Peginterferon alfa-2a: A review of approved and investigational uses

Type I and type III interferons: From basic biology and genetics to clinical development for COVID-19 and beyond

Type I and type III interferons (IFNs) constitute a key antiviral defense systems of the body, inducing viral resistance to cells and mediating diverse innate and adaptive immune functions. Defective type I and type III IFN responses have recently emerged as the 'Achilles heel' in COVID-19, with such patients developing severe disease and exhibiting a high risk for critical pneumonia and death. Here, we review the biology of type I and type III IFNs, their similarities and important functional differences, and their roles in SARS-CoV-2 infection. We also appraise the various mechanisms proposed to drive defective IFN responses in COVID-19 with particular emphasis to the ability of SARS-CoV-2 to suppress IFN production and activities, the genetic factors involved and the presence of autoantibodies neutralizing IFNs and accounting for a large proportion of individuals with severe COVID-19. Finally, we discuss the long history of the type I IFN therapeutics for the treatment of viral diseases, cancer and multiple sclerosis, the various efforts to use them in respiratory infections, and the newly emerging type III IFN therapeutics, with emphasis to the more recent studies on COVID-19 and their potential use as broad spectrum antivirals for future epidemics or pandemics.

Expression and purification of human interferon alpha 2a (IFNα2a) in the methylotrophic yeast Pichia pastoris

Human interferon alpha 2a (IFNα2a) is a secreted glycoprotein that exerts a wide spectrum of biological effects, such as triggering of antiviral, antitumor and immunosuppressive responses. IFNα2a is used as pharmaceutical polypeptide in chronic hepatitis C virus (HCV) infection, chronic myelogenous leukemia, advanced renal cell carcinoma, and metastatic malignant melanoma. So far, the pharmaceutical polypeptide of this cytokine is produced in prokaryotic expression systems (E. coli). Here we report the expression and purification of recombinant human IFNα2a in the methylotrophic yeast Pichia pastoris. The cDNA encoding for human IFNα2a, modified to bear the P. pastoris codon bias, was cloned into the pPinkα-HC vector in order to be expressed as a secreted protein upon induction. Proper expression and secretion of recombinant human IFNα2a (approximately 19 kDa) was confirmed by PCR-sequencing, SDS-PAGE and Western blot analysis following methanol-induced expression in a number of individual transformed strains. Purification of the recombinant protein was performed by affinity chromatography, achieving a robust yield of purified active form. The purified recombinant protein showed an impressive stability to thermal denaturation as observed by Differential Scanning Fluorimetry. The biological activity of the P. pastoris-produced IFNα2a was confirmed in A549 and HT29 cells by monitoring transcriptional up-regulation of a panel of known interferon-stimulated genes (ISGs). Our results document that the P. pastoris expression system is a suitable system for producing biologically functional IFNα2a in a secreted form.

MultiPep: a hierarchical deep learning approach for multi-label classification of peptide bioactivities

Peptide-based therapeutics are here to stay and will prosper in the future. A key step in identifying novel peptide-drugs is the determination of their bioactivities. Recent advances in peptidomics screening approaches hold promise as a strategy for identifying novel drug targets. However, these screenings typically generate an immense number of peptides and tools for ranking these peptides prior to planning functional studies are warranted. Whereas a couple of tools in the literature predict multiple classes, these are constructed using multiple binary classifiers. We here aimed to use an innovative deep learning approach to generate an improved peptide bioactivity classifier with capacity of distinguishing between multiple classes. We present MultiPep: a deep learning multi-label classifier that assigns peptides to zero or more of 20 bioactivity classes. We train and test MultiPep on data from several publically available databases. The same data are used for a hierarchical clustering, whose dendrogram shapes the architecture of MultiPep. We test a new loss function that combines a customized version of Matthews correlation coefficient with binary cross entropy (BCE), and show that this is better than using class-weighted BCE as loss function. Further, we show that MultiPep surpasses state-of-the-art peptide bioactivity classifiers and that it predicts known and novel bioactivities of FDA-approved therapeutic peptides. In conclusion, we present innovative machine learning techniques used to produce a peptide prediction tool to aid peptide-based therapy development and hypothesis generation.

IFN-α Suppresses Myeloid Cytokine Production, Impairing IL-12 Production and the Ability to Support T-Cell Proliferation

BACKGROUND

Interferon-α (IFN-α) can suppress production of T-cell polarizing cytokines or induce inhibitory antigen-presenting cells that suppress T-cell activation. Previous studies showed that IFN-α therapy fails to boost virus-specific T-cell immunity in patients with chronic hepatitis B virus infection. Our aim was to determine whether IFN-α exposure alters human antigen-presenting cell function in vivo.

METHODS

We investigated the immunomodulatory effects using peripheral blood mononuclear cells from healthy donors exposed to IFN-α and chronic hepatitis B (CHB) patients starting IFN-α therapy.

RESULTS

IFN-α increased HLA-DR, CD80, CD86, and PD-L1 expression on healthy donor monocytes. In contrast to the activated phenotype, IFN-α inhibited Toll-like receptor-induced cytokine production and monocyte-induced T-cell proliferation. In CHB patients, peg-IFN treatment induced an interferon-stimulated gene signature in monocytes and increased HLA-DR, CD80, CD86, and PD-L1 expression. As early as 3 days after CHB patients started treatment, IFN-α inhibited monocyte cytokine production and T-cell stimulation ex vivo. IFN-α-mediated inhibition of IL-12 production, rather than inhibitory receptor expression, was responsible for inhibition of T-cell proliferation. Addition of IL-12 restored T-cell proliferation to baseline levels.

CONCLUSIONS

Understanding how professional antigen-presenting cells respond to immunomodulation is important for both new innate and adaptive-targeted immunotherapies.

CLINICAL TRIALS REGISTRATION

NCT00962871.

Pharmacokinetics and pharmacodynamics of pegylated interferon for the treatment of hepatitis B

Introduction: Interferon (IFN) had both antiviral and immunomodulatory effects, and was one of the approved treatments for hepatitis B virus (HBV). Herein, we reviewed the pharmacokinetics and pharmacodynamics of pegylated IFN-α (PegIFN-α) for the treatment of HBV. Areas covered: The steady-state serum levels of PegIFN-α were reached within 5 to 8 weeks, and the week 48 mean trough concentrations were approximately 2-fold higher than week 1. There was also no difference of the pharmacokinetics in male or female, healthy volunteers or patients with hepatitis B or C infection. PegIFN-α did not affect the metabolism of the cytochrome P450 (CYP) isozymes, except inhibition of CYP1A2. There was also no pharmacokinetic interaction between PegIFN-α and HBV nucleot(s)ide analogues (NUCs). Forty-eight weeks of PegIFN-α achieved 32% of HBeAg seroconversion, 32-43% of HBV DNA suppression, 41-59% of ALT normalization, and 3% of HBsAg seroconversion rate with a post-treatment durable response up to 80% in the initial responders. Expert opinion: On-treatment HBsAg titer guided the treatment of HBV with PegIFN-α. The recommendation of PegIFN-α and NUC combination or switch remained controversial. New immunotherapeutic agents are now in development. Although, PegIFN-α should continue to play a role in the treatment of HBV.

