Safety of peginterferon in the treatment of chronic hepatitis C

Interferon α subtypes in HIV infection

Type I interferons (IFN), which are immediately induced after most virus infections, are central for direct antiviral immunity and link innate and adaptive immune responses. However, several viruses have evolved strategies to evade the IFN response by preventing IFN induction or blocking IFN signaling pathways. Thus, therapeutic application of exogenous type I IFN or agonists inducing type I IFN responses are a considerable option for future immunotherapies against chronic viral infections. An important part of the type I IFN family are 12 IFNα subtypes, which all bind the same receptor, but significantly differ in their biological activities. Up to date only one IFNα subtype (IFNα2) is being used in clinical treatment against chronic virus infections, however its therapeutic success rate is rather limited, especially during Human Immunodeficiency Virus (HIV) infection. Recent studies addressed the important question if other IFNα subtypes would be more potent against retroviral infections in in vitro and in vivo experiments. Indeed, very potent IFNα subtypes were defined and their antiviral and immunomodulatory properties were characterized. In this review we summarize the recent findings on the role of individual IFNα subtypes during HIV and Simian Immunodeficiency Virus infection. This includes their induction during HIV/SIV infection, their antiretroviral activity and the regulation of immune response against HIV by different IFNα subtypes. The findings might facilitate novel strategies for HIV cure or functional cure studies.

Project P.E.A.C.H. (Pathway and Education Toward Adherence and Completion in Hepatitis C Therapy): A Nurse-Driven Evidence-Based Protocol

Chronic hepatitis C virus (HCV) remains a major healthcare concern. The 24-48 week treatment of pegylated interferon and ribavirin therapy requires a tremendous amount of commitment from patients and providers. Thus, there has been a huge focus on health-related quality of life and various measures to support patient adherence and completion of the recommended HCV treatment regimen. This quality improvement project aimed to develop and test a nurse-driven evidence-based pathway that supports the care of patients receiving hepatitis C medication therapy in a tertiary, academic hepatology practice. All adult patients, 18 years and older, who were started on HCV treatment from January 20 to February 15, 2011, were included in the testing of a nurse-driven HCV pathway for the first 12 weeks of treatment. The majority of the patients treated were male (71.8% prepathway and 83.3% postpathway), of White ethnic background (61.5% prepathway and 58.3% postpathway), genotype 1 (69% prepathway and 91.7% postpathway), and had comorbid conditions classified as "other" (38.5% prepathway and 33.3% postpathway). As for treatment status, the majority of the patients were "treatment naive" in prepathway or had never received prior HCV treatment (59.0%) or "had recurrent HCV after liver transplantation" (41.7%). The 4-week treatment completion rate was 94.9% for the prepathway group and 100.0% for the postpathway group; 12-week completion rate was 87.2% (prepathway) and 58.3% for the postpathway group. The mean 4-week adherence score for the prepathway group was 2.46 and the postpathway group was 2.92. Mean lag time to treatment was decreased with 26 days in the postpathway and 43 in the prepathway. Providers and nurses expressed overall satisfaction with the nurse-driven pathway.

Cutaneous Granulomas Associated With Interferon Therapy

Treatment with interferon (IFN) could be associated with variable cutaneous adverse reactions. The aim of this study was to describe the clinicopathological spectrum of cutaneous granulomas associated with IFN therapy and identify the causal relation between IFN therapy and granulomatous reactions. The study included 18 patients (16 males and 2 females) with an average age of 48 years. Clinically, most of the lesions were solitary (83.3%) and located on the face (44.4%) and/or trunk (38.9%). The lesions were commonly presented as nodules (33.3%) or plaques (27.8%) with a common size of 5-10 cm. Granulomatous reactions were localized to the injection site in 4 cases, distributed on other body areas (remote granuloma) in 11 cases, and associated with lung involvement (systemic granuloma) in 3 cases. Histologically, injection site granuloma showed suppurative reaction in 75% and sarcoidal reaction in 25%. Remote granuloma showed tuberculoid reaction in 27.3%, interstitial in 27.3%, and sarcoidal in 45.4%. Systemic granuloma showed sarcoidal reaction in all cases. After withdrawal of IFN, only 3 lesions showed spontaneous complete clearance, whereas most of the lesions (83.3%) showed only partial improvement. Our results suggested that IFN is not a causal agent of all associated cutaneous granulomas but it mostly provokes the appearance of granulomatous reactions in susceptible individuals. Findings that prove this concept include the formation of granuloma in body sites away from the injection site, the heterogeneous pattern of granuloma both clinically and histologically, and incomplete clearance of most of the lesions after withdrawal of IFN.

