Albinterferon alfa-2b dosed every two or four weeks in interferon-naïve patients with genotype 1 chronic hepatitis C

Recent and future perspectives on engineering interferons and other cytokines as therapeutics

As crucial mediators and regulators of our immune system, cytokines are involved in a broad range of biological processes and are implicated in various disease pathologies. The field of cytokine therapeutics has gained much momentum from the maturation of conventional protein engineering methodologies such as structure-based designs and/or directed evolution, which is further aided by the advent of in silico protein designs and characterization. Just within the past 5 years, there has been an explosion of proof-of-concept, preclinical, and clinical studies that utilize an armory of protein engineering methods to develop cytokine-based drugs. Here, we highlight the key engineering strategies undertaken by recent studies that aim to improve the pharmacodynamic and pharmacokinetic profile of interferons and other cytokines as therapeutics.

A structural perspective on the design of decoy immune modulators

Therapeutic mAbs have dominated the class of immunotherapeutics in general and immune checkpoint inhibitors in particular. The high specificity of mAbs to the target molecule as well as their extended half-life and (or) the effector functions raised by the Fc part are some of the important aspects that contribute to the success of this class of therapeutics. Equally potential candidates are decoys and their fusions that can address some of the inherent limitations of mAbs, like immunogenicity, resistance development, low bio-availability and so on, besides maintaining the advantages of mAbs. The decoys are molecules that trap the ligands and prevent them from interacting with the signaling receptors. Although a few FDA-approved decoy immune modulators are very successful, the potential of this class of drugs is yet to be fully realized. Here, we review various strategies employed in fusion protein therapeutics with a focus on the design of decoy immunomodulators from the structural perspective and discuss how the information on protein structure and function can strategically guide the development of next-generation immune modulators.

Development of a long-acting direct-acting antiviral system for hepatitis C virus treatment in swine

Chronic hepatitis C virus (HCV) infection is a leading cause of cirrhosis worldwide and kills more Americans than 59 other infections, including HIV and tuberculosis, combined. While direct-acting antiviral (DAA) treatments are effective, limited uptake of therapy, particularly in high-risk groups, remains a substantial barrier to eliminating HCV. We developed a long-acting DAA system (LA-DAAS) capable of prolonged dosing and explored its cost-effectiveness. We designed a retrievable coil-shaped LA-DAAS compatible with nasogastric tube administration and the capacity to encapsulate and release gram levels of drugs while resident in the stomach. We formulated DAAs in drug-polymer pills and studied the release kinetics for 1 mo in vitro and in vivo in a swine model. The LA-DAAS was equipped with ethanol and temperature sensors linked via Bluetooth to a phone application to provide patient engagement. We then performed a cost-effectiveness analysis comparing LA-DAAS to DAA alone in various patient groups, including people who inject drugs. Tunable release kinetics of DAAs was enabled for 1 mo with drug-polymer pills in vitro, and the LA-DAAS safely and successfully provided at least month-long release of sofosbuvir in vivo. Temperature and alcohol sensors could interface with external sources for at least 1 mo. The LA-DAAS was cost-effective compared to DAA therapy alone in all groups considered (base case incremental cost-effectiveness ratio $39,800). We believe that the LA-DAA system can provide a cost-effective and patient-centric method for HCV treatment, including in high-risk populations who are currently undertreated.

The biodistribution of therapeutic proteins: Mechanism, implications for pharmacokinetics, and methods of evaluation

Therapeutic proteins (TPs) are a diverse drug class that include monoclonal antibodies (mAbs), recombinantly expressed enzymes, hormones and growth factors, cytokines (e.g. chemokines, interleukins, interferons), as well as a wide range of engineered fusion scaffolds containing IgG1 Fc domain for half-life extension. As the pharmaceutical industry advances more potent and selective protein-based medicines through discovery and into the clinical stages of development, it has become widely appreciated that a comprehensive understanding of the mechanisms of TP biodistribution can aid this endeavor. This review aims to highlight the literature that has advanced our understanding of the determinants of TP biodistribution. A particular emphasis is placed on the multi-faceted role of the neonatal Fc receptor (FcRn) in mAb and Fc-fusion protein disposition. In addition, characterization of the TP-target interaction at the cell-level is discussed as an essential strategy to establish pharmacokinetic-pharmacodynamic (PK/PD) relationships that may lead to more informed human dose projections during clinical development. Methods for incorporation of tissue and cell-level parameters defining these characteristics into higher-order mechanistic and semi-mechanistic PK models will also be presented.

Tolerability, pharmacokinetics and antiviral activity of rHSA/IFNα2a for the treatment of chronic hepatitis B infection

AIMS

A recombinant human serum albumin-interferon alpha2a fusion protein (rHSA/IFNα2a) is expected to extend the half-life of IFNα2a. This study aims to evaluate the tolerability, safety and efficacy of rHSA/IFNα2a.

METHODS

This is an open, randomized, positive control, multiple-dose ascending Phase Ib study. A panel of 32 treatment naïve and non-cirrhotic chronic hepatitis B patients were divided into four cohorts, and each received 600, 750 or 900 μg of rHSA/IFNα2a or 180 μg of PEG-IFNα2a for 3 months. Tolerability, pharmacokinetics and antiviral responses were assessed.

