Anti-hepatitis B virus efficacy of tenofovir disoproxil fumarate in HIV-infected patients

Bictegravir, emtricitabine, and tenofovir alafenamide versus dolutegravir, emtricitabine, and tenofovir disoproxil fumarate for initial treatment of HIV-1 and hepatitis B coinfection (ALLIANCE): a double-blind, multicentre, randomised controlled, phase 3 non-inferiority trial

BACKGROUND

For most adults with HIV-1 and hepatitis B virus (HBV) coinfection, initial recommended treatment is a tenofovir-containing antiretroviral regimen, but no randomised studies have compared tenofovir disoproxil fumarate with tenofovir alafenamide. We aimed to investigate whether bictegravir, emtricitabine, and tenofovir alafenamide is non-inferior to dolutegravir, emtricitabine, and tenofovir disoproxil fumarate for viral suppression in individuals with HIV-1 and HBV coinfection at 48 and 96 weeks.

METHODS

We did this randomised, double-blind, active-controlled, phase 3, non-inferiority trial at 46 outpatient centres in China, Dominican Republic, Hong Kong, Japan, Malaysia, South Korea, Spain, Taiwan, Thailand, Turkey, and the USA. Eligible participants were treatment-naive adults (aged ≥18 years) with plasma HIV-1 RNA of at least 500 copies per mL and plasma HBV DNA of at least 2000 IU/mL. Participants were randomly assigned (1:1) to receive daily oral bictegravir 50 mg, emtricitabine 200 mg, and tenofovir alafenamide 25 mg, or dolutegravir 50 mg, emtricitabine 200 mg, and tenofovir disoproxil fumarate 300 mg, each with corresponding matching placebo. Randomisation was stratified by hepatitis B e antigen (HBeAg) status (positive vs negative), HBV DNA (<8 vs ≥8 log10 IU/mL), and CD4 count (<50 vs ≥50 cells per μL) at screening. All investigators, participants, and staff providing treatment, assessing outcomes, and collecting data were masked to study treatment for 96 weeks. Coprimary endpoints were the proportion of participants with plasma HIV-1 RNA less than 50 copies per mL (defined by the US Food and Drug Administration snapshot algorithm) and plasma HBV DNA less than 29 IU/mL (using the missing-equals-failure approach) at week 48, with a prespecified non-inferiority margin of -12%. Coprimary endpoints were assessed in the full analysis set, which included all randomly assigned participants who received at least one dose of study drug and had at least one post-baseline HIV-1 RNA or HBV DNA result while on study drug. Safety endpoints were assessed in all randomly assigned participants who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, NCT03547908.

FINDINGS

Between May 30, 2018 and March 16, 2021, 381 participants were screened, of whom 243 initiated treatment (121 in the receive bictegravir, emtricitabine, and tenofovir alafenamide group; 122 in the dolutegravir, emtricitabine, and tenofovir disoproxil fumarate group). At week 48, both endpoints met the criteria for non-inferiority: 113 (95%) of 119 participants in the bictegravir, emtricitabine, and tenofovir alafenamide group and 111 (91%) of 122 participants in the dolutegravir, emtricitabine, and tenofovir disoproxil fumarate group had HIV-1 RNA less than 50 copies per mL (difference 4·1, 95% CI -2·5 to 10·8; p=0·21), and 75 (63%) of 119 participants in the bictegravir, emtricitabine, and tenofovir alafenamide group versus 53 (43%) of 122 participants in the dolutegravir, emtricitabine, and tenofovir disoproxil fumarate group had HBV DNA suppression (difference 16·6, 5·9 to 27·3; nominal p=0·0023). Drug-related adverse events up to week 96 occurred in 35 (29%) of 121 participants in the bictegravir, emtricitabine, and tenofovir alafenamide group and 34 (28%) of 122 participants in the dolutegravir, emtricitabine, and tenofovir disoproxil fumarate group. One (1%) of 121 participants in the bictegravir, emtricitabine, and tenofovir alafenamide group reported a serious adverse event (cryptococcal meningitis attributed to immune reconstitution inflammatory syndrome) that was deemed to be treatment-related.

INTERPRETATION

Coformulated bictegravir, emtricitabine, and tenofovir alafenamide is an effective therapy for adults with HIV-1 and HBV coinfection starting antiviral therapy.

FUNDING

Gilead Sciences.

Tenofovir use is associated with a decreased risk of hepatocellular carcinoma among men with HIV irrespective of coinfection status

Background & Aims

Tenofovir is recommended as part of the first-line antiretroviral therapy (ART) to treat people living with HIV (PLWH) with HBV coinfection. However, the effects of tenofovir-containing ART on hepatocellular carcinoma (HCC) risk among PLWH with/without chronic hepatitis virus infections remain unclear.

Methods

This study included 23,838 PLWH. All of them were males aged ≥20 years and followed prospectively during 2000-2017. Four major nationwide registries - the Human Immunodeficiency Virus surveillance database, Taiwan Cancer Registry, Death Certification System, and National Health Insurance Database - were applied to define ART and comorbidities and ascertain newly diagnosed HCC. Tenofovir-containing ART was identified through prescription records. Cox proportional hazards models were used to determine the association of tenofovir use with HCC incidence.

Results

HCC incidence was lower among ever users of tenofovir than among never users (24.2 and 85.7 per 100,000 person-years, respectively). Ever users had significantly reduced HCC risk (adjusted hazard ratio 0.20, 95% CI 0.13-0.31). The effect of tenofovir use on reduced risk for HCC consistently favored never users across many prespecified subgroups, including HBV or HCV coinfection (p <0.05). The findings were consistent in subgroups of PLWH diagnosed with HIV before tenofovir's approval and in those born before the nationwide roll-out of neonatal HBV vaccination.

Conclusions

Our findings underscore the need for randomized controlled trials of tenofovir in combination with long-acting injectable ART regimens to assess its safety and efficacy in PLWH, particularly in those with HBV or HCV coinfection.

Impact and implications

Tenofovir's effect on the risk of hepatocellular carcinoma (HCC) among people living with HIV with hepatitis B or C coinfection remains under investigated. This nationwide prospective cohort study, comprising 23,838 men living with HIV, showed that tenofovir-containing antiretroviral therapy was associated with reduced risk of HCC (adjusted relative risk: 0.20, 95% CI 0.13-0.31), which was consistently observed across many prespecified subgroups. The effect of tenofovir use on HCC risk should be further investigated in PLWH, particularly following the development of long-acting injectable ART regimens.

Long-term efficacy and safety of nucleos(t)ides analogues in patients with chronic hepatitis B

Nucleos(t)ide analogues with high barrier to resistance are regarded as the principal therapeutic option for chronic hepatitis B (CHB). Treatment with entecavir (ETV), tenofovir disoproxil (TDF) and the later released tenofovir alafenamide (TAF) is highly effective at controlling hepatitis B virus (HBV) infection and, in the vast majority of patients, is well tolerated. No significant differences in viral suppression have been described among the different regimens, although an earlier achievement in biochemical response has been suggested first under TDF and recently under TAF. High barrier to resistance NAs rarely achieve hepatitis B surface antigen sero-clearance, and therefore should be maintained life-long in most cases. This has increased concerns about treatment-related toxicity, especially in patients under TDF with additional risk factors for kidney and bone impairment. TAF has shown a better bone and kidney safety profile than TDF, although it is not yet available worldwide due to its higher cost. Emergence of adverse events should be monitored since treatment-switch to ETV/TAF seems to be effective and safe in HBV mono-infected subjects. Finally, although an effective antiviral treatment leads to a clear improvement in clinical outcome of CHB patients; the risk of developing hepatocellular carcinoma (HCC) is not completely avoided with viral suppression. Whether tenofovir-based regimens provide any additional benefit over ETV in HCC prevention remains unclear and requires further investigation.

Lamivudine plus tenofovir versus lamivudine plus adefovir for the treatment of hepatitis B virus in HIV-coinfected patients, starting antiretroviral therapy

Background

Combination of tenofovir disoproxil fumarate (TDF), lamivudine (3TC) and efavirenz (EFV) is preferred in the treatment of HIV/hepatitis B virus (HBV) coinfection. We postulated that a HBV active nucleoside reverse transcriptase (RT) inhibitor/nucleotide RT inhibitor backbone of adefovir dipivoxil (ADV) +3TC would be as effective as TDF +3TC for the Indian population.

