The calm after the cytokine storm: lessons from the TGN1412 trial

A Predictive Model of Vaccine Reactogenicity Using Data from an In Vitro Human Innate Immunity Assay System

A primary concern in vaccine development is safety, particularly avoiding an excessive immune reaction in an otherwise healthy individual. An accurate prediction of vaccine reactogenicity using in vitro assays and computational models would facilitate screening and prioritization of novel candidates early in the vaccine development process. Using the modular in vitro immune construct model of human innate immunity, PBMCs from 40 healthy donors were treated with 10 different vaccines of varying reactogenicity profiles and then cell culture supernatants were analyzed via flow cytometry and a multichemokine/cytokine assay. Differential response profiles of innate activity and cell viability were observed in the system. In parallel, an extensive adverse event (AE) dataset for the vaccines was assembled from clinical trial data. A novel reactogenicity scoring framework accounting for the frequency and severity of local and systemic AEs was applied to the clinical data, and a machine learning approach was employed to predict the incidence of clinical AEs from the in vitro assay data. Biomarker analysis suggested that the relative levels of IL-1B, IL-6, IL-10, and CCL4 have higher predictive importance for AE risk. Predictive models were developed for local reactogenicity, systemic reactogenicity, and specific individual AEs. A forward-validation study was performed with a vaccine not used in model development, Trumenba (meningococcal group B vaccine). The clinically observed Trumenba local and systemic reactogenicity fell on the 26th and 93rd percentiles of the ranges predicted by the respective models. Models predicting specific AEs were less accurate. Our study presents a useful framework for the further development of vaccine reactogenicity predictive models.

Uncovering the Potential of CD40 Agonism to Enhance Immune Checkpoint Blockade

In this CCR Translations, we discuss the therapeutic potential of CD40 agonism, which stimulates antigen-presenting cells (APC) to activate effector T and NK cells. CD40 agonism may lead to development of an interferon-activated, T cell-inflamed tumor microenvironment and has the potential to facilitate long-term response with immune checkpoint blockade. See related article by Weiss et al., p. 74.

Nanoparticle-induced immune response: Health risk versus treatment opportunity?

Nanoparticles (NPs) are not only employed in many biomedical applications in an engineered form, but also occur in our environment, in a more hazardous form. NPs interact with the immune system through various pathways and can lead to a myriad of different scenarios, ranging from their quiet removal from circulation by macrophages without any impact for the body, to systemic inflammatory effects and immuno-toxicity. In the latter case, the function of the immune system is affected by the presence of NPs. This review describes, how both the innate and adaptive immune system are involved in interactions with NPs, together with the models used to analyse these interactions. These models vary between simple 2D in vitro models, to in vivo animal models, and also include complex all human organ on chip models which are able to recapitulate more accurately the interaction in the in vivo situation. Thereafter, commonly encountered NPs in both the environment and in biomedical applications and their possible effects on the immune system are discussed in more detail. Not all effects of NPs on the immune system are detrimental; in the final section, we review several promising strategies in which the immune response towards NPs can be exploited to suit specific applications such as vaccination and cancer immunotherapy.

Preclinical development of ZED8, an 89Zr immuno-PET reagent for monitoring tumor CD8 status in patients undergoing cancer immunotherapy

BACKGROUND

ZED8 is a novel monovalent antibody labeled with zirconium-89 for the molecular imaging of CD8. This work describes nonclinical studies performed in part to provide rationale for and to inform expectations in the early clinical development of ZED8, such as in the studies outlined in clinical trial registry NCT04029181 [1].

METHODS

Surface plasmon resonance, X-ray crystallography, and flow cytometry were used to characterize the ZED8-CD8 binding interaction, its specificity, and its impact on T cell function. Immuno-PET with ZED8 was assessed in huCD8⁺ tumor-bearing mice and in non-human primates. Plasma antibody levels were measured by ELISA to determine pharmacokinetic parameters, and OLINDA 1.0 was used to estimate radiation dosimetry from image-derived biodistribution data.

RESULTS

ZED8 selectively binds to human CD8α at a binding site approximately 9 Å from that of MHCI making mutual interference unlikely. The equilibrium dissociation constant (K_D) is 5 nM. ZED8 binds to cynomolgus CD8 with reduced affinity (66 nM) but it has no measurable affinity for rat or mouse CD8. In a series of lymphoma xenografts, ZED8 imaging was able to identify different CD8 levels concordant with flow cytometry. In cynomolgus monkeys with tool compound ⁸⁹Zr-aCD8v17, lymph nodes were conspicuous by imaging 24 h post-injection, and the pharmacokinetics suggested a flat-fixed first-in-human dose of 4 mg per subject. The whole-body effective dose for an adult human was estimated to be 0.48 mSv/MBq, comparable to existing ⁸⁹Zr immuno-PET reagents.

CONCLUSION

⁸⁹Zr immuno-PET with ZED8 appears to be a promising biomarker of tissue CD8 levels suitable for clinical evaluation in cancer patients eligible for immunotherapy.

Novel strategies for the mitigation of cytokine release syndrome induced by T cell engaging therapies with a focus on the use of kinase inhibitors

T cell engaging therapies, like CAR-T cells and T cell engagers, redirect T cells toward tumor cells, facilitating the formation of a cytotoxic synapse and resulting in subsequent tumor cell killing. T cell receptor or CAR-T downstream signaling triggers a release of pro-inflammatory cytokines, which can induce a Cytokine Release Syndrome (CRS). The incidence of CRS is still hardly predictable among individuals and remains one of the major dose-limiting safety liabilities associated with on-target activity of T cell engaging therapies. This emphasizes the need to elaborate mitigation strategies, which reduce cytokine release while retaining efficacy. Here, we review pre-clinical and clinical approaches applied for the management of CRS symptoms in the context of T cell engaging therapies, highlighting the use of tyrosine kinase inhibitors as an emerging mitigation strategy. In particular, we focus on the effects of Bruton's tyrosine kinase (BTK), Src family including Lck, mammalian target of rapamycin (mTOR) and Janus tyrosine kinase (JAK) inhibitors on T cell functionality and cytokine release, to provide a rationale for their use as mitigation strategies against CRS in the context of T cell engaging therapies.