Prospects for repurposing CNS drugs for cancer treatment

Drug repurposing is the idea of using an already approved drug for another disease or disorder away from its initial use. This new approach ensures the reduction in high cost required for developing a new drug in addition to the time consumed, especially in the tumor disorders that show an unceasing rising rate with an unmet success rate of new anticancer drugs. In our review, we will review the anti-cancer effect of some CNS drugs, including both therapeutic and preventive, by searching the literature for preclinical or clinical evidence for anticancer potential of central nervous system drugs over the last 8 years period (2010-2018) and including only evidence from Q1 journals as indicated by Scimago website (www.scimagojr.com). We concluded that Some Central Nervous system drugs show a great potential as anti-cancer in vitro, in vivo and clinical trials through different mechanisms and pathways in different types of cancer that reveal a promising evidence for the repurposing of CNS drugs for new indications.

PEGylated liposomes: immunological responses

A commonly held view is that nanocarriers conjugated to polyethylene glycol (PEG) are non-immunogenic. However, many studies have reported that unexpected immune responses have occurred against PEG-conjugated nanocarriers. One unanticipated response is the rapid clearance of PEGylated nanocarriers upon repeat administration, called the accelerated blood clearance (ABC) phenomenon. ABC involves the production of antibodies toward nanocarrier components, including PEG, which reduces the safety and effectiveness of encapsulated therapeutic agents. Another immune response is the hypersensitivity or infusion reaction referred to as complement (C) activation-related pseudoallergy (CARPA). Such immunogenicity and adverse reactivities of PEGylated nanocarriers may be of potential concern for the clinical use of PEGylated therapeutics. Accordingly, screening of the immunogenicity and CARPA reactogenicity of nanocarrier-based therapeutics should be a prerequisite before they can proceed into clinical studies. This review presents PEGylated liposomes, immunogenicity of PEG, the ABC phenomenon, C activation and lipid-induced CARPA from a toxicological point of view, and also addresses the factors that influence these adverse interactions with the immune system.

Peginterferon α-2a for the treatment of HIV infection

INTRODUCTION

Novel approaches are urgently needed to achieve the next level of control of HIV infection beyond antiretroviral medications that will lead to the ultimate goal of curing HIV infection. Exploiting the innate immune system control of HIV is one possible component of that strategy with pegylated interferon α representing a well-characterized agent that is being applied to this effort.

AREAS COVERED

In this review, the authors summarize the history of interferon α treatment in the setting of HIV infection with a focus on clinical trials that examined the downstream effects on innate immune responses. More recently, clinical trials that administered pegylated interferon α-2a have demonstrated which interferon-stimulated genes are associated with its antiviral effects and which of these host-restriction factors may play a role in limiting the magnitude of the HIV reservoir.

EXPERT OPINION

The potential to exploit interferon α as part of a cure strategy is provocative. Whether key interferon-induced antiviral factors can be upregulated sufficiently to affect the reservoir is unknown. Additional research employing pegylated interferon α-2a is needed to identify which innate immune pathways are candidate targets for novel biological therapies for the potential cure of HIV infection.

Selective Delivery of PEGylated Compounds to Tumor Cells by Anti-PEG Hybrid Antibodies

Polyethylene glycol (PEG) is attached to many peptides, proteins, liposomes, and nanoparticles to reduce their immunogenicity and improve their pharmacokinetic and therapeutic properties. Here, we describe hybrid antibodies that can selectively deliver PEGylated medicines, imaging agents, or nanomedicines to target cells. Human IgG1 hybrid antibodies αPEG:αHER2 and αPEG:αCD19 were shown by ELISA, FACS, and plasmon resonance to bind to both PEG and HER2 receptors on SK-BR-3 breast adenocarcinoma and BT-474 breast ductal carcinoma cells or CD19 receptors on Ramos and Raji Burkitt's lymphoma cells. In addition, αPEG:αHER2 specifically targeted PEGylated proteins, liposomes, and nanoparticles to SK-BR-3 cells that overexpressed HER2, but not to HER2-negative MCF-7 breast adenocarcinoma cells. Endocytosis of PEGylated nanoparticles into SK-BR-3 cells was induced specifically by the αPEG:αHER2 hybrid antibody, as observed by confocal imaging of the accumulation of Qdots inside SK-BR-3 cells. Treatment of HER2(+) SK-BR-3 and BT-474 cancer cells with αPEG:αHER2 and the clinically used chemotherapeutic agent PEGylated liposomal doxorubicin for 3 hours enhanced the in vitro effectiveness of PEGylated liposomal doxorubicin by over two orders of magnitude. Hybrid anti-PEG antibodies offer a versatile and simple method to deliver PEGylated compounds to cellular locations and can potentially enhance the therapeutic efficacy of PEGylated medicines.

Sensitivity of PEGylated interferon detection by anti-polyethylene glycol (PEG) antibodies depends on PEG length

Attachment of poly(ethylene glycol) to proteins can mask immune epitopes to increase serum half-life, reduce immunogenicity, and enhance in vivo biological efficacy. However, PEGylation mediated epitope-masking may also limit sensitivity and accuracy of traditional ELISA. We previously described an anti-PEG-based sandwich ELISA for universal assay of PEGylated molecules. Here, we compared the quantitative assessment of PEGylated interferons by anti-PEG and traditional anti-interferon sandwich ELISA. The detection limits for PEG-Intron (12k-PEG) and Pegasys (40k-PEG) were 1.9 and 0.03 ng/mL for anti-PEG ELISA compared to 0.18 and 0.42 ng/mL for traditional anti-interferon sandwich ELISA. These results indicate that the anti-PEG sandwich ELISA was insensitive to PEGylation mediated epitope-masking and the sensitivity increased in proportion to the length of PEG. By contrast, PEG-masking interfered with detection by traditional anti-interferon sandwich ELISA. Human and mouse serum did not affect the sensitivity of anti-PEG ELISA but impeded traditional anti-interferon sandwich ELISA. The anti-PEG sandwich ELISA was comparable to anti-interferon sandwich ELISA and radioassay of 131I-Pegasys in pharmacokinetic studies in mice. The anti-PEG sandwich ELISA provides a sensitive, accurate, and convenient quantitative measurement of PEGylated protein drugs.