Objective

ADV + 3TC could be an alternative option for these HIV/HBV coinfected individuals, preserving the dually active TDF + 3TC as second-line nucleoside backbone following failure of the first-line ART.

Materials and Methods

This randomised control trial (CTRI/2012/03/002471) was carried out at the ART Centre of Calcutta School of Tropical Medicine, India. Seventy-eight (39 on each arm) treatment-naïve HIV/HBV coinfected patients were randomised to receive either the combination of lamivudine + tenofovir + EFV or lamivudine + adefovir + zidovudine + EFV and followed up for 120 weeks.

Results

Median age of the study participants was 36 years (21-62), majority were male (61/78; 78.2%) and heterosexually (39/78; 50%) infected. Baseline characteristics were identical in both arms. There was no statistically significant difference in median aspartate aminotransferase (37 vs. 29.5 U/L), alanine aminotransferase (ALT) (36 vs. 34.5 U/L), ALT normalisation rate (80 vs. 70%), AST to platelet ratio index (0.45 vs. 0.33), CD4 count (508 vs. 427 cells/mm³), HBV DNA suppression (81.8 vs. 70%), hepatitis B e antigen loss (9 vs. 5%), hepatitis B surface antigen seroclearance rate (6.06 vs. 18.75%) and death (3 vs. 3) at 120 weeks between TDF (n = 33) and ADV (n = 32), respectively.

Conclusions

Adefovir plus lamivudine is an effective alternative of tenofovir plus lamivudine in long-term HBV treatment outcome in HIV/HBV coinfected patients.

Triple positivity of HBsAg, anti-HCV antibody, and HIV and their influence on CD4+ lymphocyte levels in the highly HIV infected population of Abeokuta, Nigeria

BACKGROUND

Few studies exist on hospital-based seroprevalence of triple positivity of HIV/HBV/HCV in Nigeria.

OBJECTIVES

The study aimed at determining the triple positivity of HIV, HBsAg and HCV among HIV-infected individuals in Abeokuta, Nigeria and defining the influence of these triple infections on CD4+ counts of HIV-infected individuals as antiretroviral therapy improves in Nigeria.

METHODS

Enumeration of CD4+ levels in 183 HIV-infected persons was done with Partec Flow Cytometer. Seropositivity of HBsAg and anti-HCV antibody was detected with rapid kits.

RESULTS

From the result obtained, significance variance (p<0.05) existed between HIV positive persons and persons who tested positive to HIV/HBV/HCV triple infection before and after the commencement of HAART. Of these infections, 31(16.9%) had HBV/HCV/HIV triple infection, while 152(83.1%) had HIV mono infection only, 56(30.6%) had HBV/HIV dual infection only and 43(23.5%) had HCV/HIV dual infection only. Significant variance (p<0.05) also existed between subjects with CD4 counts of <200 cells/µl, 200-499 cells/µl and >500 cells/µl. Highest seroprevalence of HIV (35.0%) was found in age groups 35-44 years and >65 years had the least (2.7%). Significant variance (p<0.05) also existed in the progression of CD4+ lymphocytes cells between subjects with persistent decrease (32.3%) in CD4+ lymphocytes cells and those with fluctuation in their CD4+ lymphocytes cells (12.9%) after the commencement of ART.

CONCLUSION

The study further confirms that triple positivity of HIV/HBV/HCV infection is common in Abeokuta, Nigeria. Testing of these triple infections should be a big concern in the best choice and commencement of ART. Also, the study showed that consistent and prolonged use of HAART had a positive impact on the CD4 count of HIV-infected individuals.

Current and future directions for treating hepatitis B virus infection

Hepatitis B virus (HBV) persistently infects approximately 350 million people, and approximately 600000 liver-related deaths are observed per year worldwide. HBV infection is also one of the major risk factors for hepatocellular carcinoma (HCC). The persistence of serum hepatitis B e antigen (HBeAg) and high level of serum HBV DNA are thought to reflect a high HBV replication status in hepatocytes, causing cirrhosis, HCC and liver-related deaths. It has been reported that antiviral therapy, such as peginterferon and nucleos(t)ide analogues (NUCs), could suppress liver-related death by inhibiting the HBV DNA levels and inducing seroconversion from HBeAg to antibody to HBe antigen. Currently, peginterferon is widely used, but there are also several disadvantages in the use of peginterferon, such as various adverse events, the administration route and duration. It is difficult to predict the effects of treatment and interferon is contraindicated for the patients with advanced fibrosis of the liver and cirrhosis. With respect to NUCs, entecavir and tenofovir disoproxil fumarate are current the first-choice drugs. NUCs can be administered orally, and their anti-viral effects are stronger than that of peginterferon. However, because cessation of NUC administration leads to high levels of viral replication and causes severe hepatitis, they must be administered for a long time. On the other hand, the use of both interferon and NUCs cannot eliminate covalently closed circular DNA of HBV. In this review, we evaluate the natural course of chronic HBV infection and then provide an outline of these representative drugs, such as peginterferon, entecavir and tenofovir disoproxil fumarate.

Human immunodeficiency virus and coinfection with hepatitis B and C

In HIV-infected individuals, coinfection with HBV and/or HCV is common because of shared modes of transmission. It is known that HIV accelerates progression of liver disease and results in increased morbidity and mortality associated with viral hepatitis, but it is less clear if viral hepatitis has a direct effect on HIV. Treatment of viral hepatitis improves outcomes and should be considered in all HIV-infected patients. Treatment of HBV without concurrent treatment of HIV is risky because resistance can occur in both viruses if regimens are not carefully chosen.

Hepatitis B and human immunodeficiency virus co-infection

Hepatitis B and human immunodeficiency virus (HBV and HIV) infection share transmission patterns and risk factors, which explains high prevalence of chronic HBV infection in HIV infected patients. The natural course of HBV disease is altered by the HIV infection with less chance to clear acute HBV infection, faster progression to cirrhosis and higher risk of liver-related death in HIV-HBV co-infected patients than in HBV mono-infected ones. HIV infected patients with chronic hepatitis B should be counseled for liver damage and surveillance of chronic hepatitis B should be performed to screen early hepatocellular carcinoma. Noninvasive tools are now available to evaluate liver fibrosis. Isolated hepatitis B core antibodies (anti-HBc) are a good predictive marker of occult HBV infection. Still the prevalence and significance of occult HBV infection is controversial, but its screening may be important in the management of antiretroviral therapy. Vaccination against HBV infection is recommended in non-immune HIV patients. The optimal treatment for almost all HIV-HBV co-infected patients should contain tenofovir plus lamivudine or emtricitabine and treatment should not be stopped to avoid HBV reactivation. Long term tenofovir therapy may lead to significant decline in hepatitis B surface Antigen. The emergence of resistant HBV strains may compromise the HBV therapy and vaccine therapy.

Virologic and serologic outcomes of mono versus dual HBV therapy and characterization of HIV/HBV coinfection in a US cohort

OBJECTIVES

To characterize HIV/hepatitis B virus (HBV) coinfection in the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials cohort and compare long-term HBV outcomes between regimens with 1 (MONO) or 2 (DUAL) anti-HBV agents.

DESIGN

A retrospective study of coinfected AIDS Clinical Trials Group Longitudinal Linked Randomized Trials subjects who received regimens containing anti-HBV agent(s).

METHODS

Stored samples at baseline and weeks 16, 32, 48, 144, and 240 were tested for HBV DNA, HBV e antigen (HBeAg), HBV e antibody (HBeAb), and hepatitis D virus (HDV) antibody. Resistance and genotype were tested in samples with HBV DNA >600 IU/mL. MONO versus DUAL analyses were limited to HBV treatment-naive subjects (Naive-MONO, Naive-DUAL).

RESULTS

Of 150 study subjects, median age was 40 years, 96% were male; 57% white, 26% black, 13% Hispanic. Baseline median CD4 was 224 cells per cubic millimeter, HIV RNA 4.48 log10 copies/mL, HBV DNA 6.30 log10 IU/mL; 59% HBeAg positive and 65% HBeAb negative; HBV genotypes A = 69%, G = 18%, D = 7%, <2% for A/G, B, C, F, H. Coinfection with HDV was 2%. There were 49 Naive-MONO (lamivudine) and 22 Naive-DUAL (11 lamivudine + tenofovir, 11 emtricitabine + tenofovir) with detectable HBV DNA. In the 240-week follow-up, HBV DNA suppression was not significantly higher in Naive-DUAL (P = 0.14); lower baseline HBV DNA (P < 0.01) was associated with suppression. Among 32 Naive-MONO subjects with detectable HBV DNA at baseline and results at week 48, 41% suppressed; among such 15 Naive-DUAL subjects, 53% suppressed. HBeAg and HBeAb analyses showed similar trends.

