Oral administration of obeldesivir protects nonhuman primates against Sudan ebolavirus.

Obeldesivir (ODV, GS-5245) is an orally administered prodrug of the parent nucleoside of remdesivir (RDV) and is presently in phase 3 trials for COVID-19 treatment. In this work, we show that ODV and its circulating parent nucleoside metabolite, GS-441524, have similar in vitro antiviral activity against filoviruses, including Marburg virus, Ebola virus, and Sudan virus (SUDV). We also report that once-daily oral ODV treatment of cynomolgus monkeys for 10 days beginning 24 hours after SUDV exposure confers 100% protection against lethal infection. Transcriptomics data show that ODV treatment delayed the onset of inflammation and correlated with antigen presentation and lymphocyte activation. Our results offer promise for the further development of ODV to control outbreaks of filovirus disease more rapidly.

Current Trend in Antiviral Therapy for Chronic Hepatitis B.

Since active hepatitis B virus (HBV) replication is the key driver of hepatic necroinflammation and disease progression, the treatment aim of chronic hepatitis B (CHB) is to suppress HBV replication permanently to prevent hepatic decompensation, liver cirrhosis and/or hepatocellular carcinoma and prolong survival. Currently, pegylated interferon (Peg-IFN), entecavir (ETV), tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) are the first-line drugs of choice. Peg-IFN therapy has been used rarely due to its subcutaneous injection and significant side effect profile. Once daily oral ETV, TDF and TAF can suppress HBV DNA profoundly but have no direct action on cccDNA of the HBV-infected hepatocytes, hence continuing long-term therapy is usually needed to maintain HBV suppression, but the ultimate goal of HBsAg loss was rarely achieved (10 year 2%). In addition, long-term NUC therapy comes with several concerns such as increasing cost, medication adherence and loss-to-follow-up. Studies, mainly from Taiwan, have shown that finite NUCs therapy of two to three years in HBeAg-negative patients is feasible, safe and has a great benefit of much increasing HBsAg loss rate up to 30%/5 year. These have led an emerging paradigm shift to finite NUC therapy in HBeAg-negative patients globally. However, off-NUC relapse with hepatitis B flares may occur and have a risk of decompensation or even life-threatening outcomes. Therefore, proper monitoring, assessment, and retreatment decisions are crucial to ensure safety. Ideally, retreatment should be not too late to ensure safety and also not too early to allow further immune response for further HBsAg decline toward HBsAg loss. Assessment using combined HBsAg/ALT kinetics during hepatitis flare is better than biochemical markers alone to make a right retreatment decision. The strategy of finite NUC therapy has set a benchmark of high HBsAg loss rate to be achieved by the new anti-HBV drugs which are under preclinical or early phase study.

Risks and Benefits of Discontinuation of Nucleos(t)ide Analogue Treatment: A Treatment Concept for Patients With HBeAg-Negative Chronic Hepatitis B.

Systematic discontinuation of long-term treatment with nucleos(t)ide analogues (NAs) is one strategy to increase functional cure rates in patients with chronic hepatitis B e antigen (HBeAg)-negative hepatitis B. Currently, available study results are heterogeneous; however, long-term hepatitis B surface antigen (HBsAg) loss rates of up to 20% have been reported in prospective trials. This review proposes criteria that can be used when considering NA discontinuation in patients with chronic hepatitis B virus (HBV). Discontinuing NA treatment frequently results in a virologic and biochemical relapse that runs through different phases: the lag phase, reactivation phase, and consolidation phase. The HBV-DNA flares observed during the reactivation phase are often transient and most likely represent a trigger for inducing a long-term immune control by specific CD8+ T cells, and therefore do not need immediate interventions but close follow-up evaluation. Low HBsAg levels at the time of treatment cessation predict a positive long-term response to NA discontinuation associated with a higher likelihood of HBsAg clearance. Other host and viral biomarkers are currently under evaluation that may prove to be helpful to further characterize the population that may benefit most from the finite NA treatment concept. Potential harmful biochemical flares during the reactivation phase need to be identified early and can be effectively terminated by reintroducing NA treatment. Hepatic decompensation represents a risk to patients with cirrhosis undergoing NA discontinuation. Therefore, the finite NA approach should only be considered after excluding advanced fibrosis and cirrhosis and if a close follow-up of the patient and supervision by an experienced physician can be guaranteed. Conclusion: For selected patients, NA discontinuation has become a powerful tool to achieve control over HBeAg-negative HBV infections. Its significant effect represents a challenge to novel treatment approaches, but it may also serve as their enhancer.