RESULTS

Thirty-one of 32 enrolled patients completed the treatment study. The rHSA/IFNα2a treatment was better tolerated than the PEG-IFNα2a 180 μg treatment, as evidenced by blood cell counts and higher serum albumin levels. Half-life (t_1/2 ) of rHSA/IFNα2a was estimated to be 120-140 h, and is potentially suitable for a dosing interval of 2 weeks or longer. Pharmacokinetics of the last dose between rHSA/IFNα2a 750 μg and PEG-IFNα2a 180 μg, with the exception of t_1/2 , was comparable, and a similar kinetics of inhibiting HBV DNA replication was observed in both groups. Mean reductions in serum HBV DNA levels after treatment were -1.32, -2.13, -1.10 and -2.48 log10 IU/ml in the 600, 750 and 900 μg rHSA/IFNα2a groups and PEG-IFNα2a group, respectively.

CONCLUSIONS

The rHSA/IFNα2a treatment was well tolerated and can be administered biweekly. Similar efficacy in inhibiting HBV replication was observed in both PEG-IFNα2a and rHSA/IFNα2a 750 μg groups.

Albumin-based drug delivery: harnessing nature to cure disease

The effectiveness of a drug is dependent on accumulation at the site of action at therapeutic levels, however, challenges such as rapid renal clearance, degradation or non-specific accumulation requires drug delivery enabling technologies. Albumin is a natural transport protein with multiple ligand binding sites, cellular receptor engagement, and a long circulatory half-life due to interaction with the recycling neonatal Fc receptor. Exploitation of these properties promotes albumin as an attractive candidate for half-life extension and targeted intracellular delivery of drugs attached by covalent conjugation, genetic fusions, association or ligand-mediated association. This review will give an overview of albumin-based products with focus on the natural biological properties and molecular interactions that can be harnessed for the design of a next-generation drug delivery platform.

Albumin-based drug delivery: harnessing nature to cure disease

The effectiveness of a drug is dependent on accumulation at the site of action at therapeutic levels, however, challenges such as rapid renal clearance, degradation or non-specific accumulation requires drug delivery enabling technologies. Albumin is a natural transport protein with multiple ligand binding sites, cellular receptor engagement, and a long circulatory half-life due to interaction with the recycling neonatal Fc receptor. Exploitation of these properties promotes albumin as an attractive candidate for half-life extension and targeted intracellular delivery of drugs attached by covalent conjugation, genetic fusions, association or ligand-mediated association. This review will give an overview of albumin-based products with focus on the natural biological properties and molecular interactions that can be harnessed for the design of a next-generation drug delivery platform.

Enhancing Pharmacokinetics, Tumor Accumulation, and Antitumor Efficacy by Elastin-Like Polypeptide Fusion of Interferon Alpha

Genetic fusion of elastin-like polypeptide (ELP) to the C-terminus of interferon alpha (IFN) generates a well-defined IFN-ELP fusion protein with high yield and well-retained bioactivity. The fusion protein significantly enhances pharmacokinetics, tumor accumulation, and antitumor efficacy of interferon alpha in a murine cancer model.

Engineering biomimetic materials for islet transplantation

A closed-loop system that provides both the sensing of glucose and the appropriate dosage of insulin could dramatically improve treatment options for insulin-dependent diabetics. The intrahepatic implantation of allogeneic islets has the potential to provide this intimate control, by transplanting the very cells that have this inherent sensing and secretion capacity. Limiting islet transplantation, however, is the significant loss and dysfunction of islets following implantation, due to the poor engraftment environment and significant immunological attack. In this review, we outline approaches that seek to address these challenges via engineering biomimetic materials. These materials can serve to mimic natural processes that work toward improving engraftment, minimizing inflammation, and directing immunological responses. Biomimetic materials can serve to house cells, recapitulate native microenvironments, release therapeutic agents in a physiological manner, and/or present agents to direct cells towards desired responses. By integrating these approaches, superior platforms capable of improving long-term engraftment and acceptance of transplanted islets are on the horizon.

SVR12 is higher than SVR24 in treatment-naïve hepatitis C genotype 1 patients treated with peginterferon plus ribavirin

BACKGROUND

Randomized clinical trials (RCTs) of interventions for the hepatitis C virus have historically used sustained virological response (SVR) at 24 weeks after treatment (SVR24) as the key effect measure. However, recent RCTs investigating the efficacy of new direct acting agents (DAAs) have used SVR at 12 weeks after treatment (SVR12). While there is evidence to suggest SVR24 and SVR12 are similar in patients receiving new DAAs, this is unlikely to be true for patients receiving backbone peginterferon-ribavirin control treatment. Establishing the difference between SVR12 and SVR24 for patients receiving peginterferon-ribavirin treatment is therefore necessary to avoid biased interpretations of the benefits of newer DAAs.

METHODS

We searched the MEDLINE®, Embase™, and Cochrane CENTRAL for RCTs with a peginterferon-ribavirin arm that used SVR24 and/or SVR12. As no RCTs reported on both, we pooled SVR12 and SVR24 proportions using conventional meta-analysis. Proportions were pooled separately for peginterferon alpha-2a and alpha-2b. Further, a Bayesian meta-regression model was employed to estimate the difference between SVR12 and SVR24.