Advanced In Vitro Lung Models for Drug and Toxicity Screening: The Promising Role of Induced Pluripotent Stem Cells

The substantial socioeconomic burden of lung diseases, recently highlighted by the disastrous impact of the coronavirus disease 2019 (COVID-19) pandemic, accentuates the need for interventive treatments capable of decelerating disease progression, limiting organ damage, and contributing to a functional tissue recovery. However, this is hampered by the lack of accurate human lung research models, which currently fail to reproduce the human pulmonary architecture and biochemical environment. Induced pluripotent stem cells (iPSCs) and organ-on-chip (OOC) technologies possess suitable characteristics for the generation of physiologically relevant in vitro lung models, allowing for developmental studies, disease modeling, and toxicological screening. Importantly, these platforms represent potential alternatives for animal testing, according to the 3Rs (replace, reduce, refine) principle, and hold promise for the identification and approval of new chemicals under the European REACH (registration, evaluation, authorization and restriction of chemicals) framework. As such, this review aims to summarize recent progress made in human iPSC- and OOC-based in vitro lung models. A general overview of the present applications of in vitro lung models is presented, followed by a summary of currently used protocols to generate different lung cell types from iPSCs. Lastly, recently developed iPSC-based lung models are discussed.

Perspectives on the use and risk of adverse events associated with cytokine-storm targeting antibodies and challenges associated with development of novel monoclonal antibodies for the treatment of COVID-19 clinical cases

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the novel coronavirus disease 2019 (COVID-19) pandemic that lacks globally accessible effective antivirals or extensively available vaccines. Numerous clinical trials are exploring the applicability of repurposed monoclonal antibodies (mAbs) targeting cytokines that cause adverse COVID-19-related pathologies, and novel mAbs directly targeting SARS-CoV-2. However, comorbidities and the incidence of cytokine storm (CS)-associated pathological complexities in some COVID-19 patients may limit the clinical use of these drugs. Additionally, CS-targeting mAbs have the potential to cause adverse events that restrict their applicability in patients with comorbidities. Novel mAbs targeting SARS-CoV-2 require pharmacological and toxicological characterization before a marketable product becomes available. The affordability of novel mAbs across the global economic spectrum may seriously limit their accessibility. This review presents a perspective on antibody-based research efforts and their limitations for COVID-19.

Immunopathogenesis and treatment of cytokine storm in COVID-19

Severe coronavirus disease 2019 (COVID-19) is characterized by systemic hyper-inflammation, acute respiratory distress syndrome, and multiple organ failure. Cytokine storm refers to a set of clinical conditions caused by excessive immune reactions and has been recognized as a leading cause of severe COVID-19. While comparisons have been made between COVID-19 cytokine storm and other kinds of cytokine storm such as hemophagocytic lymphohistiocytosis and cytokine release syndrome, the pathogenesis of cytokine storm has not been clearly elucidated yet. Recent studies have shown that impaired response of type-1 IFNs in early stage of COVID-19 infection played a major role in the development of cytokine storm, and various cytokines such as IL-6 and IL-1 were involved in severe COVID-19. Furthermore, many clinical evidences have indicated the importance of anti-inflammatory therapy in severe COVID-19. Several approaches are currently being used to treat the observed cytokine storm associated with COVID-19, and expectations are especially high for new cytokine-targeted therapies, such as tocilizumab, anakinra, and baricitinib. Although a number of studies have been conducted on anti-inflammatory treatments for severe COVID-19, no specific recommendations have been made on which drugs should be used for which patients and when. In this review, we provide an overview of cytokine storm in COVID-19 and treatments currently being used to address it. In addition, we discuss the potential therapeutic role of extracorporeal cytokine removal to treat the cytokine storm associated with COVID-19.

In vitro toxicity model: Upgrades to bridge the gap between preclinical and clinical research

The Centers for Disease Control and Prevention (CDC) provides extensive data that indicate our need for drugs to maintain human population health. Despite the substantial availability of drugs on the market, many patients lack specific drugs. New drugs are required to tackle this issue. Moreover, we need more reliable models for testing drug toxicity, as too many drug approval failures occur with the current models. This article briefly describes various approaches of the currently used models for toxicity screening, to justify the selection of in vitro cell-based models. Cell-based toxicity models have the best potential to reliably predict drug toxicity in humans, as they are developed using the cells of the target organism. However, currently, a large gap exists between in vitro cell-based approach to toxicity testing and the clinical approach, which may be contributing to drug approval failures. We propose improvements to in vitro cell-based toxicity models, which is often an insight approach, to better match this approach with the clinical homeostatic approach. This should enable a more accurate comparison of data between the preclinical as well as clinical models and provide a more comprehensive understanding of human physiology and biological effects of drugs.

Ebola virus-mediated T-lymphocyte depletion is the result of an abortive infection

Ebola virus (EBOV) infections are characterized by a pronounced lymphopenia that is highly correlative with fatalities. However, the mechanisms leading to T-cell depletion remain largely unknown. Here, we demonstrate that both viral mRNAs and antigens are detectable in CD4⁺ T cells despite the absence of productive infection. A protein phosphatase 1 inhibitor, 1E7-03, and siRNA-mediated suppression of viral antigens were used to demonstrate de novo synthesis of viral RNAs and antigens in CD4⁺ T cells, respectively. Cell-to-cell fusion of permissive Huh7 cells with non-permissive Jurkat T cells impaired productive EBOV infection suggesting the presence of a cellular restriction factor. We determined that viral transcription is partially impaired in the fusion T cells. Lastly, we demonstrate that exposure of T cells to EBOV resulted in autophagy through activation of ER-stress related pathways. These data indicate that exposure of T cells to EBOV results in an abortive infection, which likely contributes to the lymphopenia observed during EBOV infections.