The times they are a-changing - A refined proposal for finite HBV nucleos(t)ide analogue therapy.

Although discontinuation of nucleos(t)ide analogue (NA) treatment before HBsAg loss is part of all current HBV treatment guidelines for HBeAg-positive patients who achieve HBeAg seroconversion, a treatment endpoint known to be associated with silencing of HBV transcriptional activity and restoration of HBV-specific immune control, whether it is even appropriate to consider NA discontinuation before HBsAg loss in the HBeAg-negative phase remains highly controversial. Despite the growing evidence that a relevant, albeit small, proportion of patients with HBeAg-negative disease can be cured by stopping NA treatment, the fear of discontinuation-associated relapse and the uncertainty of how to predict off-therapy response and monitor patients after discontinuation have generated scepticism and subsequently led to low implementation of this concept in the clinic. In this article, we propose a concept in which NA discontinuation-associated relapse is an integral part of the stop-to-cure approach and ultimately the trigger for achieving HBsAg loss. However, the relapse in this sense becomes functionally effective only if HBV-specific immune reinvigoration and silencing of HBV transcriptional activity have been achieved during the NA treatment period. The probability of functional cure and the severity of post-discontinuation flares depend on the underlying baseline transcriptional activity of HBV when NA therapy was started, as well as the duration of NA treatment, both factors that should be considered as we move towards individualised approaches to HBV cure.

Composition of HBsAg is predictive of HBsAg loss during treatment in patients with HBeAg-positive chronic hepatitis B.

BACKGROUND & AIMS: During treatment of chronic HBV infections, loss or seroconversion of the HBV surface antigen (HBsAg) is considered a functional cure. HBsAg consists of the large (LHBs), middle (MHBs), and small surface protein (SHBs) and their relative proportions correlate strongly with disease stage. Our aim was to assess the association between HBsAg composition and functional cure during treatment. METHODS: A total of 83 patients were retrospectively analyzed. HBsAg loss was achieved by 17/64 patients during nucleos(t)ide analogue (NA) treatment and 3/19 patients following treatment with pegylated interferon-alfa2a (PEG-IFN) for 48 weeks. Sixty-three patients without HBsAg loss were matched as controls. LHBs, MHBs and SHBs were quantified in sera collected before and during treatment. RESULTS: Before treatment, median MHBs levels were significantly lower in patients with subsequent HBsAg loss than in those without (p = 0.005). During treatment, MHBs and LHBs proportions showed a fast decline in patients with HBsAg loss, but not in patients with HBV e antigen seroconversion only or patients without serologic response. MHBs became undetectable by month 6 of NA treatment in all patients with HBsAg loss, which occurred on average 12.8 ± 8.7 (0-52) months before loss of total HBsAg. Receiver-operating characteristic analyses revealed that the proportion of MHBs was the best early predictor of HBsAg loss before NA treatment (AUC = 0.726, p = 0.019). In patients achieving HBsAg loss with PEG-IFN, the proportions of MHBs and LHBs showed similar kinetics. CONCLUSION: Quantification of HBsAg proteins shows promise as a novel tool to predict early treatment response. These assessments may help optimize individual antiviral treatment, increasing the rates of functional cure in chronically HBV-infected patients. LAY SUMMARY: The hepatitis B surface antigen (HBsAg) is a key serum marker for viral replication. Loss of HBsAg is considered stable remission, which can be achieved with antiviral treatments. We have investigated whether the ratios of the different components of HBsAg, namely the large (LHBs) and medium (MHBs) HBsAg during different treatments are associated with the occurrence of HBsAg loss. We found that LHBs and MHBs decrease earlier than total HBsAg before HBsAg loss and we propose LHBs and MHBs as promising novel biomarker candidates for predicting cure of HBV infection.

Long-term clinical benefit of Peg-IFNα and NAs sequential anti-viral therapy on HBV related HCC.

