovir (TFV) concentrations in breast milk were determined and compared with those in umbilical cord (UC) blood and amniotic fluid. Infant growth parameters were assessed at birth, and at 3, 6, and 12 months. TFV uptake experiments were conducted in vitro to elucidate the mechanisms of TFV exposure via breast milk.

RESULTS

TFV concentrations in breast milk ranged from 1.4 to 11.7 ng/mL within 24 h after dosing in the third month postpartum. The median trough concentration of TFV in breast milk was 3.7 (interquartile range, 2.6-6.2) ng/mL, which is lower than that in UC blood (median = 53.5 ng/mL) and amniotic fluid (median = 531.0 ng/mL). The low permeability of TFV in MCF-10A cells may explain the minimal exposure to TFV in breast milk. Body weights, body lengths, and head circumferences of the breastfed infants were comparable to the national standards for physical development.

CONCLUSION

Infant exposure to TFV from breast milk is much lower than the exposure from placental transfer and swallowing from amniotic fluid. The physical growth parameters of all infants in this study were normal. The findings indicate that breastfeeding is safe for infants of HBV-infected mothers who continue to receive TDF through three months postpartum.

Feasibility of hepatitis B elimination in high-income countries with ongoing immigration

BACKGROUND & AIMS

Addressing HBV is vital to meeting the World Health Organization (WHO)'s viral hepatitis elimination goals, as 47% of viral hepatitis complications can be attributed to HBV. The objective of this study is to develop an agent-based model determining which integrated strategies involving vaccination, screening, and treatment would achieve the WHO's goals.

METHODS

We developed an agent-based model to characterize the HBV epidemic in a high-income country with ongoing immigration. The spread of HBV was simulated through sexual networks and perinatal transmission. Model parameters were estimated from the literature and calibrated against historical HBV data. Sensitivity analyses were performed to assess the uncertainty.

RESULTS

We predict that under the current strategies, the incidence of acute hepatitis B, and HBV-attributable decompensated cirrhosis and hepatocellular carcinoma would decrease by 64.5%, 9.4%, and 10.5% between 2015-2030, respectively. However, the incidence of chronic hepatitis B and liver-related deaths would increase by 26.6% and 1.0% between 2015-2030, respectively. Results were sensitive to the number of immigrants and HBV prevalence in immigrants.

CONCLUSIONS

The results suggest that the current vaccination, screening, and treatment strategies will be inadequate to achieve WHO elimination goals. Even with extensive integrated scale-up in vaccination, screening, and treatment, the morbidity and mortality targets may not be reachable, highlighting the need for a re-evaluation of the global strategy for HBV, the importance of developing curative therapy for HBV, and of establishing tailored strategies to prevent long-term sequelae and improve health in immigrants.

LAY SUMMARY

We have developed a model that reflects the dynamics of hepatitis B virus (HBV) transmission in a high-income country with ongoing immigration, which enabled us to forecast the epidemiology of HBV for policy-level decision making. Our analysis suggests that current vaccination, screening, and treatment strategies are inadequate to achieve the WHO goals of eliminating chronic hepatitis B. Even with extensive integrated scale-up in vaccination, screening, and treatment, the morbidity and mortality targets may not be reachable.

Tenofovir disoproxil fumarate therapy to prevent hepatitis B virus vertical transmission-A review of maternal and infant outcomes

Hepatitis B virus (HBV) is a global health problem. Vertical transmission of HBV from HBV surface antigen (HBsAg)-positive mothers to their infants is the most common cause of HBV infection worldwide. The use of passive-active immunoprophylaxis is >90% effective in reducing the risk of vertical transmission, but immunoprophylaxis failure can occur in infants born to mothers with high viraemia. Thus, it is recommended that pregnant women with HBV-DNA level >200 000 IU/ml receive nucleos(t)ide analogue (NA) treatment [i.e. tenofovir disoproxil fumarate (TDF), lamivudine or telbivudine] during third trimester to prevent infant immunoprophylaxis failure. TDF is recommended as the first-line therapy based on available data on efficacy, safety and resistance profile. However, maternal immunological reconstitution following parturition can increase immune-mediated flares to viral antigens that is potentially exacerbated following TDF withdrawal. In this article, we review available data on the efficacy and safety of TDF administration to prevent HBV mother-to-child transmission. We also discuss changes in maternal viral markers [i.e. HBV-DNA, HBV e antigen and HBsAg] and alanine aminotransferase during follow-up post-partum in mothers received NA to prevent HBV vertical transmission.

