Research and development of next generation of antibody-based therapeutics

CD19 occupancy with tafasitamab increases therapeutic index of CART19 cell therapy and diminishes severity of CRS

ABSTRACT

In the development of various strategies of anti-CD19 immunotherapy for the treatment of B-cell malignancies, it remains unclear whether CD19 monoclonal antibody therapy impairs subsequent CD19-targeted chimeric antigen receptor T-cell (CART19) therapy. We evaluated the potential interference between the CD19-targeting monoclonal antibody tafasitamab and CART19 treatment in preclinical models. Concomitant treatment with tafasitamab and CART19 showed major CD19 binding competition, which led to CART19 functional impairment. However, when CD19+ cell lines were pretreated with tafasitamab overnight and the unbound antibody was subsequently removed from the culture, CART19 function was not affected. In preclinical in vivo models, tafasitamab pretreatment demonstrated reduced incidence and severity of cytokine release syndrome and exhibited superior antitumor effects and overall survival compared with CART19 alone. This was associated with transient CD19 occupancy with tafasitamab, which in turn resulted in the inhibition of CART19 overactivation, leading to diminished CAR T apoptosis and pyroptosis of tumor cells.

Vaporized Hydrogen Peroxide Sterilization in the Production of Protein Therapeutics: Uptake and Effects on Product Quality

The aseptic filling of drug products is carried out in pharmaceutical isolators that have been sterilized. A commonly used method for achieving a high level of sterility assurance is vaporized hydrogen peroxide (VHP) sterilization, which is favorable to other methods, such as ethylene oxide sterilization, due to its low cycle times and nontoxic residuals. While VHP cycles are often employed to create a sterile environment within an isolator, they can leave residual levels of hydrogen peroxide behind that can enter the product during fill-finish operations. Due to the oxidizing potential of hydrogen peroxide and the multiple possible sources of uptake along filling lines, the extent of the potential impact on product quality needs to be understood during pharmaceutical development. Herein, different factors affecting hydrogen peroxide uptake, points of entry along the filling line, and possible impacts on product quality are reviewed.

A comprehensive strategy for the identification of biologics by liquid-chromatography-mass spectrometry for release testing in a regulated environment

Identification (ID) testing is a regulatory requirement for biopharmaceutical manufacturing, requiring robust, GMP-qualified assays that can distinguish the therapeutic from any other in the facility. Liquid Chromatography-Mass Spectrometry (LC-MS) is a powerful analytical tool used to identify and characterize biologics. While routinely leveraged for characterization, LC-MS is relatively rare in Quality Control (QC) settings due to its perceived complexity and scarcity of MS-trained personnel. However, employing LC-MS for identification of drug products has many advantages versus conventional ID techniques, including but not limited to its high specificity, rapid turn-around time, and ease of method execution. In this work, we outline the development and implementation of a comprehensive LC-MS based ID strategy for biologics release testing. Two main workflows (WFs) were developed: i) WF1, a subunit-based assay measuring the molecular weight of the light chain (LC) and heavy chain (HC) of an antibody upon reduction, and ii) WF2, intact mass measurement of the biologic upon N-deglycosylation by PNGase F. The proposed strategy is shown to be applicable for over 40 diverse model biologics including monoclonal antibodies (mAbs), biobetters such as antibody prodrugs/afucosylated mAbs, fusion proteins, multi-specific antibodies, Fabs, and large peptides, all with excellent mass accuracy (error typically < 20 ppm) and precision. It requires a single-step sample preparation and a single click to run and process the data upon method setup. This strategy has been successfully implemented for release testing in GMP labs. Challenges and considerations for the establishment of QC-friendly methods are discussed. It is also shown that these methods can be applied to the ID of more analytically complex biotherapeutics, such as fixed-dose combination (FDC) and drug products co-formulated with trace-level additives.