RESULTS

Thirty-five RCTs including a peginterferon arm were identified. Twenty-four trials included a peginterferon alpha-2a plus ribavirin arms, of which 20 reported SVR24 and five reported SVR12. Seventeen trials included a peginterferon alpha-2b plus ribavirin arm, of which 16 reported SVR24 and one reported SVR12. Using Bayesian meta-regression, the pooled SVR12 was 6% higher than SVR24 with peginterferon alpha-2a (53% versus 47%) and 5% higher with peginterferon alpha-2b (45% versus 40%) and 95% credible intervals (CrIs) were only marginally overlapping. The meta-regression also demonstrated a marginally significant relative risk of 1.13 (95% CrI 0.99-1.26) of SVR12 versus SVR24. The conventional pairwise meta-analyses were consistent with these findings.

CONCLUSION

Considering the relatively large difference observed between SVR12 and SVR24, it seems reasonable to insist that future clinical trials report both to allow for complete transparency and clarity in their interpretation.

IFN-α subtypes: distinct biological activities in anti-viral therapy

During most viral infections, the immediate host response is characterized by an induction of type I IFN. These cytokines have various biological activities, including anti-viral, anti-proliferative and immunomodulatory effects. After induction, they bind to their IFN-α/β receptor, which leads to downstream signalling resulting in the expression of numerous different IFN-stimulated genes. These genes encode anti-viral proteins that directly inhibit viral replication as well as modulate immune function. Thus, the induction of type I IFN is a very powerful tool for the host to fight virus infections. Many viruses evade this response by various strategies like the direct suppression of IFN induction or inhibition of the IFN signalling pathway. Therefore, the therapeutic application of exogenous type I IFN or molecules that induce strong IFN responses should be of great potential for future immunotherapies against viral infections. Type I IFN is currently used as a treatment in chronic hepatitis B and C virus infection, but as yet is not widely utilized for other viral infections. One reason for this restricted clinical use is that type I IFN belongs to a multigene family that includes 13 different IFN-α subtypes and IFN-β, whose individual anti-viral and immunomodulatory properties have so far not been investigated in detail to improve IFN therapy against viral infections in humans. In this review, we summarize the recent achievements in defining the distinct biological functions of type I IFN subtypes in cell culture and in animal models of viral infection as well as their clinical usage in chronic hepatitis virus infections.

Meta-analysis: mortality and serious adverse events of peginterferon plus ribavirin therapy for chronic hepatitis C

BACKGROUND

Pegylated interferon (PEG-IFN) plus ribavirin (RBV) therapy is the current standard of care for patients with chronic hepatitis C. Determining precisely the risk of serious adverse events (SAEs) and mortality from a single study is rather difficult because of the infrequency of such events. The aim of this systematic review was to assess the rates of SAEs and the mortality of PEG-IFN/RBV therapy in a pooled large sample, and to assess the relationship between SAEs and mortality rates and therapeutic characteristics.

METHODS

A literature search was conducted using MEDLINE, EMBASE, and the Cochrane Library to identify randomized controlled trials evaluating the efficacy and safety of PEG-IFN/RBV therapy. We calculated the crude mortality and SAE rates with 95% confidence intervals (CIs).

RESULTS

Eighty studies with 153 treatment arms that included 27569 patients were enrolled (14401 patients treated with Peg-IFN alpha-2a/RBV and 13168 with Peg-IFN alpha-2b/RBV). All-cause and treatment-related deaths were observed in 50 (0.18%; 95% confidence interval [CI] 0.13-0.24%) and sixteen (0.058%; 95% CI 0.033-0.094%) patients, respectively. The crude SAE rate was 7.08% (95% CI 6.75-7.41%). Subgroup analysis revealed higher SAE rates in patients receiving PEG-IFN alpha-2a than in those with PEG-IFN alpha-2b (7.45 vs. 6.74%), and higher SAE rates with higher doses than with the lower doses in PEG-IFN-2a and 2b (11.94 vs. 6.99%, 7.10 vs. 5.05%, respectively), and with extended duration (> 48 weeks) than with standard duration (48 weeks) (15.5 vs. 6.67%) in PEG-IFN alpha-2a.

CONCLUSION

The mortality rate during PEG-IFN/RBV therapy was acceptably low, but the rate of SAEs was not negligible in a treatment for a benign disease, and the rate was affected by treatment regimens.

Randomized trial of albinterferon alfa-2b every 4 weeks for chronic hepatitis C virus genotype 2/3