Lymphopenia is a common characteristic of the disease caused by EBOV. We determined that despite the apparent lack of productive infection, EBOV is capable of entering T cells and producing both viral RNAs and proteins. Furthermore, we demonstrate that EBOV causes an abortive infection in T cells due to the presence of a cellular restriction factor. The abortive infection was associated with cell death following ER-stress induced autophagy. Collectively, these findings suggest that abortive infection in T cells is likely to contribute to lymphopenia during Ebola virus disease, which is uniformly linked with the severity of the disease. All EBOV vaccine candidates utilize GP as the sole antigen inducing a protective antibody response and in some clinical trials were shown to induce adverse side effects. The present study suggests that these effects can be associated with GP, which may lead to abortive infection of the vaccine construct in T cells contributing to the inflammatory response to the vaccines.

Regulatory Affairs 101: Introduction to Investigational New Drug Applications and Clinical Trial Applications

Testing novel drugs on fellow human beings is fraught with potential ethical concerns; however, developing drugs to treat the wide spectrum of human diseases and disorders is a moral imperative. How do we best navigate the balance between protecting the individual vs. the greater good? Global government regulatory bodies are accountable for ensuring that medical experiments on human subjects are appropriately justified and subject to close oversight. In this article, we focus on two major global health authorities, the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA), and the path to legally treating humans with new investigational products.

Adverse immunostimulation caused by impurities: The dark side of biopharmaceuticals

Drug safety is an important issue, especially in the experimental phases of development. Adverse immunostimulation (AI) is sometimes encountered following treatment with biopharmaceuticals, which can be life‐threatening if it results in a severe systemic inflammatory reaction. Biopharmaceuticals that unexpectedly induce an inflammatory response still enter the clinic, even while meeting all regulatory requirements. Impurities (of microbial origin) in biopharmaceuticals are an often‐overlooked cause of AI. This demonstrates that the current guidelines for quality control and safety pharmacology testing are not flawless. Here, based on two case examples, several shortcomings of the guidelines are discussed. The most important of these are the lack of sensitivity for impurities, lack of testing for pyrogens other than endotoxin, and the use of insensitive animal species and biomarkers in preclinical investigations. Moreover, testing for the immunotoxicity of biopharmaceuticals is explicitly not recommended by the international guidelines. Publication of cases of AI is pivotal, both to increase awareness and to facilitate scientific discussions on how to prevent AI in the future.

Animal models for analysis of immunological responses to nanomaterials: Challenges and considerations

Nanotechnology provides many solutions to improve conventional drug delivery and has a unique niche in the areas related to the specific targeting of the immune system, such as immunotherapies and vaccines. Preclinical studies in this field rely heavily on the combination of in vitro and in vivo methods to assess the safety and efficacy of nanotechnology platforms, nanoparticle-formulated drugs, and vaccines. While certain types of toxicities can be evaluated in vitro and good in vitro-in vivo correlation has been demonstrated for such tests, animal studies are still needed to address complex biological questions and, therefore, provide a unique contribution to establishing nanoparticle safety and efficacy profiles. The genetic, metabolic, mechanistic, and phenotypic diversity of currently available animal models often complicates both the animal choice and the interpretation of the results. This review summarizes current knowledge about differences in the immune system function and immunological responses of animals commonly used in preclinical studies of nanomaterials. We discuss challenges, highlight current gaps, and propose recommendations for animal model selection to streamline preclinical analysis of nanotechnology formulations.

Development of transplant immunosuppressive agents - considerations in the use of animal models

INTRODUCTION

The development of all immunosuppressant agents to date has involved the experimental use of large and small animal models. Over the last half-century, immunosuppressive drugs have extended the lives of transplant patients worldwide. However, the use of animal models in the development of these drugs is not perfect, and this has brought to light a number of issues including idiosyncratic reactions that are found in animal models but not in humans. The 2006 highly publicized case of the 'elephant man' TGN 1412 drug trial highlights the importance of being cogent of the limitations of animal models. Areas covered: This review covers the utility and limitations of the use of animal models for the development of immunosuppressant agents. This includes both large and small animal models, particularly rodent models in the transplant setting. Expert opinion: The use of animal models represents a critical stage in the development of immunosuppressive drugs. Limitations include physiological differences to humans; this is especially true of immunologically naïve lab rodents with small memory cell populations. Toxic drug levels may differ widely between species. Animal models are also costly and raise ethical concerns. However, there is currently no way to recreate the complex environment of the human immune system purely in vitro.

Structure and Composition Define Immunorecognition of Nucleic Acid Nanoparticles

Nucleic acid nanoparticles (NANPs) have evolved as a new class of therapeutics with the potential to detect and treat diseases. Despite tremendous advancements in NANP development, their immunotoxicity, one of the major impediments in clinical translation of traditional therapeutic nucleic acids (TNAs), has never been fully characterized. Here, we describe the first systematically studied immunological recognition of 25 representative RNA and DNA NANPs selected to have different design principles and physicochemical properties. We discover that, unlike traditional TNAs, NANPs used without a delivery carrier are immunoquiescent. We show that interferons (IFNs) are the key cytokines triggered by NANPs after their internalization by phagocytic cells, which agrees with predictions based on the experiences with TNAs. However, in addition to type I IFNs, type III IFNs also serve as reliable biomarkers of NANPs, which is usually not characteristic of TNAs. We show that overall immunostimulation relies on NANP shapes, connectivities, and compositions. We demonstrate that, like with traditional TNAs, plasmacytoid dendritic cells serve as the primary interferon producers among all peripheral blood mononuclear cells treated with NANPs, and scavenger receptor-mediated uptake and endosomal Toll-like receptor signaling are essential for NANP immunorecognition. The TLR involvement, however, is different from that expected for traditional TNA recognition. Based on these results, we suggest that NANP technology may serve as a prototype of auxiliary molecular language for communication with the immune system and the modulation of immune responses.

