Engineering interferons and interleukins for cancer immunotherapy.

Cytokines are a class of potent immunoregulatory proteins that are secreted in response to various stimuli and act locally to regulate many aspects of human physiology and disease. Cytokines play important roles in cancer initiation, progression, and elimination, and thus, there is a long clinical history associated with the use of recombinant cytokines to treat cancer. However, the use of cytokines as therapeutics has been limited by cytokine pleiotropy, complex biology, poor drug-like properties, and severe dose-limiting toxicities. Nevertheless, cytokines are crucial mediators of innate and adaptive antitumor immunity and have the potential to enhance immunotherapeutic approaches to treat cancer. Development of immune checkpoint inhibitors and combination immunotherapies has reinvigorated interest in cytokines as therapeutics, and a variety of engineering approaches are emerging to improve the safety and effectiveness of cytokine immunotherapy. In this review we highlight recent advances in cytokine biology and engineering for cancer immunotherapy.

B-Cell Therapies in Multiple Sclerosis.

B cells play a vital function in multiple sclerosis (MS) pathogenesis through an array of effector functions. All currently approved MS disease-modifying therapies alter the frequency, phenotype, or homing of B cells in one way or another. The importance of this mechanism of action has been reinforced with the successful development and clinical testing of B-cell-depleting monoclonal antibodies that target the CD20 surface antigen. Ocrelizumab, a humanized anti-CD20 monoclonal antibody, was approved by the Food and Drug Administration (FDA) in March 2017 after pivotal trials showed dramatic reductions in inflammatory disease activity in relapsing MS as well as lessening of disability progression in primary progressive MS. These and other clinical studies place B cells at the center of the inflammatory cascade in MS and provide a launching point for development of therapies that target selective pathogenic B-cell populations.

Distribution of therapeutic proteins into thoracic lymph after intravenous administration is protein size-dependent and primarily occurs within the liver and mesentery.

Therapeutic proteins can facilitate the targeting and treatment of lymphatic diseases (such as cancer metastases, infections and inflammatory diseases) since they are cleared via the lymphatics following interstitial (SC or IM) administration. However, therapeutic proteins are often administered intravenously (IV). Recently therapeutic proteins have been found to access the thoracic lymph in surprisingly high quantities after IV administration. The aim of this study was to determine, for the first time, the major sites of thoracic lymph access of therapeutic proteins, and the protein properties that enhance lymph access, after IV administration. In order to achieve this, novel methods were developed or optimized to collect hepatic, mesenteric or thoracic lymph from male SD rats. Four different sized PEGylated or non-PEGylated therapeutic proteins (native interferon α2b (IFN, 19kDa), PEGylated interferon α2b (IFN-PEG12, 31kDa), PEGylated interferon α2a (IFN-PEG40, 60kDa) or trastuzumab (150kDa)) were then administered via short IV infusion, and plasma and lymph concentrations of the proteins determined via ELISA. The recovery of the therapeutic proteins in the thoracic lymph duct, which collects lymph from most of the body, was significantly greater for trastuzumab, IFN-PEG40 and IFN-PEG12 (all >3% dose over 8h) when compared to native IFN (0.9% dose). Conversely, the thoracic lymph/plasma (L/P) concentration ratio and thus efficiency of extravasation and transport through the interstitium to lymph was highest for the smaller proteins IFN and IFN-PEG12 (at 90-100% vs 15-30% for trastuzumab and IFN-PEG40). The lower total recovery of IFN and IFN-PEG12 in thoracic lymph reflected more rapid systemic clearance and thus lower systemic exposure. For all therapeutic proteins, the majority (>80%) of lymph access occurred via the hepatic and mesenteric lymphatics. This lymphatic distribution pattern was supported by quantitative imaging of the lymph node distribution of IV administered Cy5 labelled trastuzumab. Optimizing the properties of IV administered therapeutic proteins represents a viable approach to better target and treat pathological states involving the lymphatics, particularly in the liver and mesentery. This includes cancer metastases, infections and inflammatory diseases. Successful development of the novel technique to collect hepatic lymph will also enable future work to evaluate tissue-specific lymph transport in health and disease.

Macrocyclization of Interferon-Poly(α-amino acid) Conjugates Significantly Improves the Tumor Retention, Penetration, and Antitumor Efficacy.