Immunoglobulin-free strategy to prevent HBV mother-to-child transmission in Cambodia (TA-PROHM): a single-arm, multicentre, phase 4 trial

BACKGROUND

Prevention of mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is based on administration of vaccine and immunoglobulins (HBIg) to newborns at birth and maternal antiviral prophylaxis for those with an HBV-DNA viral load of at 5·3 log₁₀ IU/mL or more. Many low-income and middle-income countries face difficulty in accessing HBIg and HBV-DNA quantification. The aim of this study was to evaluate the effectiveness of an HBIg-free strategy to prevent MTCT of HBV.

METHODS

TA-PROHM was a single-arm, multicentre, phase 4 trial done in five maternity units in Cambodia. Pregnant women who were positive for hepatitis B surface antigen (HBsAg), aged 18 years or older were included. Women who were HCV or HIV positive, had creatinine clearance of less than 30 mL/min, severe gravid disease, and planned to give birth outside the study sites were excluded. From Oct 4, 2017, to Jan 9, 2019, HBsAg positive pregnant women who tested positive for hepatitis B e antigen (HBeAg) with a rapid diagnostic test were eligible to receive tenofovir disoproxil fumarate. From Jan 9, 2019, women who were HBeAg negative with an alanine aminotransferase concentration of ≥40 IU/L were also eligible to receive tenofovir disoproxil fumarate. Women in the tenofovir disoproxil fumarate eligible group received 300 mg of tenofovir disoproxil fumarate orally once a day from the 24th week of gestation until 6 weeks postpartum. The primary outcome was the overall proportion of infants who were HBsAg positive at 6 months of life, confirmed by positive HBV DNA quantification. For the primary outcome, the proportion (95% CI) of infants with HBsAg at 6 months was stratified according to infant's HBIg status, duration of maternal tenofovir disoproxil fumarate treatment (>4 weeks and ≤4 weeks), and study period (before and after the change in therapeutic algorithm) and was measured in a modified intention-to-treat analysis, which excluded infants lost to follow-up or who were withdrawn before 6 months. The study is registered with ClinicalTrials.gov, NCT02937779.

FINDINGS

From Oct 4, 2017, to Nov 27, 2020, 21 251 pregnant women were screened for HBsAg, of whom 1194 (6%) were enrolled in the study: 338 (28%) were eligible to receive tenofovir disoproxil fumarate. For the tenofovir disoproxil fumarate eligible group, four (1% [95% CI 0·34-3·20]) of 317 infants had HBV infection at 6 months; in the subgroup of 271 children who did not receive HBIg, four (1% [0·40-3·74]) had HBV infection at 6 months. In absence of HBIg, MTCT HBV transmission occurred in none (0% [0-1·61]) of 227 women who received tenofovir disoproxil fumarate for more than 4 weeks before giving birth and three (8% [1·75-22·47]) of 36 women who received tenofovir disoproxil fumarate for less than 4 weeks. In the tenofovir disoproxil fumarate ineligible group, seven (1% [0·40-2·02]) of 712 infants had HBV infection at 6 months; in the subgroup of 567 children who did not receive HBIg, six (1% [0·39-2·30]) had HBV infection at 6 months.

INTERPRETATION

An immunoglobulin-free strategy using an HBeAg rapid diagnosis test and alanine aminotransferase-based algorithm to assess eligibility for tenofovir, is effective at preventing MTCT of HBV when tenofovir was initiated at least 4 weeks before birth.

FUNDING

French Agency for Research on AIDS and Viral Hepatitis and Emerging Infectious diseases.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

The role of tenofovir disoproxil fumarate for preventing vertical transmission of hepatitis B

Background

Since immunoprophylaxis failure can occur if maternal serum hepatitis B virus (HBV) DNA levels are >200,000 IU/ml, tenofovir disoproxil fumarate (TDF) therapy has been investigated for preventing mother to child transmission (PMTCT).

Methods

A literature search for maternal TDF therapy for PMTCT between 1/1/2015 and 7/1/21 on PUBMED, EMBASE, Cochrane, CNKI, and Wanfang databases was performed. Data from RCTs in English or Chinese were extracted and reviewed. The outcomes of interest included the efficacy and safety of TDF versus placebo for PMTCT.

Results

Among 11 RCTs identified from the databases, the risk-of-bias was low. All studies demonstrated that maternal TDF therapy initiated from the second or third trimester for highly viremic chronic hepatitis B mothers is highly effective and safe in the PMTCT of HBV, except one RCT performed in Thailand which showed no therapeutic advantage on TDF treatment versus placebo for PMTCT (0% vs 3% transmission). Recent emerging data suggest that maternal TDF therapy initiated at the 2nd or early 3rd trimester in mothers with HBV DNA >200,000 IU/ml achieved viremic control before delivery. In the 4-year long follow-up study for maternal TDF therapy, there were no impacts on infants’ physical growth, psychological or mental development, and bone mineral density after fetal exposure to TDF. In the light of updated efficacy and safety data from RCTs, an algorithm was proposed. The approaches in resource-limit areas were discussed.

