Treatments for hepatitis B

Novel long-acting ropeginterferon alfa-2b: Pharmacokinetics, pharmacodynamics and safety in a phase I clinical trial

AIMS

Ropeginterferon alfa-2b is a novel, long-acting pegylated interferon alfa-2b. We aimed to evaluate its safety, pharmacokinetics (PK) and pharmacodynamics (PD).

METHODS

Thirty-six subjects received single subcutaneous injection of ropeginterferon alfa-2b at doses ranging from 24 to 270 μg, and 12 subjects received pegylated IFN alfa-2a subcutaneously at 180 μg. Primary endpoints were safety/PK profiles of ropeginterferon alfa-2b, while secondary endpoints were to compare PK/PD parameters with pegylated IFN alfa-2a.

RESULTS

Adverse events in ropeginterferon alfa-2b and pegylated IFN alfa-2a groups were similar, and most of them were mild or moderate. Mean C_max increased from 1.78 to 24.84 ng/mL along with the dose escalations in ropeginterferon alfa-2b groups and was 12.95 ng/mL for pegylated IFN alfa-2a. At 180 μg, ropeginterferon alfa-2b showed statistically significant C_max geometric mean ratio (1.76; P = .0275). Mean T_max ranged from 74.52 to 115.69 h for ropeginterferon alfa-2b groups, and was 84.25 h for pegylated IFN alfa-2a. Mean AUC_0-t increased from 372.3 to 6258 ng•h/mL with the dose escalations in the ropeginterferon alfa-2b groups, while for pegylated IFN alfa-2a it was found to be 2706 ng•h/mL in pegylated IFN alfa-2a. For neopterin and 2',5'-oligoadenylate synthase, mean E_max , T_max and AUC_0-t of ropeginterferon alfa-2b were similar to those of pegylated IFNα-2a at 180 μg.

CONCLUSION

Ropeginterferon alfa-2b up to 270 μg was safe and well tolerated. The PK/PD parameters of ropeginterferon alfa-2b showed increase in dose-response. Ropeginterferon alfa-2b had higher drug exposures and showed similar safety profile when compared to pegylated IFN alfa-2a at the same dose level.

Pharmacokinetics and Pharmacodynamics of Novel Long-Acting Ropeginterferon Alfa-2b in Healthy Chinese Subjects

INTRODUCTION

Ropeginterferon alfa-2b is a novel mono-pegylated human recombinant interferon (IFN) with the addition of N-terminal proline covalently attached by a 40-kDa polyethylene (peg) moiety. The present study aimed to evaluate the pharmacokinetics (PK), pharmacodynamics (PD) profiles and safety of the product in healthy Chinese.

METHODS

Forty subjects were enrolled and treated with a single subcutaneous injection of either 180 mcg peg-IFN alfa-2a or 90, 180, and 270 mcg ropeginterferon alfa-2b.

RESULTS

The mean T_max of ropeginterferon alfa-2b was 92-141 h and the elimination half-life was 78-129 h. Dose-related, non-proportional increase in ropeginterferon alfa-2b exposure was observed, which was higher than for peg-IFN alfa-2a. The PD parameters were similar between each dose level of ropeginterferon alfa-2b. The mean T_max of β₂-microglobulin ranged from 118 to 132 h after a single dose of ropeginterferon alfa-2b. The average E_max was 3 mcg/ml in all dose levels and the mean AUEC_0-t ranged from 1608 to 1775 h/mcg/ml. The TEAEs were comparable among each treatment group and no death nor drug-related SAE was reported.

CONCLUSION

Ropeginterferon alfa-2b is safe and well tolerated after a single subcutaneous injection up to 270 mcg in healthy Chinese.

CLINICAL TRIAL REGISTRATION

www.chinadrugtrials.org.cn , CTR20190451.

Telbivudine in combination with adefovir versus adefovir monotherapy in HBeAg-positive, lamivudine-resistant chronic hepatitis B

PURPOSE

Lamivudine (LAM) resistance is common on lamivudine monotherapy for chronic hepatitis B. This study examined the safety and efficacy of telbivudine (LDT) given with adefovir (ADV) versus ADV monotherapy in patients with chronic, lamivudine-resistant HBV infection.

METHODS

An open-label, 96 week study with planned recruitment of 150 HBeAg-positive, lamivudine-experienced Asian patients with a confirmed YMDD resistance mutation, randomized 1:1 to receive ADV alone or with LDT. The study was terminated early due to difficulty in enrolling monotherapy patients. At termination, 42 patients had received study medication for 8-61 weeks. Due to incomplete enrolment, summary statistics only were prepared, without significance testing.

RESULTS

A total of 42 patients underwent rescue therapy (switch to ADV or LDT + ADV; n = 21 per group). Median treatment duration was 48 weeks in both groups. HBV DNA changes from baseline were greater in the LDT + ADV arm at all time points (Week 48: -7.4 log10 vs. -4.9 log10 copies/ml), and serum DNA was undetectable (<300 copies/mL) at week 48 in 38.5% (5/13) on LDT + ADV versus 0% (0/9) on ADV monotherapy Two patients (9.6%) on ADV monotherapy experienced virologic breakthrough without evidence of ADV resistance, but none on LDT + ADV; and no confirmed ADV resistance was observed in any on-treatment sample. HBeAg loss occurred in three patients on LDT + ADV and one patient on ADV monotherapy through week 48. Safety profiles were similar between the arms.