Analysis of the value of long-term antiviral therapy using sequential Peg-IFN therapy and nucleos(t)ide analogues (NAs) improves the prognosis of HBV-related HCC. HBV-related HCC patients were classified into sequential therapy with Peg-IFNα-2a and NAs, and NAs therapy alone. All patients were followed up for 5 years. The survival rate, HCC recurrence rate, Child-Pugh score, and side effects of drugs were evaluated. Firstly, the early and late cumulative survival rate was higher in patients receiving antiviral therapy compared with the control patients (p<0.05). Patients receiving sequential therapy with Peg-IFNα-2a and NAs showed a higher late cumulative survival rate and significantly reduced early and late recurrence rate, compared to those in the NA-alone group (p<0.05). Single NAs therapy only reduced the late recurrence rate in HCC-patients. Secondly, NAs therapy significantly increased the Child-Pugh score after five years of therapy (five-year therapy 7.03±1.50 vs. initial score 6.63±0.85; p<0.05), whereas the sequential therapy with Peg-IFNα-2a and NAs did not greatly alter the Child-Pugh score (6.88±1.26; p>0.05). Compared to the control patients, patients receiving antiviral therapy (NAs alone or sequential therapy with Peg-IFNα-2a and NAs) exhibited a significantly decreased Child-Pugh score (p<0.05). Compared to NAs alone, sequential therapy with Peg-IFNα-2a and NAs provided a more efficient strategy for improving both the five-year survival rate and the two-year or five-year recurrence rate in patients.

Outcome of nucleos(t)ide analog intervention in patients with preventive or on-demand therapy for hepatitis B virus reactivation.

Preventive or on-demand nucleos(t)ide analog (NA) therapy can prevent severe hepatitis related to hepatitis B virus reactivation (HBV-R). However, it is unclear if NA can be safely stopped in such patients after cytotoxic therapies or during immunosuppressive therapies. We retrospectively evaluated 133 patients who initiated NA therapy between 2007 and 2018. A total of 103 patients were positive for HBV surface antigen (HBsAg) at baseline, and NA therapy was started before cytotoxic or immunosuppressive therapy (preventive group). Thirty patients with resolved HBV infection were treated with NA therapy after HBV reactivation (on-demand group). Virological relapse was defined as a serum HBV DNA level >20 IU/ml. NA therapy was stopped in 12 (12%) patients (preventive group), and in 16 (53%) patients (on-demand group). After the cessation of NA therapy, the cumulative rates of relapse were 36% and 39% at 12 and 24 months, respectively. High levels of HBsAg both at baseline and at the cessation of NA therapy were related to the occurrence of relapse. Relapse did not occur in patients with HBsAg levels <20 IU/ml (preventive group). HBV relapse occurred in five (33%) patients in the on-demand group. Relapse occurred only in anti-HBs-negative patients at the cessation of NA therapy. There were no cases of hepatitis flare after the cessation of NA therapy. HBsAg predicted HBV relapse after the cessation of NA therapy in HBsAg-positive patients. Anti-HBs could be a predictive marker for NA therapy cessation in patients with resolved HBV.

Orally Bioavailable Small-Molecule CD73 Inhibitor (OP-5244) Reverses Immunosuppression through Blockade of Adenosine Production.

The adenosinergic pathway represents an attractive new therapeutic approach in cancer immunotherapy. In this pathway, ecto-5-nucleotidase CD73 has the unique function of regulating production of immunosuppressive adenosine (ADO) through the hydrolysis of AMP. CD73 is overexpressed in many cancers, resulting in elevated levels of ADO that correspond to poor patient prognosis. Therefore, reducing the level of ADO via inhibition of CD73 is a potential strategy for treating cancers. Based on the binding mode of adenosine 5'-(α,ß-methylene)diphosphate (AOPCP) with human CD73, we designed a series of novel monophosphonate small-molecule CD73 inhibitors. Among them, OP-5244 (35) proved to be a highly potent and orally bioavailable CD73 inhibitor. In preclinical studies, 35 completely inhibited ADO production in both human cancer cells and CD8+ T cells. Furthermore, 35 lowered the ratio of ADO/AMP significantly and reversed immunosuppression in mouse models, indicating its potential as an in vivo tool compound for further development.

Combination of pegylated interferon-alpha and nucleos(t)ide analogue treatment enhances the activity of natural killer cells in nucleos(t)ide analogue experienced chronic hepatitis B patients.