CONCLUSIONS

While consistent trends toward increased HBV DNA suppression, HBeAg loss and HBeAb seroconversion were observed in Naive-DUAL compared with Naive-MONO, they were not statistically significant. Overall, HDV coinfection was low.

Factors associated with delayed hepatitis B viral suppression on tenofovir among patients coinfected with HBV-HIV in the CNICS cohort

BACKGROUND

Despite widespread use in HIV and hepatitis B virus (HBV) infection, the effectiveness of tenofovir (TDF) has not been studied extensively outside of small cohorts of coinfected patients with HBV-HIV. We examined the effect of prior lamivudine (3TC) treatment and other factors on HBV DNA suppression with TDF in a multisite clinical cohort of coinfected patients.

METHODS

We studied all patients enrolled in the Centers for AIDS Research Network of Integrated Clinical Systems cohort from 1996 to 2011 who had chronic HBV and HIV infection, initiated a TDF-based regimen continued for ≥ 3 months and had on-treatment HBV DNA measurements. We used Kaplan-Meier curves and Cox-proportional hazards to estimate time to suppression (HBV DNA level <200 IU/mL or <1000 copies/mL) by selected covariates.

RESULTS

Among 397 coinfected patients on TDF, 91% were also on emtricitabine or 3TC concurrently, 92% of those tested were hepatitis B e antigen positive, 196 (49%) had prior 3TC exposure; 192 (48%) achieved HBV DNA suppression over a median of 28 months (interquartile range: 13-71). Median time to HBV DNA suppression was 17 months for those who were 3TC-naive and 50 months for those who were 3TC exposed. After controlling for other factors, prior 3TC exposure, baseline HBV DNA level >10,000 IU/mL, and lower nadir CD4 count were independently associated with decreased likelihood of HBV DNA suppression on TDF.

CONCLUSIONS

These results emphasize the role of prior 3TC exposure and immune response on delayed HBV suppression on TDF.

Incidence and risk factors for incomplete HBV DNA suppression in HIV/HBV-co-infected patients initiating tenofovir-based therapy

Suppression of hepatitis B virus (HBV)-DNA to undetectable levels is an important goal for HIV/HBV-co-infected patients receiving anti-HBV-active antiretroviral therapy (ART), and current guidelines recommend that this outcome should be reached by 1 year of treatment. However, the proportion of patients that fail to achieve an undetectable HBV DNA at this time point and its determinants remain unknown in clinical practice. The objective of this study was to determine the incidence and risk factors for incomplete HBV suppression following 1 year of tenofovir-based ART. We performed a cohort study among tenofovir-treated HIV/HBV-co-infected patients. Patients had HBV viraemia, initiated tenofovir-based ART and had HBV DNA measured at 1 year of therapy. The primary outcome was incomplete HBV suppression (HBV DNA ≥2.6 log IU/mL) at 1 year. Logistic regression determined odds ratio (ORs) of incomplete HBV suppression for risk factors of interest. Among 133 patients, 54% (95% CI, 46-63%) had incomplete HBV suppression at 1 year. Incomplete suppression was associated with higher baseline HBV DNA (OR, 1.46 per log IU/mL increase; 95% CI, 1.1-1.94) and detectable HIV viraemia at 1 year (OR, 2.52; 95% CI, 1.19-5.32). Among 66 patients with suppressed HIV RNA at 1 year, 28 (42%) failed to achieve an undetectable HBV DNA. Failure to suppress HBV DNA by 1 year occurred in a sizeable proportion of tenofovir-treated HIV/HBV-co-infected patients. Higher HBV DNA and detectable HIV viraemia were risk factors for incomplete HBV suppression.

HIV-HBV coinfection in Southern Africa and the effect of lamivudine- versus tenofovir-containing cART on HBV outcomes

BACKGROUND

This study assessed HIV-hepatitis B virus (HBV) coinfection in southern Africa in terms of prevalence, viral characteristics, occult HBV, and the effect of lamivudine- versus tenofovir-containing first-line combination antiretroviral treatment (cART) on HBV-related outcomes.

METHODS

A multicenter prospective cohort of HIV-infected adults in Zambia and South Africa who initiated cART. Outcomes by month 12 on cART were immunological recovery, hepatitis B surface antigen (HBsAg) loss, viral suppression, and drug resistance. We used descriptive statistics, logistic regression, and linear mixed models.

RESULTS

Of the 1087 participants, 92 were HBsAg seropositive, yielding a sample-weighted prevalence of 7.4% (95% confidence interval: 5.6 to 9.2), with 76% genotype HBV-A1. The estimated CD4 recovery on cART was similar between HIV monoinfection and HIV-HBV coinfection groups and between lamivudine- and tenofovir-treated participants. HBsAg loss was documented in 20% (4/20) of lamivudine-treated and 18% (3/17) of tenofovir-treated participants (P = 0.305). Viral suppression (HBV-DNA < 20 IU/mL) was achieved in 61.5% (16/26) of lamivudine-treated and 71.4% (15/21) of tenofovir-treated participants (P = 0.477). HBV pol sequencing demonstrated M204I (n = 3) and N236T (n = 1) resistance-associated mutations in 4 of 8 (50%) lamivudine-treated participants and none in tenofovir-treated participants. Occult HBV infection was present in 13.3% before cART, but by month 12, HBV-DNA was below the limit of detection (<15 IU/mL) in 90.5% (19/21) of lamivudine-treated and 100% (18/18) of tenofovir-treated participants (P = 0.179).

CONCLUSIONS

Tenofovir-containing first-line cART is preferred for HIV-HBV coinfection in Africa because of a superior resistance profile relative to lamivudine monotherapy. Extended follow-up will be needed to determine long-term complications of occult HBV coinfection. Improved access to HBsAg screening and tenofovir is needed.

Rates and impact of hepatitis on human immunodeficiency virus infection in a large African cohort

AIM: To determine the rates and impact of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections on response to long-term highly active antiretroviral therapy (HAART) in a large human immunodeficiency virus (HIV) population in Nigeria.

METHODS: HBV and HCV as well as HIV infections are endemic in sub Saharan Africa. This was a retrospective cohort study of 19 408 adults who were recruited between June 2004 and December 2010 in the AIDS Prevention Initiative in Nigeria in Nigeria programme at Jos University Teaching Hospital. Serological assays, including HBV surface antigen (HBsAg) and hepatitis C antibody were used to categorise hepatitis status of the patients. HBsAg was determined using enzyme immunoassay (EIA) (Monolisa HBsAg Ultra3; Bio-Rad). HCV antibody was tested using third generation EIA (DIA.PRO Diagnostic, Bioprobes srl, Milan, Italy). HIV RNA levels were measured using Roche COBAS Amplicor HIV-1 monitor test version 1.5 (Roche Diagnostics, GmbH, Mannheim, Germany) with a detection limit of 400 copies/mL. Flow cytometry was used to determine CD4+ cell count (Partec, GmbH Munster, Germany). Comparison of categorical and continuous variables were achieved using Pearson’s χ² and Kruskal Wallis tests respectively, on MedCalc for Windows, version 9.5.0.0 (MedCalc Software, Mariakerke, Belgium).

RESULTS: With an overall hepatitis screening rate of over 90% for each virus; HBV, HCV and HBV/HCV were detected in 3162 (17.8%), 1983 (11.3%) and 453 (2.5%) HIV infected adults respectively. The rate of liver disease was low, but highest among HIV mono-infected patients (29, 0.11%), followed by HBV co-infected patients (15, 0.08%). Patients with HBV co-infection and triple infection had higher log₁₀ HIV RNA loads (HBV: 4.6 copies/mL vs HIV only: 4.5 copies/mL, P < 0.0001) and more severe immune suppression (HBV: 645, 55.4%; HBV/HCV: 97, 56.7%) prior to initiation of HAART compared to HIV mono-infected patients (1852, 48.6%) (P < 0.0001). Of 3025 patients who were 4.4 years on HAART and whose CD4 cell counts results at baseline and end of follow up were available for analyses, CD4 increase was significantly lower in those with HBV co-infection (HBV: 144 cells/mm³; HBV/HCV: 105 cells/mm³) than in those with HCV co-infection (165 cells/mm³) and HIV mono-infection (150 cells/mm³) (P = 0.0008).

