Antiviral drugs for HBV liver disease

Serous Membrane Detachment with Ultrasonic Homogenizer Improves Engraftment of Fetal Liver to Liver Surface in a Rat Model of Cirrhosis

Liver transplantation is the most effective treatment for end-stage cirrhosis. However, due to serious donor shortages, new treatments to replace liver transplantation are sorely needed. Recent studies have focused on novel therapeutic methods using hepatocytes and induced pluripotent stem cells, we try hard to develop methods for transplanting these cells to the liver surface. In the present study, we evaluated several methods for their efficiency in the detachment of serous membrane covering the liver surface for transplantation to the liver surface. The liver surface of dipeptidyl peptidase IV (DPPIV)-deficient rats in a cirrhosis model was detached by various methods, and then fetal livers from DPPIV-positive rats were transplanted. We found that the engraftment rate and area as well as the liver function were improved in rats undergoing transplantation following serous membrane detachment with an ultrasonic homogenizer, which mimics the Cavitron Ultrasonic Surgical Aspirator® (CUSA), compared with no detachment. Furthermore, the bleeding amount was lower with the ultrasonic homogenizer method than with the needle and electric scalpel methods. These findings provide evidence that transplantation to the liver surface with serous membrane detachment using CUSA might contribute to the development of new treatments for cirrhosis using cells or tissues.

Inhibitory effect of fasiglifam on hepatitis B virus infections through suppression of the sodium taurocholate cotransporting polypeptide

Fasiglifam is a selective partial agonist of G-protein-coupled receptor 40 (GPR40), which was developed for the treatment of type 2 diabetes mellitus. However, the clinical development of fasiglifam was voluntarily terminated during phase III clinical trials due to adverse liver effects. Fasiglifam showed an inhibitory effect on sodium taurocholate cotransporting polypeptide (NTCP) in human and rat hepatocytes. Recently, NTCP was reported to be a functional receptor for human hepatitis B virus (HBV) infections. Therefore, in this study, we hypothesised that fasiglifam would be a good candidate for a novel HBV entry inhibitor, and its effects were evaluated by using NTCP-overexpressing HepG2 cells, human hepatocyte cell lines and human hepatocytes (PXB cells) obtained from PXB mice. Pre-treatment with fasiglifam at a concentration of 30 μM prior to HBV infection significantly suppressed supernatant HBV DNA levels after HBV infection in NTCP-overexpressing HepG2 cells, human hepatocyte cell lines and PXB cells. Fasiglifam did not suppress supernatant HBV DNA levels up to 50 μM in HepG2.2.15.7 cells, which are stably transfected with a complete HBV genome without HBV infection. These results indicated that fasiglifam only affect on HBV infection via NTCP inhibition. For HBV treatment of fasiglifam, further investigation including additional non clinical research in addition to the evaluation of safety and efficacy in humans would be needed in the future study.

Impact of IL28B and OAS gene family polymorphisms on interferon treatment response in Caucasian children chronically infected with hepatitis B virus

AIM

To investigate the impact of IL28B and OAS gene polymorphisms on interferon treatment responses in children with chronic hepatitis B.

METHODS

We enrolled 52 children (between the ages of 4 and 18) with hepatitis B e antigen-negative chronic hepatitis B (CHB), who were treated with pegylated interferon alfa for 48 wk. Single nucleotide polymorphisms in the OAS1 (rs1131476), OAS2 (rs1293747), OAS3 (rs2072136), OASL (rs10849829) and IL28B (rs12979860, rs12980275 and rs8099917) genes were studied to examine their associations with responses to IFN treatment in paediatric patients. We adopted two criteria for the therapeutic response, achieving an hepatitis B virus (HBV) DNA level < 2000 IU/mL and normalization of ALT activity (< 40 IU/L). To perform the analyses, we compared the patients in terms of achieving a partial response (PR) and a complete response (CR) upon measurement at the 24-wk post-treatment follow-up.

