Viral determinants predicting hepatitis B surface antigen (HBsAg) seroclearance in HIV-/HBV-coinfected patients

Design and analysis considerations for early phase clinical trials in hepatitis B (HBV) cure research: the ACTG A5394 study in persons with both HIV and HBV

With growing interest and efforts to achieve a hepatitis B (HBV) cure, HBV therapeutics have increasingly entered the clinical testing phase. In designing an early phase clinical trial aimed at HBV cure, the heterogeneity in participants and the choice of a biomarker endpoint that signals a cure requires careful consideration. We describe the key elements to consider during the development of HBV clinical trials aimed at a functional cure, and how we have addressed them in the design of a phase II AIDS Clinical Trials Group (ACTG) study, A5394 (NCT05551273). The trial we present is for persons with both HIV and HBV, a unique population that has much to gain from an HBV cure. Our decisions on the design elements are specific to the study agent and the targeted population, but our deliberations may be informative in the emerging field of early phase HBV trials aimed at cure.

Long-term follow-up of patients discontinuing bulevirtide treatment upon long-term HDV-RNA suppression

Background & Aims

Bulevirtide (BLV) is a novel antiviral drug licensed for the treatment of chronic hepatitis D. Data on the safety and efficacy of stopping BLV therapy upon long-term HDV-RNA suppression are scarce.

Methods

A total of seven patients (age, 31-68 years, four with cirrhosis) included in a prospective Austrian HDV registry discontinued BLV treatment (duration, 46-141 weeks) upon long-term HDV suppression (HDV-RNA negativity, 12-69 weeks). Pegylated interferon-ɑ2a was used in combination with BLV in two patients. HDV-RNA, alanine aminotransferase, and quantitative HBsAg levels were closely monitored during treatment-free follow-up.

Results

The seven patients were followed up for 14 to 112 weeks. Six patients completed ≥24 weeks of follow-up. HDV-RNA became detectable again in three patients within 24 weeks, whereas one additional patient showed an HDV-RNA relapse after almost 1 year. All patients who relapsed at any point had undergone BLV monotherapy. Meanwhile, HDV-RNA remained undetectable in two patients who were treated with BLV + pegylated interferon-ɑ2a. Only one patient showed significant alanine aminotransferase increases within 24 weeks of follow-up. BLV was reintroduced in three patients after 13-62 BLV-free weeks and was well tolerated, and all patients achieved virologic response again.

Conclusions

BLV discontinuation upon long-term HDV-RNA suppression seems safe. Retreatment with BLV was effective in case of virologic relapse. These findings are within a limited number of patients, and future studies are needed to define stopping rules and further investigate the safety of stopping BLV.

Impact and Implications

Limited data exist on stopping bulevirtide (BLV) treatment in patients who achieve long-term HDV-RNA suppression. In a small cohort of seven Austrian patients discontinuing BLV therapy, HDV-RNA relapses were observed in four patients during long-term follow-up, whereas significant alanine aminotransferase increases were recorded in only one. Retreatment with BLV was effective in relapsers. The safety and efficacy of stopping BLV needs to be further studied in larger cohorts.

Challenges and opportunities for hepatitis B cure in the setting of HIV--hepatitis B virus co-infection

PURPOSE OF REVIEW

To examine issues specific to HIV--HBV co-infection that are relevant to the search for and achieving hepatitis B cure in this the setting RECENT FINDINGS: In HIV--HBV co-infection, high rates of hepatitis B surface antigen (HBsAg) loss early after initiation of HBV-active antiretroviral therapy (ART) have previously been reported. Between 2012 and 2016, HBsAg loss from 2.8 to 23% was reported in numerous studies, including those already on suppressive HBV-active ART. Data published in 2018-2019 show that these rates have remained fairly stable (3.0-13.9%). However, it appears that higher HBsAg loss on starting HBV-active ART in co-infection falls within a few years to levels similar to that observed in long-term treated HBV mono-infection. Immune reconstitution and CD4+ T-cell recovery are likely to play a role in high HBsAg loss rates seen in early treated co-infection, although the mechanisms driving this are yet to be fully elucidated.

SUMMARY

High rates of HBsAg loss early after HBV-active ART initiation is unique to HIV--HBV co-infection, making it the ideal setting to investigate underlying mechanisms of HBV loss and develop new HBV cure strategies. This phenomenon could be used to enhance HBsAg loss with new therapeutic approaches currently being investigated; however, this is obstructed by excluding co-infection from such studies.