A combination of pegylated interferon-alpha (peg-IFN-α) and nucleos(t)ides analogue (NA) therapy can effectively reduce hepatitis B surface antigen (HBsAg), especially in NA-experienced chronic hepatitis B (CHB) patients. However, the immune mechanism of this therapy is unclear. Forty NA-experienced CHB patients were enrolled into this study. The frequencies of peripheral blood natural killer (NK) cells, dendritic cells (DCs), CD4+ T cells, CD8+ T cells, T helper (Th) cells, regulatory T cells (Treg ), B cells and follicular T helper (Tfh) cells were evaluated by flow cytometry. Seven of the 40 patients converted to peg-IFN-α combined with NA treatment, while the other 33 continued to NA therapy. The decrease in HBsAg was more pronounced in the combination treatment group, and only patients receiving combination treatment achieved HBsAg loss. The frequency and absolute number of CD56bright NK cells in the combination treatment group increased significantly compared with the NA treatment group, whereas the CD56dim NK cells were decreased. In the NA treatment group, the proportions of CD4+ TN , CD8+ TN , CD19+ B and cytotoxic T lymphocyte antigen-4 (CTLA-4)+ CD4+ T cells were increased, while the proportions of CD4+ TEM , CD8+ TEM , CD25+ CD4+ Treg , CD25high CD4+ Treg , CD127low CD25+ Treg , programmed cell death 1 (PD-1)+ CD4+ T, PD-1+ CD8+ T, CTLA-4+ CD8+ T, CCR4+ CD25+ Treg and CCR4+ CD25high Treg cells were decreased after therapy. For NA-experienced CHB patients who achieved low HBsAg levels, combination treatment is more likely to result in HBsAg decline and HBsAg clearance by increasing the activity of CD56bright NK cells.

Clinical characteristics of chronic hepatitis B cured by peginterferon in combination with nucleotide analogs.

OBJECTIVES: The purpose of this study was to analyze the clinical characteristics of chronic hepatitis B (CHB) cured by antiviral therapy. METHODS: Forty-two patients with CHB were enrolled. All patients had been treated with peginterferon (Peg-IFN) in combination with nucleoside analogue (NA) therapy for variable amounts of time, and all had been successfully cured of the disease. RESULTS: The combined treatment time for all participants was 124.7 ± 58.8 weeks, and the average Peg-IFN treatment time was 102.6 ± 56.1 weeks. At 24 weeks, Hepatitis B surface antigen (HBsAg) and Hepatitis B e antigen (HBeAg) had decreased more than 50% from baseline. Multivariate logistic regression analysis of the week 96 HBsAg-clearing group and the non-HBsAg-clearing group showed a statistically significant difference in baseline HBV DNA levels and week 48 HBsAg levels. Those which baseline HBV DNA was < 2.75 log10 IU/mL, and week 48 HBsAg levels were < 0.88 log10 IU/mL were more likely to achieve rapid HBsAg clearance at 96 weeks. This suggests that low levels of baseline HBV DNA and week 48 HBsAg are a predictor of rapid HBsAg clearance at 96 weeks. CONCLUSIONS: Individualized extension of combination therapy to more than 96 weeks depending on the patient's response and adverse reaction conditions can help achieve a clinical cure. Patients with low baseline HBV DNA and low HBsAg levels at 48 weeks achieve HBsAg clearance more quickly than other populations.

A disulfide based low molecular weight gel for the selective sustained release of biomolecules.

Constructing biocompatible soft materials via supramolecular approaches remains an important challenge for in vivo applications. Substantial efforts have been made to develop biocompatible non-polymeric materials allowing sustained release of biomolecules and/or drugs in vivo. Herein, we introduce disulfide based low molecular weight gels (LMWGs) allowing the in vitro selective sustained release of proteins containing thiol residues. The novel glycosylated nucleoside based bola-amphiphile (GNBA), which features a disulfide bond inserted in the hydrophobic segment, self-assembles to stabilize the resulting hydrogel. Rheological studies show the dominant elastic character and thixotropic properties of the disulfide LMWG demonstrating its injectability. In vitro and in vivo biodegradation investigations reveal that the disulfide LMWG is stable for several weeks. Importantly, disulfide bonds can be cleaved through the thiol-disulfide exchange reactions with small redox molecules such as dithiothreitol (DTT). The disulfide LMWG loaded with a thiol-containing protein (bovine serum albumin) features sustained release in vitro, whereas a dextran of the same molecular weight, lacking a thiol biomolecule, shows quick release. The disulfide GNBA is the first example of a LMWG allowing selective long term sustained release in vitro via a disulfide reshuffling mechanism.