RESULTS

The PR and CR rates were 80.8% and 42.3%, respectively. Factors such as age, gender and liver histology had no impact on the type of response (partial or complete). A statistically significant relationship between higher baseline HBV DNA and ALT activity levels and lower rates of PR and CR was shown (P < 0.05). The allele association analysis revealed that only the IL-28B rs12979860 (C vs T) and IL28B rs12980275 (A vs G) markers significantly affected the achievement of PR (P = 0.021, OR = 3.3, 95%CI: 1.2-9.2 and P = 0.014, OR = 3.7, 95%CI: 1.3-10.1, respectively). However, in the genotype analysis, only IL-28B rs12980275 was significantly associated with PR (AA vs AG-GG, P = 0.014, OR = 10.9, 95%CI: 1.3-93.9). The association analysis for CR showed that the TT genotype of IL28B rs12979860 was present only in the no-CR group (P = 0.033) and the AA genotype of OASL rs10849829 was significantly more frequent in the no-CR group (P = 0.044, OR = 0.26, 95%CI: 0.07-0.88). The haplotype analysis revealed significant associations between PR and CR and OAS haplotype (P = 0.0002 and P = 0.001, respectively), but no association with IL28B haplotype was observed.

CONCLUSION

IL28B and OAS polymorphisms are associated with different clinical outcomes in CHB children treated with interferon.

Review article: the potential of interferon and nucleos(t)ide analogue combination therapy in chronic hepatitis B infection

BACKGROUND

A short-term course of pegylated-interferon (Peg-IFN), or a long-term treatment with a third generation nucleot(s)ide analogue (NUC), of chronic hepatitis B (CHB) infection achieves viral suppression and may prevent disease progression. Owing to different mechanisms of action of the two regimens, a Peg-IFN and NUC combination treatment may be an attractive approach to enhance the off-treatment rates of virological and serological response.

AIM

To review the literature on combinations of Peg-IFN plus NUC, including the simultaneous initiation of Peg-IFN and NUC in naïve patients; an 'add-on' combination, where Peg-IFN is started at variable times after the beginning of NUC; or a 'switch-to' strategy usually from NUC to Peg-IFN.

METHODS

We performed a PubMed literature search using the following terms individually or in combination: NUC, hepatitis B virus, chronic hepatitis, interferon, pegylated-interferon, nucleos(t)ide analogues, entecavir, tenofovir. English-language articles published up to December 2015, as well as conference proceedings from international meetings were reviewed. References from selected papers were reviewed and used if relevant.

RESULTS

While combination and NUC pre-treatment failed to increase HBsAg clearance rates, more promising results were achieved in patients under long-term effective NUC therapy.

CONCLUSION

While Peg-IFN and nucleos(t)ide analogue combination therapy should not be recommended currently, the addition of or the switch to Peg-IFN in nucleos(t)ide analogue-treated patients with chronic hepatitis B infection may be useful option.

Antiviral therapy with nucleotide/nucleoside analogues in chronic hepatitis B: A meta-analysis of prospective randomized trials

Nucleotide/nucleoside analogues (antiviral therapy) are used in the therapy of HBeAg positive and HBeAg negative chronic hepatitis B. We analyzed ten selected randomized controlled with 2557 patients to estimate the effect of antiviral drugs in chronic hepatitis B with compared to placebo. Virological response, biochemical response, histological response, seroconversion of HBeAg, and loss of HBeAg were estimated as primary efficacy measures. The included studies were subjected for heterogeneity and publication bias. The heterogeneity was assessed with χ2 and I(2) statistics. Publication bias was assessed by funnel plot. Greater rates of improvement obtained in antiviral group for virological response [43.96 % vs. 3.15 %, RR = 0.57, 95 % CI = 0.54-0.61, p-value <0.00001], biochemical response [58.37 % vs. 21.87 %, RR = 0.52, 95 % CI = 0.48-0.56, p-value <0.00001], histological response [58.99 % vs. 27.13 %, RR = 0.56, 95 % CI = 0.50-0.63, p-value <0.0001], seroconversion of HBeAg [10.66 % vs. 5.56 %, RR = 0.94, 95 % CI = 0.91-0.97, p-value = 0.0005], and HBeAg loss [14.59 % vs. 9.64 %, RR = 0.92, 95 % CI = 0.88-0.96, p-value = 0.0002]. The safety analysis were carried out for adverse events such as headache [17.22 % vs. 17.34 %, OR = 1.09, 95 % CI = 0.81-1.46, p-value = 0.58], abdominal pain [16.46 % vs. 14.34 %, OR = 1.24, 95 % CI = 0.90-1.72, p-value = 0.19], and pharyngitis [22.22 % vs. 18.23 %, OR = 1.12, 95 % CI = 0.86-1.45, p-value = 0.40]. Excluding adverse events, all primary efficacy measures shown statistical significant result for chronic hepatitis treatment (p-value <0.05). Antiviral therapy provided significant benefit for the treatment of chronic hepatitis B with no measurable adverse effects.