Design and synthesis of an activity-based protein profiling probe derived from cinnamic hydroxamic acid

In our continued effort to discover new anti-hepatitis C virus (HCV) agents, we validated the anti-replicon activity of compound 1, a potent and selective anti-HCV hydroxamic acid recently reported by us. Generally favorable physicochemical and in vitro absorption, distribution, metabolism, and excretion (ADME) properties exhibited by 1 made it an ideal parent compound from which activity-based protein profiling (ABPP) probe 3 was designed and synthesized. Evaluation of probe 3 revealed that it possessed necessary anti-HCV activity and selectivity. Therefore, we have successfully obtained compound 3 as a suitable ABPP probe to identify potential molecular targets of compound 1. Probe 3 and its improved analogs are expected to join a growing list of ABPP probes that have made important contributions to not only the studies of biochemical and cellular functions but also discovery of selective inhibitors of protein targets.

Interferon therapy in hepatitis C leading to chronic type 1 diabetes

AIM: To review the prevalence, clinical data and course of interferon- associated type 1 diabetes in chronic hepatitis C virus (HCV) infection.

METHODS: Search of all interferon (INF)-related type 1 diabetes mellitus (T1DM) cases published in the English literature from 1992 to December 2013 according to the key words: chronic hepatitis C infection, diabetes mellitus type 1, insulin dependent diabetes mellitus, and interferon treatment. We found 107 cases and analyzed their clinical and laboratory data and long-term follow-up. Due to the predominance of cases described in Japanese literature, we analyzed separately cases of Caucasian and Japanese origin. In addition we describe a representative case with HCV who developed INF-related T1DM.

RESULTS: Our data show that INF treatment increases the risk of developing T1DM by 10-18 fold compared with the corresponding general population and the median age of onset was 43 years (range: 24-66 years) in Caucasians and 52 years (range: 45-63 years) in Japanese. Most patients developed T1DM during INF treatment, after a median time-period of 4.2 and 5.7 mo in Caucasian and Japanese groups, respectively. The clinical course was characterized by a fulminant course with abrupt severe hyperglycemia or ketoacidosis, a high titer of anti-islet autoantibodies and almost all patients (105/107) permanently required insulin therapy with a follow-up of up to 4 years. A substantial number of patients had evidence for other autoimmune disorders mainly thyroid diseases (25% and 31% in Caucasian and Japanese groups, respectively).

CONCLUSION: INF-associated T1DM in HCV has a fulminant course, often associated with other autoimmune diseases, and results almost inevitably in permanent insulin therapy requirement.

Adherence and completion in hepatitis C management: a systematic review

The complexity and challenge of Hepatitis C virus (HCV) medication therapy call for a comprehensive and integrated approach in management. This article includes an appraisal of the current state of the science in HCV management and the various models that support treatment completion and adherence. The patient undergoing HCV therapy may experience a wide range of symptoms such as anemia, depression, fatigue, and flu-like symptoms. These can constantly confront the patient's adherence and compliance with treatment. The article includes an analysis of the strengths, weaknesses, and limitations of the evidence. Future directions in research were also identified.

C-6 aryl substituted 4-quinolone-3-carboxylic acids as inhibitors of hepatitis C virus

Quinolone-3-carboxylic acid represents a highly privileged chemotype in medicinal chemistry and has been extensively explored as antibiotics and antivirals targeting human immunodeficiency virus (HIV) integrase (IN). Herein we describe the synthesis and anti-hepatitis C virus (HCV) profile of a series of C-6 aryl substituted 4-quinlone-3-carboxylic acid analogues. Significant inhibition was observed with a few analogues at low micromolar range against HCV replicon in cell culture and a reduction in replicon RNA was confirmed through an RT-qPCR assay. Interestingly, evaluation of analogues as inhibitors of NS5B in a biochemical assay yielded only modest inhibitory activities, suggesting that a different mechanism of action could operate in cell culture.

The design, synthesis and biological evaluations of C-6 or C-7 substituted 2-hydroxyisoquinoline-1,3-diones as inhibitors of hepatitis C virus

C7-Substituted 2-hydroxyisoquinoline-1,3-diones inhibit the strand transfer of HIV integrase (IN) and the reverse-transcriptase-associated ribonuclease H (RNH). Hepatitis C virus (HCV) NS5B polymerase shares a similar active site fold to RNH and IN, suggesting that N-hydroxyimides could be useful inhibitor scaffolds of HCV via targeting the NS5B. Herein we describe the design, chemical synthesis, replicon and biochemical assays, and molecular docking of C-6 or C-7 aryl substituted 2-hydroxyisoquinoline-1,3-diones as novel HCV inhibitors. The synthesis involved an improved and clean cyclization method, which allowed the convenient preparation of various analogs. Biological studies revealed that the C-6 analogs, a previously unknown chemotype, consistently inhibit both HCV replicon and recombinant NS5B at low micromolar range. Molecular modeling studies suggest that these inhibitors may bind to the NS5B active site.