CONCLUSION: High rates of HBV and HCV infections were found in this HIV cohort. CD4 recovery was significantly diminished in patients with HBV co-infection.

Efficacy of telbivudine on interruption of hepatitis B virus vertical transmission: a meta-analysis

BACKGROUND AND OBJECTIVES

Hepatitis B virus (HBV) infection is one of the most common infections in the world. Vertical transmission is the main reason for the continued endemic infection rates, at least in Asia. This study aimed to investigate the efficacy of telbivudine on mother-to-child transmission (MTCT) interruption.

METHODS

Studies up to April 2012 were collected by searching Pubmed, EMBASE, the Cochrane Library, EBM Review, WangFang Database and China National Knowledge Infrastructure. Serum hepatitis B surface antigen (HBsAg) and HBV DNA in newborns and infants, maternal HBV DNA negative conversion and alanine trans.aminase (ALT) normalization and adverse events were analyzed.

RESULTS

Seven clinical trials involving 644 pregnant women were included in this meta-analysis. Telbivudine resulted in lower HBsAg and HBV DNA seroprevalence in newborns and infants. When maternal viral load prior to delivery was higher than 103copies/mL, HBsAg or HBV DNA positivity had no statistical difference.

CONCLUSIONS

Telbivudine treatment has efficacy and safety on MTCT interruption during late pregnancy. In addition, we demonstrated benefit of telbivudine for mothers in terms of HBV DNA negative conversion and ALT normalization. Telbivudine treatment at the end of pregnancy should be considered in women with high viral load.

Treatment of HBeAg positive chronic hepatitis B: interferon or nucleoside analogues

Interferon alpha has restricted efficacy in as much as only a proportion of patients show a response. However, in appropriately selected HBeAg-positive and HBeAg-negative patients, sustained suppression of viral replication can be achieved, and HBeAg or even HBsAg seroconversion can be attained. Thus, finite course of interferon alpha can be successful, and offer an advantage to patient. Interferon (IFN) remains a benchmark therapy for chronic hepatitis B. The main advantages of IFN-α over nucleoside analogues are the absence of resistance and the possibility of immune-mediated clearance of hepatitis B. Unfortunately, side effects preclude the use of interferon alpha in substantial proportions of patients, and prolonged maintenance therapy to suppress hepatitis B virus (HBV) is not feasible. Nucleoside analogues are given by mouth, once per day, and the safety, potency and efficacy have improved and facilitated treatment. However, maintenance of long-term suppression is required for the majority of patients. In general, treatment of chronic hepatitis B should target patients with active disease and viral replication, preferably before the signs and symptoms of cirrhosis or significant injury has occurred. Current EASL guidelines suggest that treatment be based on the evaluation of three criteria: Serum aminotransferase levels, serum HBV DNA levels and histological grade and stage. Many questions remain unanswered on the optimal treatment of patients with chronic hepatitis B with a nucleoside vs interferon alpha. Both forms of treatment have benefits and the choice should be selected and tailored. Stopping or futility rules can be implemented in patients who fail interferon. Recent data suggest the safety and efficacy of nucleoside analogues in the third trimester of pregnancy to reduce the risk of transmission from mothers to their children.

Patterns and causes of suboptimal response to tenofovir-based therapy in individuals coinfected with HIV and hepatitis B virus

BACKGROUND

Tenofovir (TDF) is effective for treatment of hepatitis B virus (HBV) in human immunodeficiency virus (HIV) infection; however, some individuals have ongoing HBV viremia, the reasons for which are unclear. We determined the patterns and factors associated with detectable HBV DNA in HIV-HBV-coinfected subjects on highly active antiretroviral therapy (HAART).

METHODS

One hundred sixty-five HIV-HBV-coinfected individuals from the United States, Australia, and Thailand, the majority of whom were on HAART at study entry, were prospectively followed semiannually for a median of 2.8 years. Logistic regression was used to determine factors associated with detectable HBV DNA.

RESULTS

Anti-HBV regimens were TDF/emtricitabine (57%), lamivudine or emtricitabine (19%), or TDF monotherapy (13%). During follow-up, HBV DNA was detected at 21% of study visits and was independently associated with hepatitis B e antigen (HBeAg), HAART <2 years, CD4 <200 cells/mm(3), detectable HIV RNA, reporting <95% adherence, and anti-HBV regimen. TDF/emtricitabine was less likely to be associated with detectable HBV than other regimens, including TDF monotherapy (odds ratio, 2.79; P = .02). In subjects on optimal anti-HBV therapy (TDF/emtricitabine) and with undetectable HIV RNA, HBeAg, CD4 <200 mm(3), and reporting <95% adherence remained associated with detectable HBV DNA. Three main patterns of HBV viremia were observed: persistent HBV viremia, viral rebound (>1 log from nadir), and viral blips. No TDF resistance was identified.

CONCLUSIONS

Tenofovir/emtricitabine was superior to other anti-HBV regimens in long-term HBV suppression. HBV viremia on therapy was identified in 1 of 3 main patterns. Suboptimal adherence was associated with detectable HBV DNA during therapy, even when HIV was undetectable.

Five-year on-treatment efficacy of lamivudine-, tenofovir- and tenofovir + emtricitabine-based HAART in HBV-HIV-coinfected patients

Data on the efficacy of lamivudine (LAM)-, tenofovir (TDF)- and emtricitabine (FTC)-based antiretroviral therapy (HAART) in HBV-HIV coinfection are limited. We completed a retrospective analysis of HBV-HIV-coinfected patients treated at the Medical University of Vienna. One-hundred and ten coinfected patients were included, with 57% being initially HBV e-Antigen (HBeAg) positive. Baseline HBV load was significantly higher in HBeAg+ than in HBeAg- patients (5962 ± 3663 vs 20 ± 19 × 10(6) IU/mL; P < 0.0001). Over a median observation period of 83 month (range: 26-183), 87% received HAART and 91% showed a suppression of HBV replication. After 5 years of continuous treatment, HBeAg seroconversion was achieved in 21% of LAM-, 50% of TDF- (P = 0.042 vs LAM) and in 57% of TDF + FTC (P = 0.008 vs LAM)-treated patients, respectively. HBsAg loss after 5 years was found in 8% (LAM), 25% (TDF; P = 0.085 vs LAM) and 29% (TDF + FTC; P = 0.037 vs LAM) of HBeAg+ patients. In HBeAg- patients, HBsAg loss was achieved in 11% (LAM), 27% (TDF; P = 0.263 vs LAM) and 36% (TDF + FTC; P = 0.05 vs LAM), respectively. Pretreatment CD4+ counts did not influence rates of HBeAg seroconversion and of HBsAg loss. Patients with HBsAg loss had lower baseline HBV-DNA levels and higher AST/ALT levels than patients without HBsAg loss. Transient HAART-related hepatotoxicity was found in 32% (Grade I: 21%; II:7%; III:2%; IV:0%). Most HBV-HIV-coinfected patients achieve complete suppression of HBV replication despite high baseline viremia. TDF-based HAART leads to high rates of HBeAg seroconversion and HBsAg loss after 5 years of continuous exposure. One-third of HBV-HIV-coinfected patients may experience transient HAART-related hepatotoxicity.

Long-term hepatitis B virus (HBV) response to lamivudine-containing highly active antiretroviral therapy in HIV-HBV co-infected patients in Thailand

Background

Approximately 4 million of people are co-infected with HIV and Hepatitis B virus (HBV). In resource-limited settings, the majority of HIV-infected patients initiate first-line highly active antiretroviral therapy containing lamivudine (3TC-containing-HAART) and long-term virological response of HBV to lamivudine-containing HAART in co-infected patients is not well known.