Add-on pegylated interferon augments hepatitis B surface antigen clearance vs continuous nucleos(t)ide analog monotherapy in Chinese patients with chronic hepatitis B and hepatitis B surface antigen ≤ 1500 IU/mL: An observational study.

BACKGROUND: Nucleos(t)ide analog (NA) has shown limited effectiveness against hepatitis B surface antigen (HBsAg) clearance in chronic hepatitis B (CHB) patients. AIM: To evaluate the efficacy and safety of add-on peginterferon α-2a (peg-IFN α-2a) to an ongoing NA regimen in CHB patients. METHODS: In this observational study, 195 CHB patients with HBsAg ≤ 1500 IU/mL, hepatitis B e antigen (HBeAg)-negative (including HBeAg-negative patients or HBeAg-positive patients who achieved HBeAg-negative after antiviral treatment with NA) and hepatitis B virus-deoxyribonucleic acid < 1.0 × 102 IU/mL after over 1 year of NA therapy were enrolled between November 2015 and December 2018 at the Second Affiliated Hospital of Xi'an Jiaotong University, China. Patients were given the choice between receiving either peg-IFN α-2a add-on therapy to an ongoing NA regimen (add-on group, n = 91) or continuous NA monotherapy (monotherapy group, n = 104) after being informed of the benefits and risks of the peg-IFN α-2a therapy. Total therapy duration of peg-IFN α-2a was 48 wk. All patients were followed-up to week 72 (24 wk after discontinuation of peg-IFN α-2a). The primary endpoint was the proportion of patients with HBsAg clearance at week 72. RESULTS: Demographic and baseline characteristics were comparable between the two groups. Intention-to-treatment analysis showed that the HBsAg clearance rate in the add-on group and monotherapy group was 37.4% (34/91) and 1.9% (2/104) at week 72, respectively. The HBsAg seroconversion rate in the add-on group was 29.7% (27/91) at week 72, and no patient in the monotherapy group achieved HBsAg seroconversion at week 72. The HBsAg clearance and seroconversion rates in the add-on group were significantly higher than in the monotherapy group at week 72 (P < 0.001). Younger patients, lower baseline HBsAg concentration, lower HBsAg concentrations at weeks 12 and 24, greater HBsAg decline from baseline to weeks 12 and 24 and the alanine aminotransferase ≥ 2 × upper limit of normal during the first 12 wk of therapy were strong predictors of HBsAg clearance in patients with peg-IFN α-2a add-on treatment. Regarding the safety of the treatment, 4.4% (4/91) of patients in the add-on group discontinued peg-IFN α-2a due to adverse events. No severe adverse events were noted. CONCLUSION: Peg-IFN α-2a as an add-on therapy augments HBsAg clearance in HBeAg-negative CHB patients with HBsAg ≤ 1500 IU/mL after over 1 year of NA therapy.

Serial serologic changes of hepatitis D virus in chronic hepatitis B patients receiving nucleos(t)ides analogues therapy.

BACKGROUND AND AIM: The serial serologic changes of hepatitis D virus (HDV) infection among chronic hepatitis B virus (HBV) infected patients who received oral nucleotide/nucleoside analogues are elusive. METHODS: Serum anti-HDV and HDV RNA among chronic hepatitis B (CHB) patients were tested at the time of initiating anti-HBV therapy and subsequently during the follow-up period. RESULTS: The seropositive rate of anti-HDV and HDV RNA among 2850 CHB patients, was 2.7% and 0.9%, respectively. Factors associated with anti-HDV seropositivity were platelet counts (odds ratio [OR]/95% confidence intervals [CI]: 0.995/0.992-0.999; P = 0.006), HBV DNA levels (OR/CI: 0.81/0.70-0.94; P = 0.005), and hepatitis B e-antigen (HBeAg) seropositivity (OR/CI: 0.22/0.05-0.95; P = 0.04). The only factor associated with HDV RNA positivity among anti-HDV seropositive patients was age (OR/CI: 0.95/0.90-1.00; P = 0.03). The spontaneous clearance rate of serum anti-HDV antibody was 3.0 per 100 person-years with a median follow-up period of 3.5 years (range 2-12 years), whereas the seroclearance rate of HDV RNA was 4.3 per 100 person-years among anti-HDV seropositive patients after a median follow-up period of 6.0 years (range 2-11 years). A baseline anti-HDV titer < 0.5 cut-off index was the only factor predictive of anti-HDV seroclearance (hazard ratio [HR]/CI: 30.11/3.73-242.85; P = 0.001). CONCLUSIONS: HDV infection was not common among patients treated for HBV in Taiwan. Seroclearance of anti-HDV and HDV RNA did occur over time, albeit the chance is rare.