Cyclization and polymer conjugation are two commonly used approaches for enhancing the pharmacological properties of protein drugs. However, cyclization of parental proteins often only affords a modest improvement in biochemical or cell-based in vitro assays. Moreover, very few studies have included a systematic pharmacological evaluation of cyclized protein-based therapeutics in live animals. On the other hand, polymer-conjugated proteins have longer circulation half-lives but usually show poor tumor penetration and suboptimal pharmacodynamics due to increased steric hindrance. We herein report the generation of a head-to-tail interferon-poly(α-amino acid) macrocycle conjugate circ-P(EG3Glu)20-IFN by combining the aforementioned two approaches. We then compared the antitumor pharmacological activity of this macrocycle conjugate against its linear counterparts, N-P(EG3Glu)20-IFN, C-IFN-P(EG3Glu)20, and C-IFN-PEG. Our results found circ-P(EG3Glu)20-IFN to show considerably greater stability, binding affinity, and in vitro antiproliferative activity toward OVCAR3 cells than the three linear conjugates. More importantly, circ-P(EG3Glu)20-IFN exhibited longer circulation half-life, remarkably higher tumor retention, and deeper tumor penetration in vivo. As a result, administration of the macrocyclic conjugate could effectively inhibit tumor progression and extend survival in mice bearing established xenograft human OVCAR3 or SKOV3 tumors without causing severe paraneoplastic syndromes. Taken together, our study provided until now the most relevant experimental evidence in strong support of the in vivo benefit of macrocyclization of protein-polymer conjugates and for its application in next-generation therapeutics.

Tissue and time specific expression pattern of interferon regulated genes in the chicken.

BACKGROUND: Type I interferons are major players against viral infections and mediate their function by the induction of Interferon regulated genes (IRGs). Recently, it became obvious that these cytokines have a multitude of additional functions. Due to the unique features of the chickens' immune system, available data from mouse models are not easily transferable; hence we performed an extensive analysis of chicken IRGs. RESULTS: A broad database search for homologues to described mammalian IRGs (common IRGs, cIRGs) was combined with a transcriptome analysis of spleen and lung at different time points after application of IFNα. To apply physiological amounts of IFN, half-life of IFN in the chicken was determined. Interestingly, the calculated 36 min are considerably shorter than the ones obtained for human and mouse. Microarray analysis revealed many additional IRGs (newly identified IRGs; nIRGs) and network analysis for selected IRGs showed a broad interaction of nIRGs among each other and with cIRGs. We found that IRGs exhibit a highly tissue and time specific expression pattern as expression quality and quantity differed strongly between spleen and lung and over time. While in the spleen for many affected genes changes in RNA abundance peaked already after 3 h, an increasing or plateau-like regulation after 3, 6 and 9 h was observed in the lung. CONCLUSIONS: The induction or suppression of IRGs in chickens is both tissue and time specific and beside known antiviral mechanisms type I IFN induces many additional cellular functions. We confirmed many known IRGs and established a multitude of so far undescribed ones, thus providing a large database for future research on antiviral mechanisms and additional IFN functions in non-mammalian species.

PEGylated interferon displays differences in plasma clearance and bioavailability between male and female mice and between female immunocompetent C57Bl/6J and athymic nude mice.

Gender and immune status can considerably impact on the pharmacokinetics (PK) of macromolecular and small molecule drugs. However, these effects are often not considered in drug development. We aimed to quantitatively evaluate effects of gender and immune status on the PK of PEGylated interferon in frequently used murine models. Chronically cannulated female athymic nude and female and male immunocompetent C57Bl/6J mice (n = 24 in total) received a single intravenous or subcutaneous (s.c.) dose of PEGylated interferon. Serial blood samples were taken for 48 h. Noncompartmental analysis and population PK modeling with covariate analysis were performed to evaluate the data. The PK of PEGylated interferon followed a three compartment disposition model with two sequential compartments for s.c. absorption. Female nude mice had significantly higher plasma clearance than C57Bl/6J mice (0.503 vs. 0.397 mL/h). Male mice had a slower absorption rate constant (0.138 h(-1)) and extent (46.2%) of s.c. absorption than female mice (0.274 in C57Bl/6J and 0.374 h(-1) in nude, 60.8% in both). Thus, gender and immune status significantly impacted on important PK parameters of PEGylated interferon in murine models commonly utilized in drug development. It is critical to take into account these differences when choosing animal models and conducting translational pharmacology research.

Ledipasvir-sofosbuvir: interferon-/ribavirin-free regimen for chronic hepatitis C virus infection.