The long-term benefits of nucleos(t)ide analogs in compensated HBV cirrhotic patients with no or small esophageal varices: A 12-year prospective cohort study

BACKGROUND & AIMS

Esophageal varices (EV) are a marker of disease severity in compensated cirrhosis due to hepatitis B virus (HBV) which predicts also the risk of hepatocellular carcinoma (HCC), clinical decompensation and anticipated liver related death. The dynamics and prognostic significance of EV in patients under long-term HBV suppression by nucleos(t)ide analogs (NUC), are poorly known.

METHODS

A standardized protocol (Baveno) including 414 upper gastrointestinal (GI) endoscopies was applied to 107 HBeAg-negative compensated cirrhotic patients (93% Child-Pugh A) during a median of 12 (range 2 to 17) years of NUC therapy. Patients who initially started on lamivudine (LMV) and then developed resistance (LMV-R), were rescued by early administration of adefovir, or were switched to tenofovir. Surveillance included serum HBV DNA every three months and abdominal ultrasound every six months.

RESULTS

Twenty-seven patients had baseline F1 EV which regressed in 18, remained unchanged in eight and progressed in one patient; the 12-year cumulative incidence of EV regression was 83% (95% CI: 52-92%). De novo F1/F2 EV developed in 6/80 patients with a 12-year cumulative incidence of 10% (95% CI: 5-20%). Six of seven patients with de novo varices or progression of pre-existing varices had either a clinical breakthrough due to LMV-R and/or developed a HCC. No bleedings from ruptured EV occurred, 12 patients died (9 HCC) and 15 were transplanted (13 HCC): the 12-year cumulative incidence of HCC and overall survival was 33% (95% CI: 24-42%) and 76% (95% CI: 67-83%), respectively.

CONCLUSIONS

Long-term pharmacological suppression of HBV in HBeAg-seronegative patients with compensated cirrhosis leads to a significant regression of pre-existing EV accompanied by a negligible risk of developing de novo EV.

Extended survival of patients with persistently suppressed hepatitis B transplanted for hepatocellular carcinoma

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) has become a major cause of liver-related death and indication to liver transplantation (LT) in patients with chronic hepatitis B virus (HBV) infection following the widespread adoption of antiviral therapy with nucleos(t)ide analogs (NUCs). Yet, the long-term outcome of patients undergoing liver transplantation for an HCC developed during effective NUC treatment is unknown.

METHODS

We evaluated 101 patients with persistently compensated cirrhosis who were consecutively transplanted for HCC in two centers in Milan. At LT, 91 (90%) patients had undetectable serum HBV DNA (<12 IU/ml) and 90 (89%) were within Milan criteria (MC). All patients received post-transplant HBV prophylaxis with specific immunoglobulins (HBIgs) and NUCs. End-points were long-term patient survival and recurrence of HCC and HBV.

RESULTS

During 106 (range 3-165) months following LT, HCC recurred in 11 (11%) patients (nine beyond MC at explant, two with HBV recurrence). Age (HR 1.1, 95%CI 1.0-1.2, P = 0.04) and exceeding MC (HR 9.6, 95%CI 2.9-32, P < 0.0001) were the only independent pretransplant predictors of tumour recurrence. The 10-year cumulative rate of HCC recurrence was 7% among patients transplanted within MC compared with 45% among those beyond MC at LT (P = 0.004). Overall, 18 patients (18%, nine HCC, nine non liver-related events) died with a 10-year cumulative probability of overall and liver-related survival of 79% and 89% respectively.