Adverse events of nucleos(t)ide analogues for chronic hepatitis B: a systematic review.

Nucleos(t)ide analogues (NAs) are the main drug category used in chronic hepatitis B (CHB) treatment. Despite the fact that NAs have a favourable safety profile, undesired adverse events (AEs) may occur during the treatment of CHB. Given the eminent number of patients currently receiving NAs, even a small risk of any of these toxicities can represent a major medical issue. The main objective of this review was to analyse information available on AEs associated with the use of NAs in published studies. We choose the following MesH terms for this systematic review: chronic hepatitis B, side effects and treatment. All articles published from 1 January 1990 up to 19 February 2018 in MEDLINE of PubMed, EMBASE, the Cochrane Library and LILACS databases were searched. A total of 120 articles were selected for analysis, comprising 6419 patients treated with lamivudine (LAM), 5947 with entecavir (ETV), 3566 with tenofovir disoproxil fumarate (TDF), 3096 with telbivudine (LdT), 1178 with adefovir dipivoxil (ADV) and 876 with tenofovir alafenamide (TAF). The most common AEs in all NAs assessed were abdominal pain/discomfort, nasopharyngitis/upper respiratory tract infections, fatigue, and headache. TAF displays the highest density of AEs per patient treated among NAs (1.14 AE/treated patient). In conclusion, treatment of CHB with NAs is safe, with a low incidence of AEs. Despite the general understanding TAF being safer than TDF, the number of patients treated with TAF still is too small in comparison to other NAs to consolidate an accurate safety profile. PROSPERO Registration No. CRD42018086471.

Nucleoside analog monotherapy for prophylaxis in Hepatitis B liver transplant patients is safe and efficacious.

BACKGROUND: Combination therapy with HBIG and NAs has reduced HBV recurrence post LT. Despite its efficacy, costs of HBIG remain prohibitive. With high-potency NAs, HBIG's use has been questioned. We aim to evaluate the efficacy and safety of HBIG-free regimens in patients transplanted for HBV-related liver disease. METHODS: A review of LT patients at the National University Hospital, Singapore from 2001 to 2015 was performed. Patients transplanted for HBV were divided by antiviral treatment received: high- or low-potency NAs, or a combination of HBIG with high-potency NAs. Post-transplant outcomes were reviewed till data censure. Primary outcome was recurrence of HBV viremia post-transplant, while secondary outcomes were HBsAg sero-clearance, graft survival and mortality. RESULTS: Among 58 patients, 51 (88%) had persistent HBV viral suppression. Patients on a high-potency agent had significantly higher viral suppression compared to those on a low-potency agent (97% vs 72%, p = 0.02). This was also seen in patients with VL detectable at transplant (100% vs 50%, p < 0.01). None of the 16 patients with VL detectable at transplant and treated with high-potency agents developed recurrence. 42 patients (72%) achieved persistent HBsAg sero-clearance. Although this was higher in the high-potency NA-only group, it was not statistically significant (p = 0.56). There were no graft failures or mortalities attributed to HBV recurrence. CONCLUSION: With the use of high-potency agents, HBIG may not be necessary in the treatment of patients transplanted for HBV-related liver disease, even in the presence of detectable VL at time of transplant.

Effects of IFN monotherapy versus combined therapy on HBeAg seroconversion or seroclearance in HBeAg-positive chronic hepatitis B patients: A meta-analysis.