Albinterferon alfa-2b (albIFN) is a fusion protein of recombinant human albumin/recombinant interferon (IFN)-α-2b, with ∼200-h half-life. Safety/efficacy of albIFN q4wk was evaluated in 391 treatment-naive patients with chronic hepatitis C virus (HCV) genotype 2/3. Patients were randomized 3:4:4:4 to one of four open-label treatment groups: pegylated IFN (Peg-IFN)-α-2a 180 μg qwk or albIFN 900, 1200 or 1500 μg q4wk, plus oral ribavirin 800 mg/day, for 24 weeks. Primary efficacy endpoint was sustained virologic response (SVR; HCV RNA <20 IU/mL 24 weeks post-treatment). SVR rates were as follows: 85%, 76%, 76% and 78% with Peg-IFNα-2a and albIFN 900, 1200 and 1500 μg, respectively (P = NS); corresponding rapid virologic response rates (HCV RNA <43 IU/mL at week 4) were as follows: 78%, 49% (P < 0.001), 60% (P = 0.01) and 71%. SVR rates were not influenced by interleukin 28B genotype, although rapid virologic response rates were greater with interleukin 28B CC (P = NS). Serious adverse event rates were as follows: 4%, 11%, 3% and 3% with Peg-IFNα-2a and albIFN 900, 1200 and 1500 μg, respectively. No increase in serious/severe respiratory events was noted with albIFN. Fewer absolute neutrophil count reductions <750/mm(3) occurred with albIFN (P = 0.03), leading to fewer IFN dose reductions. Haemoglobin reductions <10 g/dL were less frequent with albIFN 900 and 1200 μg vs 1500 μg and Peg-IFNα-2a (P = 0.02), leading to fewer ribavirin dose reductions. albIFN administered q4wk produced fewer haematologic reductions than Peg-IFNα-2a, but had numerically lower SVR rates (P = NS) in patients with chronic HCV genotype 2/3.

Differences in clinical outcomes among hepatitis C genotype 1-infected patients treated with peginterferon alpha-2a or peginterferon alpha-2b plus ribavirin: a meta-analysis

Background

With the development of new direct acting antiviral (DAA) therapy for hepatitis C, the backbone peginterferon alpha used may be of importance in maximizing treatment outcomes. To this end, the rates of sustained virologic response (SVR), relapse, and treatment discontinuation among hepatitis C genotype 1-infected patients given peginterferon alpha-2a plus ribavirin or peginterferon alpha-2b plus ribavirin were determined using a meta-analysis.

Methods

Randomized trials examining peginterferon alpha-2a or peginterferon alpha-2b co-administered with ribavirin for 48 weeks were included. Data were extracted on SVR, relapse, and treatment discontinuations for treatment-naïve and treatment-experienced patients. Pooled proportions using fixed and random effects meta-analysis were calculated.

Results

Twenty-six trials provided data on patients treated with peginterferon alpha-2a plus ribavirin, and 19 trials provided data on patients treated with peginterferon alpha-2b plus ribavirin. Five trials were direct head-to-head evaluations. In the subset of trials that included head-to-head evaluations, no significant differences were observed between the two treatments for treatment-naïve (relative risk [RR]: 1.07, 95% confidence intervals [CI]: 0.97–1.18) and treatment-experienced patients (RR: 1.27, 95% CI: 0.58–2.77). Using only active trial arms, a larger proportion of the treatment- naïve patients who were provided peginterferon alpha-2a plus ribavirin achieved a SVR (47%), which is greater than that of treatment-naïve patients who were provided peginterferon alpha- 2b plus ribavirin (40% SVR achievement); however, a larger proportion of treatment- experienced patients who were provided peginterferon alpha-2b plus ribavirin achieved a SVR (16%) when compared with treatment-experienced patients given peginterferon alpha-2a plus ribavirin (12% SVR achievement). A larger proportion of relapses occurred among both treatment-naïve and treatment-experienced patients given peginterferon alpha-2a plus ribavirin, when compared with treatment-naïve and treatment-experienced patients taking peginterferon alpha-2b plus ribavirin. The proportion of patients discontinuing treatment was greater among treatment-naïve patients taking peginterferon alpha-2a plus ribavirin, but smaller among treatment-experienced patients.

Conclusion

There are small differences in treatment outcomes for different types of peginterferon- alpha. Patient status and complexity of administration may differentiate clinical outcomes.

Using albumin to improve the therapeutic properties of diabetes treatments

Achieving tight glycaemic control remains an unmet need for many patients with type 2 diabetes, despite improved treatments. To meet glycaemic targets, attempts have been made to improve existing drugs and to develop new classes of drugs. Recent advances include insulin analogues that more closely mimic physiologic insulin levels, and incretin-based therapies, which capitalize on the glucoregulatory properties of native glucagon-like peptide-1 (GLP-1). Although promising, these agents are associated with limitations, including hypoglycaemia with insulin, gastrointestinal adverse events with GLP-1 receptor agonists and frequent dosing with both classes. Albumin is an abundant natural drug carrier that has been used to improve the half-life, tolerability and efficacy of a number of bioactive agents. Here, we review the physiologic roles of albumin and how albumin technologies are being used to prolong duration of action of therapies for diabetes, including insulin and incretin-based therapies.

Interferon combination therapy for HIV/hepatitis C virus coinfection

IFN-α has been the cornerstone of chronic hepatitis C virus (HCV) treatment for over a decade. Yet, rates of sustained virologic response of HCV infection to interferon-based therapy, particularly in difficult-to-treat populations, have been disappointingly low. This is particularly true in HIV/HCV coinfection, in which less than a third of patients typically respond to therapy. New HCV protease inhibitors, most of which will need to be administered with pegylated interferon, are in development, but comprehensive, long-term data for their use in coinfected patients is not yet available. Understanding the basis of this population's poor response to interferon-based therapy is crucial to future exploration of new therapeutic options, immunotherapy and prognosis in HIV/HCV-coinfected population.