Methodology/Principal Finding

HIV-HBV co-infected patients enrolled in the PHPT cohort (ClinicalTrials.gov NCT00433030) and initiating a 3TC-containing-HAART regimen were included. HBV-DNA, HIV-RNA, CD4+ T-cell counts and alanine transaminase were measured at baseline, 3 months, 12 months and then every 6 months up to 5 years. Kaplan-Meier analysis was used to estimate the cumulative rates of patients who achieved and maintained HBV-DNA suppression. Of 30 co-infected patients, 19 were positive for HBe antigen (HBeAg). At initiation of 3TC-containing-HAART, median HBV DNA and HIV RNA levels were 7.35 log₁₀ IU/mL and 4.47 log₁₀ copies/mL, respectively. At 12 months, 67% of patients achieved HBV DNA suppression: 100% of HBeAg-negative patients and 47% of HBeAg-positive. Seventy-three percent of patients had HIV RNA below 50 copies/mL. The cumulative rates of maintained HBV-DNA suppression among the 23 patients who achieved HBV-DNA suppression were 91%, 87%, and 80% at 1, 2, and 4 years respectively. Of 17 patients who maintained HBV-DNA suppression while still on 3TC, 4 (24%) lost HBsAg and 7 of 8 (88%) HBeAg-positive patients lost HBeAg at their last visit (median duration, 59 months). HBV breakthrough was observed only in HBeAg-positive patients and 6 of 7 patients presenting HBV breakthrough had the rtM204I/V mutations associated with 3TC resistance along with rtL180M and/or rtV173L.

Conclusions

All HBeAg-negative patients and 63% of HBeAg-positive HIV-HBV co-infected patients achieved long-term HBV DNA suppression while on 3TC-containing-HAART. This study provides information useful for the management of co-infected patients in resource-limited countries where the vast majority of co-infected patients are currently receiving 3TC.

Hepatitis B surface antigen declines and clearance during long-term tenofovir therapy in patients coinfected with HBV and HIV

BACKGROUND

The kinetics of hepatitis B surface antigen (HBsAg) are predictive in HBV-infected patients treated with pegylated interferon. Knowledge about the value of HBsAg levels in patients coinfected with HBV and human immunodeficiency virus (HIV) is lacking.

METHODS

We quantified serum HBsAg in a Dutch multicenter cohort of 104 patients coinfected with HIV and HBV who were treated with tenofovir disoproxil fumarate (TDF) as part of highly active antiretroviral therapy. The median duration of therapy was 57 months (interquartile range, 34-72 months).

RESULTS

Hepatitis B e antigen (HBeAg)-positive patients achieved a decline of 2.2 log IU/mL in HBsAg, whereas HBeAg-negative patients only achieved a decline of 0.6 log IU/mL during 6 years of TDF therapy. Declines in HBsAg at months 6 and 12 correlated with CD4 cell count for HBeAg-positive patients. Five HBeAg-positive patients (8%) and 3 HBeAg-negative patients (8%) cleared HBsAg. HBeAg-negative patients who cleared HBsAg had lower baseline HBsAg as compared to patients who remained HBsAg positive. The majority of patients who cleared HBsAg achieved this end point within the first year. In HBeAg-positive patients, decline in HBsAg at month 6 was predictive of achieving HBsAg seroclearance.

CONCLUSIONS

Receipt of TDF therapy by HIV/HBV-coinfected patients for up to 6 years led to a significant decrease in HBsAg in the HBeAg-positive population. HBsAg kinetics early during treatment were predictive of HBsAg seroclearance and correlated with an increased CD4 cell count, underlining the importance of immune restoration in HBV clearance.

Role of molecular diagnostics in the management of viral hepatitis B

INTRODUCTION

Despite the availability of a safe and effective vaccine, chronic hepatitis B virus (HBV) infection continues to be a global health concern with an estimated 350 - 400 million people infected worldwide. Globally, HBV is the leading cause of chronic liver disease that may progress to cirrhosis and hepatocellular carcinoma. Therefore, accurate diagnosis and classification of the disease are important to determine whether therapy is needed.

AREAS COVERED

The review contains an overview of recent data on the existing and emerging developments in the molecular diagnostic and monitoring tools for chronic liver disease.

EXPERT OPINION

Monitoring of HBV viral load is the most widely used method in assessing liver disease severity, predicting development of cirrhosis and hepatocellular carcinoma, deciding initiation of antiviral therapy, assessing treatment response as well as early detection of emergence of drug resistance. Some recent studies have downplayed the importance of viral load in HBV management. Phenotyping/genotyping methods can establish emergent resistance to antivirals. Increasing number of reports suggest that clinical outcome and efficacy of antiviral treatment might vary with HBV genotype and precore/core promoter mutants. The importance of covalently closed circular DNA is also becoming apparent in this regard. Further studies on the development of newer molecular methods for a better management of chronic hepatitis B (CHB) will minimize morbidity in CHB.

Long-term outcome of primary non-responders to tenofovir therapy in HIV/HBV-co-infected patients: impact of HBV genotype G

AIM

To evaluate the early virological response (EVR) to combined tenofovir-lamivudine or emtricitabine regimen in HBV/HIV-co-infected patients and the long-term efficacy of tenofovir.

METHODS

In this retrospective monocentric study, among the 166 HIV/HBV-co-infected patients regularly followed from 2003 to 2008 at Bichat Claude Bernard Hospital, 61 patients had received, either de novo combination therapy with tenofovir and lamivudine or emtricitabine (group I, n = 15) or add-on tenofovir to lamivudine therapy (group II, n = 46). The HBV polymerase region was sequenced and analysed for all patients with available samples.

RESULTS

All 15 group I patients achieved EVR vs 32 (82%) of group II patients (P = 0.15). Seven adherent group II patients met criteria for primary non-response, but achieved delayed response (DR) to therapy. In these seven patients, when compared with the 39 group II patients, there was a trend to longer duration of lamivudine pre-treatment and to higher rate of lamivudine-resistant mutants; and HBV genotype-G proportion was higher (P = 0.026). No virological breakthrough occurred after a median of 46 months follow up.

CONCLUSION

In these HBV/HIV-co-infected patients, first-line HBV therapy with tenofovir and emtricitabine or lamivudine was associated with EVR. However, DR to tenofovir was observed in 15% of patients who added tenofovir to lamivudine therapy, of whom four of seven (57%) had genotype G-HBV infection. No resistance was evidenced after 46 months of therapy even in patients with DR to tenofovir. At last, a good renal safety profile of TDF was observed after a median follow-up of 4 years of therapy.

Predictors of HBeAg status and hepatitis B viraemia in HIV-infected patients with chronic hepatitis B in the HAART era in Brazil

Background

HBV-HIV co-infection is associated with an increased liver-related morbidity and mortality. However, little is known about the natural history of chronic hepatitis B in HIV-infected individuals under highly active antiretroviral therapy (HAART) receiving at least one of the two drugs that also affect HBV (TDF and LAM). Information about HBeAg status and HBV viremia in HIV/HBV co-infected patients is scarce. The objective of this study was to search for clinical and virological variables associated with HBeAg status and HBV viremia in patients of an HIV/HBV co-infected cohort.

Methods

A retrospective cross-sectional study was performed, of HBsAg-positive HIV-infected patients in treatment between 1994 and 2007 in two AIDS outpatient clinics located in the São Paulo metropolitan area, Brazil. The baseline data were age, sex, CD4 T+ cell count, ALT level, HIV and HBV viral load, HBV genotype, and duration of antiretroviral use. The variables associated to HBeAg status and HBV viremia were assessed using logistic regression.

Results

A total of 86 HBsAg patients were included in the study. Of these, 48 (56%) were using combination therapy that included lamivudine (LAM) and tenofovir (TDF), 31 (36%) were using LAM monotherapy, and 7 patients had no previous use of either one. Duration of use of TDF and LAM varied from 4 to 21 and 7 to 144 months, respectively. A total of 42 (48. 9%) patients were HBeAg positive and 44 (51. 1%) were HBeAg negative. The multivariate analysis revealed that the use of TDF for longer than 12 months was associated with undetectable HBV DNA viral load (serum HBV DNA level < 60 UI/ml) (p = 0. 047). HBeAg positivity was associated with HBV DNA > 60 UI/ml (p = 0. 001) and ALT levels above normality (p = 0. 038).

Conclusion

Prolonged use of TDF containing HAART is associated with undetectable HBV DNA viral load. HBeAg positivity is associated with HBV viremia and increased ALT levels.