Conclusions

TDF is safe for both mothers and infants as the preferred therapy for PMTCT in highly viremic mothers. TDF should be initiated at the second or early third trimester in the combination of the appropriate infants’ immunoprophylaxis.

Comparative efficacy and safety of pharmacologic interventions to prevent mother-to-child transmission of hepatitis B virus: a systematic review and network meta-analysis

OBJECTIVE

This study investigated the efficacy and safety of pharmacologic interventions to prevent vertical transmission of the hepatitis B virus.

DATA SOURCES

Medline, Cochrane, and Scopus databases were searched up to October 28, 2020.

STUDY ELIGIBILITY CRITERIA

All randomized controlled trials reporting vertical hepatitis B virus transmission with pharmacologic intervention were included.

METHODS

Risk of bias was assessed using the Cochrane Risk-of-Bias tool, version 2. Treatment efficacy was estimated using stratified network meta-analysis on the basis of maternal hepatitis B envelope antigen status.

RESULTS

Nineteen studies were included for mothers positive for hepatitis B surface and envelope antigens. Pooling indicated that a combination of hepatitis B vaccination and hepatitis B immunoglobulin in infants significantly reduced transmission risk compared with vaccination alone, with a risk ratio of 0.52 (95% confidence interval; 0.30-0.91). Only the addition of maternal tenofovir disoproxil fumarate, but not telbivudine, lamivudine, or maternal hepatitis B immunoglobulin further reduced transmission risk compared with a combination of hepatitis B vaccination and hepatitis B immunoglobulin in infants, with a pooled risk ratio of 0.10 (0.03-0.35). Twelve studies conducted in mothers with hepatitis B surface antigen positivity and mixed, unknown, or negative hepatitis B envelope antigen status provided limited evidence to suggest that maternal hepatitis B immunoglobulin combined with hepatitis B vaccination and immunoglobulin in infants was the likely best treatment, but this failed to reach statistical significance compared with a combination of hepatitis B vaccination and immunoglobulin in infants. Similarly, infant hepatitis B immunoglobulin, added to vaccination, likely provides additional benefit but failed to reach statistical significance.

CONCLUSION

A combination of hepatitis B vaccination and immunoglobulin in infants is the cornerstone for prevention of vertical transmission for mothers positive for both hepatitis B surface and envelope antigens. The addition of maternal tenofovir to this infant combination regimen was considered the likely most effective treatment. For infants of mothers with hepatitis B surface antigen positivity and mixed, unknown, or negative hepatitis B envelop antigen status, no additional agents provided further benefit beyond hepatitis B vaccination alone.

Kinetics of hepatitis B surface antigen in pregnant women with and without tenofovir disoproxil fumarate

Tenofovir disoproxil fumarate (TDF) is the preferred treatment to prevent mother-to-infant transmission in highly viremic HBV-infected women. Data on hepatitis B surface antigen (HBsAg) levels in pregnant women are lacking. We aimed to investigate prepartum and postpartum HBsAg kinetics and its correlation with HBV DNA in pregnant women. HBV-infected mothers with HBV DNA ≥7.5 log₁₀  IU/ml were tested for HBsAg and HBV DNA from baseline to 6 months postpartum. Of the 186 pregnant women with comparable baseline HBsAg and HBV DNA, 101 received TDF from the third trimester until 1 month postpartum. At delivery, TDF group had mildly lower HBsAg (4.32 ± 0.47 vs. 4.54 ± 0.35 log₁₀  IU/ml, p = .0004) and markedly lower HBV DNA (4.26 ± 0.97 vs. 8.11 ± 0.70 log₁₀  IU/ml, p < .0001) than the control group. In the TDF group, mean reduction of HBsAg and HBV DNA from baseline to delivery were 0.22 ± 0.38 and 3.96 ± 0.93 log₁₀  IU/ml. HBsAg reduction had a positive correlation (r = .309; p = .0017) with HBV DNA reduction, and was predictive of HBV DNA reduction ≥3 log₁₀  IU/ml (area under the receiver operating characteristic curve, 0.67; 95% confidence interval, 0.50-0.82). At 6 months postpartum, TDF and control group had comparable HBsAg and HBV DNA. In conclusion, HBsAg decreased slightly at delivery in pregnant women receiving TDF. For monitoring the effect of antiviral therapy during pregnancy, HBV DNA is a better marker than HBsAg. Our data provided valuable information regarding monitoring HBV-infected pregnant women using antiviral therapy.

