Consolidation therapy for HBeAg-positive Asian chronic hepatitis B patients receiving lamivudine treatment: a multicentre study

Efficacy of Peginterferon alfa-2b in Nucleoside Analogue Experienced Patients with Negative HBeAg and Low HBsAg: A Non-Randomized Clinical Trial

INTRODUCTION

Hepatitis B surface antigen (HBsAg) clearance is the treatment goal for hepatitis B e antigen (HBeAg)-negative patients with chronic hepatitis B (CHB). However, its rate is extremely low with nucleoside (acid) analogues (NAs) monotherapy. Peginterferon could enhance HBsAg clearance. This study aimed to evaluate the efficacy of peginterferon alfa-2b (PegIFNα-2b) in NAs-experienced patients with CHB with negative HBeAg and low HBsAg level.

METHODS

HBeAg-negative patients with CHB who had received NAs therapy over 24 weeks with HBsAg < 1500 IU/mL and HBV DNA < 100 IU/mL were enrolled. Patients received either PegIFNα-2b add-on therapy (n = 108) or continuous NAs monotherapy (n = 75). The primary endpoint was HBsAg clearance rate at week 48.

RESULTS

At week 48, serum HBV DNA was undetectable among all PegIFNα-2b add-on therapy patients. Almost all patients maintained HBV DNA suppression in the PegIFNα-2b add-on group (100%, 108/108) and NAs monotherapy group (97.33%, 73/75). Only patients with PegIFNα-2b add-on therapy achieved HBsAg clearance (50.93%, 55/108) and HBsAg seroconversion (48.15%, 52/108) at week 48. Patients with baseline HBsAg < 100 IU/mL achieved the highest HBsAg clearance rate and HBsAg seroconversion rate at week 48 (60.87%, 28/46 and 58.70%, 27/46 respectively). HBsAg clearance and HBsAg seroconversion at week 72 had no significant difference with continuing or discontinuing PegIFNα-2b therapy after 48 weeks of treatment. PegIFNα-2b add-on therapy was well tolerated.

CONCLUSIONS

PegIFNα-2b add-on therapy increases HBsAg clearance rate and seroconversion rate for HBeAg-negative patients with CHB, particularly for those with lower HBsAg level. It would be unnecessary to prolong PegIFNα-2b duration after 48 weeks of PegIFNα-2b treatment.

Exploration of nucleos(t)ide analogs cessation in chronic hepatitis B patients with hepatitis B e antigen loss

BACKGROUND

Nucleos(t)ide analogs (NAs) cessation in chronic hepatitis B (CHB) patients remains a matter of debate in clinical practice. Current guidelines recommend that patients with hepatitis B e antigen (HBeAg) seroconversion discontinue NAs after relatively long-term consolidation therapy. However, many patients fail to achieve HBeAg seroconversion after the long-term loss of HBeAg, even if hepatitis B surface antigen (HBsAg) loss occurs. It remains unclear whether NAs can be discontinued in this subset of patients.

AIM

To investigate the outcomes and factors associated with HBeAg-positive CHB patients with HBeAg loss (without hepatitis B e antibody) after cessation of NAs.

METHODS

We studied patients who discontinued NAs after achieving HBeAg loss. The Cox proportional hazards model was used to identify predictors for virological relapse after cessation of NAs. The cut-off value of the consolidation period was confirmed using receiver operating characteristic curves; we confirmed the cut-off value of HBsAg according to a previous study. The log-rank test was used to compare cumulative relapse rates among groups. We also studied patients with CHB who achieved HBeAg seroconversion and compared their cumulative relapse rates. Propensity score matching analysis (PSM) was used to balance baseline characteristics between the groups.

RESULTS

We included 83 patients with HBeAg loss. The mean age of these patients was 32.1 ± 9.5 years, and the majority was male (67.5%). Thirty-eight patients relapsed, and the cumulative relapse rate at months 3, 6, 12, 24, 36, 60, 120, and 180 were 22.9%, 36.1%, 41.0%, 43.5%, 45.0%, 45.0%, 45.0%, and 52.8%, respectively. Twenty-six (68.4%) patients relapsed in the first 3 mo after NAs cessation, and 35 patients (92.1%) relapsed in the first year after NAs cessation. Consolidation period (≥ 24 mo vs < 24 mo) (HR 0.506, P = 0.043) and HBsAg at cessation (≥ 100 IU/mL vs < 100 IU/mL) (HR 14.869, P = 0.008) were significant predictors in multivariate Cox regression. In the PSM cohort, which included 144 patients, there were lower cumulative relapse rates in patients with HBeAg seroconversion (P = 0.036).

CONCLUSION

HBeAg-positive CHB patients with HBeAg loss may be able to discontinue NAs therapy after long-term consolidation, especially in patients with HBsAg at cessation < 100 IU/mL. Careful monitoring, especially in the early stages after cessation, may ensure a favorable outcome.