Avoiding Exploitation in Phase I Clinical Trials: More than (Un)Just Compensation

Lowering compensation to research subjects to protect them from “undue inducement” is a misguided attempt to shoehorn a concern about exploitation into the framework of autonomy. We suggest that oversight bodies should be less concerned about undue influence than about exploitation of subjects. Avoiding exploitation in human subjects research requires not only increasing compensation, but enhancing the dignity of research participation.

Rational Design of Mouse Models for Cancer Research

The laboratory mouse is widely considered as a valid and affordable model organism to study human disease. Attempts to improve the relevance of murine models for the investigation of human pathologies led to the development of various genetically engineered, xenograft and humanized mouse models. Nevertheless, most preclinical studies in mice suffer from insufficient predictive value when compared with cancer biology and therapy response of human patients. We propose an innovative strategy to improve the predictive power of preclinical cancer models. Combining (i) genomic, tissue engineering and regenerative medicine approaches for rational design of mouse models with (ii) rapid prototyping and computational benchmarking against human clinical data will enable fast and nonbiased validation of newly generated models.

Cancer and Aging - the Inflammatory Connection

Aging and cancer are highly correlated biological phenomena. Various cellular processes such as DNA damage responses and cellular senescence that serve as tumor suppressing mechanisms throughout life result in degenerative changes and contribute to the aging phenotype. In turn, aging is considered a pro-tumorigenic state, and constitutes the single most important risk factor for cancer development. However, the causative relations between aging and cancer is not straight forward, as these processes carry contradictory hallmarks; While aging is characterized by tissue degeneration and organ loss of function, cancer is a state of sustained cellular proliferation and gain of new functions. Here, we review the molecular and cellular pathways that stand in the base of aging related cancer. Specifically, we deal with the inflammatory perspective that link these two processes, and suggest possible molecular targets that may be exploited to modify their courses.

Novel CD28 antagonist mPEG PV1-Fab' mitigates experimental autoimmune uveitis by suppressing CD4+ T lymphocyte activation and IFN-γ production

Autoimmune Uveitis is an important chronic inflammatory disease and a leading cause of impaired vision and blindness. This ocular autoimmune disorder is mainly mediated by T CD4⁺ lymphocytes poising a T_H1 phenotype. Costimulatory molecules are known to play an important role on T cell activation and therefore represent interesting therapeutical targets for autoimmune disorders. CD28 is the prototypical costimulatory molecule for T lymphocytes, and plays a crucial role in the initiation, and maintenance of immune responses. However, previous attempts to use this molecule in clinical practice achieved no success. Thus, we evaluated the efficacy of mPEG PV1-Fab’ (PV1), a novel selective CD28 antagonist monovalent Fab fragment in the treatment of Experimental Autoimmune Uveitis (EAU). Here, we showed that PV1 treatment decreases both average disease score and incidence of EAU. A decrease in the activation profile of both T CD4⁺ and T CD8⁺ eye-infiltrating lymphocytes was evidenced. In the periphery, T CD4⁺ cells from PV1-treated mice also showed a decrease in their activation status, with reduced expression of CD69, CD25, and PD-1 molecules. This suppression was not dependent on Treg cells, as both their frequency and absolute number were lower in PV1-treated mice. In addition, frequency of CD4⁺IFN-γ⁺ T cells was significantly lower in PV1-treated group, but not of IL-17-producing T cells. Moreover, after specific restimulation, PV1 blockade selectively blocked IFN-γ production by CD4⁺ lymphocytes Taken together, our data suggest that mPEG PV1-Fab’ acts mainly on IFN-γ-producing CD4⁺ T cells and emphasize that this specific CD28 blockade strategy is a potential specific and alternative tool for the treatment of autoimmune disorders in the eye.

Ethical considerations and challenges in first-in-human research

First-in-human (FIH) research is a translational process to move a new potential therapy from bench to bedside. Major ethical challenges of an FIH trial arise because of the indeterminate nature of the risks involved and the controversial risk-benefit justification. Severe adverse events and death of subjects who participated in FIH research in the past have led to an increased attention on ethical considerations in the design and conduct of such research. Furthermore, novel therapies in the current decade, such as molecular-targeted, gene transfer, and pluripotent stem cells therapies, have led to numerous emerging ethical challenges or different ethical assessment and justification frameworks for FIH research. This article presents, discusses, and interlinks ethical considerations and challenges in FIH research through a review of related ethical principles and their application to each ethical issue with given examples. Possible solutions to address each ethical challenge are presented. The scope of this article focuses on 4 major ethical issues in FIH research: risk-benefit assessment and justification for the conduct of research, selection of a suitable target population, informed consent, and conflict of interest.

Biology-inspired microphysiological system approaches to solve the prediction dilemma of substance testing

The recent advent of microphysiological systems - microfluidic biomimetic devices that aspire to emulate the biology of human tissues, organs and circulation in vitro - is envisaged to enable a global paradigm shift in drug development. An extraordinary US governmental initiative and various dedicated research programs in Europe and Asia have led recently to the first cutting-edge achievements of human single-organ and multi-organ engineering based on microphysiological systems. The expectation is that test systems established on this basis would model various disease stages, and predict toxicity, immunogenicity, ADME profiles and treatment efficacy prior to clinical testing. Consequently, this technology could significantly affect the way drug substances are developed in the future. Furthermore, microphysiological system-based assays may revolutionize our current global programs of prioritization of hazard characterization for any new substances to be used, for example, in agriculture, food, ecosystems or cosmetics, thus, replacing laboratory animal models used currently. Thirty-six experts from academia, industry and regulatory bodies present here the results of an intensive workshop (held in June 2015, Berlin, Germany). They review the status quo of microphysiological systems available today against industry needs, and assess the broad variety of approaches with fit-for-purpose potential in the drug development cycle. Feasible technical solutions to reach the next levels of human biology in vitro are proposed. Furthermore, key organ-on-a-chip case studies, as well as various national and international programs are highlighted. Finally, a roadmap into the future is outlined, to allow for more predictive and regulatory-accepted substance testing on a global scale.