CONCLUSIONS

Extended survival of HBV cirrhotics transplanted for HCC can be achieved by coupling MC at listing with persistent pharmacological suppression of HBV.

Irbesartan, an FDA approved drug for hypertension and diabetic nephropathy, is a potent inhibitor for hepatitis B virus entry by disturbing Na(+)-dependent taurocholate cotransporting polypeptide activity

The liver-specific Na(+)-dependent taurocholate cotransporting polypeptide (NTCP) was recently identified as an entry receptor for hepatitis B virus (HBV) hepatotropic infection. In this study, an NTCP-overexpressing HepG2 cell line named HepG2.N9 susceptible to HBV infection was established using transcription activator-like effector nucleases (TALEN) technology. Using this cell line, irbesartan, the new NTCP-interfering molecule reported recently, was demonstrated here to effectively inhibit HBV infection with an IC50 of 3.3μM for hepatitis B e antigen (HBeAg) expression and exhibited no obvious cytotoxicity up to 1000μM. Irbesartan suppressed HBV uptake weakly but inhibited HBV covalently closed circular DNA (cccDNA) formation efficiently at physiological temperature. These results suggested that irbesartan targeted HBV infection at a post-uptake prior to cccDNA formation step such as the cell membrane fusion. Based on these findings, irbesartan, an FDA approved drug for hypertension and diabetic nephropathy, could be a potential candidate for treatment of HBV infection although further in vivo experiments are required.

The efficacy of zinc finger antiviral protein against hepatitis B virus transcription and replication in tansgenic mouse model

AIM

The zinc finger antiviral protein (ZAP) is a mammalian host restriction factor, and it could inhibit HBV RNA synthesis in vitro experiments. However, the role of ZAP against HBV in vivo environment is unclear. This study aimed to investigate whether ZAP could act against HBV transcription and replication in ZAP tansgenic mouse model.

METHODS

HBV-replication-competent plasmid pHBV4.1 was transferred to ZAP transgenic ICR mouse via the tail vein using a hydrodynamic in vivo transfection procedure, and ICR mouse were used as controls. HBV RNA and HBV DNA replication intermediates in the liver were respectively analyzed by Northern blotting and Southern blotting. The expression of hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) in the liver tissue was detected by immunohistochemical staining.

RESULTS

As compared to ICR control mouse, the levels of 3.5 kb mRNA in ZAP transgenic mouse were decreased by 8.4%; while the level of HBV DNA replication intermediates was decreased by 82%. In addition, the expression of HBsAg and HBcAg in ZAP transgenic mouse liver were both significantly less than that of ICR control mouse.

CONCLUSIONS

Our findings suggest that ZAP could inhibit HBV replication in vivo in mice, which offers a new target for anti-HBV drug development.

Optimal therapy of chronic hepatitis B: how do I treat my HBeAg-negative patients?

HBeAg negative chronic hepatitis B (CHB) is a frequent, progressive and difficult-to-cure phase of CHB. The end-point of therapy is to persistently suppress viral replication to halt progression of liver disease. Two different treatment strategies are currently available: a short-term course of pegylated interferon alpha (PEG-IFN) or long-term therapy with nucleot(s)ide analogues (NA), i.e. entecavir or tenofovir. Young patients with mild-to-moderate stages of liver disease can benefit from a 48-week course of PEG-IFN, while NA may be preferred in patients with more severe liver disease, in older patients, and in those who do not respond, are unwilling or have contraindications to PEG-IFN. Nucleot(s)ide analogues provide persistent viral suppression and biochemical normalization in almost all patients, together with the regression of fibrosis and the prevention of decompensation, but the effect on hepatocellular carcinoma rates is limited. Thus, NAs have become the most popular treatment strategy worldwide but lifelong administration is associated with high cost, unknown safety and adherence issues and an unknown risk of drug-resistance over time as well as limited rates of HBsAg seroclearance. On the other hand, PEG-IFN treatment may achieve a SVR in nearly a quarter of patients ultimately leading to HBsAg loss in almost 30-50%. Interestingly, response rates to PEG-IFN may further increase with more careful patient selection based on age, ALT and HBV DNA levels at baseline and by applying early on-treatment stopping rules based on HBV DNA and HBsAg kinetics. The combination of NA and PEG-IFN is not currently recommended but numerous studies are ongoing.