Amantadine and rimantadine for influenza A in children and the elderly

BACKGROUND

Influenza is an acute respiratory illness caused by influenza A and B viruses. Complications may occur, especially among children and the elderly.

OBJECTIVES

To assess the effectiveness and safety of amantadine and rimantadine in preventing, treating and shortening the duration of influenza A in children and the elderly.

SEARCH METHODS

We searched CENTRAL (2014, Issue 9), MEDLINE (1966 to September week 4, 2014) and EMBASE (1980 to October 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing amantadine and/or rimantadine with no intervention, placebo, other antivirals or different doses or schedules of amantadine or rimantadine in children and the elderly with influenza A.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the search results. We extracted and analysed data using the standard Cochrane methodology.

MAIN RESULTS

We identified 12 studies (2494 participants: 1586 children and 908 elderly) comparing amantadine and rimantadine with placebo, paracetamol (one trial: 69 children) or zanamivir (two trials: 545 elderly) to treat influenza A.Amantadine was effective in preventing influenza A in children (773 participants, risk ratio (RR) 0.11; 95% confidence interval (CI) 0.04 to 0.30). The assumed risk of influenza A in the control group was 10 per 100. The corresponding risk in the rimantadine group was one per 100 (95% CI 0 to 3). Nevertheless, the quality of the evidence was low and the safety of the drug was not well established.For treatment, rimantadine was beneficial in abating fever on day three of treatment in children: one selected study with low risk of bias, moderate evidence quality and 69 participants (RR 0.36; 95% CI 0.14 to 0.91). The assumed risk was 38 per 100. The corresponding risk in the rimantadine group was 14 per 100 (95% CI 5 to 34).Rimantadine did not show any prophylactic effect in the elderly. The quality of evidence was very low: 103 participants (RR 0.45; 95% CI 0.14 to 1.41). The assumed risk was 17 per 100. The corresponding risk in the rimantadine group was 7 per 100 (95% CI 2 to 23).There was no evidence of adverse effects caused by treatment with amantadine or rimantadine.We found no studies assessing amantadine in the elderly.

AUTHORS' CONCLUSIONS

The quality of the evidence combined with a lack of knowledge about the safety of amantadine and the limited benefits of rimantadine, do not indicate that amantadine and rimantadine compared to control (placebo or paracetamol) could be useful in preventing, treating and shortening the duration of influenza A in children and the elderly.

Does consideration and assessment of effects on health equity affect the conclusions of systematic reviews? A methodology study

Introduction

Tackling health inequities both within and between countries remains high on the agenda of international organizations including the World Health Organization and local, regional and national governments. Systematic reviews can be a useful tool to assess effects on equity in health status because they include studies conducted in a variety of settings and populations. This study aims to describe the extent to which the impacts of health interventions on equity in health status are considered in systematic reviews, describe methods used, and assess the implications of their equity related findings for policy, practice and research.

Methods

We conducted a methodology study of equity assessment in systematic reviews. Two independent reviewers extracted information on the reporting and analysis of impacts of health interventions on equity in health status in a group of 300 systematic reviews collected from all systematic reviews indexed in one month of MEDLINE, using a pre-tested data collection form. Any differences in data extraction were resolved by discussion.

Results

Of the 300 systematic reviews, 224 assessed the effectiveness of interventions on health outcomes. Of these 224 reviews, 29 systematic reviews assessed effects on equity in health status using subgroup analysis or targeted analyses of vulnerable populations. Of these, seven conducted subgroup analyses related to health equity which were reported in insufficient detail to judge their credibility. Of these 29 reviews, 18 described implications for policy and practice based on assessment of effects on health equity.

Conclusion

The quality and completeness of reporting should be enhanced as a priority, because without this policymakers and practitioners will continue lack the evidence base they need to inform decision-making about health inequity. Furthermore, there is a need to develop methods to systematically consider impacts on equity in health status that is currently lacking in systematic reviews.

Amantadine and rimantadine for influenza A in children and the elderly

BACKGROUND

The effectiveness and safety of amantadine (AMT) and rimantadine (RMT) for preventing and treating influenza A in adults has been systematically reviewed. However, little is known about these treatments in children and the elderly.

OBJECTIVES

To systematically review the effectiveness and safety of AMT and RMT in preventing and treating influenza A in children and the elderly.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 2) which contains the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register, MEDLINE (1966 to June week 3, 2011) and EMBASE (1980 to June 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing AMT and/or RMT with placebo, control, other antivirals or different doses or schedules of AMT or RMT, or both, or no intervention, in children and the elderly.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and assessed methodological quality. We resolved disagreements by consensus. In all comparisons except for one, we separately analysed the trials in children and the elderly using Review Manager software.

MAIN RESULTS

A total of 12 studies involving 2494 participants (1586 children and adolescents and 908 elderly) compared AMT and RMT with placebo, paracetamol (one trial; 69 children) or zanamivir (two trials; 545 seniors). All studies were RCTs but most were still susceptible to bias. Two trials in the elderly had a high risk of bias because of incomplete outcome data. In one of those trials there was also a lack of outcome assessment blinding. Risk of bias was unclear in 10 studies due to unclear random sequence generation and allocation concealment. Only two trials in children were considered to have a low risk of bias.AMT was effective in preventing influenza A in children. A total of 773 participants were included in this outcome (risk ratio (RR) 0.11; 95% confidence interval (CI) 0.04 to 0.30). The assumed risk of influenza in the control group was 10 per 100 and the corresponding risk in the RMT group was one per 100 (95% CI 0 to 3). The quality of the evidence was considered low. For treatment purposes, RMT was beneficial for abating fever on day three of treatment. For this purpose one study was selected with low risk of bias and included 69 children (RR 0.36; 95% CI 0.14 to 0.91). The assumed risk was 38 per 100 and the corresponding risk in the RMT group was 14 per 100, 95% CI 5 to 34. The quality of the evidence was moderate.RMT did not show a prophylactic effect against influenza in the elderly, but the quality of evidence was considered very low. There were 103 participants (RR 0.45; 95% CI 0.14 to 1.41, for an assumed risk of 17 per 100 and a corresponding risk in the RMT group of 7 per 100, 95% CI 2 to 23). We did not identify any AMT trials in the elderly that met our inclusion criteria.There was no evidence of adverse effects of AMT and RMT in children or an adverse effect of RMT in the elderly. We did not identify any AMT trials in the elderly that met our inclusion criteria.

AUTHORS' CONCLUSIONS

AMT is effective in preventing influenza A in children but the NNTB is high (NNTB: 12 (95% CI 9 to 17). RMT probably helps the abatement of fever on day three of treatment, but the quality of the evidence is poor. Due to the small number of available studies, we could not reach a definitive conclusion on the safety of AMT or the effectiveness of RMT in preventing influenza in children and the elderly.