Translating Treg Therapy in Humanized Mice

Regulatory T cells (Treg) control immune cell function as well as non-immunological processes. Their far-reaching regulatory activities suggest their functional manipulation as a means to sustainably and causally intervene with the course of diseases. Preclinical tools and strategies are however needed to further test and develop interventional strategies outside the human body. “Humanized” mouse models consisting of mice engrafted with human immune cells and tissues provide new tools to analyze human Treg ontogeny, immunobiology, and therapy. Here, we summarize the current state of humanized mouse models as a means to study human Treg function at the molecular level and to design strategies to harness these cells for therapeutic purposes.

Clinical evaluation of compounds targeting PD-1/PD-L1 pathway for cancer immunotherapy

Significant enthusiasm currently exists for new immunotherapeutic strategies: blocking the interaction between programmed death-1 receptor on T-cells and programmed death-ligand 1 on tumor cells to boost immune system stimulation to fight cancer. Immunomodulation with the antiprogrammed death-1/programmed death-ligand 1 monoclonal antibodies has shown to mediate tumor shrinkage and extend overall survival from several pivotal phase I/II studies in melanoma, renal cell carcinoma, and non-small cell lung cancer. This has prompted multiple large ongoing phase III trials with the expectation for fast-track FDA approvals to satisfy unmet medical needs. Compounds targeting the programmed death-1 pathway that are in clinical trials fall into two major categories, namely antiprogrammed death-1 antibodies: Nivolumab, MK-3475, and pidilizumab; and antiprogrammed death-ligand 1 antibodies: MPDL3280A, BMS-936559, MEDI4736, and MSB0010718C. We reviewed the clinical efficacy and safety of each compound based upon major registered clinical trials and published clinical data. Overall, response rate of more than 20% is consistently seen across all these trials, with maximal response of approximately 50% achieved by certain single antiprogrammed death-1 agents or when used in combination with cytotoxic T-lymphocyte antigen-4 blockade. The responses seen are early, durable, and have continued after treatment discontinuation. Immune-related adverse events are the most common side effects seen in these clinical trials. Overall, the skin and gastrointestinal tract are the most common organ systems affected by these compounds while hepatic, endocrine, and neurologic events are less frequent. These side effects are low grade, manageable, and typically resolve within a relatively short time frame with a predictable resolution pattern given proper management. We therefore propose detailed guidelines for management of major immune-related adverse events that are anticipated with antiprogrammed death-1/programmed death-ligand 1 therapies based on general experience with other monoclonal antibodies and the established management algorithms for immune-related adverse events for cytotoxic T-lymphocyte antigen-4 blockade with ipilimumab. We anticipate that the antiprogrammed death-1 strategy will become a viable and crucial clinical strategy for cancer therapy.

Immunotherapeutic strategies in autoimmune uveitis

Autoimmune uveitis is an organ-specific disorder characterized by irreversible lesions to the eye that predominantly affect people in their most productive years and is among the leading causes of visual deficit and blindness. Currently available therapies are effective in the treatment of a wide spectrum of uveitis, but are often associated with severe side effects. Here, we review ongoing research with promising immunomodulatory therapeutic strategies, describing their specific features, interactions and the responses triggered by the targeted immune molecules that aim to minimize clinical complications and the likelihood of disease relapse. We first review the main features of the disease, diagnostic tools, and traditional forms of therapy, as well as the animal models predominantly used to understand the pathogenesis and test the novel intervention approaches aiming to control the acute immune and inflammatory responses and to dampen chronic responses. Both exploratory research and clinical trials have targeted either the blockade of effector pathways or of their companion co-stimulatory molecules. Examples of targets are T cell receptors (CD3), their co-stimulatory receptors (CD28, CTLA-4) and corresponding ligands (B7-1 and B7-2, also known as CD80 and CD86), and cytokines like IL-2 and their receptors. Here, we summarize the available evidence on effectiveness of these treatments in human and experimental uveitis and highlight a novel CD28 antagonist monovalent Fab′ antibody, FR104, which has shown preclinical efficacy suppressing effector T cells while enhancing regulatory T cell function and immune tolerance in a humanized graft-versus-host disease (GVHD) mice model and is currently being tested in a mouse autoimmune uveitis model with encouraging results.

Approaches to modelling the human immune response in transition of candidates from research to development

This review considers the steps required to evaluate a candidate biodefense vaccine or therapy as it emerges from the research phase, in order to transition it to development. The options for preclinical modelling of efficacy are considered in the context of the FDA's Animal Rule.

Human immunity in vitro - solving immunogenicity and more

It has been widely recognised that the phylogenetic distance between laboratory animals and humans limits the former's predictive value for immunogenicity testing of biopharmaceuticals and nanostructure-based drug delivery and adjuvant systems. 2D in vitro assays have been established in conventional culture plates with little success so far. Here, we detail the status of various 3D approaches to emulate innate immunity in non-lymphoid organs and adaptive immune response in human professional lymphoid immune organs in vitro. We stress the tight relationship between the necessarily changing architecture of professional lymphoid organs at rest and when activated by pathogens, and match it with the immunity identified in vitro. Recommendations for further improvements of lymphoid tissue architecture relevant to the development of a sustainable adaptive immune response in vitro are summarized. In the end, we sketch a forecast of translational innovations in the field to model systemic innate and adaptive immunity in vitro.

T regulatory cells in childhood arthritis--novel insights

In recent years, there have been many new developments in the field of regulatory T cells (Treg), challenging the consensus on their behaviour, classification and role(s) in disease. The role Treg might play in autoimmune disease appears to be more complex than previously thought. Here, we discuss the current knowledge of regulatory T cells through animal and human research and illustrate the recent developments in childhood autoimmune arthritis (juvenile idiopathic arthritis (JIA)). Furthermore, this review summarises our understanding of the fields and assesses current and future implications for Treg in the treatment of JIA.