The relationship between IL-28B polymorphisms and the response to peginterferon alfa-2a monotherapy in anti-HBe-positive patients with chronic HBV infection

The impact of interleukin 28B (IL-28B) on the results of interferon (IFN)-based therapy in patients chronically infected with hepatitis B virus (HBV) is poorly understood. The aim of this study was to evaluate the relationship between IL-28B markers and the response to IFN monotherapy in Polish patients with anti-hepatitis B e (HBe)-positive chronic hepatitis B (CHB). We determined three single-nucleotide polymorphisms (SNPs) of IL-28B (rs12979860, rs12980275, and rs8099917) in 86 patients who were treated with pegylated interferon (PEG-IFN) for 48 weeks. The effectiveness of the therapy was evaluated based on the virological and biochemical response. The primary efficacy parameters were the HBV DNA viral load below 400 IU/ml and 2,000 IU/ml in combination with alanine aminotransferase (ALT) normalization (<40 IU/l), measured 24 weeks after the treatment. Viral load below 400 IU/ml or 2,000 IU/ml with ALT normalization was achieved by 37 % and 46 % of patients, respectively. It has been shown that the distribution of IL-28B genotypes in the dominant genetic model in patients with different therapeutic success differ significantly only for rs12979860. The IL-28B rs12979860 CC genotype was associated with lower treatment success [odds ratio (OR), 0.31; p = 0.025 and OR, 0.37; p = 0.044 for <400 IU/ml HBV DNA with <40 IU/l ALT, and <2,000 IU/ml HBV DNA with <40 IU/l ALT, respectively]. However, in the conditional logistic regression analysis adjusted by factors associated with combined response, rs12979860 was significantly associated only with <400 IU/ml HBV DNA with <40 IU/l ALT (OR, 0.24; p = 0.026). IL-28B polymorphisms have prognostic significance in assessing the treatment effectiveness based on the virological and biochemical response of patients with anti-HBe-positive CHB.

An aptamer targets HBV core protein and suppresses HBV replication in HepG2.2.15 cells

Hepatitis B virus (HBV)-related hepatitis is a major health concern worldwide. As current anti-HBV therapies are limited, it is essential to develop new strategies. Aptamer, a newly developed adaptive molecule (single-strand DNA or RNA also known as nucleotide antibody), is a new strategy for clinical diagnosis and therapy due to its high affinity and specificity. In the present study, by systematic evolution of ligand by exponential enrichment (SELEX), aptamers were screened against the core protein of HBV (HBc) from a random ssDNA library. Quantitative PCR (qPCR) results showed that the binding proportions of the SELEX-enriched aptamer pools were increased with the SELEX rounds, until round seven. Thus, the pool of round seven was cloned. Following the sequence analysis of a total of 90 clones by Macaw software, five aptamer candidates were selected and their affinity to HBc was tested by dot blot. Apt.No.28, which had sequence replicates in the clones, was shown to have a high affinity. Furthermore, by agarose gel electrophoresis-capillary transfer-blotting and qPCR, Apt.No.28 was shown to inhibit the assembly of the nucleocapsid, reducing extracellular HBV DNA whose synthesis relied on the formation of the nucleocapsid, indicating its role in suppressing HBV replication. The results provided a new ideal targeting molecule and may facilitate the strategy for targeted therapy as well as drug development of HBV-related diseases.

Liquid oral suspension adefovir dipivoxil (GS-02-526): an update on treatments for hepatitis B infection

Though the global epidemiology of hepatitis B virus infection has declined due to effective immunization, chronic hepatitis B (CHB) remains a serious public health problem and there is still a need for more treatment options that are efficient, safe and simple for different kinds of CHB patients. Adefovir dipivoxil (ADV) liquid suspension (GS-02-526), as a new form of oral ADV, not only has competent antiviral efficacy, but is also more convenient for patients with swallowing difficulties or patients with impaired renal function requiring dosage adjustment. The clinical data evaluating the safety, tolerability and antiviral activity of liquid suspension of ADV as well as its tablet are summarized in this article. The availability of liquid oral suspension of ADV would allow more patients to receive timely and reasonable antiviral treatments.