Interferon-α in acute myeloid leukemia: an old drug revisited

Interferon-α (IFN-α), a type I IFN, is a well-known antitumoral agent. The investigation of its clinical properties in acute myeloid leukemia (AML) has been prompted by its pleiotropic antiproliferative and immune effects. So far, integration of IFN-α in the therapeutic arsenal against AML has been modest in view of the divergent results of clinical trials. Recent insights into the key pharmacokinetic determinants of the clinical efficacy of IFN along with advances in its pharmaceutical formulation, have sparked renewed interest in its use. This paper reviews the possible applicability of IFN-α in the treatment of AML and provides a rational basis to re-explore its efficacy in clinical trials.

Single-dose pharmacokinetics, safety, and tolerability of albinterferon alfa-2b in subjects with end-stage renal disease on hemodialysis compared to those in matched healthy volunteers

Albinterferon alfa-2b (albIFN) is being developed, in combination with ribavirin, for the treatment of hepatitis C virus infection. This study was designed to evaluate the pharmacokinetics, safety, and tolerability of a 900-μg dose of albIFN administered as a single subcutaneous injection in end-stage renal disease (ESRD) patients on hemodialysis and matched healthy volunteers (by age [±5 years], weight [±5 kg], and gender). The maximum concentration in plasma (C(max)) and the area under the concentration-time curve from time zero to infinity (AUC(0-∞)) were 42.8 ± 14.0 ng/ml and 16,414 ± 4,203 ng·h/ml, respectively, for healthy volunteers, while the C(max) and AUC(0-∞) were 49.9 ± 20.9 ng/ml and 18,919 ± 8,008 ng·h/ml, respectively, for ESRD patients. The geometric least-squares mean ratios were 1.15 (90% confidence interval [CI], 0.78, 1.68) for C(max) and 1.11 (90% CI, 0.83, 1.48) for AUC(0-∞). Adverse events were as expected for an interferon (e.g., flu-like symptoms), with the main laboratory adverse event being a decline in total white blood cell count, which was specifically related to a decline in the neutrophil count. This effect was somewhat greater in the ESRD patients, with the maximal decreases in neutrophil counts from those at the baseline being (-2.6 ± 0.32) × 10(9) and (-2.19 ± 0.58) × 10(9) cells/liter for the ESRD patients and the healthy volunteers, respectively. This study indicates no significant effect of renal failure on the pharmacokinetics of albIFN. Safety and tolerability were as expected for an interferon.

Pharmacodynamics of PEG-IFN-alpha-2a in HIV/HCV co-infected patients: implications for treatment outcomes

BACKGROUND & AIMS

The pharmacokinetics and pharmacodynamics of pegylated-interferon-alpha-2a (PEG-IFN) have not been described in HCV/HIV co-infected patients. We sought to estimate the pharmacokinetics and pharmacodynamics of PEG-IFN and determine whether these parameters predict treatment outcome.

METHODS

Twenty-six HCV/human immunodeficiency virus (HIV)-co-infected patients were treated with a 48-week regimen of PEG-IFN (180 microg/week) plus ribavirin (11 mg/kg/day). HCV RNA and PEG-IFN concentrations were obtained from samples collected until week 12. A modeling framework that includes pharmacokinetic and pharmacodynamic parameters was developed.

RESULTS

Five patients discontinued treatment. Seven patients achieved a sustained virological response (SVR). PEG-IFN concentrations at day 8 were similar to steady-state levels (p=0.15) and overall pharmacokinetic parameters were similar in SVRs and non-SVRs. The maximum PEG-IFN effectiveness during the first PEG-IFN dose and the HCV-infected cell loss rate (delta), were significantly higher in SVRs compared to non-SVRs (median 95% vs. 86% [p=0.013], 0.27 vs. 0.11 day(-1) [p=0.006], respectively). Patients infected with HCV genotype 1 had a significantly lower average first-week PEG-IFN effectiveness (median 70% vs. 88% [p=0.043]), however, 4- to 12-week PEG-IFN effectiveness was not significantly different compared to those with genotype 3 (p=0.114). Genotype 1 had a significantly lower delta compared to genotype 3 (median 0.14 vs. 0.23 day(-1) [p=0.021]). The PEG-IFN concentration that decreased HCV production by 50% (EC(50)) was lower in genotype 3 compared to genotype 1 (median 1.3 vs. 3.4 [p=0.034]).

CONCLUSIONS

Both the HCV-infected cell loss rate (delta) and the maximum effectiveness of the first dose of PEG-IFN-alpha-2a characterised HIV co-infected patients and were highly predictive of SVR. Further studies are needed to validate these viral kinetic parameters as early on-treatment prognosticators of response in patients with HCV and HIV.

Moyamoya in a child treated with interferon for recurrent osteosarcoma

Moyamoya is a cerebral vasculopathy of unknown etiology rarely described as a late effect after the treatment of childhood cancer. We describe a 12-year-old female who developed moyamoya after the completion of systemic chemotherapy, surgery, and adjuvant interferon alpha for osteosarcoma with pulmonary metastases. Given the importance of characterizing late effects after the treatment of childhood cancer, the potential role of interferon alpha in the development of moyamoya is discussed.

Very-Low-Dose Pegylated Interferon a2a Plus Ribavirin Therapy for Advanced Liver Cirrhosis Type C: A Possible Therapeutic Alternative without Splenic Intervention

Despite the recent progress in interferon (IFN) therapies for chronic hepatitis C, liver cirrhosis remains refractory. One of the major obstacles to successful IFN therapy is low platelet count. Currently, splenic interventions, such as partial splenic embolization (PSE) or surgical splenectomy, have been applied effectively and make standard IFN therapy possible. However, there may be a group of patients with low platelet counts who can be treated without splenic intervention. We here report two patients with advanced type C liver cirrhosis who were successfully treated using very-low-dose pegylated interferon a2a plus ribavirin. One patient had a very low platelet count (2.5 x 10(4)/mul) due to splenomegaly before treatment. However, pretreatment serum HCV titers were low in both patients and early viral responses were obtained in both. Because PSE or splenectomy may still have some safety concerns, this attenuated IFN treatment protocol can be an alternative therapeutic option for patients with advanced type C liver disease, but good virological factors for sustained virological response.

Pegylated long-acting human growth hormone is well-tolerated in healthy subjects and possesses a potential once-weekly pharmacokinetic and pharmacodynamic treatment profile

BACKGROUND

Recombinant human GH (rhGH) is usually administered as a daily sc injection, which may be both inconvenient and distressing for patients. NNC126-0083 is a pegylated rhGH developed with the aim of reducing serum clearance and thereby prolonging the exposure leading to once-weekly sc administration.