CONCLUSION

LDT + ADV combination treatment showed better outcomes against lamivudine resistant HBV than ADV alone, with a similar safety profile.

Safety and efficacy of oral HD-03/ES given for six months in patients with chronic hepatitis B virus infection

AIM: To investigate the safety and efficacy of the formulation HD-03/ES capsules in the management of patients with chronic hepatitis B infection.

METHODS: A total of 25 patients were recruited to the study and were given HD-03/ES, two capsules twice daily for six months. Clinical assessment of symptoms and signs were done using the “clinical observation table” once a month before and after the treatment. Biochemical investigations of total bilirubin, ALT, AST, serum protein for liver function tests were done every month after initiating treatment. Serum was analyzed for HBV markers for HBsAg, HBeAg and HBV DNA at baseline, 4 and 6 mo after therapy using ELISA kits from Roche.

RESULTS: After 6 mo of therapy with HD-03/ES, a significant reduction of ALT values from 66.5 ± 11.1 to 39.1 ± 5.2 (P < 0.01) and a significant HBsAg loss (52%, P < 0.001), HBeAg loss (60%, P < 0.05) and HBV DNA loss (60%, P < 0.05) was observed. Adverse effects were mild and never warranted withdrawal of the drug.

CONCLUSION: The results of this pilot study indicate that HD-03/ES might be a safe and effective treatment for chronic hepatitis B infection and a long-term multicentric comparator trial is warranted and under way.

Article Commentary: Occupational Risks of Blood Exposure in the Operating Room

Bloodborne pathogens continue to be a source of occupational infection for healthcare workers, but particularly for surgeons. Over 1 per cent of the U.S. population has one or more chronic viral infections. Hepatitis B is the infection that has the longest known role as an occupational pathogen, but infection with this virus is largely preventable with the use of the effective hepatitis B vaccine. Hepatitis C affects the largest number of people in the United States, and there is no vaccine available for the prevention of this infection. HIV infection still has not been associated with a documented transmission in the operating room environment, but six cases of probable occupational transmission have been reported. A total of 57 healthcare workers have had documented occupational infection since the epidemic of HIV infection began. Infection of blood-borne pathogens to patients from infected surgeons remains a concern. Surgeons who are e-antigen-positive for hepatitis B have been well documented to be an infection risk to patients in the operating room. Only four surgeons have been documented to transmit hepatitis C, although other transmissions have occurred in the care of patients when practices of infection control have been violated. No surgical transmission of HIV to a patient has been identified at this time. Prevention of occupational infection requires use of protective barriers, avoidance of exposure risk by modification of techniques, and a constant awareness of sharp instruments in the operating room. Blood exposure in the operating room carries risk of infection and should be avoided. It is likely that other infectious agents will emerge as operating room threats. Surgeons must maintain vigilance in avoiding blood exposure and percutaneous injury.

Inhibition of viral replication reduces regulatory T cells and enhances the antiviral immune response in chronic hepatitis B

Regulatory T cells (Treg) play a key role in the impaired immune response that is typical for a chronic Hepatitis B virus (HBV) infection. To gain more insight in the mechanism that is responsible for this impaired immune response, the effect of viral load reduction resulting from treatment with the nucleotide analogue adefovir dipivoxil on the percentages of Treg and HBV-specific T-cell responses was analyzed. Peripheral blood mononuclear cells (PBMC) of 12 patients were collected at baseline and during treatment. In parallel to the decline in viral load, we found a decline in circulating Treg, combined with an increase in HBV core antigen-specific IFN-gamma production and proliferation. The production of IL10 did not decrease during therapy. In conclusion, adefovir induced viral load reduction results in a decline of circulating Treg together with a partial recovery of the immune response.

Hepatitis B prophylaxis post-liver transplant without maintenance hepatitis B immunoglobulin therapy

BACKGROUND

We examined outcomes in recipients who underwent a liver transplant for HBV-induced liver disease and received a protocol for prophylaxis that did not use HBIG maintenance.

RESULTS

Between October 2002 and July 2005, a total of 14 liver transplant recipients were identified that met the study criteria. Mean recipient age was 47.6 yr; mean donor age was 37.2 yr. Category of transplant was as follows: cadaveric liver (n = 10, 71%), cadaveric split-liver (n = 2, 14%), and cadaveric liver-kidney (n = 2, 14%). Liver disease was diagnosed at a mean of 7.3 yr before transplant; three (21%) had a coexisting hepatocellular cancer at the time of transplant. Pre-transplant, all 14 (100%) recipients were hepatitis B surface antigen (HBsAg) positive, and 11 (79%) were HBV DNA positive (mean viral load of 251.2 pg/mL). Three (21%) were E antigen positive, and one (7%) was D antigen positive. Pre-transplant, seven patients (50%) were on anti-viral therapy and there was documented diminution in viral loads after initiating anti-viral therapy in 3 cases. Three (21%) were hepatitis C virus (HCV) antigen positive and all had low-RNA titers. With mean follow-up of 14.1 months, all 14 patients are alive with a functioning graft. Mean ALT, AST and total bilirubin values are currently at 43.2, 32.2, and 0.84, respectively. One recipient remains HBsAg surface antigen positive post-transplant but has normal lab values. The remaining recipients have no evidence of HBV recurrence by serology and protocol biopsies. The regimen has been well tolerated without the need for drug reduction or discontinuation because of side-effects.