Functional Cure of Hepatitis B Virus Infection in Individuals With HIV-Coinfection: A Literature Review

In individuals infected with hepatitis B virus (HBV), the loss of hepatitis B surface antigen (HBsAg) is the ultimate therapeutic goal, which defines "functional cure." For individuals living with human immunodeficiency virus (HIV), functional cure occurs roughly 2 per 100 person-years during potent anti-HBV containing antiretroviral therapy. Although this rate may be higher than expected in treated HBV mono-infected individuals, rates of functional cure widely vary between studies (0.6-10.5 per 100 person-years). Similar to HBV mono-infection, the phase of HBV infection, HBV (sub-)genotypes and hepatitis B "e" Ag-negative variants are associated with functional cure in treated HIV-HBV co-infection. In specifically HIV-HBV co-infected individuals, strong increases in CD4+ T cell counts after treatment initiation have also been linked to functional cure, yet this finding is inconsistent across studies. Several markers directly or indirectly reflecting HBV activity are being developed to predict functional cure, such as quantification of HBsAg, hepatitis B core-related antigen, HBsAg protein composition, anti-hepatitis B core antibodies and interferon-gamma-inducible protein 10. Few have been assessed during treatment in HIV-HBV co-infected individuals and none have been validated to predict functional cure. Novel therapeutics for HBV cure are essential for individuals with HIV-HBV co-infection and need to be separately evaluated in this population.

Subclinical and Clinical Outcomes in Patients Coinfected With HIV and Chronic Hepatitis B Virus From Clinical Outpatient Centers in France: Protocol for an Ambispective, Longitudinal Cohort Study

Background

Previous large-scale studies have examined the effect of chronic hepatitis B virus (HBV) infection on overall and cause-specific mortality in individuals with HIV. However, few studies have collected data on the subclinical indicators of HBV that lead to these severe outcomes in the coinfected population.

Objective

In this study, we aim to describe the procedures of a cohort study extension aimed at assessing HBV-DNA replication, serological markers of HBV (hepatitis B e antigen [HBeAg] and hepatitis B surface antigen), and liver fibrosis and how these subclinical outcomes relate to mortality in predominately tenofovir-treated, coinfected patients with HIV-HBV. We assessed the characteristics at cohort inclusion of those who participated in the cohort extension, as well as those who did not participate due to being lost to follow-up or death.

Methods

Patients with HIV and chronic HBV who completed follow-up in a prospective cohort study conducted in 4 outpatient centers (Paris and Lyon, France; 2002-2011) were invited to participate in a cross-sectional visit from November 2016 to March 2018, during which a comprehensive evaluation of HIV- and HBV-related disease was undertaken. Virological and clinical data since the previous study visit were retrospectively collected.

Results

Of the 308 individuals enrolled in the cohort, 147 (47.7%) participated in the cross-sectional study. At this visit, most participants were HBeAg negative (111/134, 82.8% with available data), had undetectable HBV DNA (124/132, 93.9% with available data), and were undergoing antiretroviral therapy containing tenofovir disoproxil fumarate or tenofovir alafenamide (114/147, 77.6%). There were no significant differences in characteristics at cohort inclusion between those who did and did not complete the cross-sectional visit, except for a lower proportion with an AIDS-defining illness (30/147, 20.5% vs 49/161, 30.4%, respectively; P=.04). Of the 161 nonparticipating individuals, 42 (26.1%) died, 41 (25.4%) were lost to follow-up and known to be alive, and 78 (48.4%) were lost to follow-up with unknown vital status. Most differences in characteristics at cohort inclusion were observed between deceased individuals and those participating in the cross-sectional visit or those lost to follow-up. With this extension, the median follow-up time of the overall cohort is presently 9.2 years (IQR 3.4-14.6).

Conclusions

Extended follow-up of the French HIV-HBV cohort will provide important long-term data on the subclinical trajectory of HBV disease in the coinfected population. The biases due to the relatively high rate of those lost to follow-up need to be assessed in future studies of this cohort.

International Registered Report Identifier (IRRID)

DERR1-10.2196/24731

Long-Term TDF-Inclusive ART and Progressive Rates of HBsAg Loss in HIV-HBV Coinfection-Lessons for Functional HBV Cure?

BACKGROUND

Tenofovir disoproxil fumarate (TDF) is effective in suppressing HIV and hepatitis B virus (HBV) replication in HIV-HBV coinfection although HBV DNA can persist in some individuals on TDF-containing antiretroviral therapy (ART). We initiated a prospective longitudinal study to determine durability of HBV virological control and clinical outcomes after prolonged TDF-based ART in HIV-HBV coinfection.

METHODS

Ninety-two HIV-HBV coinfected participants on, or about to commence, TDF-containing ART from Australia (n = 41) and Thailand (n = 52) were enrolled. Participants were followed 6-monthly for 2 years, then annually to 5 years. Laboratory and clinical assessments and a serum sample were collected at each study visit. These analyses compare follow-up at 2 and 5 years.