OBJECTIVES

In this first human dose trial, the safety, tolerability, pharmacokinetics, and pharmacodynamic parameters of a single administration of NNC126-0083 were evaluated.

SUBJECTS AND METHODS

Seven groups of eight healthy male volunteers were dosed once with a single sc administration of NNC126-0083 (n = 6) or placebo (n = 2). The doses were escalated between the cohorts in a sequential mode. Blood samples for assessment of safety, pharmacokinetics, and pharmacodynamic response (IGF-I, IGF binding protein-3, free IGF-I) as well as GH binding protein were taken up to 240 h after dosing.

RESULTS

Seven doses of NNC126-0083 were administered. After NNC126-0083 administration, a significant deviation from pharmacokinetic dose proportionality was observed for the highest doses. A strong dose-dependent pharmacodynamic response was seen with elevated levels of IGF-I and IGF binding protein-3 for all doses administered. The elevation was maintained for more than 1 wk for the highest doses. All doses of NNC126-0083 were well tolerated. No local tolerability issues were identified.

CONCLUSION

After a single sc administration of NNC126-0083 in healthy male volunteers, a sustained dose-dependent pharmacodynamic response was induced. These results indicate that NNC126-0083 has the potential for an efficacious, well-tolerated, once-weekly rhGH compound in the treatment of GH deficiency in adults.

Pegylated IFN-alpha2a and ribavirin in the treatment of hepatitis C

Chronic hepatitis C is a major worldwide health problem with an estimated prevalence of 1.6-2%. The prognosis of chronic hepatitis C depends on the rate of fibrosis progression which, over a 20-30-year time span, may determine the risk of developing cirrhosis and its complications, namely hepatocellular carcinoma, liver decompensation, hepatic encefalopathy and espohageal variceal bleeding. The only therapeutic measure able to halt this progressive process is HCV eradication by interferon (IFN)-based therapies. HCV clearance benefits patients with chronic hepatitis C, by preventing the progression to cirrhosis, as well as those with established cirrhosis, by effectively reducing the risk of liver-related complications. The latest innovation in anti-HCV treatment has been the pegylation of the IFN molecule through the attachment of one or more polyethylene glycols to the IFN molecule, drastically modifying the immunological, pharmacokinetic and pharmacodynamic properties of the drug. Following the demonstration of a more potent antiviral effect in terms of sustained virological response rates in Phase III randomized trials, pegylated IFN coupled with ribavirin has become the standard of care for chronic hepatitis C. Currently, two forms of pegylated IFN exist (alpha2a and alpha2b), which differ significantly in terms of pharmacokinetics and dynamics, is whether these peculiarities translate into different efficacy rates being still being debated.

Strategies to prolong the plasma residence time of peptidedrugs

Well established as well as recently developed strategies to prevent the fast clearance of peptide drugs from the circulation are reviewed.

Association of genetic polymorphisms with interferon-induced haematologic adverse effects in chronic hepatitis C patients

Interferon (IFN)-based combination therapy with ribavirin has become the gold standard for the treatment of chronic hepatitis C virus infection. Haematologic toxicities, such as neutropenia, thrombocytopenia, and anaemia, however, frequently cause poor treatment tolerance, resulting in poor therapeutic efficacy. The aim of this study was to identify host genetic polymorphisms associated with the efficacy or haematologic toxicity of IFN-based combination therapy in chronic hepatitis C patients. We performed comprehensive single nucleotide polymorphism detection in all exonic regions of the 12 genes involved in the IFN signalling pathway in 32 healthy Japanese volunteers. Of 167 identified polymorphisms, 35 were genotyped and tested for an association with the efficacy or toxicity of IFN plus ribavirin therapy in 240 chronic hepatitis C patients. Multiple logistic regression analysis revealed that low viral load, viral genotypes 2 and 3, and a lower degree of liver fibrosis, but none of the genetic polymorphisms, were significantly associated with a sustained virologic response. In contrast to efficacy, multiple linear regression analyses demonstrated that two polymorphisms (IFNAR1 10848-A/G and STAT2 4757-G/T) were significantly associated with IFN-induced neutropenia (P = 0.013 and P = 0.011, respectively). Thrombocytopenia was associated with the IRF7 789-G/A (P = 0.031). In conclusion, genetic polymorphisms in IFN signalling pathway-related genes were associated with IFN-induced neutropenia and thrombocytopenia in chronic hepatitis C patients. In contrast to toxicity, the efficacy of IFN-based therapy was largely dependent on viral factors and degree of liver fibrosis.

Functionally relevant decreases in activatory receptor expression on NK cells are associated with pulmonary tuberculosis in vivo and persist after successful treatment

Correlates for the initiation of Mycobacterium tuberculosis hominis (Mth) replication from latency are needed in order to improve Mth control. In order to analyze if perturbations of peripheral NK cells may be associated with exit from Mth latency, sequential patients with newly diagnosed lung tuberculosis (TB) were studied. Peripheral NK cells were analyzed by cytofluorometry, in vitro culture and functional assays. At the onset of lung TB, imbalances in NK cell subsets were evident. Decreased CD56(bright)CD16(+/-) subsets with significantly compromised NKp30 and NKp46 expression and with specifically decreased gamma-IFN production upon triggering were evident. These features were not completely restored when purified NK cells were cultured in vitro. Culture supplementation with alpha-IFN increased only NKp30 expression in TB and healthy donors. Extensive peripheral NK cell triggering was evident in these patients, as shown by the expression of NK cell activation markers and of the lymph node-homing chemokine receptor CCR7 on CD16(+) CD56(dull) cells. Significant persistence of decreased NKp30 and NKp46 after successful treatment with a standard four-drug regimen was detected after full recovery. NK cell function is deeply affected in patients at the onset of pulmonary TB. The involvement of multiple activatory receptors may provide a relevant contribution to the spread of mycobacteria exiting from latency.

Nanoparticles for human liver-specific drug and gene delivery systems: in vitro and in vivo advances

A wide variety of nanoparticles (NPs) that can deliver incorporated therapeutic materials such as compounds, proteins, genes and siRNAs to the human liver have been developed to treat liver-related diseases. This review describes NP-based drug and gene delivery systems such as liposomes (including lipoplex), polymer micelles, polymers (including polyplex) and viral vectors. It focuses upon the modification of these NPs to enhance liver specificity or delivery efficiency in vitro and in vivo. We discuss recent advances in drug and gene delivery systems specific to the human liver utilizing bio-nanocapsules comprising hepatitis B virus (HBV) envelope L protein, which has a pivotal role in HBV infection. These NP-based medicines may offer novel strategies for the treatment of liver-related diseases and contribute to the development of nanomedicines targeting other tissues.

