Chronic Hepatitis B Infection: New Approaches towards Cure

Chronic hepatitis B virus (HBV) infection leads to the development of cirrhosis and hepatocellular carcinoma. Lifelong treatment with nucleotides/nucleoside antiviral agents is effective at suppressing HBV replication, however, adherence to daily therapy can be challenging. This review discusses recent advances in the development of long-acting formulations for HBV treatment and prevention, which could potentially improve adherence. Promising new compounds that target distinct steps of the virus life cycle are summarized. In addition to treatments that suppress viral replication, curative strategies are focused on the elimination of covalently closed circular DNA and the inactivation of the integrated viral DNA from infected hepatocytes. We highlight promising long-acting antivirals and genome editing strategies for the elimination or deactivation of persistent viral DNA products in development.

Australian consensus recommendations for the management of hepatitis B

INTRODUCTION

The prevalence of hepatitis B virus (HBV) infection in Australia is nearly 1%. In certain well defined groups the prevalence is far greater, yet an estimated 27% of people living with HBV infection remain undiagnosed. Appropriate screening improves detection, increases opportunity for treatment, and ultimately reduces the significant morbidity and mortality associated with the development of liver fibrosis and hepatocellular carcinoma (HCC).

MAIN RECOMMENDATIONS

This statement highlights important aspects of HBV infection management in Australia. There have been recent changes in nomenclature and understanding of natural history, as well as a newly defined upper limit of normal for liver tests that determine phase classification and threshold for antiviral treatment. As the main burden of hepatitis B in Australia is within migrant and Indigenous communities, early identification and management of people living with hepatitis B is essential to prevent adverse outcomes including liver cancer and cirrhosis.

CHANGE IN MANAGEMENT AS A RESULT OF THIS GUIDELINE

These recommendations aim to raise awareness of the current management of hepatitis B in Australia. Critically, the timely identification of individuals living with hepatitis B, and where appropriate, commencement of antiviral therapy, can prevent the development of cirrhosis, HCC and mother-to-child transmission as well as hepatitis B reactivation in immunocompromised individuals. Recognising patient and viral factors that predispose to the development of cirrhosis and HCC will enable clinicians to risk-stratify and appropriately implement surveillance strategies to prevent these complications of hepatitis B.

APASL clinical practice guideline on hepatitis B reactivation related to the use of immunosuppressive therapy

BACKGROUND & AIM

Hepatitis B reactivation related to the use of immunosuppressive therapy remains a major cause of liver-related morbidity and mortality in hepatitis B endemic Asia-Pacific region. This clinical practice guidelines aim to assist clinicians in all disciplines involved in the use of immunosuppressive therapy to effectively prevent and manage hepatitis B reactivation.

METHODS

All publications related to hepatitis B reactivation with the use of immunosuppressive therapy since 1975 were reviewed. Advice from key opinion leaders in member countries/administrative regions of Asian-Pacific Association for the study of the liver was collected and synchronized. Immunosuppressive therapy was risk-stratified according to its reported rate of hepatitis B reactivation.

RECOMMENDATIONS

We recommend the necessity to screen all patients for hepatitis B prior to the initiation of immunosuppressive therapy and to administer pre-emptive nucleos(t)ide analogues to those patients with a substantial risk of hepatitis and acute-on-chronic liver failure due to hepatitis B reactivation.

Hepatitis B in the Northern Territory: insights into the changing epidemiology of an ancient condition

Background

Aboriginal and Torres Strait Islander people are disproportionately affected by hepatitis B virus (HBV) infection. A proposed mismatch between standard vaccines and the HBV/C4 sub‐genotype prevalent in Aboriginal people in the Northern Territory (NT) may reduce vaccine effectiveness.

Aims

To determine HBV prevalence in the NT by Indigenous status and to explore patterns of immunity following implementation of universal vaccination, using a large longitudinal diagnostic dataset.

Methods

A retrospective analysis of all available HBV serology results in the NT from 1991 to 2011 was conducted, with HBV prevalence and vaccination status analysed according to adigenous status, age and sex using individuals' patterns of HBsAg, anti‐HBs and anti‐HBc serology over repeated tests.