Antiviral Agents Against Ebola Virus Infection: Repositioning Old Drugs and Finding Novel Small Molecules

Ebola virus (EBOV) causes a deadly hemorrhagic syndrome in humans with mortality rate up to 90%. First reported in Zaire in 1976, EBOV outbreaks showed a fluctuating trend during time and fora long period it was considered a tragic disease confined to the isolated regions of the African continent where the EBOV fear was perpetuated among the poor communities. The extreme severity of the recent 2014-16 EBOV outbreak in terms of fatality rate and rapid spread out of Africa led to the understanding that EBOV is a global health risk and highlights the necessity to find countermeasures against it. In the recent years, several small molecules have been shown to display in vitro and in vivo efficacy against EBOV and some of them have advanced into clinical trials. In addition, also existing drugs have been tested for their anti-EBOV activity and were shown to be promising candidates. However, despite the constant effort addressed to identify anti-EBOV therapeutics, no approved drugs are available against EBOV yet. In this chapter, we describe the main EBOV life cycle steps, providing a detailed picture of the druggable viral and host targets that have been explored so far by different technologies. We then summarize the small molecules, nucleic acid oligomers, and antibody-based therapies reported to have an effect either in in silico, or in biochemical and cell-based assays or in animal models and clinical trials, listing them according to their demonstrated or putative mechanism of action.

HBsAg Loss with Peg-interferon Alfa-2a in Hepatitis B Patients with Partial Response to Nucleos(t)ide Analog: New Switch Study

Background and Aims: Hepatitis B surface antigen (HBsAg) loss is seldom achieved with nucleos(t)ide analog (NA) therapy in chronic hepatitis B patients but may be enhanced by switching to finite pegylated-interferon (Peg-IFN) alfa-2a. We assessed HBsAg loss with 48- and 96-week Peg-IFN alfa-2a in chronic hepatitis B patients with partial response to a previous NA. Methods: Hepatitis B e antigen (HBeAg)-positive patients who achieved HBeAg loss and hepatitis B virus DNA <200 IU/mL with previous adefovir, lamivudine or entecavir treatment were randomized 1:1 to receive Peg-IFN alfa-2a for 48 (n = 153) or 96 weeks (n = 150). The primary endpoint of this study was HBsAg loss at end of treatment. The ClinicalTrials.gov identifier is NCT01464281. Results: At the end of 48 and 96 weeks' treatment, 14.4% (22/153) and 20.7% (31/150) of patients, respectively, who switched from NA to Peg-IFN alfa-2a cleared HBsAg. Rates were similar irrespective of prior NA or baseline HBeAg seroconversion. Among those who cleared HBsAg by the end of 48 and 96 weeks' treatment, 77.8% (14/18) and 71.4% (20/28), respectively, sustained HBsAg loss for a further 48 weeks. Baseline HBsAg <1500 IU/mL and week 24 HBsAg <200 IU/mL were associated with the highest rates of HBsAg loss at the end of both 48- and 96-week treatment (51.4% and 58.7%, respectively). Importantly, extending treatment from 48 to 96 weeks enabled 48.3% (14/29) more patients to achieve HBsAg loss. Conclusions: Patients on long-term NA who are unlikely to meet therapeutic goals can achieve high rates of HBsAg loss by switching to Peg-IFN alfa-2a. HBsAg loss rates may be improved for some patients by extending treatment from 48 to 96 weeks, although the differences in our study cohort were not statistically significant. Baseline and on-treatment HBsAg may predict HBsAg loss with Peg-IFN alfa-2a.

Evaluation of the Activity of Lamivudine and Zidovudine against Ebola Virus

In the fall of 2014, an international news agency reported that patients suffering from Ebola virus disease (EVD) in Liberia were treated successfully with lamivudine, an antiviral drug used to treat human immunodeficiency virus-1 and hepatitis B virus infections. According to the report, 13 out of 15 patients treated with lamivudine survived and were declared free from Ebola virus disease. In this study, the anti-Ebola virus (EBOV) activity of lamivudine and another antiretroviral, zidovudine, were evaluated in a diverse set of cell lines against two variants of wild-type EBOV. Variable assay parameters were assessed to include different multiplicities of infection, lengths of inoculation times, and durations of dosing. At a multiplicity of infection of 1, lamivudine and zidovudine had no effect on EBOV propagation in Vero E6, Hep G2, or HeLa cells, or in primary human monocyte-derived macrophages. At a multiplicity of infection of 0.1, zidovudine demonstrated limited anti-EBOV activity in Huh 7 cells. Under certain conditions, lamivudine had low anti-EBOV activity at the maximum concentration tested (320 μM). However, lamivudine never achieved greater than 30% viral inhibition, and the activity was not consistently reproducible. Combination of lamivudine and zidovudine showed no synergistic antiviral activity. Independently, a set of in vitro experiments testing lamivudine and zidovudine for antiviral activity against an Ebola-enhanced green fluorescent protein reporter virus was performed at the Centers for Disease Control and Prevention. No antiviral activity was observed for either compound. A study evaluating the efficacy of lamivudine in a guinea pig model of EVD found no survival benefit. This lack of benefit was observed despite plasma lamivudine concentrations in guinea pig of about 4 μg/ml obtained in a separately conducted pharmacokinetics study. These studies found no evidence to support the therapeutic use of lamivudine for the treatment of EVD.