Silybin treatment is associated with reduction in serum ferritin in patients with chronic hepatitis C

GOALS

The goal of this study was to examine the effect of a standardized silybin and soy phosphatidylcholine complex (IdB 1016) on serum markers of iron status.

BACKGROUND

Milk thistle and its components are widely used as an alternative therapy for liver disease because of purported antioxidant, anti-inflammatory, and iron chelating properties.

STUDY

Thirty-seven patients with chronic hepatitis C and Batts-Ludwig fibrosis stage II, III, or IV were randomized to 1 of 3 doses of IdB 1016 for 12 weeks. Serum ferritin, serum iron, total iron binding capacity, and transferrin-iron saturation were measured at baseline, during treatment, and 4 weeks thereafter. Wilcoxon signed rank tests were used to compare baseline and posttreatment values.

RESULTS

There was a significant decrease in serum ferritin from baseline to end of treatment (mean, 244 vs. 215 mug/L; median, 178 vs. 148 mug/L; P=0.0005); 78% of subjects had a decrease in serum ferritin level. There was no significant change in serum iron or transferrin-iron saturation. Multivariate logistic regression analysis in a model that included dose, age, sex, HFE genotype, history of alcohol use, and elevated baseline ferritin levels demonstrated that stage III or IV fibrosis was independently associated with decreased posttreatment serum ferritin level.

CONCLUSIONS

Treatment with IdB 1016 is associated with reduced body iron stores, especially among patients with advanced fibrosis stage.

Bioconjugation of oligonucleotides for treating liver fibrosis

Liver fibrosis results from chronic liver injury due to hepatitis B and C, excessive alcohol ingestion, and metal ion overload. Fibrosis culminates in cirrhosis and results in liver failure. Therefore, a potent antifibrotic therapy is urgently needed to reverse scarring and eliminate progression to cirrhosis. Although activated hepatic stellate cells (HSCs) remain the principle cell type responsible for liver fibrosis, perivascular fibroblasts of portal and central veins as well as periductular fibroblasts are other sources of fibrogenic cells. This review will critically discuss various treatment strategies for liver fibrosis, including prevention of liver injury, reduction of inflammation, inhibition of HSC activation, degradation of scar matrix, and inhibition of aberrant collagen synthesis. Oligonucleotides (ODNs) are short, single-stranded nucleic acids, which disrupt expression of target protein by binding to complementary mRNA or forming triplex with genomic DNA. Triplex forming oligonucleotides (TFOs) provide an attractive strategy for treating liver fibrosis. A series of TFOs have been developed for inhibiting the transcription of alpha1(I) collagen gene, which opens a new area for antifibrotic drugs. There will be in-depth discussion on the use of TFOs and how different bioconjugation strategies can be utilized for their site-specific delivery to HSCs or hepatocytes for enhanced antifibrotic activities. Various insights developed in individual strategy and the need for multipronged approaches will also be discussed.

Amantadine and rimantadine for influenza A in children and the elderly

BACKGROUND

Although amantadine (AMT) and rimantadine (RMT) are used to relieve or treat influenza A symptoms in healthy adults, little is known about the effectiveness and safety of these antivirals in preventing and treating influenza A in children and the elderly.

OBJECTIVES

The aim of this review was to systematically consider evidence on the effectiveness and safety of AMT and RMT in preventing and treating influenza A in children and the elderly.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2007, issue 3); MEDLINE (1966 to July 2007) and EMBASE (1980 to July 2007).

SELECTION CRITERIA

Randomised or quasi-randomised trials comparing AMT and/or RMT in children and the elderly with placebo, control, other antivirals or comparing different doses or schedules of AMT and/or RMT or no intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and assessed methodological quality. Disagreements were resolved by consensus. In all comparisons except for one, the trials in children and in the elderly were analysed separately. Data were analysed and reported using Cochrane Review Manager 4.2. software.

MAIN RESULTS

In children, RMT was effective in the abatement of fever on day three of treatment. AMT showed a prophylactic effect against influenza A infection. AMT and RMT were not related to an increase in the occurrence of adverse effects. RMT also was considered to be well tolerated by the elderly, but showed no prophylactic effect. Different doses were comparable in the prophylaxis of influenza in the elderly, as well as in reporting adverse effects. Zanamivir prevented influenza A more effectively than RMT in the elderly.

AUTHORS' CONCLUSIONS

AMT was effective in the prophylaxis of influenza A in children. As confounding matters might have affected our findings, caution should be taken when considering which patients should to be given this prophylactic. Our conclusions about effectiveness of both antivirals for the treatment of influenza A in children were limited to a proven benefit of RMT in the abatement of fever on day three of treatment. Due to the small number of available studies we could not reach a definitive conclusion on the safety of AMT or the effectiveness of RMT in preventing influenza in children and the elderly.

Hydrophilic biodegradable microspheres of interferon-alpha and its pharmacokinetics in mice

The goal of this research was to prepare a kind of hydrophilic sustained release microspheres of interferon-alpha (IFN-alpha), alginate-chitosan microspheres (ACM) of IFN, and investigate its pharmacokinetics in mice. Alginate microspheres of IFN-alpha were first prepared by an emulsion method and further incubated in chitosan to form IFN-ACM. The influences of isopropanol, bovine serum albumin (BSA), and pH adjustment by isoelectric point of IFN were studied. The optimized IFN-ACM was obtained with smooth and round morphology, size of 2.18 +/- 0.43 microm and entrapment efficiency of 40%. All the concentrations of IFN-alpha were determined by IFN assay kits. Finally the pharmacokinetics of IFN-ACM suspension was studied in ICR mice by intramuscular (I.M.) routes. Compared with IFN solution, C(max) of IFN-ACM reduced 2.3-fold, and time to achievement of maximum serum concentrations (T(max)) increased 4-fold. Meanwhile the area under the concentration-time curve (AUC) was the same as that of solution. The concentration-time profiles presented the prolonged serum levels of IFN from IFN-ACM.

Postmarketing hepatic adverse event experience with PEGylated/non-PEGylated drugs: a disproportionality analysis

OBJECTIVE

To compare reporting frequencies of hepatic adverse events between PEGylated and non-PEGylated formulations of active medicinal compounds in spontaneous reporting systems using a data mining algorithm (DMA).