Impact of lamivudine on HIV and hepatitis B virus-related outcomes in HIV/hepatitis B virus individuals in a randomized clinical trial of antiretroviral therapy in southern Africa

OBJECTIVE

To examine HIV and hepatitis B virus (HBV)-related outcomes in HIV/HBV-coinfected participants in the PHIDISA II study by use of HBV-active vs. non-HBV-active antiretroviral therapy (ART).

DESIGN AND METHODS

PHIDISA II was a randomized study of ART therapy in HIV-infected adults employing zidovudine along with didanosine, or lamivudine along with stavudine in a factorial 2x2 design. HIV/HBV-coinfected participants by randomization received HBV-active or non-HBV-active ART. The following outcomes of interest were examined: immunological recovery and HIV RNA suppression; hepatic flare; HBV DNA suppression; and mortality.

RESULTS

HIV/HBV coinfection was present in 106 of 1771 (6%) of participants. Participants with HIV/HBV coinfection were more likely to be men, and have higher baseline alanine aminotransferase, lower albumin, and lower platelets than those with HIV monoinfection. Median CD4 cell gain and HIV RNA suppression was similar across all groups. Hepatic flare was observed in 9.4% of coinfected and 0.02% monoinfected participants. HBV DNA suppression (<55 IU/ml) at week 48 was observed in only 33% of those on lamivudine vs. 13% in those on no HBV-active drugs (P = 0.13). Mortality over follow-up was significantly greater in coinfected (17%) than monoinfected (11%) participants (P = 0.04).

CONCLUSION

In summary, the use of lamivudine-containing ART in HIV/HBV participants in PHIDISA II resulted in little additional benefit over that of ART itself and failed to impact on the greater mortality in this group. These data provide strong support for recent guidelines advocating the use of tenofovir in all HIV-HBV-coinfected individuals initiating ART.

Management of HIV and hepatitis virus coinfection

IMPORTANCE OF THE FIELD

Liver disease related to infection with hepatitis C virus (HCV) and/or hepatitis B virus (HBV) is a frequent cause of morbidity and mortality in those infected with the human immunodeficiency virus (HIV) in this era of highly active antiretroviral therapy (HAART). Although progress has been made in the treatment of HBV and HCV in the setting of HIV-coinfection, there is a lack of data in certain areas and several aspects of the management are unclear at this time.

AREAS COVERED IN THIS REVIEW

Available data on the treatment of HBV and HCV infections, especially in the HIV-coinfected patient, are presented. Practical aspects of the management of these patients are reviewed, including diagnosis, treatment indications, monitoring, and toxicities. The impact of HAART on liver disease, end-stage-liver disease, and new therapeutic approaches are also reviewed.

WHAT THE READER WILL GAIN

There are two modalities for the treatment of chronic HBV infection: interferon and nucleos(t)ide reverse transcriptase inhibitors (NRTI). The latter is the mainstream of therapy for HIV-HBV-coinfected patients. The double antiviral activity of NRTI requires coordination and careful selection of treatment for both viruses to avoid selection of resistance mutations and toxicity. Combination of pegylated interferon and ribavirin, the current standard treatment for chronic hepatitis C, has significant toxicity and limited efficacy in HIV-HCV-coinfected individuals. Oral anti-HCV treatments are currently under development and need to be studied in the HIV-coinfected population. Liver transplantation has a better outcome in HBV- than in HCV-HIV-coinfected patients. HAART seems to have a positive impact on the liver disease of HBV- and/or HCV-coinfected subjects but the CD4 threshold above which the benefit might take place is unknown at this time.

TAKE HOME MESSAGE

Anti-HBV treatment in the HIV-coinfected patient relies on the available NRTIs with activity against both viruses. Whereas HBV suppression can be achieved with this approach, toxicities and the selection of HBV-resistant variants result in challenging clinical scenarios. Current anti-HCV treatment (pegylated interferon and ribavirin) has limited efficacy in the HIV-coinfected patient, and STAT-C drugs are eagerly awaited.

Treatment of special populations with chronic hepatitis B infection

All therapeutic agents that are currently in use for the treatment of chronic hepatitis B have been administered to a large number of patients in clinical trials in order to be approved as efficacious and safe. Nevertheless, in these trials, many patients have been excluded either because they have decompensated cirrhosis, or they belong to groups with comorbidities that can seriously affect the underlying liver disease, or where the treatment for chronic hepatitis B virus infection can be contraindicated. Such groups of patients are those with hepatitis D virus, hepatitis C virus and HIV coinfections, patients who have undergone transplantation or are immunosuppressed due to chemotherapy or other treatment, patients with end-stage renal disease under dialysis, acute and fulminant hepatitis B and also, children and pregnant women. In this article, all of the aspects of treatment of these special categories are discussed, since for many of these patients, treatment is of a greater importance compared with the standard patient with chronic hepatitis B, and in real life they represent a great percentage of chronic hepatitis B virus infection patients.

Antiviral therapy in patients co-infected with hepatitis B virus and human immunodeficiency virus

The rapid spread of human immunodeficiency virus (HIV) in China has made hepatitis B virus (HBV)/HIV co-infection become a common clinical condition. HBV/HIV co-infection substantially alters the natural course of HBV or HIV mono-infection as well as their management. Therapy for HBV infection in HIV-co-infected patients is based on whether or not there is an indication for anti-HIV therapy. In patients with no indication for anti-HIV therapy, interferon-α(IFN-α) or adefovir dipivoxil (ADV) is recommended. In patients with an indication of anti-HIV therapy, a backbone of highly active anti-retroviral therapy should include tenofovir disoproxil fumarate (TDF) in combination with lamivudine (LAM) or emtricitabine (FTC). Switching to or adding ETV/ADV is recommended in patients who develop LAM/FTC resistance. LdT has no activity against HIV and is therefore not recommended for anti-HBV therapy in patients with HBV/HIV co-infection.

[Long-term therapy for chronic hepatitis B in HIV co-infected patients]

As human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are acquired through the same routes of contamination, the prevalence of HBV serological markers found in the HIV-infected population is approximately 7%. Liver-related mortality and morbidity is higher in HIV/HBV co-infected patients than in HBV mono-infected patients. Both viruses must be considered before a treatment decision is made. According to the European consensus conference on the treatment of chronic hepatitis B and C in HIV coinfected patients, treatment is based on whether there is an existing indication of anti- HIV therapy or not. In patients with no indication of anti-HIV therapy, drugs with dual anti-viral activity (lamivudine, entecavir, tenofovir disoproxil fumarate) should not be used due to the risk of developing HIV-resistance. Interferon or adefovir in combination with telbivudine are recommended. In patients with an indication of anti-HIV therapy, a backbone of highly active anti-retroviral therapy should include tenofovir in combination with lamivudine or emtricitabine. The same regimen is recommended in patients who develop lamivudine resistance.

Tenofovir improves the outcome in patients with spontaneous reactivation of hepatitis B presenting as acute-on-chronic liver failure

Spontaneous reactivation of chronic hepatitis B (CHB) is an important cause of acute-on-chronic liver failure (ACLF). Antiviral drugs may help reduce the high morbidity and mortality in such patients, especially in places where liver transplant is not available. The aim was to evaluate the efficacy of tenofovir and to determine the predictors of mortality in patients with spontaneous reactivation of CHB with ACLF. Consecutive patients of ACLF due to spontaneous reactivation of CHB were randomized to receive either tenofovir or placebo. The primary endpoint was survival at 3 months. Of the 90 patients with ACLF of different etiologies, 27 (26%) were due to reactivation of CHB and were enrolled. The median baseline hepatitis B virus (HBV) DNA level was 9 × 10(5) IU/mL. Fourteen patients received tenofovir and 13 placebo. At 3 months the probability of survival was higher in the tenofovir than the placebo group (8/14 [57%] versus 2/13 [15%], respectively; P = 0.03). The cause of death in the 15 patients was progressive liver failure leading to multiorgan failure. Liver transplantation could not be offered due to its nonavailability. In the surviving patients, there was a significant improvement in the Child-Turcotte Pugh (CTP) and model for endstage liver disease (MELD) scores and significant decline in the HBV DNA levels in the tenofovir group, whereas these parameters did not change significantly in the placebo group. More than 2 log reduction in HBV DNA levels at 2 weeks was found to be an independent predictor of survival.