RESULTS

12.0% (95% confidence interval 6.8 to 20.2) of total study entry cohort (n = 92) or 15.3% (95% confidence interval: 8.8 to 25.3) of those with data to year 5 (n = 72) lost hepatitis B surface antigen (HBsAg). The only statistically significant association with HBsAg loss was lower study entry quantitative HBsAg. CD4 T-cell count increased by a median 245 cells/mm3 between the preTDF sample and 5 years of follow-up. By year 5, 98.5% of the cohort had undetectable HBV DNA (<15 IU/mL) and 91.4% had undetectable HIV RNA (<20 copies/mL).

CONCLUSIONS

HBsAg loss was high and ongoing over 5 years of follow-up in HIV-HBV coinfected individuals on TDF-containing ART and undetectable HBV was almost universal. Although the pattern of HBsAg loss temporarily parallels immune reconstitution, we could not identify predictive immune markers. The high rate of HBsAg loss in HIV-HBV coinfection may offer valuable insights into the search for a functional HBV cure.

Long-term observation on hepatitis B surface antigen seroclearance in therapy experienced HIV/HBV co-infected Chinese

The aim of this retrospective study was to observe hepatitis B surface antigen (HBsAg) seroclearance and explore predictors of HBsAg loss in HIV/HBV-co-infected patients receiving long-term lamivudine or both tenofovir and lamivudine containing therapies. Quantification of HBsAg, hepatitis B e antigen and HBV DNA before and after initiation of HBV-active antiretroviral therapy in a total of 268 HIV/HBV-co-infected patients started treatment between 2005 and 2017 were performed. Over a median of 65.63 months of follow-up, 10 (3.7%) were observed HBsAg loss and the quantification of HBsAg in 7 (2.6%) patients were less than 50 IU/mL. With the prolongation of antiretroviral therapy duration time, the rates of HBsAg seroclearance tended to increase gradually, rising from 1.8% (3/163) during 2-4 years treatment to 29.4% (10/34) after antiretroviral therapy for up to 10 years. Lower baseline qHBsAg and HBV DNA levels and strong 12-month declines in qHBsAg were significantly associated with HBsAg seroclearance. The event of HBsAg seroclearance is uncommon among Chinese individuals with HIV/HBV co-infection who have been treated with anti-HBV containing antiretroviral therapy, and lifelong therapy for HBV is needed for HIV/HBV co-infected patients. Baseline qHBsAg and HBV DNA levels and qHBsAg decline rate were predictors for HBsAg seroclearance.

HIV-hepatitis B virus coinfection: epidemiology, pathogenesis, and treatment

: HIV infection has a significant impact on the natural history of chronic hepatitis B virus (HBV) infection, with increased levels of HBV DNA, accelerated progression of liver disease and increased liver-associated mortality compared with HBV monoinfection. Widespread uptake and early initiation of HBV-active antiretroviral therapy has substantially improved the natural history of HIV-HBV coinfection but the prevalence of liver disease remains elevated in this population. In this paper, we review recent studies examining the natural history and pathogenesis of liver disease and seroconversion in HIV-HBV coinfection in the era of HBV-active antiretroviral therapy and the effects of HIV directly on liver disease. We also review novel therapeutics for the management of HBV with a particular emphasis on clinical strategies being developed for an HBV cure and an HIV cure and their impact on HIV-HBV coinfected individuals.

The role of quantitative hepatitis B surface antigen revisited

In the past 10years, there has been a lot of enthusiasm surrounding the use of serum hepatitis B surface antigen (HBsAg) quantification to predict disease activity and monitor treatment response in chronic hepatitis B. The measurement of HBsAg levels have been standardized in IU/ml, and nowadays it is almost a mandatory measurement due to the development of new antiviral treatments aiming at HBsAg seroclearance, i.e., functional cure of hepatitis B. Recently, there has been an improved understanding of the molecular virology of HBsAg, and particularly the relative roles of covalently closed circular DNA and integrated hepatitis B virus (HBV) DNA. This has shed new light on the interpretation of HBsAg levels in different phases of chronic hepatitis B. HBsAg level can assist the differentiation of immune tolerance and immune clearance in hepatitis B e antigen (HBeAg)-positive patients, and it can predict inactive disease and spontaneous HBsAg seroclearance in HBeAg-negative patients. The determination of HBsAg level is pivotal to individualize pegylated interferon (PegIFN) treatment; it is the key investigation to decide early termination of PegIFN among non-responders. Among patients treated by nucleos(t)ide analogues, responders tend to have dramatic reduction of HBsAg to low levels, which may be followed by HBsAg seroclearance. With newer data on combination treatment of PegIFN and nucleos(t)ide analogues as well as emerging new antiviral agents, HBsAg quantification is expected to become increasingly important to monitor and guide antiviral therapy for chronic hepatitis B.