Optimizing Conjugation Chemistry, Antibody Conjugation Site, and Surface Density in Antibody-Nanogel Conjugates (ANCs) for Cell-Specific Drug Delivery

Targeted delivery of therapeutics using antibody-nanogel conjugates (ANCs) with a high drug-to-antibody ratio has the potential to overcome some of the inherent limitations of antibody-drug conjugates (ADCs). ANC platforms with simple preparation methods and precise tunability to evaluate structure-activity relationships will greatly contribute to translating this promise into clinical reality. In this work, using trastuzumab as a model antibody, we demonstrate a block copolymer-based ANC platform that allows highly efficient antibody conjugation and formulation. In addition to showcasing the advantages of using an inverse electron-demand Diels-Alder (iEDDA)-based antibody conjugation, we evaluate the influence of antibody surface density and conjugation site on the nanogels upon the targeting capability of ANCs. We show that compared to traditional strain-promoted alkyne-azide cycloadditions, the preparation of ANCs using iEDDA provides significantly higher efficiency, which results in a shortened reaction time, simplified purification process, and enhanced targeting toward cancer cells. We also find that a site-specific disulfide-rebridging method in antibodies offers similar targeting abilities as the more indiscriminate lysine-based conjugation method. The more efficient bioconjugation using iEDDA allows us to optimize the avidity by fine-tuning the surface density of antibodies on the nanogel. Finally, with trastuzumab-mertansine (DM1) antibody-drug combination, our ANC demonstrates superior activities in vitro compared to the corresponding ADC, further highlighting the potential of ANCs in future clinical translation.

Antibody engineering and its therapeutic applications

As a natural function, antibodies defend the host from infected cells and pathogens by recognizing their pathogenic determinants. Antibodies (Abs) gained wide acceptance with an enormous impact on human health and have predominantly captured the arena of bio-therapeutics and bio-diagnostics. The scope of Ab-based biologics is vast, and it is likely to solve many unmet clinical needs in future. The majority of attention is now devoted to developing innovative technologies for manufacturing and engineering Abs, better suited to satisfy human needs. The advent of Ab engineering technologies (AET) led to phenomenal developments leading to the generation of Abs-/Ab-derived molecules with desirable functional properties proportional to their expanding requirements. Evolution brought by AET, from the naturally occurring Ab forms to several advanced Ab formats and derivatives, was much needed as it is of great interest to the pharmaceutical industry. Thus, numerous advancements in AET have propelled success in therapeutic Ab development, along with the potential for ever-increasing improvements. Unique characteristics of Abs, such as its diversity, specificity, structural integrity and an array of possible applications, together inspire continuous innovation in the field. Overall, the AET could assist in conquer of several limitations of Abs in terms of their applicability in the field of therapeutics, diagnostics and research; AET has so far led to the production of next-generation Abs, which have revolutionized these arenas. Here in this review, we discuss the various distinguished engineering platforms for Ab development and the progress in modern therapeutics by the so-called "next-generation Abs."

Past, Present and (Foreseeable) Future of Biological Anti-TNF Alpha Therapy

Due to the key role of tumor necrosis factor-alpha (TNF-α) in the pathogenesis of immunoinflammatory diseases, TNF-α inhibitors have been successfully developed and used in the clinical treatment of autoimmune disorders. Currently, five anti-TNF-α drugs have been approved: infliximab, adalimumab, golimumab, certolizumab pegol and etanercept. Anti-TNF-α biosimilars are also available for clinical use. Here, we will review the historical development as well as the present and potential future applications of anti-TNF-α therapies, which have led to major improvements for patients with several autoimmune diseases, such as rheumatoid arthritis (RA), ankylosing spondylitis (AS), Crohn's disease (CD), ulcerative colitis (UC), psoriasis (PS) and chronic endogenous uveitis. Other therapeutic areas are under evaluation, including viral infections, e.g., COVID-19, as well as chronic neuropsychiatric disorders and certain forms of cancer. The search for biomarkers able to predict responsiveness to anti-TNF-α drugs is also discussed.

Targeted Drug Delivery Using a Plug-to-Direct Antibody-Nanogel Conjugate

Targeted drug delivery using antibody-drug conjugates has attracted great attention due to its enhanced therapeutic efficacy compared to traditional chemotherapy. However, the development has been limited due to a low drug-to-antibody ratio and laborious linker-payload optimization. Herein, we present a simple and efficient strategy to combine the favorable features of polymeric nanocarriers with antibodies to generate an antibody-nanogel conjugate (ANC) platform for targeted delivery of cytotoxic agents. Our nanogels stably encapsulate several chemotherapeutic agents with a wide range of mechanisms of action and solubility. We showcase the targetability of ANCs and their selective killing of cancer cells over-expressing disease-relevant antigens such as human epidermal growth factor receptor 2, epidermal growth factor receptor, and tumor-specific mucin 1, which cover a broad range of breast cancer cell types while maintaining low to no toxicity to non-targeted cells. Overall, our system represents a versatile approach that could impact next-generation nanomedicine in antibody-targeted therapeutics.