Comparison of the efficacy and safety of tenofovir and telbivudine in interrupting mother-to-child transmission of hepatitis B virus

The present study is aimed to evaluate and compare the efficacy and safety of tenofovir (TDF) and telbivudine (TBV) in interrupting hepatitis B virus (HBV) mother-to-child transmission (MTCT), and to provide evidence-based treatment options to clinicians and patients.Hepatitis B e-antigen (HBeAg)-positive pregnant women (644 in total) with high HBV DNA load (≥2 × 105 IU/mL) and who received TDF (n = 214) or TBV (n = 380) in the second or third trimester, or received no treatment (n = 50) were included in this retrospective analysis.HBV DNA levels in mothers at delivery were significantly lower than baseline in the 2 treatment groups. HBV DNA levels in the TDF group were significantly different between the mothers receiving treatment in the second trimester and those receiving treatment in the third trimester; however, significant difference was not observed in the TBV group. The proportion of hepatitis B surface antigen (HBsAg)-positive infants at the age of 7 to 12 months in the TDF, TBV, and control groups were 0.00% (0/174), 0.30% (1/331), and 5.0% (2/40) with a significant difference between the treatment groups and the control group, but no difference between the TDF and TBV group (P > .05). However, no serious adverse events were observed in infants and mothers of all groups.TBV and TDF can effectively reduce the HBV DNA level and MTCT rate in pregnant women with high HBV DNA load (≥2 × 105 IU/mL); both antiviral drugs are safe for infants and mothers. Since TDF was more effective in reducing HBV DNA levels during the second trimester, its use during the period is recommended to prevent HBV MTCT.

Distribution Evaluation of Tenofovir in the Breast Milk of Mothers With HBeAg-Positive Chronic HBV Infection After Treatment With Tenofovir Alafenamide and Tenofovir Disoproxil Fumarate by a Sensitive UPLC-MS/MS Method

Tenofovir alafenamide (TAF) is a novel prodrug of tenofovir (TFV) that has been approved for the treatment of chronic hepatitis B virus (HBV) infection. It has greater plasma stability and more favorable renal safety than tenofovir disoproxil fumarate (TDF), the first approved oral prodrug of TFV. However, the distribution of TFV in the breast milk of mothers treated with TAF is still unclear. In this study, sixteen participants with chronic HBV infection were enrolled and received antiretroviral therapy with 25 mg of TAF or 300 mg of TDF daily from 24 to 28 weeks of gestation until the 4th week postpartum. For the first time, the distribution of TFV in the breast milk of mothers with chronic HBV infection treated with TAF and its difference from TDF were evaluated by using a sensitive UPLC-MS/MS method. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C18 column (1.7 µm 2.1 × 100 mm). Mass spectrometry analysis was performed in positive electrospray ionization mode and multiple reaction monitoring (MRM) conditions of transitions m/z 288.1→176.2 for TFV. This method was linear from 0.5 to 500 ng/ml. Surprisingly, on the third postpartum day, the median Cmax of TFV in the breast milk was much higher in the mothers treated with TAF (101.2 ng/ml) than TDF (21.6 ng/ml) at a similar Tmax of 4 h. Accordingly, the median AUC0-8 value was 755.6 ng h/mL in the mothers taking TAF, which was at a 5-fold higher level than TDF. The concentration of TFV in the breast milk of mothers in both groups decreased with increasing lactation time. These data indicated that there was a relatively higher exposure of TFV in the breast milk of mothers taking TAF, despite the lower dosage compared to TDF. This study provides support for further evaluating the safety of breastfeeding after the administration of TAF and TDF.

Advances in treatment and prevention of hepatitis B

Chronic hepatitis B (CHB) continues to contribute to worldwide morbidity and mortality significantly. Scientists, clinicians, pharmaceutical companies, and health organizations have dedicated substantial Intellectual and monetary resources to finding a cure, increasing immunization rates, and reducing the global burden of CHB. National and international health-related organizations including the center for disease control, the national institute of health, the American Association for the study of liver disease (AASLD), The European association for the study of the Liver (EASL), The Asia Pacific association for the study of the Liver (APASL) and the world health organization release periodic recommendations for disease prevention and treatment. Our review of the most recent guidelines by EASL, AASLD, APASL, and Taiwan Association for the Study of the Liver revealed that an overwhelming majority of cited studies were published before 2018. We reviewed Hepatitis B-related literature published 2018 onwards to identify recent developments and current barriers that will likely direct future efforts towards eradicating hepatitis B. The breakthrough in our understanding of the hepatitis B virus life cycle and resulting drug development is encouraging with significant room for further progress. Data from high-risk populations, most vulnerable to the devastating effects of hepatitis B infection and reactivation remain sparse. Utilization of systems approach, optimization of experimental models, identification and validation of next-generation biomarkers, and precise modulation of the human immune response will be critical for future innovation. Within the foreseeable future, new treatments will likely complement conventional therapies rather than replace them. Most Importantly, pragmatic management of CHB related population health challenges must be prioritized to produce real-world results.