CONCLUSION

Tenofovir significantly reduces HBV-DNA levels, improves CTP and MELD scores, and reduces mortality in patients with severe spontaneous reactivation of CHB presenting as ACLF. Reduction in HBV-DNA levels at 2 weeks should be a desirable goal and is a good predictor of survival.

Efficacy of tenofovir disoproxil fumarate/emtricitabine compared with emtricitabine alone in antiretroviral-naive HIV-HBV coinfection in Thailand

BACKGROUND

Therapy for chronic hepatitis B with tenofovir disoproxil fumarate (TDF) and lamivudine (3TC) or emtricitabine (FTC) is currently recommended for HIV-HBV coinfection. However, there is limited randomized data on the efficacy of combined therapy with TDF and FTC, especially in antiretroviral (ARV)-naive patients.

METHODS

This was a prospective randomized clinical trial comparing the efficacy of HBV monotherapy with FTC versus TDF/FTC combination therapy in ARV-naive HIV-HBV coinfection. HIV-HBV-coinfected patients initiating ARV were randomized to either FTC/zidovudine/efavirenz (EFV; n=6) or TDF/FTC/EFV (n=10). The primary end point was the time-weighted area under the curve (TWAUC) of HBV DNA at 48 weeks.

RESULTS

The median baseline CD4(+) T-cell count was 64 cells/μl (interquartile range [IQR] 36-172), plasma HIV type-1 RNA was 4.90 log(10) copies/ml (IQR 4.58-5.44) and plasma HBV DNA was 8.76 log(10) copies/ml (IQR -8.45-8.82). A total of 11/16 (69%) patients were hepatitis B e antigen (HBeAg)-positive. The median TWAUC decrease in HBV DNA was -5.32 log(10) copies/ml in the TDF/FTC group compared with -3.25 log(10) copies/ml in the FTC group (P=0.03). At week 48, 90% of the TDF/FTC group and 33% of the FTC group had plasma HBV DNA<170 copies/ml (P=0.036, intention-to-treat analysis). HBeAg loss was observed in 4/11 (36%) HBeAg-positive patients. Hepatic flares were observed in 3/16 (19%) of patients.

CONCLUSIONS

TDF/FTC combination therapy resulted in a significantly greater decrease in HBV DNA than FTC monotherapy, with a greater proportion of patients with undetectable HBV DNA at week 48. Our study supports the current recommendation of ARV containing TDF/FTC as the treatment of choice for patients with HIV-HBV coinfection.

Long-term therapy with tenofovir is effective for patients co-infected with human immunodeficiency virus and hepatitis B virus

BACKGROUND & AIMS

We investigated the long-term efficacy and renal safety of tenofovir disoproxil fumarate (TDF), administered to patients co-infected with human immunodeficiency virus and hepatitis B virus (HBV) as part of an antiretroviral therapy.

METHODS

We performed a multicenter, prospective cohort study of 102 patients co-infected with human immunodeficiency virus and HBV who were treated with TDF.

RESULTS

At baseline, 80% of patients had a detectable viral load (HBV DNA >20 IU/mL). Among patients positive for hepatitis B e antigen (HBeAg) (n = 67), 92% had a virologic response (HBV DNA <20 IU/mL) after 5 years of treatment. There was no difference between patients with or without lamivudine resistance at baseline (P = .39). Loss rates of HBeAg and hepatitis B s antigen (HBsAg) were 46% and 12%, respectively. Among HBeAg-negative patients (n = 15), 100% had a virologic response after 4 years of treatment and 2 (13%) lost HBsAg. Twenty subjects (20%, all HBeAg-negative) had undetectable HBV DNA at baseline; during a median follow-up period of 52 months (interquartile range, 41-63 mo), 19 (95%) maintained a virologic response and 2 (10%) lost HBsAg. Overall, one patient acquired a combination of resistance mutations for anti-HBV drugs and experienced a virologic breakthrough. Three (3%) patients discontinued TDF because of increased serum creatinine levels. The estimated decrease in renal function after 5 years of TDF therapy was 9.8 mL/min/1.73 m(2), which was most pronounced shortly after TDF therapy was initiated.

CONCLUSIONS

TDF, administered as part of antiretroviral therapy, is a potent anti-HBV agent with a good resistance profile throughout 5 years of therapy. Only small nonprogressive decreases in renal function were observed.

Virology and clinical sequelae of drug-resistant HBV in HIV-HBV-coinfected patients on highly active antiretroviral therapy

Several of the nucleoside/nucleotide analogues used to treat HIV also inhibit HBV replication, with lamivudine being the oldest of this group. Thus, prior to licensing of tenofovir, many HIV-HBV-coinfected individuals received lamivudine as the only drug active against HBV as part of an anti-HIV regimen, which set the stage for the emergence of drug-resistant HBV. In coinfected persons, lamivudine-resistant HBV develops more rapidly than in HBV-monoinfected persons, but it is not known if this is true for the newer agents. Owing to overlapping reading frames of the HBV polymerase and surface antigens, drug-resistant changes in HBV Pol can lead to mutations in the envelope. This review will discuss studies of drug-resistant HBV in HIV-infected persons including drug-resistant mutations that have been identified and clinical sequelae of these mutations.

Hepatitis B in HIV: available treatment options and approach to therapy

In the past 5 years, three new drugs were approved for hepatitis B, bringing the total number of therapies to five nucleos(-t)ide analogues and two interferons. Some of these drugs are also active against HIV. As the complexity of hepatitis B treatment increases, it becomes important for practitioners to be familiar with the potency, resistance patterns, and response rates for each hepatitis B agent. In this article, the efficacy in HIV and the best regimens for coinfected patients are discussed for those needing treatment for both infections. A particular emphasis is placed on cross-resistance among hepatitis B drugs.

Antiretroviral therapy for treatment-naïve patients: a review of recent literature and the updated guidelines

The improved efficacy and safety of antiretroviral agents have fundamentally changed the face of HIV infection. Advances in antiretroviral therapy have dramatically improved the prognosis of HIV infection, which is now on a par with other chronic illnesses. This article addresses the optimal timing of antiretroviral therapy initiation and the optimal drug choices for initial regimens, with a focus on recent data and published guidelines issued by the US Department of Health and Human Services and the International AIDS Society-USA.

Antiviral treatment of chronic hepatitis B virus (HBV) infections

While 25 compounds have been formally licensed for the treatment of HIV infection (AIDS), only seven licensed products are currently available for the treatment of chronic hepatitis B virus (HBV) infection: interferon-α, pegylated interferon-α, lamivudine, adefovir (dipivoxil), entecavir, telbivudine and tenofovir (disoproxil fumarate). In contrast to the treatment of HIV infections where the individual drugs are routinely used in combination, for the treatment of chronic HBV infection the individual drugs are generally used in monotherapy. In principle, combination drug therapy should allow reducing the likelihood of drug-resistant development.

Frequent hepatitis B virus rebound among HIV-hepatitis B virus-coinfected patients following antiretroviral therapy interruption

BACKGROUND

The impact of antiretroviral therapy (ART) interruption in HIV-hepatitis B virus (HBV)-coinfected patients was examined in the Strategic Management of AntiRetroviral Therapy (SMART) study.

METHODS

Plasma HBV DNA was measured in all hepatitis B surface antigen-positive (HBV-positive) participants at baseline, and at months 1, 2, 4, 6, 8, 10, and 12.

RESULTS

Among HBV-positive participants in the ART interruption (drug conservation) (n = 72) and ART continuation (virological suppression) (n = 62) arms, HBV DNA rebound of more than 1 log from baseline at months 1-4 was seen in 31-33% (P = 0.003) and 3-4% (P = 0.017), respectively. Thirteen HBV-positive participants had HBV DNA rebound of more than 3 log, including 12 in the drug conservation arm, of which eight were on tenofovir-containing regimens. Factors independently associated with a HBV DNA rebound were drug conservation arm (P = 0.0002), nondetectable HBV DNA at baseline (P = 0.007), and black race (P = 0.03). Time to ART reinitiation was shorter (7.5, 15.6, and 17.8 months; P < 0.0001) and proportion reinitiating greater (62.5, 46.5, and 39.7%; P = 0.0002) among HBV-positive participants as compared with hepatitis C virus-positive and non-HBV/hepatitis C virus participants in the drug conservation arm. No hepatic decompensation events occurred among HBV-positive participants in either arm.