OBJECTIVES: To review the pharmacology, efficacy, and safety of ledipasvir-sofosbuvir for the treatment of chronic hepatitis C virus (HCV). DATA SOURCES: A literature search through clinicaltrials.gov, EMBASE, and PubMed was conducted (January 1966 to October 2014) using the terms ledipasvir, sofosbuvir, GS-5885, and GS-7977. References from retrieved articles and abstracts presented at recent meetings were reviewed for any additional material. The prescribing information was also reviewed. STUDY SELECTION/DATA EXTRACTION: Phase 1, 2, and 3 human and animal studies describing the pharmacology, pharmacokinetics, efficacy, and safety of ledipasvir and sofosbuvir for HCV were identified. DATA SYNTHESIS: Ledipasvir-sofosbuvir, a fixed-dose combination (FDC) tablet inhibiting nonstructural (NS) 5A and 5B proteins, without peginterferon and ribavirin is indicated for adult patients with genotype 1 HCV infection who are treatment naïve or experienced, with or without cirrhosis. Pivotal trials (n = 1952) have demonstrated that once-daily administration of ledipasvir-sofosbuvir for 12 or 24 weeks is effective at achieving sustained virological response (SVR) rates (94%-99%) in treatment-naïve patients (12 weeks), treatment-experienced patients without cirrhosis (12 weeks), and treatment-experienced patients with cirrhosis (24 weeks). Treatment-naïve patients without cirrhosis and baseline viral levels of less than 6 million IU/mL may be considered for 8 weeks of treatment. The most common adverse drug events (ADEs) associated with ledipasvir-sofosbuvir include headache, fatigue, insomnia, nausea, and diarrhea. CONCLUSIONS: Ledipasvir-sofosbuvir is the first interferon- and ribavirin-free FDC agent that has SVR rates much greater than 94%, with minimal ADEs, for the treatment of chronic HCV genotype 1 in naïve and treatment-experienced patients.

PEGylated recombinant human interferon-ω as a long-acting antiviral agent: structure, antiviral activity and pharmacokinetics.

Recombinant human interferon-ω (rhIFN-ω) exhibits a potent antiviral activity. Because of poor pharmacokinetics (PK) of rhIFN-ω, frequent dosing of rhIFN-ω is necessitated to achieve the sustained antiviral efficacy. PEGylation can efficiently improve the PK of rhIFN-ω while substantially decrease its bioactivity. The structure, antiviral activity and PK of the PEGylated rhIFN-ω were measured to establish their relationship with PEGylation sites, polyethylene glycol (PEG) mass and PEG structure. Accordingly, N-terminus and the lysine residues were selected as the PEGylation sites. PEGs with Mw of 20kDa and 40kDa were used to investigate the effect of PEG mass. Linear and branched PEGs were used to investigate the effect of PEG structure. PEGylation decreased the antiviral activity of rhIFN-ω and improved its PK. The PEGylation sites determine the bioactivity of the PEGylated rhIFN-ω and the conjugated PEG mass determines the PK. N-terminally PEGylated rhIFN-ω with 40kDa linear PEG maintains 21.7% of the rhIFN-ω antiviral activity with a half-life of 139.6h. Thus, N-terminally PEGylated rhIFN-ω with linear 40kDa PEG is a potential antiviral agent for long-acting treatment of the viral diseases.

What the infectious disease physician needs to know about pegylated interferon and ribavirin.

The treatment of chronic hepatitis C is rapidly evolving from triple therapy to regimens that do not require interferon or even ribavirin. However, pegylated interferon and ribavirin will remain the backbone of hepatitis C therapy for the time being. This review summarizes the pharmacokinetics of peginterferon and ribavirin with a particular emphasis on their side-effect profile and management. Finally, the continued role of peginterferon and ribavirin in future therapies will be discussed.

Metal ions guided self-assembly of therapeutic proteins for controllable release: from random to ordered aggregation.

PURPOSE: To make a comparative study on sustained delivery performance of rhIFN with random amorphous and spherical crystal-like ordered self-assemblies. METHODS: The rhIFN self-assemblies were identified in batch crystallization mode. Physico-chemical characteristics were compared, including morphology, XRD, FTIR, CD, biological potency, the dissolution behaviors in vitro and plasma pharmacokinetics in vivo. Moreover, molecular simulation was performed to better understand their binding site and mode. RESULTS: Here, we suggest that random amorphous and spherical ordered self-assemblies allow for long action without new molecular entities generation or carriers employed. By manipulating supersaturation, the ordered aggregates were self-organized at high concentration of Zn(II) (>100 mM) in pH 5.5-6.0, which was the first time that spherical semi-crystals of rhIFN can act as a depot source for the sustained delivery of biologically active proteins. The secondary structure and biological potency of rhIFN were unchanged after aggregation. Compared with that of the native rhIFN, both self-assemblies exhibited slower absorption and extended elimination profiles after s.c. administration, which were characterized as 4.75 ± 0.82 h and 10.58 ± 1.86 h of terminal half-life for random amorphous and spherical ordered self-assemblies, respectively. CONCLUSIONS: The work described here demonstrates the possibility of self-assemblies of biomacromolecules for controllable release application of therapeutic proteins.