METHODS

Statistical DMAs are being promoted as a means of identifying drug-event combinations that are disproportionately reported in large spontaneous reporting systems databases, a critical data source for pharmacovigilance. After a review of case reports of hepatotoxicity with PEGylated drugs possibly associated with the polyethylene glycol moiety, we carried out a retrospective disproportionality analysis of WHO's multinational drug safety database for events related to hepatic dysfunction comparing PEGylated versus non-PEGylated formulations of four active moieties. A threshold of posterior interval (PI) 95% lower limit >0 was used to define a signal of disproportionate reporting with a drug and an event and 90% PIs of the information component were compared to identify statistical differences between the two compounds.

RESULTS

On the basis of a total of 18 477 cases containing at least one of the drug pairs, we found disproportionate reporting for hepatic-related events with both PEGylated and non-PEGylated formulations. Overlapping of 90% PIs of the information components, however, suggested that there was no statistically significant difference between the frequency of hepatic injury reported with PEGylated versus non-PEGylated drug formulations.

CONCLUSION

We did not find significant indicators of differential reporting of hepatic injury between PEGylated and non-PEGylated drug formulations in this exploratory analysis using one DMA. The analysis also suggests that comparative disproportionality methodology although not in itself determinative, could be one useful component of a risk management plan for monitoring the postmarketing experience of drug delivery systems that uses multiple methods and data streams.

Ribavirin with either standard or pegylated interferon to treat recurrent hepatitis C after liver transplantation

AIM

To investigate the efficacy of two anti-viral protocols in hepatitis C virus-reinfected liver transplant recipients.

METHODS

In this prospective study, 26 liver transplant patients were treated with standard interferon-alpha2b for 12 months or standard interferon-alpha2b for 3 months followed by pegylated interferon-alpha2b for 9 months. Interferon was combined with ribavirin in all patients. The histological course of the study population was compared with an untreated historic control group (n = 38) with similar baseline characteristics.

RESULTS

The sustained virological response rates in the standard interferon group and in the pegylated interferon group were 27.3% and 26.7%, respectively. Only 29% of patients with sustained virological response had end of treatment histological response, whereas 47% of viral non-responders showed end of treatment histological response. The percentage of patients with histological improvement was significantly higher in the study population when compared to the controls. Univariate analysis indicated that hepatitis C virus genotype non-1, high baseline alanine aminotransferase, the time interval between liver transplant and interferon therapy and the body mass index predicted sustained virological response. In the multivariate model, baseline alanine aminotransferase and the body mass index remained a significant predictor of sustained virological response.

CONCLUSIONS

Both treatment regimens offer similar efficacy profiles. Failure to eradicate hepatitis C virus should not lead to treatment discontinuation if serial liver biopsies demonstrate histological response.

Antibody against poly(ethylene glycol) adversely affects PEG-asparaginase therapy in acute lymphoblastic leukemia patients

BACKGROUND

Rapid clearance of poly(ethylene glycol)-asparaginase (PEG-ASNase) has been reported for up to one-third of patients treated for acute lymphoblastic leukemia (ALL), potentially rendering their treatment ineffective. A 25% occurrence of an antibody against PEG (anti-PEG) was previously reported in healthy blood donors. The objective of the study was to determine whether anti-PEG was associated with rapid clearance PEG-ASNase.

METHODS

The investigation reanalyzed stored sera from pediatric patients enrolled in the ALL Berlin-Frankfurt-Muenster 2000 studies. Twenty-eight samples were selected to include 15 subjects with undetectable ASNase activity after receiving PEG-ASNase. Sixteen subjects treated with unmodified ASNase were also included, 8 with low ASNase activity. Sera were tested for anti-PEG using 2 techniques: 1) serology, by agglutination of PEG-coated red blood cells; 2) flow cytometry, by analysis of 10 microm PEG beads stained for bound immunoglobulins. RESULTS. Of the 15 sera from PEG-ASNase-treated patients with undetectable ASNase activity, anti-PEG was detected in 9 by serology and in 12 by flow cytometry. Anti-PEG was detected in 1 PEG-ASNase-treated patient with lower ASNase activity (123 U/L). No relation was observed between anti-PEG and serum ASNase activity for patients treated with unmodified ASNase.

CONCLUSIONS

The presence of anti-PEG was very closely associated with rapid clearance of PEG-ASNase. Further comprehensive studies are warranted to fully elucidate the effect of anti-PEG on PEG-conjugated agents. Screening and monitoring for anti-PEG may allow identification of patients for whom a modified dosing strategy or use of a non-PEGylated drug would be appropriate.

Peginterferon-α2a in the treatment of chronic hepatitis C

Chronic hepatitis C virus infection occurs worldwide and affects over 2.7 million adults in North America. Current standard of care is the combination of pegylated (peg) interferon and ribavirin for 24 weeks in hepatitis C virus genotypes 2 or 3 and at least 48 weeks in chronic hepatitis C virus infection genotypes 1 or 4. Peginterferon-α2a is a 40-kDa linear pegylated molecule that alters the pharmacokinetic properties of unmodified interferon-α. In clinical trials evaluating the combination of peginterferon-α2a and ribavirin in chronic chronic hepatitis C virus infection, sustained virologic response rates have been achieved in 46–52% of patients with genotype 1 and 76–80% of patients with genotypes 2 or 3. Studies on the role of longer treatment duration and retreatment in prior nonresponders are in progress. The main toxicities of peginterferon-α2a are flu-like symptoms and neuropsychiatric disorders, especially depression and cytopenias, and are found in similar rates to those observed with regular inteferon. Future areas of study include the role of peginterferon-α2a in combination with the newer oral chronic hepatitis C virus infection active agents in development.

Long-acting interferon-alpha 2a modified with a trimer-structured polyethylene glycol: preparation, in vitro bioactivity, in vivo stability and pharmacokinetics

The proper selection of size and shape for polyethylene glycol (PEG) is one of the most important points in PEGylation technology. Therefore, PEGs of various sizes and shapes have been widely developed to endow specific properties. In this study, a unique, trimer-structured, 43 kDa PEG was conjugated to interferon-alpha 2a (IFN) by forming an amide bond to improve the pharmacokinetic properties and minimize the loss of IFN bioactivity. Mono-PEGylated IFN (PEG(3)-IFN) prepared by utilizing this unique PEG was purified and characterized by cation-exchange chromatography and MALDI-TOF mass spectrometry. The in vitro bioactivity, in vivo stability, and pharmacokinetics of PEG(3)-IFN were examined and compared to those of native IFN. PEG(3)-IFN exhibited comparable in vitro bioactivities to native IFN and an excellent stability of the conjugation linkage in rat serum and various organs following subcutaneous injection. Furthermore, it showed slow absorption and markedly reduced clearance in rats, thereby increasing the biological half-life by about 40-fold compared to that of native IFN. This is the first report on the application of unique, trimer-structured PEG to bioactive proteins. The results suggest that unique, trimer-structured 43 kDa PEG can provide some advantages to improve the pharmacokinetic properties and to maintain the bioactivity of therapeutic proteins in clinical use.