Structural variants of IFNα preferentially promote antiviral functions

IFNα, a cytokine with multiple functions in innate and adaptive immunity and a potent inhibitor of HIV, exerts antiviral activity, in part, by enhancing apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3 (APOBEC3) family members. Although IFNα therapy is associated with reduced viral burden, this cytokine also mediates immune dysfunction and toxicities. Through detailed mapping of IFNα receptor binding sites, we generated IFNα hybrids and mutants and determined that structural changes in the C-helix alter the ability of IFN to limit retroviral activity. Selective IFNα constructs differentially block HIV replication and their directional magnitude of inhibition correlates with APOBEC3 levels. Importantly, certain mutants exhibited reduced toxicity as reflected by induced indoleamine 2,3-dioxygenase (IDO), suggesting discreet and shared intracellular signaling pathways. Defining IFN structure and function relative to APOBEC and other antiviral genes may enable design of novel IFN-related molecules preserving beneficial antiviral roles while minimizing negative effects.

Pegylated interferons for the treatment of chronic hepatitis C: pharmacological and clinical differences between peginterferon-alpha-2a and peginterferon-alpha-2b

Chronic infection with hepatitis C virus (HCV) is a major healthcare problem, affecting an estimated 170 million people worldwide. Interferon-alpha has formed the basis of treatment regimens since the identification of HCV, either alone or in conjunction with the nucleoside analogue ribavirin. The relatively recent introduction of pegylated forms of interferon-alpha, with greater stability and in vivo activity, has substantially improved sustained virological response (SVR) rates compared with unmodified interferon-alpha, with SVR rates of 35-66% when used in conjunction with ribavirin in randomized controlled trials. Two pegylated interferon (peginterferon)-alpha molecules are commercially available for the treatment of chronic hepatitis C, and these differ in the size and nature of the covalently attached polyethylene glycol (PEG) moiety, with resulting differences in pharmacokinetics and in dosing regimens. Peginterferon-alpha-2b has a linear 12 kDa PEG chain covalently attached primarily to histidine-34 of interferon-alpha-2b via an unstable urethane bond that is subject to hydrolysis once injected, releasing native interferon-alpha-2b. The branched, 40 kDa PEG chain of peginterferon-alpha-2a is covalently attached via stable amide bonds to lysine residues of interferon-alpha-2a, and circulates as an intact molecule. Consequently, peginterferon-alpha-2a has a very restricted volume of distribution, longer half-life and reduced clearance compared with native interferon-alpha-2a, and can be given once weekly independently of bodyweight. Peginterferon-alpha-2b has a shorter half-life in serum than peginterferon-alpha-2a and requires bodyweight-based dosing. The majority of head-to-head randomized controlled trials, including the large, randomized IDEAL (Individualized Dosing Efficacy versus Flat Dosing to Assess Optimal Pegylated Interferon Therapy) trial (n = 3070), demonstrated similar SVR rates for peginterferon-alpha-2a and peginterferon-alpha-2b (41% vs 39% in IDEAL), in combination with ribavirin; however, two randomized controlled trials (n = 431 and 320) demonstrated a statistically significant benefit for peginterferon-alpha-2a (66% vs 54%, and 69% vs 54%). Furthermore, two large retrospective studies and one prospective observational study in real-life settings have shown a significant benefit for peginterferon-alpha-2a versus peginterferon-alpha-2b, although SVR rates were generally lower than those seen in controlled trials. The use of interferon-alpha with or without ribavirin is frequently associated with a range of adverse effects, including influenza-like symptoms, haematological changes and neuropsychiatric disturbances, and this is true also of the peginterferons, with similar levels of adverse events, dose reduction and discontinuation from treatment. Peginterferon-alpha-2a and peginterferon-alpha-2b appear from comparative studies to be similarly tolerated, with few differences of clinical significance noted. Peginterferon plus ribavirin, as the standard of care for patients with chronic hepatitis C, may in the future form the basis of improved treatment regimens that include new, targeted anti-HCV agents to increase SVR rates even further.