Global Burden of Hepatitis B Infection in People Living With Human Immunodeficiency Virus: A Systematic Review and Meta-analysis

BACKGROUND

This meta-analysis was conducted to estimate the global burden of hepatitis B virus (HBV) infection in people living with human immunodeficiency virus (PLWH).

METHODS

We searched multiple databases for studies published between January 1990 and December 2017. HBV infection (hepatitis B surface antigen) was diagnosed with serological assays. A random-effects meta-analysis served to pool data.

RESULTS

We included 358 studies (834 544 PLWH from 87 countries). The pooled prevalence of HBV infection was 8.4% (95% confidence interval [CI], 7.9%-8.8%), among which 26.8% (95% CI, 22.0%-31.9%) was positive to hepatitis B e antigen. HBV prevalence (with 95% CIs) differed according to region: West and Central Africa, 12.4% (11.0%-13.8%); Middle East and North Africa, 9.9% (6.0%-14.6%); Asia and the Pacific, 9.8% (8.7%-11.0%); Eastern and Southern Africa, 7.4% (6.4%-8.4%); Western and Central Europe and North America, 6.0% (5.5%-6.7%); and Latin America and the Caribbean, 5.1% (4.2%-6.2%) (P < .0001). The prevalence decreased from 10.4% in low-developed to 6.6% in highly developed countries (P < .0001) and increased from 7.3% in countries with HIV prevalence ≤1% to 9.7% in countries with HIV prevalence >1% (P < .0001). Globally, we estimated that there were 3 136 500 (95% CI, 2 952 000-3 284 100) cases of HBV in PLWH, with 73.8% of estimated regional cases from sub-Saharan Africa and 17.1% from Asia and the Pacific.

CONCLUSIONS

This study suggests a high burden of HBV infection in PLWH, with disparities according to region, level of development, and country HIV prevalence.

Tenofovir disoproxil fumarate for prevention of mother-to-child transmission of hepatitis B virus: A systematic review and meta-analysis of randomised control trials

Hepatitis B virus (HBV) infection caused by mother-to-child transmission (MTCT) continues to pose challenges to global health. This study aimed to assess the efficacy and safety of tenofovir disoproxil fumarate (TDF) for preventing HBV MTCT. PubMed and the Cochrane Central Register of Controlled Trials were searched through August 2020. Randomised controlled trials (RCTs) were selected that evaluated the efficacy and safety of TDF for preventing MTCT of HBV compared with the standard of care, placebo or other HBV therapies. The primary outcomes were HBV MTCT rate and maternal HBV DNA level. Secondary outcomes were infant and maternal safety outcomes. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines, and prospectively registered on PROSPERO (CRD42020186275). Of 240 citations, three RCTs that involved 651 participants were included. The pooled result showed that TDF can reduce the risk of HBV MTCT after 6 months postpartum by 80% (risk ratio [RR] 0.2, 95% confidence interval [CI 0.06-0.7], n = 584) with low heterogeneity (I²  = 0%). TDF demonstrated HBV DNA suppression at delivery, though there was heterogeneity among individual studies (RR 0.13, 95% CI [0.08-0.20] and (RR 0.36, 95% CI [0.27-0.49]). Maternal and infant safety outcomes were comparable among treated and untreated mothers and infants born to them. The quality of evidence varied from high to very low. There is evidence that TDF effectively interrupted MTCT of HBV and suppressed HBV DNA level. Available studies on safety are very limited and heterogeneous, emphasising the need for additional RCTs with complete safety indicators.

Pharmacokinetics of oral tenofovir disoproxil fumarate in pregnancy and lactation: a systematic review

BACKGROUND

Tenofovir disoproxil fumarate (TDF), the oral prodrug of tenofovir (TFV), is advocated in pregnancy for prevention of mother-to-child transmission (PMCT) with failure of hepatitis B immunoglobulin and vaccination. The pharmacokinetics of TDF monotherapy for PMCT-HBV is important if deployment is to emulate the success of multiple antiretrovirals (ARVs) for PMCT-HIV in resource-constrained settings.

METHODS

This systematic review followed a protocol and is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA) guidelines. We included studies that enrolled pregnant women who received oral TDF therapy as monotherapy or in combination with other ARVs: irrespective of the reason for receiving the drug (for example, HIV, HBV or pre-exposure prophylaxis); and reported pharmacokinetics.