Association of IL28B SNP and HCV genotypes with response to antiviral therapy in patients with chronic hepatitis C

AIM: To explore the association of IL28B single nucleotide polymorphism (SNP) and hepatitis C virus (HCV) genotypes with response to pegylated interferon-α and ribavirin therapy in patients with chronic hepatitis C.

METHODS: Blood samples from patients who were sustained virological responders (SVR) or non-responders (NR) after pegylated interferon-α and ribavirin therapy for chronic hepatitis C, were collected and used for genotyping of HCV and IL28B SNP rs12979860.

RESULTS: Of 30 patients with sustained virological response, 3 were infected with HCV-1b, 27 with non-HCV-1b; 29 had a C/C genotype of rs12979860, 1 had a T/C genotype. Of 30 patients with non-response, 12 were infected with HCV-1b, 18 with non-HCV-1b; 20 had a C/C genotype of rs12979860, 10 had a T/C genotype. Patients who were infected with non-HCV-1b had better SVR rate than those with HCV 1b infection. Patients who had a C/C genotype of rs12979860 had better SVR rate than those with a T/C genotype.

CONCLUSION: IL28B SNP and HCV genotypes could be predictive of response to antiviral therapy in patients with chronic hepatitis C.

Hepatitis C therapy: other players in the game

Therapies in addition to the direct-acting antiviral agents (DAA) under evaluation for chronic hepatitis C include host targets such as cyclophilin inhibitors and immunomodulators. Both passive and therapeutic vaccines hold promise for the future. Although the numbers of drug categories and individual agents are increasing, only a handful of the non-DAAs seem to be ready to move on to phase III trials. New interferon agents are in development, and ribavirin variants are still under consideration. The role of the other players in the overall armamentarium against hepatitis C virus is still evolving.

Current therapies for chronic hepatitis C

Hepatitis C virus affects more than 180 million people worldwide and as many as 4 million people in the United States. Given that most patients are asymptomatic until late in the disease progression, diagnostic screening and evaluation should be performed in patients who display high-risk behaviors associated with acquisition of hepatitis C. Chronic hepatitis C is associated with cirrhosis, hepatic failure, and death; therefore, treatment is aimed at reducing these complications, as well as improving quality of life and minimizing adverse effects. The American Association for the Study of Liver Diseases Practice Guidelines on the Diagnosis, Management, and Treatment of Hepatitis C represent the gold standard for guidance on the management of hepatitis C. Standard treatment for hepatitis C is peginterferon alpha in combination with ribavirin. Currently, two pegylated interferon products are approved by the U.S. Food and Drug Administration for the treatment of hepatitis C. The duration of therapy with peginterferon and ribavirin is dictated by viral genotype and virologic response. Additional therapies are under investigation for treatment of chronic hepatitis C and show early promise of comparative efficacy and fewer adverse effects. Special considerations in certain populations, including patients coinfected with human immunodeficiency virus, those with end-stage renal disease, injection drug users, pregnant women, and pediatric patients, should guide treatment decisions.

Safety and efficacy of treatment for chronic hepatitis C with a focus on pegylated interferons: the backbone of therapy today and in the future

INTRODUCTION

Approximately 170 million people are infected with HCV. The efficacy of treatment for chronic hepatitis C has increased markedly over the last 2 decades. Optimal patient management requires thorough knowledge of the adverse effect profiles of drugs used for this condition and strategies to mitigate these effects.

AREAS COVERED

The efficacy, safety and tolerability data associated with IFN-based therapy, with particular attention given to the two licensed pegylated IFNs (peg-IFNs), are identified by focused searches of Medline. Recommendations for the management of adverse events are also given. Focused searches of PubMed are done using the terms peginterferon and chronic hepatitis C. The results of large randomized clinical trials are emphasized.

EXPERT OPINION

Patients receiving treatment with peg-IFN plus ribavirin for chronic hepatitis C must be monitored closely for adverse events. These events can be effectively managed to maximize patients' adherence and thus the chance of treatment success. Direct-acting antiviral agents are expected to be approved in the near future and will be used in select patients with a peg-IFN plus ribavirin 'backbone'.

Efficacy and safety of a novel pegylated interferon alpha-2a in Egyptian patients with genotype 4 chronic hepatitis C

BACKGROUND

Hepatitis C virus (HCV) genotype 4 is a common infection in Egypt and is the leading cause of liver disease.

OBJECTIVE

To study the efficacy and safety of a novel 20 kD pegylated interferon alpha-2a derived from Hansenula polymorpha in combination with ribavirin for the treatment of Egyptian patients with genotype 4 chronic hepatitis C (CHC).

METHODS

One hundred seven patients with genotype 4 CHC were involved in the present study. Liver biopsy was performed in all patients. All patients received a fixed weekly dose of 160 µg of a novel pegylated interferon in combination with ribavirin in standard and adjusted doses. Serum HCV RNA levels were assessed by a real-time sensitive polymerase chain reaction assay at four, 12, 48 and 72 weeks after the start of therapy. Patients demonstrating an early virological response (EVR) completed a 48-week course of treatment.