CONCLUSION

HBV DNA rebound following ART interruption is common and may be associated with accelerated immune deficiency in HIV-HBV-coinfected patients.

Efficacy and safety of tenofovir disoproxil fumarate in patients with chronic hepatitis B

Chronic hepatitis B (CHB) is prevalent worldwide. It may cause cirrhosis and hepatocellular carcinoma. Treatment for this condition may need to be lifelong, thus the drugs used must be both efficacious and safe. Clinical trials of tenofovir have demonstrated a good safety profile for this drug and it has potent antiviral properties. However, to better characterize the safety of this drug, the postmarketing surveillance must be taken into account. Clinicians need to be vigilant, as infrequent adverse events may be revealed during this phase. The current review presents a detailed exposé of preclinical and clinical data on tenofovir to increase awareness of possible adverse events and drug-drug interactions, based on the large experience of this drug in human immunodeficiency virus (HIV) treatment (and to date in patients with CHB). Several recommendations that may help the clinician to prevent the development of adverse events associated with tenofovir disoproxil fumarate (TDF) treatment are outlined, along with a suggested surveillance protocol for the timely and proper identification of possible renal and bone toxicity.

Nucleotide HIV reverse transcriptase inhibitors: tenofovir and beyond

PURPOSE OF REVIEW

This review describes the class of nucleotide HIV reverse transcriptase inhibitors and summarises recent findings related to tenofovir and its oral prodrug tenofovir disoproxil fumarate, currently the only nucleotide approved for the treatment of HIV infection. In addition, novel strategies in the design of anti-HIV nucleotides and their prodrugs are discussed.

RECENT FINDINGS

A number of studies have demonstrated a potent and durable clinical efficacy of tenofovir disoproxil fumarate in combination with other antiretrovirals, particularly lamivudine or emtricitabine and efavirenz. The prophylactic antiretroviral effect of tenofovir and tenofovir disoproxil fumarate has been characterized in various animal models and is currently being evaluated in controlled clinical studies. In addition, efficacy of tenofovir disoproxil fumarate against hepatitis B virus has been established and is currently being explored in phase III trials. The identification of GS-7340, an alternative prodrug of tenofovir has raised the possibility of using phosphonoamidates as novel prodrugs allowing for an effective intracellular delivery of nucleotides.

SUMMARY

The concept of nucleotides as a novel class of antiretroviral therapeutics has been successfully validated through tenofovir disoproxil fumarate, a nucleotide prodrug that exhibits potent and durable clinical efficacy and favourable safety profile both in treatment-naïve and experienced HIV-infected patients. Several novel nucleotide reverse transcriptase inhibitors such as GS-9148, PMDTA, and PMEO have recently emerged from continuing preclinical drug discovery efforts.

Tenofovir for the treatment of hepatitis B virus

Tenofovir disoproxil fumarate is a nucleotide analog reverse transcriptase inhibitor recently approved by the United States Food and Drug Administration (FDA) for the treatment of chronic hepatitis B virus (HBV) infection in adults. Tenofovir has been available in the United States for the treatment of human immunodeficiency virus (HIV) since 2001. It blocks HBV replication in liver cells and is available as a once-daily oral formulation. The efficacy of tenofovir for the treatment of chronic HBV has been demonstrated to be superior to adefovir in randomized controlled trials, which led to its FDA approval for use in chronic HBV. Because of its potent antiviral activity, favorable safety profile, and higher barrier to the development of resistance, tenofovir should replace adefovir as a first-line monotherapy option in the treatment of HBV in monoinfected patients. In the HIV-HBV-coinfected population, tenofovir is already a preferred agent in combination with other anti-HBV agents (lamivudine or emtricitabine), which are cotreatments for HIV as well. In addition, tenofovir monotherapy or in combination with nucleoside analogs are options for patients who have developed resistance to other therapies for chronic HBV, including lamivudine and adefovir.

Safety and efficacy of telbivudine for the treatment of chronic hepatitis B

Telbivudine was recently approved for the treatment of chronic hepatitis B. Phase III studies indicated its antiviral potency with 6- to 6.5-log copies/mL reductions in hepatitis B DNA levels at year 1, comparable to other potent agents such as entecavir or tenofovir. Genotypic resistance rates, however, reached 25% at year 2 in hepatitis B e-antigen positive subjects and 11% in hepatitis B e-antigen negative subjects, preventing it from becoming a preferred first-line drug for hepatitis B. Furthermore, its signature resistance mutation (a change from methionine to isoleucine at position 204 in the reverse transcriptase domain of the hepatitis B polymerase) also confers cross-resistance to entecavir, lamivudine, and emtricitabine. Telbivudine is well tolerated, with elevations in creatine phosphokinase being the most common abnormality observed in clinical trials. Most often, elevations were asymptomatic. Future research in hepatitis B will focus on the best ways to use existing therapies, including telbivudine, sequentially or in combination in order to maximize viral suppression and minimize the development of antiviral resistance.

Reduced glomerular filtration rate but sustained virologic response in HIV/hepatitis B co-infected individuals on long-term tenofovir

Reports have described a decrease in glomerular filtration rate (eGFR) associated with tenofovir disoproxil fumarate (TDF) use in HIV positive individuals. However, no study has examined renal function over a prolonged period in HIV/hepatitis B virus (HBV) co-infected patients. We assessed the long-term durability and toxicity of TDF in a cohort of 39 e antigen (eAg) positive co-infected patients commenced on TDF 245 mg daily either in addition to or as part of standard antiretroviral therapy. Immunological and virological parameters were followed to 260 weeks, with the median follow-up period being 251 weeks (range 69-290 weeks). eGFR was calculated using the Modification in Diet in Renal Disease equation. On treatment at 260 weeks, 88% (14/16) had HIV viral load <50 copies/mL, median CD4 count rose from 318 to 532 cells/mm(3), median alanine aminotransferase (ALT) fell from 61 IU/L to 42 IU/L, with 35% (7/20) having a normal ALT, median HBV DNA fell from 69 x 10(6) copies/mL to 500 copies/mL, with 75% (12/16) having an undetectable HBV DNA level and 55% (6/11) becoming eAg negative. Of those with detectable HBV DNA, none had TDF resistance mutations. The eGFR declined by 22.19 mL/min/1.73 mm(2) from baseline (P = 0.023) over this period, which was unaffected by protease inhibitor use, baseline CD4 count, ALT or HBV DNA level. Three patients discontinued TDF therapy due to renal dysfunction. In conclusion, TDF has sustained efficacy but is associated with a significant decline in eGFR. Further larger studies are required to clarify this observation.

Anti-hepatitis B virus activity in vitro of combinations of tenofovir with nucleoside/nucleotide analogues

BACKGROUND

Long-term management of some chronic hepatitis B patients might require combination therapy using drugs with distinct resistance profiles to sustain viral suppression and to reduce the resistance-associated failure. Tenofovir disoproxil fumarate (TDF), approved for hepatitis B virus (HBV) and HIV-1 treatment, is active against wildtype HBV and HBV containing YMDD mutations, which confer resistance to emtricitabine (FTC), lamivudine (3TC) and telbivudine (LdT) and contribute to entecavir (ETV) resistance. We therefore evaluated the in vitro anti-HBV activity of tenofovir (TFV), the active parent drug of TDF, combined with FTC, 3TC, ETV, LdT and adefovir (AFV).

METHODS

The anti-HBV activities of the compounds were tested using the AD38 cell line that expresses wild-type HBV from a tetracycline-controllable promoter. Intracellular HBV DNA levels were quantified using real-time PCR assay and cytotoxicities were assessed with XTT assays. The antiviral data of the drug combinations were evaluated using MacSynergy analyses on the basis of the Bliss independence model as well as isobologram analyses on the basis of the Loewe additivity theory.

RESULTS

All drug combinations tested, FTC+TFV, 3TC+TFV, ETV+TFV, LdT+TFV and AFV+TFV, showed additive antiviral interactions as analysed by MacSynergy. Isobologram analyses revealed that these combination pairs were additive, with the exception of FTC+TFV, which demonstrated slight synergistic activity. No cytotoxic or antagonistic effects were observed with any of the combinations tested.

CONCLUSIONS

The combination of TFV with FTC, 3TC, ETV, LdT or AFV had additive to slightly synergistic anti-HBV effects in vitro. These results support the use of TDF as a component in combination regimens with currently available anti-HBV nucleoside analogues.