CONCLUSION

Longer follow-up is needed, but this regimen may represent an alternative to chronic HBIG maintenance therapy.

Antisense oligonucleotides targeted against asialoglycoprotein receptor 1 block human hepatitis B virus replication

Chronic hepatitis B virus (HBV) infection is a major worldwide public health problem. Better therapeutics and treatment strategies are urgently needed because of ineffective clinical treatment. Our previous study showed that asialoglycoprotein receptor 1 (ASGPR1) was upregulated by HBV but downregulated by lamivudine in HepG2.2.15 cells. It has also been reported that ASGPR is a candidate receptor for HBV attachment to hepatocytes. Therefore, as a major subunit of ASGPR, ASGPR1, might be a potential target for anti-HBV drugs. To validate this hypothesis, antisense oligonucleiotides (ASODNs) were used to downregulate ASGPR1 level in HepG2.2.15 cells. By using the MFOLD web server and BLAST searches, five ASODNs theoretically targeting ASGPR1 were selected. After 72 h post-transfection, HBV-DNA level in cell medium were examined by real-time polymerase chain reaction (PCR). Hepatitis B surface antigen (HBsAg) and Hepatitis B e antigen (HBeAg) were detected using enzyme-linked immunosorbent assay (ELISA). ASGPR1 mRNA and protein level were measured by semi-quantitative reverse transcriptase (RT)-PCR and Western blot analysis respectively. The results showed that ASODN2 significantly downregulated ASGPR1 level. It also reduced HBV-DNA, HBsAg and HBeAg level in cell medium as observed with lamivudine. In contrast, the sense sequence and scrambled sequence of ASODN2 had no effect on ASGPR1 and HBV markers in HepG2.2.15 cells. This indicated that ASODN2 could specifically reduce HBV replication in vitro. Additionally, cell proliferation and apoptosis assay suggested that downregulation of ASGPR1 did not affect cell viability. We, therefore, proposed that ASODNs targeted against ASGPR1 could block HBV replication without the influence of other changes, and ASGPR1 could be targeted for anti-HBV drug development.

Mechanisms of liver fibrosis

Liver fibrosis represents a significant health problem worldwide of which no acceptable therapy exists. The most characteristic feature of liver fibrosis is excess deposition of type I collagen. A great deal of research has been performed to understand the molecular mechanisms responsible for the development of liver fibrosis. The activated hepatic stellate cell (HSC) is the primary cell type responsible for the excess production of collagen. Following a fibrogenic stimulus, HSCs change from a quiescent to an activated, collagen-producing cell. Numerous changes in gene expression are associated with HSC activation including the induction of several intracellular signaling cascades, which help maintain the activated phenotype and control the fibrogenic and proliferative state of the cell. Detailed analyses in understanding the molecular basis of collagen gene regulation have revealed a complex process offering the opportunity for multiple potential therapeutic strategies. However, further research is still needed to gain a better understanding of HSC activation and how this cell maintains its fibrogenic nature. In this review we describe many of the molecular events that occur following HSC activation and collagen gene regulation that contribute to the fibrogenic nature of these cells and provide a review of therapeutic strategies to treat this disease.

The potential anti-HBV effect of amantadine in combination with ursodeoxycholic acid and biphenyl dimethyl dicarboxylate in HepG2 2.2.15 cells

Experimental studies have demonstrated that the triple combination of amantadine (A)/ ursodeoxycholic acid (UDCA, U)/ biphenyl dimethyl dicarboxylate (DDB, D) might have a preferential antiviral effect compared with that observed in interferon-induced antiviral signal pathways, such as those of STAT1alpha and the 6-16 genes. To confirm the result, this study examined whether the signal transduction for the antiviral activity in HepG2 2.2.15 was induced dependently or independently of interferon. To accomplish this, the correlation between the STAT1alpha and 6-16 genes, and nitric oxide, for the mediation of the antiviral activity was assessed. The increase in nitric oxide in the UDCA groups suggests that the inhibition of viral gene replication was enhanced by the amantadine combinations (AU and AUD), and might be more effective if incubated for longer periods. It was found that STAT1alpha was activated by the amantadine combination, although to a lesser extent than that of interferon-alpha, and the primary endpoints examined for the inhibition of gene expression (HBsAg and HBcAg) were remarkably well regulated. This suggests that the amantadine triple, or at least the double, combination had better clinical benefits than those of IFN-alpha and the nucleoside analogue single treatment. This demonstrates that the amantadine combination might be a substitute for the existing HBV therapy if the results of in vivo and in vitro studies concur.