RESULTS

The area under the concentration-time curve (AUC), maximum plasma concentrations (C_max) and last measurable plasma concentration (C_last) of TFV were decreased in the second and third trimester compared with first trimester or post-partum. In none of the manuscripts was the non-pregnant HBV threshold of C_max of 300 ng/ml reached, but the 50% effective concentration (EC₅₀) of TFV is lower for treatment of HBV compared with HIV. The TFV concentration in breastfed infants was 0.03% of the recommended infant dose.

CONCLUSIONS

Most knowledge of pharmacokinetics of TFV in pregnancy results from studies on HIV involving multiple ARVs. Increased TFV clearance occurred in the second and third trimester when optimal TFV concentrations are required to maximize suppression of HBV in the window before birth. Dose or duration adjustments will be better conceptualized with concurrent analysis of the pharmacokinetics of TFV monotherapy and hepatitis B pharmacodynamics in pregnancy.

A programme to treat chronic hepatitis B in Kiribati: progress and challenges

Problem

Over 290 million people worldwide suffer from chronic hepatitis B (CHB), with the highest prevalence in the Pacific islands. Mortality attributable to this disease exceeds that from HIV, tuberculosis and malaria combined in this region.

Context

CHB is a major health problem in the Pacific island nation of Kiribati. Medical care is complicated by vast expanses of ocean separating population centres in its constituent islands. Birth-dose hepatitis B immunization rates need improvement. High rates of obesity, metabolic syndrome, and co-infection with hepatitis B and hepatitis D in Kiribati make treatment less effective. Staff allocation, training and retention are difficult. Limited infrastructure creates challenges in training, communications, laboratory testing and record-keeping.

Action

We have established a CHB treatment programme in Kiribati based on World Health Organization (WHO) guidelines and local needs. It includes direct patient care; laboratory, radiology and pharmacy support; public education; training; and data management. Thousands of individuals have been screened, and 845 hepatitis B-positive patients have had blood sent to Australia for molecular testing. Patient education pamphlets, medical training programmes and treatment protocols have been developed. Seventy-nine patients have started treatment. Regular onsite visits by technical experts are scheduled throughout the year.

Lessons learnt and discussion

This is the first national CHB treatment programme established in the Pacific islands region. Unique challenges exist in Kiribati, as they do in each nation affected by CHB. Close engagement with local partners, knowledge of the barriers involved, flexibility, advocacy, and support from WHO and volunteer technical experts are key attributes of a successful treatment programme.

Efficacy and safety of antiviral prophylaxis during pregnancy to prevent mother-to-child transmission of hepatitis B virus: a systematic review and meta-analysis

BACKGROUND

To eliminate mother-to-child transmission (MTCT) of hepatitis B virus (HBV), peripartum antiviral prophylaxis might be required for pregnant women infected with HBV who have a high risk of MTCT despite infant immunoprophylaxis. We aimed to determine the efficacy and safety of peripartum antiviral prophylaxis to inform the 2020 WHO guidelines.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, Scopus, CENTRAL, CNKI, and Wanfang for randomised controlled trials and non-randomised studies of peripartum antiviral prophylaxis versus placebo or no prophylaxis, with no language restriction, published from database inception until March 28, 2019. We used search terms covering HBV, antiviral therapy, and pregnancy. We included studies that enrolled pregnant women with chronic infection with HBV who received antiviral prophylaxis anytime during pregnancy; that included any of the following antivirals: adefovir, emtricitabine, entecavir, lamivudine, telbivudine, tenofovir alafenamide fumarate, and tenofovir disoproxil fumarate; and that reported the following outcomes: MTCT, indicated by infant HBsAg positivity or HBV DNA positivity, or both, at age 6-12 months, and any infant or maternal adverse events. Two reviewers independently extracted data. Our primary endpoint was MTCT based on infant HBsAg positivity. We assessed pooled odds ratios (ORs) of the efficacy of peripartum antiviral prophylaxis to reduce the risk of MTCT. We assessed safety of prophylaxis by pooling risk differences. The protocol for the systematic review was pre-registered in PROSPERO, CRD42019134614.

FINDINGS

Of 7463 articles identified, 595 articles were eligible for full-text review and 129 studies (in 157 articles) were included. The following antivirals were assessed in the meta-analysis: tenofovir disoproxil fumarate 300 mg (19 studies, with 1092 mothers and 1072 infants), lamivudine 100-150 mg (40 studies, with 2080 mothers and 2007 infants), and telbivudine 600 mg (83 studies, with 6036 mothers and 5971 infants). The pooled ORs for randomised controlled trials were similar, at 0·10 (95% CI 0·03-0·35) for tenofovir disoproxil fumarate, 0·16 (0·10-0·26) for lamivudine, and 0·14 (0·09-0·21) for telbivudine. The pooled ORs in non-randomised studies were 0·17 (0·10-0·29) for tenofovir disoproxil fumarate, 0·17 (0·12-0·24) for lamivudine, and 0·09 (0·06-0·12) for telbivudine. We found no increased risk of any infant or maternal safety outcomes after peripartum antiviral prophylaxis.