Results

100 790 individuals were tested (33.4% Indigenous) between 1991 and 2011 (26.1% of the 2011 NT population), with a total of 211 802 tests performed. In 2011, the proportion of HBV positive individuals in the NT was 3.17% (5.22% in Indigenous populations) compared to previous 2011 estimates of 1.70% (3.70% in Indigenous populations). The vaccine failure rate was lower than expected with only one presumed vaccinated person subsequently developing HBsAg positivity (0.02%). Evidence of suboptimal vaccine efficacy by breakthrough anti‐HBc positivity in vaccinated individuals was demonstrated in 3.1% of the vaccinated cohort, of which 86.4% identified as Indigenous (HR 1.17). No difference in HBeAg positivity or seroconversion was observed between Indigenous and non‐Indigenous individuals living with CHB.

Conclusions

The burden of CHB in Indigenous people in the NT has previously been underestimated. A higher HBV prevalence in the NT than described in previous cross‐sectional studies was found, including a higher prevalence in Indigenous people. Evidence of suboptimal vaccine efficacy was demonstrated predominantly in Indigenous individuals.

Liver failure from delayed hepatitis B reactivation in anti-HBc-positive patient following rituximab for B-cell lymphoma

A 93-year-old man was admitted with 1 week of frank jaundice and abdominal pain. His medical history included diffuse large B-cell lymphoma treated with rituximab and cyclophosphamide, hydroxydaunomycin, oncovin and prednisolone (R-CHOP) chemotherapy 10 months prior. His investigations revealed marked hyperbilirubinemia with a total bilirubin of 355 μmol/L, along with a 17-fold elevation in alanine transaminase and impaired hepatic synthetic function. He tested hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (HBsAb) negative, hepatitis B core antibody (HBcAb) positive and had elevated hepatitis B virus DNA level at 13 691 IU/L. This was in the setting of radiological evidence of suspected cirrhosis. He was later found to have tested positive for HBcAb and negative for HBsAg and HBsAb prior to chemotherapy, but had not received antiviral prophylaxis. He was diagnosed with fulminant hepatitis secondary to delayed hepatitis B reactivation in the setting of rituximab. Hepatitis B reactivation and the role of screening and antiviral prophylaxis in isolated HBcAb-positive patients is reviewed.

Bispecific antibody therapy, its use and risks for infection: Bridging the knowledge gap

Relapsed haematological malignancies have a poor disease prognosis with current therapies. Bispecific antibodies (BsAbs) are becoming increasingly recognised for their efficacy in the treatment of these malignancies and are approved for the treatment of B-cell acute lymphoblastic leukaemia (B-ALL). BsAbs are manufactured to consist two variable chain fragments combined by a peptide linker amongst other structures to increase the half-life of the molecules. BsAbs function by bringing targeted tumour cells in close proximity of T-cells to allow killing via perforin and granzyme release. The increasing numbers of trials of BsAbs has highlighted their toxicity profile, including cytokine release syndrome (CRS), cytopaenia and hypogammaglobulinemia - which all increase risks for infection. The patterns and risks for infections with these novel agents remain unclear. This review article provides an overview of the risks of infection with various BsAbs platforms. A review of clinical trials reveals rates of infections amongst patients on BsAbs between 15 and 45% with a high proportion grade 3 severity or higher. A predominance of bacterial respiratory and line-related infections were identified amongst all haematological malignancies. In particular, high rates of febrile neutropaenia were identified in use of BsAbs in myeloid malignancy. Infection patterns identified in this review are utilised to inform infection prevention practice, including focused infection screening, line management, prophylaxis and vaccination strategies. Prophylaxis strategies against Pneumocystis pneumonia, herpes simplex and herpes zoster, candida and mould infections are considered, along with vaccination strategies against respiratory viral and bacterial infections. The long-term impacts of BsAbs on the immune system continue to be established.