Potential role of human-specific genes, human-specific microRNAs and human-specific non-coding regulatory RNAs in the pathogenesis of systemic sclerosis and Sjögren's syndrome

The etiology and pathogenesis of human autoimmune diseases remain unknown despite intensive investigations. Although remarkable progress has been accomplished through genome wide association studies in the identification of genetic factors that may predispose to their occurrence or modify their clinical presentation to date no specific gene abnormalities have been conclusively demonstrated to be responsible for these diseases. The completion of the human and chimpanzee genome sequencing has opened up novel opportunities to examine the possible contribution of human specific genes and other regulatory elements unique to the human genome, such as microRNAs and non-coding RNAs, towards the pathogenesis of a variety of human disorders. Thus, it is likely that these human specific genes and non-coding regulatory elements may be involved in the development or the pathogenesis of various disorders that do not occur in non-human primates including certain autoimmune diseases such as Systemic Sclerosis and Primary Sjögren's Syndrome. Here, we discuss recent evidence supporting the notion that human specific genes or human specific microRNA and other non-coding RNA regulatory elements unique to the human genome may participate in the development or in the pathogenesis of Systemic Sclerosis and Primary Sjögren's Syndrome.

Dynamics of a cytokine storm

Six volunteers experienced severe inflammatory response during the Phase I clinical trial of a monoclonal antibody that was designed to stimulate a regulatory T cell response. Soon after the trial began, each volunteer experienced a “cytokine storm”, a dramatic increase in cytokine concentrations. The monoclonal antibody, TGN1412, raised serum concentrations of both pro- and anti-inflammatory cytokines το very hiγh values during the first day, while lymphocyte and monocyte concentrations plummeted. Because the subjects were healthy and had no prior indications of immune deficiency, this event provided an unusual opportunity to study the dynamic interactions of cytokines and other measured parameters. Here, the response histories of nine cytokines have been modeled by a set of linear ordinary differential equations. A general search procedure identifies parameters of the model, whose response fits the data well during the five-day measurement period. The eighteenth-order model reveals plausible cause-and-effect relationships among the cytokines, showing how each cytokine induces or inhibits other cytokines. It suggests that perturbations in IL2, IL8, and IL10 have the most significant inductive effect, while IFN-γ and IL12 have the greatest inhibiting effect on other cytokine concentrations. Although TNF-α is a major pro-inflammatory factor, IFN-γ and three other cytokines have faster initial and median response to TGN1412 infusion. Principal-component analysis of the data reveals three clusters of similar cytokine responses: [TNF-α, IL1, IL10], [IFN-γ, IL2, IL4, IL8, and IL12], and [IL6]. IL1, IL6, IL10, and TNF-α have the highest degree of variability in response to uncertain initial conditions, exogenous effects, and parameter estimates. This study illuminates details of a cytokine storm event, and it demonstrates the value of linear modeling for interpreting complex, coupled biological system dynamics from empirical data.

CD28 ligation increases macrophage suppression of T-cell proliferation

When compared to spleen or lymph node cells, resident peritoneal cavity cells respond poorly to T-cell activation in vitro. The greater proportional representation of macrophages in this cell source has been shown to actively suppress the T-cell response. Peritoneal macrophages exhibit an immature phenotype (MHC class II(lo), B7(lo)) that reduces their efficacy as antigen-presenting cells. Furthermore, these cells readily express inducible nitric oxide synthase (iNOS), an enzyme that promotes T-cell tolerance by catabolism of the limiting amino acid arginine. Here, we investigate the ability of exogenous T-cell costimulation to recover the peritoneal T-cell response. We show that CD28 ligation failed to recover the peritoneal T-cell response and actually suppressed responses that had been recovered by inhibiting iNOS. As indicated by cytokine ELISpot and neutralizing monoclonal antibody (mAb) treatment, this 'cosuppression' response was due to CD28 ligation increasing the number of interferon (IFN)-γ-secreting cells. Our results illustrate that cellular composition and cytokine milieu influence T-cell costimulation biology.Cellular & Molecular Immunology advance online publication, 23 April 2012; doi:10.1038/cmi.2012.13.

Granzyme B- and Fas ligand-mediated cytotoxic function induced by mitogenic CD28 stimulation of human memory CD4+ T cells

Some human memory CD4(+) T cells have cytotoxic functions best understood in the context of viral infections; however, their possible role in pathologic processes is understudied. The novel discovery that mitogenic CD28 antibodies induced proliferation and expansion of Tregs offered therapeutic promise for autoimmune disorders. However, the failed TGN1412 trial forced reassessment of this concept. As memory CD4(+) T cells are known to produce toxic molecules, including granzyme B (GrzB) and FasL, we wondered whether mitogenic CD28 was able to induce these cytotoxic molecules. A commercially available mitogenic human CD28 mAb (clone ANC28.1) was used to determine whether mitogenic CD28 induces cytotoxic function from human memory CD4(+) T cells. We found that stimulation of memory CD4(+) T cells by ANC28.1, as well as by conventional costimulation (CD3/CD28 mAb), robustly induced enzymatically active GrzB, along with increased surface expression of FasL. These functional phenotypes were induced in association with increased expression of T cell activation markers CD69 and CD25, and elimination of target cells by ANC28.1-activated memory CD4(+) T cells involved both GrzB and FasL. Additionally, ANC28.1-activated memory CD4(+) T cells caused disruption of epithelial cell monolayer integrity, which was partially mediated by GrzB. These findings reveal functions of memory CD4(+) T cells previously unknown to be induced by mitogenic CD28, and suggest that these pathogenic mechanisms may have been responsible for some of the widespread tissue destruction that occurred in the TGN1412 trial recipients.