INTERPRETATION

Peripartum antiviral prophylaxis is highly effective at reducing the risk of HBV MTCT. Our findings support the 2020 WHO recommendation of administering antivirals during pregnancy, specifically tenofovir disoproxil fumarate, for the prevention of HBV MTCT.

FUNDING

World Health Organization.

Efficacy and safety of antiviral therapy for HBV in different trimesters of pregnancy: systematic review and network meta-analysis

BACKGROUND

Several antiviral agents licenced for blocking mother-to-child transmission (MTCT) of HBV, but their relative efficacy beginning from different trimesters has scarce been evaluated. We aimed to conduct a network meta-analysis to statistically differ the efficacy and safety of each antiviral agents initiating on different timings in preventing mother-to-infant transmission of HBV.

METHODS

Studies were included from PubMed, EMBASE, Web of Science, and Cochrane databases through July 1, 2019. Eligible studies recruited randomized controlled trials and nonrandomized studies reporting about infant or/and maternal efficacy and safety outcomes and were screened by two investigators independently. Extracted data were analyzed by pair-wised and network meta-analysis, respectively.

RESULTS

3 Randomized and 32 nonrandomized studies enrolling 6738 pregnant female were included. Using network analysis, any antiviral agent interrupted HBV vertical transmission much more effectively than placebo. No agent showed significant efficacy different from others, but a strong trend toward significance was found in telbivudine and tenofovir, of which had the highest probability of being ranked the first- or second-best treatment for reducing MTCT of HBV. The treatment applied in the first and second trimester had a similar efficacy in preventing MTCT. Compared with the initiation during the third trimester, lower rate of MTCT was revealed when antiviral therapy was administrated before third trimester, (RR = 0.045, 95% CI 0.0053 to 0.20); a similar effect at delivery on suppressing maternal HBV DNA level and converting serum HBeAg were achieved if the timing of antiviral treatment started prior, but an obvious improvement of normalizing ALT flare was calculated out; no statistically differences among maternal and fetal safety outcomes were found if mothers received antiviral agents before pregnant 28 weeks.

CONCLUSION

This network meta-analysis recommended the earlier use of telbivudine or tenofovir, tends to be better to prevent MTCT of HBV in pregnancy with no increased adverse maternal or fetal outcomes.

The Administration of Tenofovir Disoproxil Fumarate for Pregnant Japanese Women with Chronic Hepatitis B

The appropriate management of hepatitis B virus (HBV) infection during pregnancy has not been established in Japan. We herein report five HBV-infected pregnant Japanese women who received tenofovir disoproxil fumarate (TDF). Two of them had been born after the introduction of nationwide immunoprophylaxis and were vertically infected with HBV, highlighting the need to address mother-to-child transmission further. In both entecavir-experienced and nucleoside/nucleotide analog-naïve mothers, TDF suppressed HBV replication without serious adverse events. All five children were free from congenital disorders, growth impairment, and HBV infection. TDF showed safety and efficacy for pregnant woman with chronic hepatitis B and might have helped prevent mother-to-child transmission.

Clinical efficacy and safety in telbivudine- or tenofovir-treated hepatitis B e antigen-positive pregnant women

BACKGROUND

Telbivudine (LdT) and tenofovir (TDF) are widely used in pregnant women to prevent vertical transmission; however, limited data are available on the differences in clinical efficacy and safety between the two drugs.

METHODS

A total of 307 hepatitis B e antigen (HBeAg)-positive pregnant women with complete follow-up data were enrolled, the patients with alanine aminotransferase (ALT) levels <1×ULN at baseline were enrolled to cohort 1 for treatment from 28 ±4 weeks gestation to delivery, while ALT levels >1×ULN at baseline were enrolled to cohort 2 for treatment from 28 ±4 weeks gestation and continued after delivery. The clinical efficacy and safety was compared in LdT- and TDF-treated patients. In addition, 32 patients in cohort 1 were analysed for nucleoside analogue (NA)-related resistance mutations at baseline and after delivery.