RESULTS

The overall sustained virological response (SVR) was 60.7%. The SVR in patients with a rapid virological response was significantly higher (91.7%) than in patients with complete EVR (67.74%) (P=0.033) and partial EVR (56.14%) (P=0.003). SVR was also significantly higher in patients with a low degree of liver fibrosis according to Metavir score (F1 and F2) (67.57%) compared with those with a high degree of liver fibrosis (F3 and F4) (45.45%) (P=0.017). The baseline viral load had no impact on SVR in the present series nor were any serious adverse events reported.

CONCLUSION

The novel pegylated interferon alpha-2a assessed in the present study was effective for the treatment of patients with genotype 4 CHC, and was safe and well tolerated.

Peginterferon and ribavirin treatment for hepatitis C virus infection

Pegylated interferon α (IFNα) in combination with ribavirin is currently recommended as a standard-of-care treatment for chronic hepatitis C virus (HCV) infection. This combination therapy has drastically improved the rate of sustained virological response, specifically in difficult-to-treat patients. Recently, individualized treatment, such as response-guided therapy, is being developed based on host-, HCV- and treatment-related factors. Furthermore, modified regimens with currently available medications, novel modified IFNα and ribavirin or combinations with specifically targeted antiviral therapy for HCV agents, are currently being investigated. The purpose of this review is to address some issues and epoch-making topics in the treatment of chronic HCV infection, and to discuss more optimal and highly individualized therapeutic strategies for HCV-infected patients.

Preparation of CHO cell-derived rhIFN-ω-Fc with improved pharmacokinetics

Interferon-omega (IFN-ω) may be a useful, promising and alternative antiviral agent, in addition to IFN-α-2a and IFN-α-2b. To improve the pharmacokinetics of IFN-ω for clinical use, the recombinant human IFN-ω-Fc fusion protein (rhIFN-ω-Fc) was expressed in a Chinese hamster ovary cell line (CHO-S), due to the longer serum half-life of rhIFN-ω-Fc compared to the native IFN-ω protein, and purified by affinity chromatography. Physicochemical characterization of the purified fusion protein was performed by SDS-PAGE electrophoresis, dot blot analysis and N-terminal amino acid sequence analysis. The results show that rhIFN-ω-Fc was highly expressed at the predicted size and with the N-terminal amino acid sequence. The antiviral activity was determined by the ability of IFNs to inhibit the cytopathic effects (CPEs) of vesicular stomatitis virus (VSV) on the human amnion WISH cells. The rhIFN-ω-Fc expressed in CHO-S cells has a specific activity of 1.6×10(7) IU/mg compared to rhIFN-ω expressed in yeast, which has a specific activity of 7×10(7) IU/mg. Equimolar concentrations of rhFN-ω and rhIFN-ω-Fc were administered to rabbits for pharmacokinetics comparison. The terminal half-life of rhIFN-ω-Fc was 35 times higher than that of rhIFN-ω. Thus, rhIFN-ω-Fc can be used as a prospective antiviral candidate especially for the treatment of chronic viral disease, such as hepatitis C virus (HCV) infection.

Albinterferon Alfa-2b was not inferior to pegylated interferon-α in a randomized trial of patients with chronic hepatitis C virus genotype 2 or 3

BACKGROUND & AIMS

A phase 3 active-controlled study was conducted to assess the efficacy/safety of albinterferon alfa-2b (albIFN), a novel, long-acting, genetic fusion polypeptide of recombinant human albumin and interferon alfa-2b, in patients with chronic hepatitis C virus (HCV) genotype 2/3.

METHODS

In all, 933 patients were randomized to open-label subcutaneous treatment with pegylated interferon-alfa-2a (Peg-IFNalfa-2a) 180 μg/wk, or albIFN 900 or 1200 μg every 2 weeks for 24 weeks, each administered with oral ribavirin 800 mg/day. The primary end point of the study was sustained virologic response (SVR) (HCV-RNA level, <15 IU/mL at week 48). During the study, the data monitoring committee recommended dose modification for all patients receiving albIFN 1200 μg to 900 μg, impacting 38% of this treatment arm.

RESULTS

By intention-to-treat analysis, SVR rates were 84.8% (95% confidence interval, 80.4%-88.6%), 79.8% (95% confidence interval, 74.9%-84.1%), and 80.0% (95% confidence interval, 75.1%-84.3%) with Peg-IFNalfa-2a, and albIFN 900 and 1200 μg, respectively. The primary hypothesis of noninferiority of SVR was established for albIFN 900 μg (P = .009) and 1200 μg (P = .006). Independent positive predictors of SVR by multivariate regression analysis were pretreatment HCV-RNA level less than 400,000 IU/mL, age younger than 45 years, body mass index less than 30 kg/m(2), genotype 2, normal γ-glutamyl transpeptidase and increased alanine aminotransferase levels at baseline, fibrosis stage F0-F2, no steatosis, and Asian geographic region (Peg-IFNalfa-2a only). The 3 treatment groups showed similar rates of serious (7%-8%) and severe (13%-16%) adverse events, and discontinuations owing to adverse events (3.6%-5.5%).

CONCLUSION

Albinterferon alfa-2b 900 μg every 2 weeks provides an alternative efficacious treatment option in patients with chronic HCV genotype 2 or 3.