The case for conducting first-in-human (phase 0 and phase 1) clinical trials in low and middle income countries

BACKGROUND

Despite the increase in the number of clinical trials in low and middle income countries (LMICs), there has been little serious discussion of whether First in Human (FIH; phase 0 and phase 1) clinical trials should be conducted in LMICs, and if so, under what conditions. Based on our own experience, studies and consultations, this paper aims to stimulate debate on our contention that for products meant primarily for conditions most prevalent in LMICs, FIH trials should preferably be done first in those countries.

DISCUSSION

There are scientific and pragmatic arguments that support conducting FIH trials in LMIC. Furthermore, the changing product-development and regulatory landscape, and the likelihood of secondary benefits such as capacity building for innovation and for research ethics support our argument. These arguments take into account the critical importance of protecting human subjects of research while developing capacity to undertake FIH trials.

SUMMARY

While FIH trials have historically not been conducted in LMICs, the situation in some of these countries has changed. Hence, we have argued that FIH should be conducted in LMICs for products meant primarily for conditions that are most prevalent in those contexts; provided the necessary protections for human subjects are sufficient.

The pathogenesis of infection and immune response

An understanding of the pathogenesis of infection, and the complex and fascinating 'relationship', or interaction, between the infecting organism and the host are advantageous when caring for patients with infections/infectious diseases, particularly as many of the clinical features of infection are as a consequence of the defence mechanisms mounted by the immune system. This article aims to provide a brief overview of the pathogenesis of infection, explaining how the two branches of the immune system, the innate/natural immune response, and the adaptive/acquired immune response, mount an attack against invading bacteria. Reference is made to bacteria such as Staphylococcus aureus, Clostridium difficile, Streptococcus pyogenes, Neisseria meningitidis and Mycobacterium tuberculosis, and their effect on the human host and the immune response, through the processes of attachment/entry, evasion of host defences, replication, and damage to the host.

CCC meets ICU: redefining the role of critical care of cancer patients

BACKGROUND

Currently the majority of cancer patients are considered ineligible for intensive care treatment and oncologists are struggling to get their patients admitted to intensive care units. Critical care and oncology are frequently two separate worlds that communicate rarely and thus do not share novel developments in their fields. However, cancer medicine is rapidly improving and cancer is eventually becoming a chronic disease. Oncology is therefore characterized by a growing number of older and medically unfit patients that receive numerous novel drug classes with unexpected side effects.

DISCUSSION

All of these changes will generate more medically challenging patients in acute distress that need to be considered for intensive care. An intense exchange between intensivists, oncologists, psychologists and palliative care specialists is warranted to communicate the developments in each field in order to improve triage and patient treatment. Here, we argue that "critical care of cancer patients" needs to be recognized as a medical subspecialty and that there is an urgent need to develop it systematically.

CONCLUSION

As prognosis of cancer improves, novel therapeutic concepts are being introduced and more and more older cancer patients receive full treatment the number of acutely ill patients is growing significantly. This development a major challenge to current concepts of intensive care and it needs to be redefined who of these patients should be treated, for how long and how intensively.

Cytokine Storm in the Pediatric Oncology Patient

Cytokine storm is an immune reaction to an acute or chronic injury and may be caused by a disease itself or by treatment directed at an underlying disease. The result is an overwhelming release of cytokines which can cause a sepsis-like response and may lead to multi-system organ failure and even death. Because it occurs in various settings, oncology nurses need to be aware of this process when assessing the pediatric oncology patient. Early recognition and treatment initiation is imperative and may lead to better outcomes for the patient.

Clinically validated approaches to the treatment of autoimmune diseases

IMPORTANCE OF THE FIELD

Autoimmune diseases are pathological conditions in which "self-tolerance" has been broken, and an immune response has been mounted against the body's own tissues. More than seventy autoimmune diseases have been described, some of which are systemic and others of which are organ-specific. Although many of these diseases are rare, the collective prevalence of autoimmune diseases in the United States alone is between 5 and 8%, and is increasing.

AREAS COVERED IN THIS REVIEW

Herein, we review the exciting advances made during the past decade (1999 - 2009) in the development of clinically-validated agents for the treatment of autoimmune disease. We focus on five of the most prevalent conditions: rheumatoid arthritis, psoriasis, multiple sclerosis, Crohn's disease, and systemic lupus erythematosus. The discussion is largely restricted to agents - both small molecules and macromolecules - that have advanced through randomized, controlled clinical trials.

WHAT THE READER WILL GAIN

An overview of the pathogenesis of each disease is provided, along with a description of the therapies. Results from pivotal clinical trials are tabulated for four of the disease areas. We also provide summaries of experiences with both failed clinical trials and side effects observed during the course of clinical investigations. We conclude the review with thoughts on current challenges in the field and the prospect for future innovations.

TAKE HOME MESSAGE

During the past decade, some of the largest advances in the treatment of autoimmune disease have arisen from highly potent and selective macromolecule-based therapies (e.g. antibodies, recombinant proteins and fusion proteins). Together, these clinical experiences have provided insight into the critical mechanisms in autoimmune pathogenesis, including inflammatory cytokine release, T-cell migration and co-stimulation, and B-cell function.

The safety and side effects of monoclonal antibodies

Monoclonal antibodies (mAbs) are now established as targeted therapies for malignancies, transplant rejection, autoimmune and infectious diseases, as well as a range of new indications. However, administration of mAbs carries the risk of immune reactions such as acute anaphylaxis, serum sickness and the generation of antibodies. In addition, there are numerous adverse effects of mAbs that are related to their specific targets, including infections and cancer, autoimmune disease, and organ-specific adverse events such as cardiotoxicity. In March 2006, a life-threatening cytokine release syndrome occurred during a first-in-human study with TGN1412 (a CD28-specific superagonist mAb), resulting in a range of recommendations to improve the safety of initial human clinical studies with mAbs. Here, we review some of the adverse effects encountered with mAb therapies, and discuss advances in preclinical testing and antibody technology aimed at minimizing the risk of these events.