Advances in the treatment of hepatitis B virus/hepatitis C virus coinfection

INTRODUCTION

Patients with chronic hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfection are at a high risk of developing liver cirrhosis and hepatocellular carcinoma, and consequently, warrant effective treatment.

AREAS COVERED

Effective treatment should eradicate HCV infection and inhibit HBV replication but without serious adverse reactions. Careful evaluation of disease progression, predominance of one virus over another, comorbidities and concomitant hepatitis delta virus and/or HIV infection are essential for better therapy choices. In the case of HCV predominance, Peg-interferon plus ribavirin with or without a first-generation directly acting antiviral (DAA) should be the first choice, but future treatments will be DAA-based and interferon-free. In the case of HBV predominance, tenofovir or entecavir should be part of treatment. Patients should be closely monitored for early identification and treatment of HCV or HBV reactivation.

EXPERT OPINION

High potency and high genetic barrier nucleos(t)ide analogues to inhibit HBV replication have been used for years, with no urgency for new drugs. Several DAAs for interferon-free therapy for HCV eradication will be available in the near future. We hope that the high cost of these drugs will not be a limitation to their use in developing countries. Further investigation of HBV/HCV interaction is needed before and during the administration of new therapies.

Systematic review with meta-analysis: do interferon lambda 3 polymorphisms predict the outcome of interferon-therapy in hepatitis B infection?

BACKGROUND

Interferon lambda 3 (IFN-λ3) polymorphisms are the strongest genetic predictor of outcome of hepatitis C virus infection and of response to Pegylated interferon (PegIFN)-based therapy. Whether this holds true for hepatitis B virus (HBV) infection is matter of controversy.

AIM

To review the association between host genomics and spontaneous or interferon-induced clearance of HBV with specific reference to the recently identified interleukin 28B gene now renamed IFN-λ3.

METHODS

A literature search was performed on MEDLINE, EMBASE and Web of Science for English articles and abstracts using free text words and combinations of the following terms 'IL28B', 'IFN lambda', 'genomics', 'hepatitis B virus', 'interferon' 'GWAS', 'treatment', 'SNPs', 'HLA', 'polymorphisms'.

RESULTS

Genome-wide association studies convincingly demonstrated an association between SNPs in the HLA locus and spontaneous resolution of HBV infection in subgroups of Asian patients, yet no information is available for Caucasians. The preliminary observations of an association between IFN-λ3 SNP and virological and serological responses to IFN in both HBeAg-positive and -negative patients could not be replicated by subsequent studies. Yet, majority of studies performed so far suffer several limitations in terms of sample size, selection of the patients, endpoints of therapy, treatment strategies and duration of follow-up.

CONCLUSIONS

While host genetics is associated with an increased likelihood of spontaneous clearance of HBV among genotype B/C patients, the relationship between IFN-λ3 polymorphisms and response to IFN has not been confirmed. Further studies in large cohorts of homogeneous patients are required, before this genetic test can be recommended in clinical practice.

HBeAg-negative chronic hepatitis B: why do I treat my patients with nucleos(t)ide analogues?

The aim of chronic hepatitis B (CHB) antiviral therapy is to persistently suppress HBV and improve survival by preventing the progression of liver damage to cirrhosis, end-stage liver disease or hepatocellular carcinoma (HCC), thus preventing early liver-related death. In HBeAg-negative patients who do not or will not respond to or be treated with pegylated interferon (PEG-IFN), the administration of third generation nucleot(s)ide analogues (NAs), i.e., entecavir (ETV) and tenofovir disoproxil fumarate (TDF), is the treatment of choice. Long-term administration of ETV or TDF suppresses HBV replication in >95% of patients after 5 years of treatment with high rates of biochemical normalization, regression of fibrosis and cirrhosis at histology as well as preventing clinical decompensation but not HCC, in compensated cirrhosis and improving survival. No major safety issues have been recorded with either drug. The need for long-term, perhaps indefinite, treatment is the main limitation of NA therapy with possible associated costs, unknown long-term safety and the low rates of HBsAg seroclearance. The latter is important since HBsAg seroclearance is still the best stopping rule for HBeAg-negative NA-treated patients, including those with cirrhosis. For this reason new trials based upon a combination of PEG-IFN and third generation NAs in both naïve and NA-responder HBeAg-negative patients are ongoing.