Neonatal Fc receptor: from immunity to therapeutics

The neonatal Fc receptor (FcRn), also known as the Brambell receptor and encoded by Fcgrt, is a MHC class I like molecule that functions to protect IgG and albumin from catabolism, mediates transport of IgG across epithelial cells, and is involved in antigen presentation by professional antigen presenting cells. Its function is evident in early life in the transport of IgG from mother to fetus and neonate for passive immunity and later in the development of adaptive immunity and other functions throughout life. The unique ability of this receptor to prolong the half-life of IgG and albumin has guided engineering of novel therapeutics. Here, we aim to summarize the basic understanding of FcRn biology, its functions in various organs, and the therapeutic design of antibody- and albumin-based therapeutics in light of their interactions with FcRn.

Albinterferon Alfa-2b was not inferior to pegylated interferon-α in a randomized trial of patients with chronic hepatitis C virus genotype 1

BACKGROUND & AIMS

The current standard of care for patients with chronic hepatitis C virus (HCV) genotype 1 is once-weekly pegylated interferon-α (Peg-IFNα) plus daily ribavirin for 48 weeks. We evaluated the efficacy/safety of albinterferon alfa-2b (albIFN), a novel, long-acting, genetic fusion polypeptide of albumin and IFNα-2b.

METHODS

In the phase 3 ACHIEVE-1 trial, 1331 patients were assigned equally to 3 open-label, 48-week treatment groups: Peg-IFNα-2a 180 μg every week, or albIFN 900 or 1200 μg every 2 weeks administered subcutaneously, with weight-based oral ribavirin 1000-1200 mg/day. During the study, the data monitoring committee recommended dose modification for all patients receiving albIFN 1200 μg to 900 μg because of increased pulmonary adverse events (AEs) in the 1200-μg arms of both ACHIEVE studies. Main outcome measure was sustained virologic response (SVR; undetectable serum HCV RNA at week 72).

RESULTS

Intention-to-treat SVR rates were 51.0% (225/441), 48.2% (213/442), and 47.3% (208/440) with Peg-IFNα-2a, and albIFN 900 and 1200 μg, respectively. The primary objective of showing noninferiority of albIFN 900 μg (P < .001) and 1200 μg (P = .003) vs Peg-IFNα-2a for SVR was achieved. Multivariate modeling indicated consistency of treatment effect across subgroups. Serious/severe AE rates were 23.1%, 24.0%, 28.2%; treatment discontinuation rates because of AEs were 4.1%, 10.4%, 10.0%; discontinuation rates because of respiratory AEs were 0%, 0.9%, 1.6%; with Peg-IFNα-2a, and albIFN 900 and 1200 μg, respectively. Hematologic abnormality rates were comparable across the Peg-IFNα-2a and albIFN 900-μg groups.

CONCLUSIONS

albIFN 900 μg every 2 weeks showed comparable efficacy, with similar serious/severe AE rates, although with a higher discontinuation rate, vs Peg-IFNα-2a in patients with chronic HCV genotype 1.

Potential treatment options and future research to increase hepatitis C virus treatment response rate

Hepatitis C virus (HCV) is a liver-tropic blood-borne pathogen that affects more than 170 million people worldwide. Although acute infections are usually asymptomatic, up to 90% of HCV infections persist with the possibility of long-term consequences such as liver fibrosis, cirrhosis, steatosis, insulin resistance, or hepatocellular carcinoma. As such, HCV-associated liver disease is a major public health concern. Although the currently available standard of care therapy of pegylated interferon α plus ribavirin successfully treats infection in a subset of patients, the development of more effective, less toxic HCV antivirals is a health care imperative. This review not only discusses the limitations of the current HCV standard of care but also evaluates upcoming HCV treatment options and how current research elucidating the viral life cycle is facilitating the development of HCV-specific therapeutics that promise to greatly improve treatment response rates both before and after liver transplantation.

Management of posttransplant hepatitis C infection

PURPOSE OF REVIEW

Chronic hepatitis C virus (HCV) infection is the leading cause of liver transplantation. Outcome of HCV-associated liver transplantation has been worse than transplantation from other causes. This is mostly related to universal recurrence of HCV in the allograft leading to graft and patient loss or retransplantation. Current antiviral therapies (AVTs) are inadequate and ineffective in the vast majority of the patients with intolerable side effects in most. However, a sustained virologic response (SVR) is associated with improved graft and patient survival. New specifically targeted AVTs for HCV (STAT-C) agents in development will significantly improve the success of AVT. This review focuses on recent data in peritransplant management of HCV with special emphasis on predictors of outcome, diagnosis, prevention and control of reinfection with newer treatments on the horizon.

RECENT FINDINGS

In the immediate pretransplant setting, AVT should be considered in select patients to eradicate the virus. Careful donor selection, immunosuppression (IMS) modulation with steroid and calcineurin inhibitor (CNI) minimization, avoidance of T-cell-depleting treatments and acute rejection episodes, and control of metabolic syndrome can improve allograft outcomes and improve the response to AVT. AVT prior to significant damage to the allograft is strongly recommended.

SUMMARY

With modified novel IMS protocols, careful donor selection, and AVT prior to significant damage to the allograft we can improve the outcome of posttransplant hepatitis C infection. Albeit there are no available data on new antiviral agents, STAT-Cs will have a significant impact in this setting in the near future.