BACKGROUND AND AIMS: Recent available treatment guidelines are pointing up clearance or seroconversion of hepatitis B e-antigen (HBeAg) as a valuable endpoint in treating HBeAg-positive chronic hepatitis B (CHB) patients. To evaluate the effect of combination therapy [interferon (IFN) plus nucleos(t)ide analogues (NAs)] versus IFN monotherapy on HBeAg seroconversion or seroclearance in HBeAg-positive CHB patients. METHODS: All available controlled clinical studies, published from Jan 2000 to Sep 2018, with CHB receiving IFN and NA combination therapy or IFN monotherapy were included. Risk ratio (RR) and their 95% confidence intervals (CIs) was estimated with a fixed-effects model when I2 <50% for the test for heterogeneity. Publication bias was measured using Egger's test. RESULTS: Twelve studies were included. Our meta-analysis demonstrated that IFN and NA combination therapy had a superior HBeAg seroconversion rate or clearance rate compared with IFN monotherapy at the end of treatment (EOT). Sub-analysis showed IFN plus adefovir dipivoxi (ADV) therapy had a better HBeAg seroconversion or seroclearance rate at EOT or at the end of follow-up (EOF). CONCLUSION: Compared with IFN monotherapy, the combined therapy had a higher e-antigen serological response at EOT, but failed to improve the sustained response at EOF. Only combination therapy with IFN and ADV is superior to IFN monotherapy at the EOT or EOF for HBeAg seroconversion or seroclearance in HBeAg-positive CHB patients. The effect of other combination therapies is not superior to IFN monotherapy.

Overcoming the delivery barrier of oligonucleotide drugs and enhancing nucleoside drug efficiency: The use of nucleolipids.

With the rapid development of synthetic technology and biological technology, many nucleic acid-based drugs have entered the clinical trials. However, their inherent disabilities in actively and efficiently penetrating cell membranes still severely restrict their further application. The main drawback of cationic lipids, which have been widely used as nonviral vectors of nucleic acids, is their high cytotoxicity. A series of nucleoside-based or nucleotide-based nucleolipids have been reported in recent years, due to their oligonucleotide delivery capacity and low toxicity in comparison with cationic lipids. Lipophilic prodrugs of nucleoside analogs have extremely similar structures with nucleolipid vectors and are thus helpful for improving the transmembrane ability. This review introduces the progress of nucleolipids and provides new strategies for improving the delivery efficiency of nucleic acid-based drugs, as well as lipophilic prodrugs of nucleosides or nucleotides for antiviral or anticancer therapies.

Emerging tools in the changing landscape of chronic hepatitis B management.

Introduction: The availability of a preventative vaccine, interferon, and nucleos(t)ide analogs have provided progress in the control of chronic hepatitis B (CHB). Despite this, it remains a major contributor to global morbidity and mortality. Developments in our understanding of the pathogenesis of CHB and the emergence of new therapies are paving the way, as we move toward HBV cure.Areas covered: We performed bibliographical searches of online databases to review the literature regarding conventional disease phases of CHB. We provide the latest evidence challenging the perception of the natural history of CHB, noting that previously considered quiescent disease phases may not represent benign disease states devoid of progression. We explore the use of potential novel immunological and viral tools which should enhance disease stratification and management decisions in the coming years. Finally, we discuss the timing of treatment and how this could be initiated earlier to improve treatment outcomes, preventing sequelae of chronic infection.Expert opinion: The treatment paradigm in CHB is set to change with multiple novel agents in early phase clinical trials with the aim of a functional cure. An improved understanding of disease pathogenesis and the timing of treatment will be critical to the success of new therapies.

Finite nucleos(t)ide analog therapy in HBeAg-negative chronic hepatitis B: an emerging paradigm shift.

Potent nucleos(t)ide analogs (NUC), such as entecavir and tenofovir disoproxil fumarate, are able to suppress HBV DNA to undetectable level. These agents have no direct action on cccDNA, which is a very stable template for HBV production, hence long-term or even life-long NUC therapy is required in HBeAg-negative patients to maintain HBV suppression and to achieve the ultimate goal of HBsAg loss. However, there are concerns of indefinite or life-long NUC therapy, including drug resistance, financial burden, adherence and willingness for indefinite long-term NUC therapy. Patients lost to follow-up and hence, not monitored may risk severe relapse that may deteriorate to hepatic decompensation or even hepatic failure. This Review integrated the cumulated evidence and assessed the strategy of finite NUC therapy in HBeAg-negative patients which was first tried in early 2000s. Earlier Asian findings that 2-year NUC therapy is feasible and safe have founded APASL stopping rule for patients on NUC therapy over 2-3 years since 2008. Subsequent studies have supported the strategy of finite NUC therapy, which has finally been accepted as an option by American and European liver associations since 2016. More recent studies have further shown greatly increased HBsAg loss rate (up to 5-year 39%) after stopping NUC therapy. The cumulated evidence has shown that the paradigm shift from indefinite long-term therapy to finite NUC therapy in HBeAg-negative patients is emerging. More studies are needed to fine-tuning the strategy including research for the optimal duration of consolidation therapy, timing to stop and to start re-treatment.