An effective strategy for the humanization of antibody fragments under an accelerated timeline

The use of monoclonal antibodies (mAbs) in therapy is gradually advancing and discussions entail its safety, rentability and effectiveness. To this date, around a hundred mAbs have been approved by the FDA for the treatment of various diseases. Aiming for their large-scale production, recombinant DNA technology is mainly employed, and antibodies can be expressed in various eukaryotic and prokaryotic systems. Moreover, considering their heterologous origin and potential immunogenicity, various strategies have been developed for mAb humanization, considering that around 50 % of commercial mAbs are humanized. Hence, we introduce LimAb7, a mouse mAb capable of binding and neutralizing brown spider's Loxosceles intermedia dermonecrotic toxins in vivo/in vitro. This antibody has been produced in mouse and humanized scFv and diabody formats, however results indicated losses in antigen-binding affinity, stability, and neutralizing ability. Intending to develop evolved, stable, and neutralizing antibody fragments, we report for the first time the design of humanized antibody V-domains produced as Fab fragments, against spider venom toxins. Improvements in constructs were observed regarding their physicochemical stability, target binding and binding pattern maintenance. As their neutralizing features remain to be characterized, we believe this data sheds new light on antibody humanization by producing a parental molecule in different recombinant formats.

Camelid Single-Domain Antibodies: Promises and Challenges as Lifesaving Treatments

Since the discovery of camelid heavy-chain antibodies in 1993, there has been tremendous excitement for these antibody domains (VHHs/sdAbs/nanobodies) as research tools, diagnostics, and therapeutics. Commercially, several patents were granted to pioneering research groups in Belgium and the Netherlands between 1996–2001. Ablynx was established in 2001 with the aim of exploring the therapeutic applications and development of nanobody drugs. Extensive efforts over two decades at Ablynx led to the first approved nanobody drug, caplacizumab (Cablivi) by the EMA and FDA (2018–2019) for the treatment of rare blood clotting disorders in adults with acquired thrombotic thrombocytopenic purpura (TPP). The relatively long development time between camelid sdAb discovery and their entry into the market reflects the novelty of the approach, together with intellectual property restrictions and freedom-to-operate issues. The approval of the first sdAb drug, together with the expiration of key patents, may open a new horizon for the emergence of camelid sdAbs as mainstream biotherapeutics in the years to come. It remains to be seen if nanobody-based drugs will be cheaper than traditional antibodies. In this review, I provide critical perspectives on camelid sdAbs and present the promises and challenges to their widespread adoption as diagnostic and therapeutic agents.

Monoclonal antibodies in diabetic retinopathy

INTRODUCTION

Diabetic retinopathy (DR), as one of the main complications of diabetes, is among the leading causes of blindness and visual impairment worldwide.

AREAS COVERED

Current clinical therapies include photocoagulation, vitrectomy, and anti-vascular endothelial growth factor (VEGF) therapies. Bevacizumab and ranibizumab are two monoclonal antibodies (mAbs) inhibiting angiogenesis. Intravitreal ranibizumab and bevacizumab can decrease the rate of blindness and retinal thickness, and improve visual acuity whether as monotherapy or combined with other treatments. They can increase the efficacy of other treatments and decrease their adverse events. Although administered intravitreally, they also might enter the circulation and cause systemic effects. This study is aimed to review our current knowledge about mAbs, bevacizumab and ranibizumab, in DR including superiorities, challenges, and limitations. Meanwhile, we tried to shed light on new ideas to overcome these limitations. Our latest search was done in April 2021 mainly through PubMed and Google Scholar. Relevant clinical studies were imported.

EXPERT OPINION

Future direction includes detection of more therapeutic targets considering other components of DR pathophysiology and shared pathogenesis of DR and neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, the treat-and-extend regimen, and new ways of drug delivery and other routes of ocular drug administration.

