Combination of Entecavir or Tenofovir with Pegylated Interferon-α for Long-Term Reduction in Hepatitis B Surface Antigen Levels: Simultaneous, Sequential, or Add-on Combination Therapy

Long-term entecavir therapy of chronic hepatitis B in real-life setting-Importance of quantitative HBsAg level

BACKGROUND

The global burden of chronic hepatitis B remains high and the best possible treatment remains long-term viral suppression expecting cure.

METHODS

Total 154 patients of chronic hepatitis B (48 HBeAg positive, e + ve) treated with oral entecavir (0.5 mg/1 mg per day) were recruited from June 2007 and followed prospectively until December 2022 for persistent HBV DNA negativity, HBeAg and HBsAg loss/seroconversion and other liver and drug-related events in real-life settings.

RESULTS

The mean duration of therapy was 6.78 (2-14) years with 1364 person-years of follow-up. All patients were HBV DNA negative by 15 months and remained so until the last follow-up. As many as 16.7% lost HBeAg after eight to 13 years of therapy, but not HBsAg. The mean fall in serum HBsAg level per year was 0.158 log IU/mL, being significantly higher in e + ve patients at baseline and until two years of therapy. The decline was significant until six years in e + ve patients compared to two years in e - ve ones. None had biochemical or virological breakthrough (except eight defaulters), flares or any untoward effects. The incidence of liver-related events, hepatocellular carcinoma and death was 10.4%, 1.9% and 14.3%, respectively, and 5.2% deaths were liver-related whose predictors were presence of cirrhosis (log rank 46.5, p > 0.001) and higher HBsAg level > 4 log IU/mL (log rank 18.15, p < 0.001) at baseline.

CONCLUSION

Long-term entecavir therapy provides additional benefits of continuous reduction of serum HBsAg levels beyond suppression of HBV DNA.

Natural History and Hepatitis B Virus Surface Antigen (HBsAg) Spontaneous Seroclearance in Hepatitis B Virus e-Antigen (HBeAg)-Negative Patients with Inactive Chronic Infection: A Multicenter Regional Study from South Italy

Spontaneous HBsAg seroclearance has been mainly studied in populations from Asia, Australia, the Pacific Islands, and Polynesia. For the first time, we evaluated the spontaneous HBsAg seroclearance and its possible associated factors and the risk of disease progression in HBeAg-negative patients with inactive infection all coming from the same region in South Italy. In this multicenter retrospective study, 146 patients were selected after 18 months of observation and followed for a median of 82 months (IQR 60-107). For our analyses, they were divided into three groups based on their HBsAg levels: <100 IU/mL, 100-1000 IU/mL, and >1000 IU/mL. Crude and adjusted hazard ratios (HRs) for HBsAg seroclearance were determined. During the follow-up period, three patients (2.0%) showed a disease progression with an increased liver stiffness, whereas 17 (11.6%) cleared the HBsAg. Patients with HBsAg levels <100 IU/mL had the highest probability of HBsAg seroclearance compared to the other two groups (p = 0.009). In the multivariate analysis, the HBsAg level <100 IU/mL was the only parameter independently associated with HBsAg seroclearance (adjusted HR = 3.53; CI 1.29-9.69; p = 0.01). In patients with chronic HBV inactive infection, HBsAg levels <100 IU/mL predicted the highest probability of HBsAg seroclearance.

Interferon and interferon-stimulated genes in HBV treatment

Human hepatitis B virus (HBV) is a small enveloped DNA virus with a complex life cycle. It is the causative agent of acute and chronic hepatitis. HBV can resist immune system responses and often causes persistent chronic infections. HBV is the leading cause of liver cancer and cirrhosis. Interferons (IFNs) are cytokines with antiviral, immunomodulatory, and antitumor properties. IFNs are glycoproteins with a strong antiviral activity that plays an important role in adaptive and innate immune responses. They are classified into three categories (type I, II, and III) based on the structure of their cell-surface receptors. As an effective drug for controlling chronic viral infections, Type I IFNs are approved to be clinically used for the treatment of HBV infection. The therapeutic effect of interferon will be enhanced when combined with other drugs. IFNs play a biological function by inducing the expression of hundreds of IFN-stimulated genes (ISGs) in the host cells, which are responsible for the inhibiting of HBV replication, transcription, and other important processes. Animal models of HBV, such as chimpanzees, are also important tools for studying IFN treatment and ISG regulation. In the present review, we summarized the recent progress in IFN-HBV treatment and focused on its mechanism through the interaction between HBV and ISGs.

Controversies in Treating Chronic HBV: The Role of PEG-interferon-alfa

Pegylated interferon-alpha therapy is one of the first-line chronic hepatitis B treatment. Finite treatment duration, absence of drug resistance, delayed response, and higher hepatitis B surface antigen loss than nucleos(t)ides analog therapy are the advantages of pegylated interferon-alpha treatment. Common side effects and subcutaneous injections requirement limit its use. Identifying patients likely to respond to pegylated interferon-alpha and optimizing treatment is reasonable. Motivating patients to complete the 48-week treatment is necessary. Treatment is stopped or switched to other treatment strategies in patients with stopping rule criteria. Combination therapy with nucleos(t)ides analog may improve response, but remains controversial.

Review of Current and Potential Treatments for Chronic Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection remains a major global health burden. Millions of people are at risk for complications of chronic HBV infection, despite the widespread availability of an effective prophylactic vaccine. The current available treatments for HBV infection-interferon and nucleos(t)ide analogues-are effective at suppressing viral replication and decreasing the risk of cirrhosis. However, these treatments have a number of limitations, creating the need for alternative therapeutic agents. Recent advances in drug therapy have heralded a new horizon of novel therapeutic approaches for chronic HBV infection, with several promising antiviral and immunomodulatory agents currently in preclinical or clinical testing. This article reviews the current landscape of HBV treatments and highlights the most recent therapeutic strategies designed to directly target HBV or to improve immune response during chronic infection.