Pharmacology and therapeutic potential of interferons.

Interferon (IFN) is widely recognised to be an integral part of the innate immune response to viral infection. Since its initial discovery in 1957 by Isaacs and Lindenmann, various IFN sub-types have been identified and there are now three distinct classes recognised-Type I (IFN-α and IFN-ß), Type II (IFN-γ) and Type III (IFN-λ), distinguished by their differing receptors. As well as displaying profound antiviral activity in vivo, IFN has anti-proliferative, cytotoxic and anti-tumoural roles. In an attempt to harness their immunomodulatory potential, investigators and clinicians have investigated the use of IFNs for the treatment of human diseases with considerable success. For example, IFN-α preparations are now a critical component in the treatment of chronic Hepatitis C infection and IFN-ß therapy is now the first line treatment for relapsing remitting multiple sclerosis. However, IFN therapy is also associated with significant morbidity and in some patients is poorly tolerated. In this review, we explore the scientific basis for IFN therapy and outline its therapeutic scope. We describe the commonly encountered side effects and attempt to explain the less well recognised pulmonary complications including emerging evidence of life threatening and irreversible pulmonary vascular pathology. Finally, we look to the future of interferon drug treatment, examining the potential for emerging therapies.

Mathematical modeling of HCV infection and treatment.

In the last decade, viral kinetic modeling has played an important role in the analysis of HCV RNA decay after the initiation of antiviral therapy. Models have provided a means of evaluating the antiviral effectiveness of therapy and of estimating parameters, such as the rate of virion clearance and the rate of loss of HCV-infected cells, and they have suggested mechanisms of action for both interferon-alpha and ribavirin. The inclusion of homeostatic proliferation of infected and uninfected hepatocytes in existing viral kinetic models has allowed prediction of most observed HCV RNA profiles under treatment, for example, biphasic and triphasic viral decay and viral rebound to baseline values after the cessation of therapy. In addition, new kinetic models have taken into consideration the different pharmacokinetics of standard and pegylated forms of interferon and have incorporated alanine aminotransferase kinetics and aspects of immune responses to provide a more comprehensive picture of the biology underlying changes in HCV RNA during therapy. Here, we describe our current understanding of the kinetics of HCV infection and treatment.

Establishment of antihuman IFN-alpha8-specific monoclonal antibodies and their application in the enzyme-linked immunosorbent assay (ELISA).

In the present study, we describe the generation of a series of anti-interferon-alpha8 (IFN-alpha8)-specific monoclonal antibodies (mAbs), their characterization, and the establishment of a sandwich enzyme-linked immunosorbent assay (ELISA) system for human IFN-alpha8. The sandwich ELISA system is highly sensitive to human natural IFN-alpha8 (nIFN-alpha8), with a minimum detection limit of 50 pg/mL, which did not cross-react with the other IFN preparations and several cytokines tested. Using this ELISA system, pharmacokinetic properties of an IFN-alpha preparation administered in mice were examined. We found that IFN-alpha8 has higher vascular permeability and stability than IFN-alpha2 in the circulation. These results suggest that this ELISA would be very useful for determination of IFN-alpha8 protein concentrations in various experimental samples and also of pharmacokinetic properties of IFN-alpha preparations in human.

Novel controlled-release Lemna-derived IFN-alpha2b (Locteron): pharmacokinetics, pharmacodynamics, and tolerability in a phase I clinical trial.

Locteron, a newly developed controlled-release formulation of Lemna-derived free (unpegylated) recombinant interferon-alpha2b (IFN-alpha2b, Biolex Therapeutics, Pittsboro, NC) in poly(ether-ester) microspheres (PolyActive, OctoPlus N.V., Leiden, the Netherlands), was evaluated in 27 volunteers injected with either 20, 80, or 320 microg Locteron (equivalent to 6.25, 25, or 100 x 10(6) IU, respectively), 80 microg pegylated IFN-alpha2b (PEG-IFN-alpha2b), microspheres not containing IFN-alpha2b, or placebo. Serum free or PEG-IFN-alpha2b and two biomarkers of IFN activity, neopterin and 2',5'-oligoadenylate synthetase (2',5'-OAS), were measured. After injection of 320 microg Locteron, serum IFN-alpha2b remained elevated through 14 days. The elimination half-life of Locteron was more than 2-fold that of PEG-IFN-alpha2b. The effects of 80 microg Locteron and 80 microg PEG-IFN-alpha2b on both neopterin and 2',5'-OAS were in a comparable range. Serum persistence of both these biomarkers was similar at 14 days after 320 microg Locteron compared with 7 days after 80 microg PEG-IFN-alpha2b. Mild, moderate, or severe influenza-like symptoms developed in all 6 subjects receiving 80 microg PEG-IFN-alpha2b. No such symptoms occurred after 20 or 80 microg Locteron doses. Among the 4 recipients of 320 microg Locteron, 1 experienced mild and 2 experienced moderate influenza-like symptoms. Locteron merits further clinical investigation as a hepatitis C therapy suitable for dosing once per 2 weeks.