RESULTS

The results showed that HBV DNA levels were significantly lower at delivery than at baseline (P<0.001), but the decreases in HBV DNA, ALT, total bilirubin and total bile acid levels did not differ between the LdT- and TDF-treated patients at different time points (P>0.05) in the two cohorts. However, gastrointestinal adverse effects (vomiting) occurred more frequently in TDF-treated than LdT-treated patients (6.6% versus 0.0%; P=0.001). The results of NA-related resistance mutations analysis in cohort 1 revealed that short-term LdT or TDF treatment did not significantly change the NA-related resistance mutations (P>0.05).

CONCLUSIONS

This study revealed that the clinical efficacy in LdT- or TDF-treated HBeAg-positive Chinese pregnant women is similar, and gastrointestinal adverse effects occurred more frequently in TDF-treated patients.

Present and Future Therapies for Chronic Hepatitis B

Chronic hepatitis B (CHB) remains the leading cause of liver-related morbidity and mortality across the world. If left untreated, approximately one-third of these patients will progress to severe end-stage liver diseases including liver failure, cirrhosis, and hepatocellular carcinoma (HCC). High level of serum HBV DNA is strongly associated with the development of liver failure, cirrhosis, and HCC. Therefore, antiviral therapy is crucial for the clinical management of CHB. Current antiviral drugs including nucleoside/nucleotide analogues (NAs) and interferon-α (IFN-α) can suppress HBV replication and reduce the progression of liver disease, thus improving the long-term outcomes of CHB patients. This chapter will discuss the standard and optimization antiviral therapies in treatment-naïve and treatment-experienced patients, as well as in the special populations. The up-to-date advances in the development of new anti-HBV agents will be also discussed. With the combination of the current antiviral drugs and the newly developed antiviral agents targeting the different steps of the viral life cycle or the newly developed agents modulating the host immune responses, the ultimate eradication of HBV will be achieved in the future.

Comparing the Efficacy and Safety of Treating Chronic Hepatitis B Infection during Pregnancy with Lamivudine, Telbivudine, and Tenofovir: A Meta-analysis

Background and Aims: The perinatal transmission of hepatitis B virus (HBV) remains an important global health problem. Here, a systematic review and meta-analysis were conducted to evaluate the evidence regarding the efficacy and maternal/fetal safety of treating pregnant women with lamivudine, telbivudine (LdT), and tenofovir (TDF). Methods: A PubMed and Scopus search resulted in 1,076 records, which were reduced to 36, containing 7,717 pregnant women with chronic HBV infection and 7467 infants meeting the inclusion criteria. The latest search was in August 2019. Results: Treatment with LdT, but not lamivudine and TDF, could significantly reduce the hepatitis B virus surface antigen-positive rate (odds ratio (OR) = 0.37) in infants; it also led to higher rates of hepatitis B e antigen loss (OR = 12.14), hepatitis B e antigen seroconversion (OR = 8.93), and alanine aminotransferase normalization in mothers (OR = 1.49). Each of these treatments was able to significantly reduce HBV DNA positivity at birth (total OR = 0.19) and mother-to-child-transmission of HBV (total OR = 0.15), and to cause higher rates of HBV DNA suppression in mothers (total OR = 25.53). However, nucleos(t)ide analogues might also be involved in creatine kinase elevation (total OR = 7.48). In contrast, no significant association was found between nucleos(t)ide analogue therapy and preterm/premature births, congenital malformation, low birth weight, and abortion or fetal/infant death. The results suggested LdT's high capability of preventing mother-to-child-transmission. However, TDF failed to show significant associations to a reduced risk of mother-to-child-transmission, probably due to the low number of patients included. Conclusions: Although using either lamivudine, LdT, or TDF could lead to more favorable maternal/fetal outcomes, LdT seemed to show more potential in resolving certain infant- and maternal-related outcomes. More studies on the safety profile of such treatments are required.

The epidemiology of hepatitis B virus infection in Korea

The global burden of hepatitis B virus (HBV) infection is profound, and represents a public health threat as chronic infection can lead to liver cirrhosis, hepatocellular carcinoma, and death. The risk factors for chronic hepatitis B-related liver disease differ according to HBV endemicity, hepatitis B e-antigen seropositivity, and viral load. It is important to identify these risk factors and start antiviral treatment at an appropriate time according to current guidelines. The most crucial step in reducing HBV infection is prevention in infancy or early childhood, as infection at an early stage may lead to chronicity. South Korea was formerly an HBV-endemic area, but the epidemiology of HBV infection was changed by the introduction of vaccination in 1983 and nationwide immunization in 1995. The government and the private sector made efforts to reduce the prevalence of HBV infection, and Korea is on target to meet the World Health Organization goal of eliminating viral hepatitis by 2030. To eliminate hepatitis worldwide, the costs of antiviral treatment to prevent perinatal HBV transmission in pregnant women with high viremia should be covered by a national program, and strategies to reduce the prevalence of HBV infection in immigrant populations are needed.