Abbott RealTime HBV assay is more sensitive in detection of low viral load and little impacted by drug resistant mutation in chronic hepatitis B patients under nucleot(s)ide analogues therapy

BACKGROUND

Selection of drug-resistant strains may lead to failure of HBV antiviral therapy. There is little information whether there is detection difference in drug resistant mutations between different viral load assays of HBV.

OBJECTIVES

This study is aimed to investigate whether there is drug-resistant strains related detection difference between Abbott RealTime HBV (RealTime) and CobasAmpliPrep/CobasTaqMan HBV assays 2.0 (TaqMan).

STUDY DESIGN

One hundred and thirty-four CHB patients who received HBV anti-viral therapy were enrolled. HBV virological markers were tested 3 months apart regularly. Serum HBV DNA levels were determined using the TaqMan and RealTime. YMDD (rt180M and rt204V) mutation was checked in patients who experienced virologic breakthrough (VBT).

RESULTS

The correlation of HBV DNA observed between the RealTime and TaqMan was good for all 571 samples (R2 = 0.797; P<0.001). However, the correlation in the 434 samples with HBV DNA level <3 log10 IU/ml was not as good as in all samples (R2 = 0.457). Overall, 21.5% of samples had a detection difference of ≥ 1 log10 IU/ml with 91.9% of these having HBV DNA level <3 log10 IU/ml. Twenty-four patients experienced VBT. Three of these patients had acquired the YMDD mutation and exhibited discordant viral load results between the two methods tested. In each case, persistent HBV DNA was detected by RealTime and undetectable with TaqMan. Of the patients who experienced a VBT and had acquired YMDD mutation, 4.7% had undetectable HBV DNA by TaqMan while all were detectable with RealTime.

CONCLUSIONS

RealTime assay is more sensitive and is little impacted by the development of drug resistant mutation.

Consensus cost-effectiveness model for treatment of chronic hepatitis B in Asia Pacific countries

PURPOSE

The Asian Pacific Association for the Study of the Liver (APASL) convened an international working party to develop a consensus cost-effectiveness model for treatment of Hepatitis B in Asia Pacific countries in March 2010.

METHODS

The working party consisted of expert hepatologists, virologists and epidemiologists from 11 representative countries in the Asia Pacific region. Meetings were conducted at the 20th APASL Annual Meeting in 2010 to determine consensus estimates for modeling and at the 21st and 22nd APASL meetings in 2011 and 2012, respectively to review and approve the models.

RESULTS

The consensus cost-effectiveness model used Singapore as base case analysis and was validated using actual data from the Singapore Cancer, Diseases and Death Registries. Simulation for Singapore, China, Thailand, Pakistan, Taiwan and Korea were performed. Antivirals with high resistance barriers like entecavir and tenofovir had the highest retail cost but were the most cost-effective therapy in developed countries such as Singapore, Taiwan and Korea while generic tenofovir was most cost effective in Thailand and Pakistan. The cost effectiveness of different treatment strategies varied significantly between countries and was affected by medication cost, economic affordability, access to liver transplantation and the prevailing health of the general population.

CONCLUSION

Choosing treatment strategies for hepatitis B based on low retail drug cost can be misleading because more expensive drugs may be more cost effective when considering long-term health outcomes and costs. Cost-effectiveness data should be individualized to countries based on their unique socio-economic conditions. Governmental policies which subsidize more costly drugs that have lower risk of drug resistance can benefit more patients.

A genome-wide association study on chronic HBV infection and its clinical progression in male Han-Taiwanese

It is common to observe the clustering of chronic hepatitis B surface antigen (HBsAg) carriers in families. Intra-familial transmission of hepatitis B virus (HBV) could be the reason for the familial clustering of HBsAg carriers. Additionally, genetic and gender factors have been reported to be involved. We conducted a three-stage genome-wide association study to identify genetic factors associated with chronic HBV susceptibility. A total of 1,065 male controls and 1,623 male HBsAg carriers were included. The whole-genome genotyping was done on Illumina HumanHap550 beadchips in 304 healthy controls and HumanHap610 beadchips in 321 cases. We found that rs9277535 (HLA-DPB1, P = 4.87×10(-14)), rs9276370 (HLA-DQA2, P = 1.9×10(-12)), rs7756516 and rs7453920 (HLA-DQB2, P = 1.48×10(-11) and P = 6.66×10(-15) respectively) were significantly associated with persistent HBV infection. A novel SNP rs9366816 near HLA-DPA3 also showed significant association (P = 2.58×10(-10)). The "T-T-G-G-T" haplotype of the five SNPs further signified their association with the disease (P = 1.48×10(-12); OR = 1.49). The "T-T" haplotype composed of rs7756516 and rs9276370 was more prevalent in severe disease subgroups and associated with non-sustained therapeutic response (P = 0.0262). The "G-C" haplotype was associated with sustained therapeutic response (P = 0.0132; OR = 2.49). We confirmed that HLA-DPB1, HLA-DQA2 and HLA-DQB2 loci were associated with persistent HBV infection in male Taiwan Han-Chinese. In addition, the HLA-DQA2 and -DQB2 complex was associated with clinical progression and therapeutic response.