Efficacy of interferon for chronic hepatitis B in patients with nucleoside and nucleotide combination therapy failure

Heterogeneity of immune control in chronic hepatitis B virus infection: Clinical implications on immunity with interferon-α treatment and retreatment

Hepatitis B virus (HBV) infection is a global public health issue. Interferon-α (IFN-α) treatment has been used to treat hepatitis B for over 20 years, but fewer than 5% of Asians receiving IFN-α treatment achieve functional cure. Thus, IFN-α retreatment has been introduced to enhance antiviral function. In recent years, immune-related studies have found that the complex interactions between immune cells and cytokines could modulate immune response networks, in-cluding both innate and adaptive immunity, triggering immune responses that control HBV replication. However, heterogeneity of the immune system to control HBV infection, particularly HBV-specific CD8⁺ T cell heterogeneity, has consequ-ential effects on T cell-based immunotherapy for treating HBV infection. Altogether, the host’s genetic variants, negative-feedback regulators and HBV components affecting the immune system's ability to control HBV. In this study, we reviewed the literature on potential immune mechanisms affecting the immune control of HBV and the clinical effects of IFN-α treatment and retreatment.

New therapeutic options for persistent low-level viremia in patients with chronic hepatitis B virus infection: Increase of entecavir dosage

Chronic hepatitis B virus (HBV) infection (CHB) is a public health concern worldwide. Current therapies utilizing nucleos(t)ide analogs (NA) have not resulted in a complete cure for CHB. Furthermore, patients on long-term NA treatment often develop low-level viremia (LLV). Persistent LLV, in addition to causing the progression of liver disease or hepatocellular carcinoma, may shed light on the current plight of NA therapy. Here, we review the literature on LLV, NA treatment, and various doses of entecavir to find a strategy for improving the efficacy of this antiviral agent. For LLV patients, three therapeutic options are available, switching to another antiviral monotherapy, interferon-α switching therapy, and continuing monotherapy. In real-world clinical practice, entecavir overdose has been used in antiviral therapy for CHB patients with NA refractory and persistent LLV, which encouraged us to conduct further in-depth literature survey on dosage and duration related entecavir studies. The studies of pharmacodynamics and pharmacokinetics show that entecavir has the maximal selected index for safety, and has great potential in inhibiting HBV replication, in all of the NAs. In the particular section of the drug approval package published by the United States Food and Drug Administration, entecavir doses 2.5-20 mg/d do not increase adverse events, and entecavir doses higher than 1.0 mg/d might improve the antiviral efficacy. The literature survey led us to two suggestions: (1) Increasing entecavir dose to 1.0 mg/d for the treatment of NA naïve patients with HBV DNA >2 × 10⁶ IU/mL is feasible and would provide better prognosis; and (2) Further research is needed to assess the long-term toxic effects of higher entecavir doses (2.5 and 5.0 mg/d), which may prove beneficial in treating patients with prior NA treatment, partial virological response, or LLV state.

Combination or sequential therapy with entecavir and interferon in chronic hepatitis B patients: Current status, problems and prospects

Sixteen years have passed since the initial antiviral treatment of chronic hepatitis B (CHB). Goal of the antiviral treatment is not only to suppress viral replication, but to achieve sustained response after a limited period of treatment and then discontinuation of drugs. Nucleos(t)ide analogues (NAs) and interferons are two types of therapeutic agents with different antiviral mechanisms for treatment of CHB. Monotherapy with NAs or interferons can only achieve ideal goal in a part of CHB patients, and combination and/or sequential therapy with both is an important attempt for CHB treatment in recent years. For patients previously treated with NAs, interferons can be used to replace NAs or in combination with them for a limited period. If interferons do not show good efficacy, then NAs, alone or in combination with interferons, can be used. For patients with high viral load, initial combination therapy may show better efficacy. According to the baseline and response guidelines, the treatment plan should be optimized frequently, and the treatment compliance emphasized with maintenance, medication and examination, along with the administration of chronic diseases, in order to ensure that HBV DNA level is lower than baseline level. For those who have had a continuous drop of HBsAg and HBeAg levels, prolonged treatment or combination of the treatment with dendritic cell (DC) therapy and immunotherapy may achieve more persistent immune control.