Hepatitis B Virus Screening and Management for Patients With Cancer Prior to Therapy: ASCO Provisional Clinical Opinion Update

PURPOSE

This Provisional Clinical Opinion update presents a clinically pragmatic approach to hepatitis B virus (HBV) screening and management.

PROVISIONAL CLINICAL OPINION

All patients anticipating systemic anticancer therapy should be tested for HBV by 3 tests-hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc) total immunoglobulin (Ig) or IgG, and antibody to hepatitis B surface antigen-but anticancer therapy should not be delayed. Findings of chronic HBV (HBsAg-positive) or past HBV (HBsAg-negative and anti-HBc-positive) infection require HBV reactivation risk assessment.Patients with chronic HBV receiving any systemic anticancer therapy should receive antiviral prophylactic therapy through and for minimum 12 months following anticancer therapy. Hormonal therapy alone should not pose a substantial risk of HBV reactivation in patients with chronic HBV receiving hormonal therapy alone; these patients may follow noncancer HBV monitoring and treatment guidance. Coordination of care with a clinician experienced in HBV management is recommended for patients with chronic HBV to determine HBV monitoring and long-term antiviral therapy after completion of anticancer therapy.Patients with past HBV infection undergoing anticancer therapies associated with a high risk of HBV reactivation, such as anti-CD20 monoclonal antibodies or stem-cell transplantation, should receive antiviral prophylaxis during and for minimum 12 months after anticancer therapy completion, with individualized management thereafter. Careful monitoring may be an alternative if patients and providers can adhere to frequent, consistent follow-up so antiviral therapy may begin at the earliest sign of reactivation. Patients with past HBV undergoing other systemic anticancer therapies not clearly associated with a high risk of HBV reactivation should be monitored with HBsAg and alanine aminotransferase during cancer treatment; antiviral therapy should commence if HBV reactivation occurs.Additional information is available at www.asco.org/supportive-care-guidelines.

Infectious Complications of Biological and Small Molecule Targeted Immunomodulatory Therapies

The past 2 decades have seen a revolution in our approach to therapeutic immunosuppression. We have moved from relying on broadly active traditional medications, such as prednisolone or methotrexate, toward more specific agents that often target a single receptor, cytokine, or cell type, using monoclonal antibodies, fusion proteins, or targeted small molecules. This change has transformed the treatment of many conditions, including rheumatoid arthritis, cancers, asthma, and inflammatory bowel disease, but along with the benefits have come risks. Contrary to the hope that these more specific agents would have minimal and predictable infectious sequelae, infectious complications have emerged as a major stumbling block for many of these agents. Furthermore, the growing number and complexity of available biologic agents makes it difficult for clinicians to maintain current knowledge, and most review articles focus on a particular target disease or class of agent. In this article, we review the current state of knowledge about infectious complications of biologic and small molecule immunomodulatory agents, aiming to create a single resource relevant to a broad range of clinicians and researchers. For each of 19 classes of agent, we discuss the mechanism of action, the risk and types of infectious complications, and recommendations for prevention of infection.

Reactivation of Hepatitis B Virus in Patients with Multiple Myeloma

Reactivation of hepatitis B virus (HBV) is a well-known complication in patients with hematological malignancies during or after cytotoxic chemotherapy. If the initiation of antiviral therapy is delayed in patients with HBV reactivation, these patients can develop severe hepatitis and may die of fulminant hepatitis. The preventive strategy for HBV reactivation in patients with malignant lymphoma has already been established based on some prospective studies. As there was an increased number of novel agents being approved for the treatment of multiple myeloma (MM), the number of reported cases of HBV reactivation among MM patients has gradually increased. We conducted a Japanese nationwide retrospective study and revealed that HBV reactivation in MM patients is not rare and that autologous stem cell transplantation is a significant risk factor. In this study, around 20% of all patients with HBV reactivation developed HBV reactivation after 2 years from the initiation of therapy, unlike malignant lymphoma. This might be due to the fact that almost all of the patients received chemotherapy for a long duration. Therefore, a new strategy for the prevention of HBV reactivation in MM patients is required.