The impact of hepatitis C virus infection on work absence, productivity, and healthcare benefit costs

Chronic hepatitis C virus (HCV) infection is generally considered an asymptomatic disease. However, studies have shown that HCV has a substantial negative impact on patients' quality of life and functioning. This study was designed to compare absenteeism, productivity, and health cost between employees with and without HCV infection in the United States. Employee records from multiple large employers in the United States were obtained from the Human Capital Management Services Research Reference Database and were assessed for demographics, salary, healthcare use, work loss, and workers' compensation. HCV-infected subjects were identified by International Classification of Diseases 9th revision Clinical Modification codes. Controls were randomly selected from employees not diagnosed with HCV. T-tests and chi-square tests were used to determine if there were differences in demographic characteristics. Regression modeling compared days absent (among benefit-eligible employees) and productivity (among employees with data on task-oriented activities), while controlling for the impact of confounding factors. A total of 339,456 subjects were evaluated. Employees with HCV (n = 1664) had significantly more lost work days per employee than the control cohort (n = 337,792), including sick leave, short-term disability, and long-term disability. HCV-infected workers had 4.15 more days of absence per employee than the control cohort. Productivity was measured by units of work processed per hour; employees with HCV processed 7.5% fewer units per hour than employees without HCV (P > 0.05). All healthcare benefit costs among HCV employees were significantly higher than the same costs among employees without HCV. Overall, the total incremental difference was $8352 per year.

CONCLUSION

This real world study provides evidence that there is a substantial indirect burden of illness and describes a relationship between HCV infection, productivity, increased absenteeism, and higher healthcare benefit costs.

Development of novel antiviral therapies for hepatitis C virus

Over 170 million people worldwide are infected with hepatitis C virus (HCV), a major cause of liver diseases. Current interferon-based therapy is of limited efficacy and has significant side effects and more effective and better tolerated therapies are urgently needed. HCV is a positive, single-stranded RNA virus with a 9.6 kb genome that encodes ten viral proteins. Among them, the NS3 protease and the NS5B polymerase are essential for viral replication and have been the main focus of drug discovery efforts. Aided by structure-based drug design, potent and specific inhibitors of NS3 and NS5B have been identified, some of which are in late stage clinical trials and may significantly improve current HCV treatment. Inhibitors of other viral targets such as NS5A are also being pursued. However, HCV is an RNA virus characterized by high replication and mutation rates and consequently, resistance emerges quickly in patients treated with specific antivirals as monotherapy. A complementary approach is to target host factors such as cyclophilins that are also essential for viral replication and may present a higher genetic barrier to resistance. Combinations of these inhibitors of different mechanism are likely to become the essential components of future HCV therapies in order to maximize antiviral efficacy and prevent the emergence of resistance.

The complex interrelationships between chronic lung and liver disease: a review

Lung complications may occur as a result of hepatic disease from any cause and represent a highly heterogeneous group of conditions. Early recognition of such complications may be challenging but is crucial both in forming a meaningful differential diagnosis and in avoiding severe sequelae and irreversible damage. Although a number of different pathogenetic mechanisms are likely to be involved, chronic liver dysfunction may cause pulmonary manifestations because of alterations in the production or clearance of circulating cytokines and other mediators. This is likely to be the case in hepatopulmonary syndrome, portopulmonary hypertension and primary biliary cirrhosis, although their pathogenesis remains largely speculative. Moreover, the severity of lung manifestations may or may not correspond to that of liver impairment, making disease outcome often unpredictable. Congenital and inflammatory disorders, however, may primarily affect both the liver and lung. Apart from specific diseases, a number of medications can also result in pulmonary and hepatic toxic effects. This is particularly important with cytokine therapy - used to treat viral hepatitis, among other diseases - because treatment consists of drug discontinuation, which, in turn, may cause reactivation or progression of the underlying disease that the drug was used for. This review summarizes salient diagnostic and therapeutic aspects of these often misdiagnosed conditions and highlights, based on the most recent literature, the need for early referral of such patients to centres with specific expertise in the field. In fact, a multidisciplinary approach involving pulmonologists, hepatologists and, in particularly severe cases, transplant surgeons has been already proven successful.

Adverse effects of drugs in the treatment of viral hepatitis

The hepatitis B virus (HBV) and the hepatitis C virus (HCV) affect approximately 400-500 million individuals worldwide. Both infections are characterised by a significant morbidity and mortality: chronic hepatitis B and C may evolve towards the development of cirrhosis and primary hepatocellular carcinoma. During the last two decades, several new antivirals have been developed that are active against HBV and HCV, allowing sustained cure rates in a significant proportion of patients. All these drugs have side effects, which may represent a major barrier to achieve cure in many patients in need. I will review the most common adverse events reported during the therapy of chronic hepatitis B and C, with some recommendations for proper management.

Advances in viral hepatitis: 50 years of Australian gastroenterology

Viral hepatitis classification, treatments and pathogenesis has been increasingly defined over the past 50 years. Australian researchers have made significant contributions in the areas of viral hepatitis A vaccine development, treatment outcomes for chronic hepatitis B and C, the role of liver transplantation and the pathogenesis of injury and disease progression. This review outlines some of these contributions.