Fundamentals of clinical immunotoxicology

Whereas animal studies are invaluable for screening various chemical and drugs for immunotoxic potential, such systems are necessarily limited in their predictive value for humans given the differences in physiology, immune system structure and function, and various other parameters between humans and nonhuman animals. However, prospective experimental studies in humans are not always practical or ethical. What is needed is an approach for combining animal data, human data collected in the course of clinical studies, and modern tools of bioinformatics and systems biology. In this chapter, we will explore current assays and methodologies for assessing immunotoxic potential in humans using this multi--parameter approach.

Safety of biologics, lessons learnt from TGN1412

In 2006, a first-in-man phase-I clinical trial of an immunomodulatory mAb, TGN1412, ended in disaster when six healthy recipients suffered a life-threatening systemic inflammatory response, termed a 'Cytokine Storm'. A subsequent investigation concluded that these serious adverse events, not predicted by pre-clinical safety testing, were unforeseen biological effects in man. However, the adverse events had been exacerbated by administration of a near-maximum immuno-stimulatory dose to volunteers, because the calculation of a safe starting dose in man had been based upon results from pre-clinical safety testing in a non-responsive species. In hindsight, many lessons have been learnt from this experience and these have prompted a revision of the European guidelines for first-in-man phase-I clinical trials of biologics. Perhaps the most important lesson is that greater caution needs to be exercised when evaluating new biologics.

Enhancing the ability of experimental autoimmune encephalomyelitis to serve as a more rigorous model of multiple sclerosis through refinement of the experimental design

Advancing the understanding of the mechanisms involved in the pathogenesis of multiple sclerosis (MS) likely will lead to new and better therapeutics. Although important information about the disease process has been obtained from research on pathologic specimens, peripheral blood lymphocytes and MRI studies, the elucidation of detailed mechanisms has progressed largely through investigations using animal models of MS. In addition, animal models serve as an important tool for the testing of putative interventions. The most commonly studied model of MS is experimental autoimmune encephalomyelitis (EAE). This model can be induced in a variety of species and by various means, but there has been concern that the model may not accurately reflect the disease process, and more importantly, it may give rise to erroneous findings when it is used to test possible therapeutics. Several reasons have been given to explain the shortcomings of this model as a useful testing platform, but one idea provides a framework for improving the value of this model, and thus, it deserves careful consideration. In particular, the idea asserts that EAE studies are inadequately designed to enable appropriate evaluation of putative therapeutics. Here we discuss problem areas within EAE study designs and provide suggestions for their improvement. This paper is principally directed at investigators new to the field of EAE, although experienced investigators may find useful suggestions herein.

CD28 co-stimulation down regulates Th17 development

Th17 cells are implicated in host defence and autoimmune diseases. CD28/B7 co-stimulation is involved in the induction and progression of autoimmune diseases, but its role in controlling murine Th17 cell fate remains to be clarified. We here report that soluble anti-CD28 mAb suppressed the differentiation of anti-CD3-stimulated naïve CD4⁺ T cells into IL-17-producing cells. CD28 co-stimulation reduced the frequency of proliferating cells that produce IL-17. We provide evidence for an IL-2 and IFN-γ-dependent mechanism of CD28-mediated IL-17 suppression. CD28 blockade of Th17 development was correlated with a decrease rather than an increase in the percentage of Foxp3⁺ T cells. In APC/T cell co-cultures, mature dendritic cells (DC) were less efficient than immature DC in their ability to support Th17 cell differentiation, while CTLA4-Ig, an agent blocking CD28/B7 and CTLA4/B7 interactions, facilitated both murine and human Th17 differentiation. This study identifies the importance of B7 co-stimulatory molecules in the negative regulation of Th17 development. These unexpected results caution targeting the CD28/B7 pathways in the treatment of human autoimmune diseases.

Public awareness and views on unlicensed use of medicines in children

AIMS

To explore awareness and views of the general public on unlicensed use of medicines in children and on the participation of children in clinical trials.

METHODS

Members of the public completed a questionnaire survey administered by face-to-face interview in public areas in N. Ireland. The main outcome measures were the views on unlicensed use of medicines in children and on clinical trials in children.

RESULTS

One thousand participants (59.2% female) took part; 610 were parents. Most participants (86%) had no previous knowledge about unlicensed use of medicines in children. Being a parent did not influence this nor did being a parent of a child who suffered from a health problem (P > 0.05). Most participants (92%) felt that parents should be told about unlicensed use of medicines, with the doctor most frequently selected as the person who should inform parents. At the outset, only 1.8% of participants felt that the use of medicines in children was unsafe. However, having been informed about unlicensed use of medicines, this proportion increased dramatically (62.4%; P < 0.001). Views on whether participants would enter a child of their own into a clinical trial varied according to the health status of the child (P < 0.05) i.e. a child in good health (3.9%) vs a child with a life-threatening condition (41.9%).

CONCLUSIONS

There is limited public knowledge of unlicensed use of medicines in children and a general reluctance to involve children in clinical trials unless the child to be involved has a life-threatening condition.

Immunotoxicity of monoclonal antibodies

Monoclonal antibodies (mAbs) are large molecules intended to bind to specific targets often expressed on the immune system, and to treat various immunopathological conditions. Therefore, mAbs can be considered to have a high potential for immunotoxicity, which is reflected in the clinical experience accumulated on mAbs-induced adverse effects related to immunosuppression, immunostimulation and hypersensitivity (immunogenicity). So far, non clinical immunotoxicity studies have been inadequate to address all safety issues in relation to the possible immunotoxicity of mAbs, because they are fraught with limitations and pitfalls primarily related to the lack of relevant animal species. In addition, clinical studies rarely include validated end-points dedicated to the prediction of immunotoxicity. With the ongoing development of mAbs as novel therapeutic strategies for a wide variety of diseases, efforts should be paid to improve our understanding of mAbs-induced immunotoxic effects and design dedicated strategies to assess their immunological safety, both non clinically and clinically.