Hepatitis B surface antigen quantification as a predictor of seroclearance during treatment in HIV-hepatitis B virus coinfected patients from Sub-Saharan Africa

BACKGROUND AND AIM

In Sub-Saharan Africa, seroclearance of hepatitis B surface antigen (HBsAg) and hepatitis B "e" antigen (HBeAg), including their quantifiable markers, have rarely been evaluated during long-term antiviral treatment among patients coinfected with HIV and hepatitis B virus (HBV).

METHODS

In this prospective cohort study from two randomized-control trials in Côte d'Ivoire, 161 antiretroviral-naïve HIV-HBV coinfected patients starting lamivudine (n = 76) or tenofovir/emtricitabine (n = 85) containing antiretroviral therapy were included. HBV DNA was quantified using an in-house assay (detection limit = 12 copies/mL) and HBsAg quantification (qHBsAg) using the Elecsys assay.

RESULTS

Overall, 33 (20.5%) patients were HBeAg positive, 121 (75.2%) had detectable HBV DNA, and 92/93 (98.9%) harbored HBV genotype E. Median treatment duration was 35.5 months (interquartile range: 24.3-36.4). Among HBeAg-positive patients, cumulative proportion with HBeAg seroclearance was 46.3% (n = 14). Overall, cumulative proportion of HBsAg seroclearance was 6.6% (n = 10). Lower baseline qHBsAg levels and strong 12-month declines in qHBsAg were significantly associated with HBsAg seroclearance for both HBeAg-negative and HBeAg-positive patients. When taken at certain levels, these determinants provided moderate sensitivity (Se) and specificity (Sp) in predicting HBsAg seroclearance at month 36 (≤ 1000 IU/mL at baseline, Se = 0.80, Sp = 0.80; ≥ 1.0 log10  IU/mL drop at month 12, Se = 0.57, Sp = 1.00). Instead, qHBsAg levels ≤ 100 or ≤ 10 IU/mL at month 12 were optimal (both Se = 0.90 and Sp = 1.00). Detectable HBV-DNA provided fairly high Se and Sp when evaluated at baseline (Se = 1.00, Sp = 0.80), but not at month 12 (Se = 0.80, Sp = 0.40).

CONCLUSIONS

HBsAg seroclearance rates are not common in patients from Sub-Saharan Africa treated with anti-HBV containing antiretroviral therapy. qHBsAg levels at 12 months of treatment may accurately predict HBsAg seroclearance.

Rates and determinants of hepatitis B 'e' antigen and hepatitis B surface antigen seroclearance during long-term follow-up of patients coinfected with HIV and hepatitis B virus

OBJECTIVE

This study determines rates and risk factors associated with hepatitis B surface antigen (HBsAg) and hepatitis B 'e' antigen (HBeAg) seroclearance, two important prognostic indicators during infection with hepatitis B virus (HBV), in a large contemporary cohort of patients coinfected with HIV-HBV.

DESIGN

Prospective cohort study of predominately antiretroviral therapy (ART) experienced, coinfected patients.

METHODS

Participants enrolled in the French HIV-HBV Cohort had complete HBV serological battery conducted at inclusion and every yearly visit. Piecewise-exponential survival models were used to determine risk factors associated with seroclearance.

RESULTS

A total of 290 patients, of whom 151 (52.1%) were HBeAg positive, had been followed for a median 7.4 years (interquartile range [IQR] = 3.1-8.0). Tenofovir (TDF) containing ART became increasingly more frequent, as rates of undetectable HBV-DNA increased accordingly (at baseline = 39.3%, end of follow-up = 91.0%). In HBeAg-positive patients, 60 of 151 had HBeAg seroclearance (cumulative 46.4% at end of follow-up) after a median 3.0 years (IQR = 2.0-4.9). Overall, 17 of 290 patients had HBsAg seroclearance (cumulative 7.4% at end of follow-up) after a median 4.6 years (IQR = 2.1-7.2). Lower levels of time-averaged cumulative HBV-DNA were significantly associated with both HBeAg and HBsAg seroclearance (P < 0.001 and P = 0.01, respectively). In post hoc analysis among patients initiating TDF, incidence rates of HBeAg seroclearance peaked at year 4 of TDF treatment (13.1/100 person-years), whereas a steep drop in HBsAg seroclearance incidence rates occurred after year 3 (at year 3 = 1.2/100 person-years versus thereafter = 0.6/100 person-years).

CONCLUSION

HBsAg seroclearance and, to a lesser extent, HBeAg seroclearance remain difficult endpoints for patients coinfected with HIV-HBV to achieve. HBV-DNA suppression, associated with effective treatment, is strongly linked to seroclearance, but this mostly occurs within the first years of ART-containing highly potent anti-HBV activity.