Vitiligo associated with pegylated interferon and ribavirin treatment of patients with chronic hepatitis C: a case report

The use of pegylated interferon (PEG-IFN) and ribavirin is considered standard therapy for patients with chronic hepatitis C. Many adverse effects of IFN appear to be of autoimmune origin. Vitiligo is a hypomelanotic disease, whose cause, despite many investigations, remains unknown, although some evidence points to an autoimmune pathogenesis. This report describes a case of vitiligo that occurred during the third month of treatment with PEG-IFN and ribavirin. The sustained virologic response was the result of a 52-week regimen; however, hypomelanotic cutaneous patches persisted. Autoimmune adverse effects of IFN therapy, which may include vitiligo, should be carefully monitored. The decision about whether to discontinue treatment should be discussed with the patient, who must be informed that the lesions may persist.

Hepatitis B and C viruses in infants and young children

Advances during the past 20 years have led to a better understanding of the prevention, diagnosis, and treatment of acute and chronic hepatitis B (HBV) and hepatitis C (HCV) infections in the pediatric population. Universal vaccination and prenatal testing for HBV have decreased the incidence rate of acute HBV infections from more than 3/100,000 to 0.34/100,000 in all children. Diagnosis of chronic HBV is confirmed with positive serologic testing on two occasions at least 6 months apart. Current approved therapies with interferon alpha and lamivudine for children with chronic HBV infection have shown some efficacy, but results have been variable. In contrast, the lack of an effective HCV vaccine and the risk of mother-to-child transmission may increase the number of children with vertically acquired HCV that ultimately go on to develop liver fibrosis or cirrhosis. Diagnosis of HCV in the neonate should be postponed until after the child reaches 1 year of age because infants may have transient viremia. Treatment for HCV infected children has not been studied extensively. Peginterferon alpha-2a and Ribavirin are not currently approved for pediatric use; however, recent studies in children have shown potential benefit. More effective and less toxic therapies for young patients with HBV and HCV are needed, as are methods to interrupt perinatal transmission of HBV and HCV.

Chronic hepatitis C virus infection in older adults

Most of the older adults with chronic hepatitis C virus infection acquired the disease earlier in life. These patients often present with complications of liver disease, mainly cirrhosis and hepatocellular carcinoma. The burden of chronic hepatitis C virus infection in elderly persons is expected to increase significantly in the United States during the next 2 decades. It seems important that, for elderly patients with chronic hepatitis C, the risk-benefit of combination antiviral therapy consisting of pegylated interferon and ribavirin should be assessed on an individual basis. Assessment should be performed in all cases before considering treatment, and it should include evaluation of the degree of liver fibrosis by means of liver biopsy or, possibly, by means of noninvasive methods. Novel antiviral drugs that may have fewer adverse effects, such as protease inhibitors, may serve as potential alternatives. It is recommended that elderly patients (up to the age of 75 years) be included in randomized trials of chronic hepatitis C virus infection treatment.

Innate immunity for biodefense: a strategy whose time has come

Defense against biothreat agents requires a broad-spectrum approach. Modulation of the innate immune system might fulfill this requirement. Hackett's previous review of innate immune activation as a broad-spectrum biodefense strategy identified several unresolved questions. The current article is a systematic approach to answering those questions with the focused participation of research groups developing this technology. Our team of academic and industry participants reviewed the promising agents and came to the following conclusions. It is feasible to construct a biodefense platform combining synergistic agents that activate the innate immune system against a broad range of pathogens on the basis of conserved microbial components by using a nasal spray for immune activation in the respiratory and gastrointestinal tracts because these are the most likely routes of attack. It might also be possible to include agents that inhibit molecular events leading to septic shock. Innate immune-activating agents designed to activate Toll-like and other receptors will probably provide protection against the biothreat pathogen spectrum for periods ranging from 2 to 14 days for IFNs up to 26 weeks for immunomodulatory oligonucleotides. Initial treatment is proposed on the first index case or biosensor alert. Boost doses would be required. Harmful inflammation is possible, but thus far, only transient fever has been observed. Autoimmune reaction and retroviral activation have not been seen thus far in preclinical and human trials of many of these compounds. Toll-like receptor agonists caused cytokine production in all subjects tested, but genetic polymorphism reduced the response to IFN in African American subjects.

Novel type I interferon IL-28A suppresses hepatitis C viral RNA replication

Interferon alpha (IFN-alpha)-based therapy is the currently approved treatment for chronic hepatitis C viral infection. The sustained antiviral response rate is approximately 50% for genotype-1 infection. The major challenge to the HCV community is to improve antiviral efficacy and to reduce the side effects typically seen in IFNalpha-based therapy. One of the strategies is to identify new interferons, which may have better efficacy and less undesirable side effects. In this report, we examined the role of IL-28A (IFN lambda2), a novel type I IFN, in suppression of human hepatitis C viral RNA replication. We have cloned both the human genomic DNA and cDNA of IL-28A, and evaluated their biological activity using HCV RNA replicon cell culture system. The results show that IL-28A effectively inhibits HCV subgenomic RNA replication in a dose-dependent manner. Treatment of human hepatoma cells with IL-28A activates the JAK-STAT signaling pathway and induces the expression of some interferon-stimulated genes (ISGs), such as 6-16 and 1-8U. We also demonstrate that IL-28A induces expression of HLA class I antigens in human hepatoma cells. Moreover, IL-28A appears to specifically suppress HCV IRES-mediated translation. Although IL-28A receptor shares one subunit with the IL-10 receptor, IL-10 treatment has no detectable effect on IL-28A-induced antiviral activity. Interestingly, IL-28A can synergistically enhance IFNalpha antiviral efficacy. Our results suggest that IL-28A antiviral activity is associated with the activation of the JAK-STAT signaling pathway and expression of ISGs. The effectiveness of IL-28A antiviral activity and its synergistic effect on IFN-alpha indicate that IL-28A may be potentially used to treat HCV chronic infection.

Protein drug stability: a formulation challenge

The increasing use of recombinantly expressed therapeutic proteins in the pharmaceutical industry has highlighted issues such as their stability during long-term storage and means of efficacious delivery that avoid adverse immunogenic side effects. Controlled chemical modifications, such as substitutions, acylation and PEGylation, have fulfilled some but not all of their promises, while hydrogels and lipid-based formulations could well be developed into generic delivery systems. Strategies to curb the aggregation and misfolding of proteins during storage are likely to benefit from the recent surge of interest in protein fibrillation. This might in turn lead to generally accepted guidelines and tests to avoid unforeseen adverse effects in drug delivery.