Development of Therapy Based on the Exploration of Biological Events Underlying the Pathogenetic Mechanisms of Chronic Hepatitis B Infection.

According to the World Health Organization (WHO), an estimated 296 million people are chronically infected with hepatitis B virus (HBV). Approximately 15-25% of these people develop complications such as advanced chronic liver diseases (ACLDs). Mortality due to HBV-related complications accounted for an estimated 882,000 deaths in 2019. Potent preventive vaccines have already restricted new HBV infections, and several drugs are available to treat chronic HBV infections. However, the positive impacts of these drugs have been recorded in only a few patients with chronic HBV infection. These drugs do not show long-term efficacy and cannot halt the progression to complications. Thus, more effective and evidence-based therapeutic strategies need to be urgently developed for patients with chronic HBV infection. CHB is a pathological entity induced by HBV that progresses due to impaired host immunity. This indicates the inherent limitations of antiviral-drug-based monotherapy for treating patients with chronic HBV infection. Additionally, commercially available antiviral drugs are not available to patients in developing and resource-constrained countries, posing a challenge to achieving the following WHO goal: "Elimination of Hepatitis by 2030". As such, this review aimed to provide insights regarding evidence-based and effective management strategies for chronic HBV infection.

Safety profile, antiviral capacity, and liver protection of a nasal therapeutic vaccine in patients with chronic hepatitis B: Five-year-follow-up outcomes after the end of treatment.

Introduction: There is a pressing need to develop novel drugs for treating patients with chronic hepatitis B (CHB), as commercially available antiviral drugs are endowed with safety and efficacy concerns. Methods: A phase III clinical trial was conducted with a therapeutic vaccine containing two antigens of the hepatitis B virus (HBV; named NASVAC) in 78 patients with CHB expressing both HBV DNA and elevated levels of alanine aminotransferase (ALT) in the blood. Five years after the end of treatment (EOT), 60 NASVAC-recipient patients were enrolled in this long-term follow-up study to evaluate the safety, antiviral potential, and liver-protective capacity of NASVAC. Results: NASVAC exhibited an excellent safety profile 5 years after EOT. The levels of HBV DNA in the sera were reduced in 55 of the 60 patients, and 45 of them were negative for HBV DNA in the sera. ALT levels were also normalized in 40 of the 60 patients 5 years after EOT. None of the patients receiving NASVAC developed liver cirrhosis or cancer. Discussion: The present study is the first to exhibit long-term follow-up data of a finite immune therapy for CHB that is safe and endowed with potent antiviral and liver-protecting capacities.

Innovative Therapies Targeting the Virus and the Host for Treating Chronic Hepatitis B Virus Infection: From Bench to Bedside.

Chronic hepatitis B (CHB) is a highly complicated pathological process in which the disease is initiated by the hepatitis B virus (HBV); however, host immune responses are primarily responsible for variable extents of liver damage. If the patients with CHB remain untreated, many CHB patients will eventually develop complications like cirrhosis of the liver (LC) and hepatocellular carcinoma (HCC). In 2019, an estimated 882,000 patients died due to HBV-related complications worldwide. Accordingly, several drugs with antiviral properties have been used to treat CHB patients during the last four decades. However, the treatment outcome is not satisfactory because viral suppression is not usually related to the containment of progressive liver damage. Although proper reconstruction of host immunity is essential in CHB patients, as of today, there is no acceptable immune therapeutic protocol for them. These realities have exposed new, novel, and innovative therapeutic regimens for the management of CHB patients. This review will update the scope and limitation of the different innovative antiviral and immune therapeutic approaches for restoring effective host immunity and containing the virus in CHB patients to block progression to LC and HCC.

The Safety and Efficacy of a Therapeutic Vaccine for Chronic Hepatitis B: A Follow-Up Study of Phase III Clinical Trial.

The objective of the present study was to assess the safety and efficacy of a therapeutic vaccine containing both HBsAg and HBcAg (NASVAC) in patients with chronic hepatitis B (CHB) three years after the end of treatment (EOT) as a follow-up of a phase III clinical trial. NASVAC was administered ten times by the nasal route and five times by subcutaneous injection. A total of 59 patients with CHB were enrolled. Adverse events were not seen in any of the patients. Out of the 59 CHB patients, 54 patients exhibited a reduction in HBV DNA, compared with their basal levels. Although all the patients had alanine transaminase (ALT) above the upper limit of normal (>42 IU/L) before the commencement of therapy, the levels of ALT were within the ULN level in 42 patients. No patient developed cirrhosis of the liver. The present study, showing the safety and efficacy of NASVAC 3 years after the EOT, is the first to report follow-up data of an immune therapeutic agent against CHB. NASVAC represents a unique drug against CHB that is safe, of finite duration, can be administered by the nasal route, is capable of reducing HBV DNA and normalizing ALT, and contains hepatic fibrosis.

Sustained Antiviral and Liver Protection by a Nasal Therapeutic Vaccine (NASVAC, Containing Both HBsAg and HBcAg) in Patients with Chronic Hepatitis B: 2-Year Follow-Up of Phase III Clinical Trial.

A phase III clinical trial in treatment-naïve patients with chronic hepatitis B (CHB) revealed the safety and considerable therapeutic efficacy of a vaccine containing both hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) (NASVAC) at the end of treatment (EOT) and 24 weeks after EOT. Two years after EOT, we checked HBV DNA, alanine aminotransferase (ALT), and hepatitis B e antigen (HBeAg). The data reveal that 33 of 66 NASVAC-recipient CHB patients became negative for HBV DNA in the blood two years after EOT. The ALT levels were within the upper limit of normal (ULN) in 37 patients, although all 66 CHB patients had elevated ALT (above ULN) before the start of therapy. Out of the total twelve HBeAg-positive patients, eight patients became negative for HBeAg. None of the patients developed cirrhosis of the liver within this period. NASVAC is a finite treatment regimen with sustained antiviral and liver-protecting properties. This study is the first to report follow-up data of immune therapy for CHB. NASVAC, an immune therapy of finite duration, is endowed with sustained antiviral and liver protection properties in CHB patients.