Prolonged Combination Therapy is More Effective than Monotherapy in Management of Chronic Hepatitis B Patients With Sustained Virological Response: An Experience From a 'Real-World' Clinical Setting

BACKGROUND

Little is known about the duration of combination therapy for patients with chronic hepatitis B (CHB) and suboptimal response to nucleos(t)ide analogues(NAs) monotherapy.

OBJECTIVES

This study aimed to assess whether monotherapy could be used for treatment of CHB patients, who poorly responded to Adefovir Dipivoxil (ADV) but obtained good responses after at least 12-month lamivudine (LAM) or telbivudine (LdT) add-on therapy.

PATIENTS AND METHODS

Forty-five patients were enrolled, and the baseline time-point was determined according to enrollment data. Twenty-six patients chose to continue combination therapy (LAM+ADV or LdT+ADV, Group A) and 19 patients switched to single-drug maintenance therapy (LAM or LdT or ADV, Group B).

RESULTS

There were no significant differences between two groups in baseline characteristics (P > 0.05). At 12th month, sustained virological response rate was greater in group A compared to group B (96.2% vs. 47.4%, P < 0.001), and the rates of NAs-associated resistance were 0% in group A and 15.8% in group B. Alanine aminotransferase normalization rate was also significantly higher in group A compared with group B (92.3% vs. 36.8%, P < 0.001). Among hepatitis positive patients with Be antigen (HBeAg)-, 40% (4/10) in group A and 9.1% (1/11) in group B achieved HBeAg seroconversion at the 12th month. Of patients in group B with positive-HBeAg before the previous combination therapy and detectable HBV DNA at 6 months of previous combination therapy were associated with high risks of viral relapse after switching to single-drug maintenance therapy.

CONCLUSIONS

Prematurely switching to single-drug maintenance therapy would be resulted in viral relapse, and prolonged combination therapy was effective to maintain sustained responses for patients with initial suboptimal response to ADV.

Results of treatment of chronic hepatitis B with pegylated interferon

Persistent viral eradication or suppression through a defined course of Pegylated-interferon (PegIFN) or the administration of a long-term potent nucleot(s)ide analogues (NUCs) can impact positively the natural course of HBV infection by preventing disease progression. Despite the higher rates of off-therapy response achieved with PegIFN compared with NUC, its benefits are restricted to a subgroup of patients only. To increase the rates of patients who may benefit from PegIFN treatment, minimizing the adverse events, careful patient selections based on baseline features and on treatment HBsAg kinetics for individual treatment optimization are required.

Blocking peptides against HBV: preS1 protein selected from a phage display library

The PreS1 protein is present on the outermost part of the hepatitis B virus (HBV) surface and has been shown to have a pivotal function in viral infectivity and assembly. The development of reagents with high affinity and specificity for PreS1 is of great significance for early diagnosis and treatment of HBV infection. A phage display library of dodecapeptide was screened for interactions with purified PreS1 protein. Alignment of the positive phage clones revealed a putative consensus PreS1 binding motif of HX(n)HX(m)HP/R. Moreover, a peptide named P7 (KHMHWHPPALNT) was highly enriched and occurred with a surprisingly high frequency of 72%. A thermodynamic study revealed that P7 has a higher binding affinity to PreS1 than the other peptides. Furthermore, P7 was able to abrogate the binding of HBV virions to the PreS1 antibody, suggesting that P7 covers key functional sites on the native PreS1 protein. This newly isolated peptide may, therefore, be a new therapeutic candidate for the treatment of HBV. The consensus motif could be modified to deliver imaging, diagnostic, and therapeutic agents to tissues affected by HBV.