[Role of tenofovir in HIV and hepatitis C virus coinfection]. / Papel de tenofovir en la coinfección por el virus de la inmunodeficiencia humana y el virus de la hepatitis C.

Chronic hepatitis C virus (HCV) infection is common in HIV-infected individuals, especially if the route of infection is intravenous (e.g. intravenous drug use or blood transfusion). Prognosis is poorer in patients with HCV and HIV coinfection than in those with HCV monoinfection, mainly due to the immunodepression caused by HIV infection and probably also to a direct effect of HIV on the liver. Moreover, although antiretroviral therapy can cause liver damage, there is little doubt about the net benefits obtained with triple therapy in coinfected individuals, since suppression of HIV replication and immune recovery help to halt liver damage. However, not all antiretroviral agents are equal and those with the lowest hepatotoxicity and best metabolic profile should be used in coinfected patients, since hepatic steatosis accelerates progression of hepatic fibrosis and insulin resistance hampers the success of treatment with interferon and ribavirin. Tenofovir is currently one of the safest nucleos(t)ide analogues, due to its low hepatotoxicity and its lack of negative interference on treatment of HCV infection.

[Pharmaceutical device of IFN].

Recently, new types of interferon (IFN) agents, such as pegylated IFN (PEG-IFN) and consensus IFN, have been developed for strong therapeutic effect and used in clinical stage. PEG-IFN, which is the conjugation of IFN and polyethylene glycol, was designed to long circulate in blood and decrease antibody production. Consensus IFN was designed to combine amino acid frequently appeared in IFN-alpha subtypes. Although they improved IFN therapy, it is also important to pay attention to side effect. Characteristics of new type IFN agents were summarized focused on their pharmaceutical designs.

Pegylated interferons for the treatment of chronic hepatitis B.

Five drugs are approved for the treatment of chronic hepatitis B: conventional interferon (IFN) alfa, lamivudine, adefovir dipivoxil, pegylated interferon (peginterferon) alfa-2a and entecavir. Conventional IFN monotherapy has a narrow range of efficacy, should be administered subcutaneously and is commonly associated with adverse effects. Lamivudine is cheaper and well tolerated, but the virological response may not be durable and prolonged lamivudine treatment is commonly associated with the emergence of drug-resistant mutants. Adefovir dipivoxil is potent but with nephrotoxicity at higher doses. Entecavir is active against both lamivudine- and adefovir dipivoxil-naïve and -resistant HBV, however, its long-term efficacy remains to be evaluated. Peginterferon alfa-2a has recently been shown to be superior to conventional IFN and lamivudine in the treatment of both HBeAg-positive and -negative chronic hepatitis B. By using peginterferon alfa-2a monotherapy, the overall virological and serological responses are around 30%-44%. However, peginterferon alfa-2a in combination with lamivudine does not improve the results at the end of follow-up. Adverse effects are usually tolerable and comparable with conventional IFN. Similar efficacy of peginterferon alfa-2b has also been demonstrated in HBeAg-positive chronic hepatitis B. These observations suggest an important and even a primary role of peginterferon alfa in the treatment of chronic HBV infection.

Pegylated IFNs for chronic hepatitis C: an update.

For over a decade, IFN-alpha(2) has been the standard treatment for chronic hepatitis C. However, the drug's rapid clearance and short half-life have led to low rates of sustained virological response. Pegylation is a well-established method of modifying the pharmacological properties of IFNs, causing significant improvements in pharmacokinetics, which in turn lead to improved efficacy. Two pegylated forms of IFN-alpha(2) have been developed: PEG-IFN-alpha(2b) and PEG-IFN-alpha(2a), and their efficacy has been established in randomised, controlled trials. However, the two differ significantly in structure, in vitro activity and pharmacological properties, and this may translate into -differences in clinical efficacy. Comparative trials have been initiated that will provide insight into relative importance of pharmacokinetics, bioactivity and dosing regimen.