An Intercompany Perspective on Compatibility and In-use Stability Studies to Enable Administration Of Biopharmaceutical Drug Products

In-use stability and compatibility studies are often used in biotherapeutic development to assess stability and compatibility of biologic drugs with diluents and/or administration components at relevant conditions for the target route of administration (commonly intravenous, subcutaneous or intramuscular), to assure that patient safety and product efficacy are maintained during clinical use. To gain an understanding of current industry approaches for in-use stability and compatibility studies, the Formulation Workstream of the BioPhorum Development Group (BPDG), an industry-wide consortium, conducted an inter-company collaboration exercise, which included five bench-marking surveys around in-use stability and compatibility studies of biologic drugs. The results of this industry collaboration provide insights into the practicalities of these studies and how they are being used to support administration of biologics from early clinical programs to marketed products. The surveys queried topics including regulatory strategies and feedback; clinical in-use formulation, patient and site considerations; clinical blinding, masking and placebo approaches; study setup, execution and reporting; and clinical in-use stability and compatibility testing to provide a comprehensive picture of the range of common industry practices. This paper discusses the survey results and presents various approaches which can be used to guide the strategy and design of an in-use stability and compatibility program based on clinical and biomolecule needs.

Identification, characterization and control of a sequence variant in monoclonal antibody drug product: a case study

Sequence variants (SV) in protein bio therapeutics can be categorized as unwanted impurities and may raise serious concerns in efficacy and safety of the product. Early detection of specific sequence modifications, that can result in altered physicochemical and or biological properties, is therefore desirable in product manufacturing. Because of their low abundance, and finite resolving power of conventional analytical techniques, they are often overlooked in early drug development. Here, we present a case study where trace amount of a sequence variant is identified in a monoclonal antibody (mAb) based therapeutic protein by LC-MS/MS and the structural and functional features of the SV containing mAb is assessed using appropriate analytical techniques. Further, a very sensitive selected reaction monitoring (SRM) technique is developed to quantify the SV which revealed both prominent and inconspicuous nature of the variant in process chromatography. We present the extensive characterization of a sequence variant in protein biopharmaceutical and first report on control of sequence variants to < 0.05% in final drug product by utilizing SRM based mass spectrometry method during the purification steps.

Binding affinity determination of therapeutic antibodies to membrane protein targets: Kinetic Exclusion Assay using cellular membranes for anti-CD20 antibody

Antibody-based therapeutics targeting membrane proteins have evolved as a major modality for the treatment of cancer, inflammation and autoimmune diseases. There are numerous challenges, ranging from desired epitope expression to reliable binding/functional assays which are associated with developing antibodies for this target class. Specifically, having a robust methodology for characterizing antibody interaction with a membrane protein target is essential for providing guidance on dosing, potency and thus expected efficacy. Fluorescence-activated cell sorting (FACS) has been commonly used to characterize antibodies binding to membrane protein targets. FACS provides information about the antibody-receptor complex (antibody bound to cells) and the apparent equilibrium dissociation constant (K_D^') is elucidated by fitting the antibody-receptor binding isotherm as a function of total antibody concentration to a nonlinear regression model. Conversely, Kinetic Exclusion Assay (KinExA) has been used to measure solution-based equilibrium dissociation constant (K_D) of antibodies. Here, K_D is determined by measuring the free antibody concentration at equilibrium in a series of solutions in which the antibody is at constant concentration and the receptor (either in the membrane or the cell) is titrated. We measured the binding affinity of the anti-CD20 antibody, Rituximab, using both FACS and KinExA. There was ~25-fold difference in the binding affinity measured by these two techniques. We have explored this discrepancy through additional experiments around the mathematical framework involved in the analysis of these two different binding assays. Finally, our study concluded that KinExA enables accurate measurement of the K_D for strong protein-protein interactions (sub-nanomolar values) compared to FACS.

AbPredict 2: a server for accurate and unstrained structure prediction of antibody variable domains

SUMMARY

Methods for antibody structure prediction rely on sequence homology to experimentally determined structures. Resulting models may be accurate but are often stereochemically strained, limiting their usefulness in modeling and design workflows. We present the AbPredict 2 web-server, which instead of using sequence homology, conducts a Monte Carlo-based search for low-energy combinations of backbone conformations to yield accurate and unstrained antibody structures.

AVAILABILITY AND IMPLEMENTATION

We introduce several important improvements over the previous AbPredict implementation: (i) backbones and sidechains are now modeled using ideal bond lengths and angles, substantially reducing stereochemical strain, (ii) sampling of the rigid-body orientation at the light-heavy chain interface is improved, increasing model accuracy and (iii) runtime is reduced 20-fold without compromising accuracy, enabling the implementation of AbPredict 2 as a fully automated web-server (http://abpredict.weizmann.ac.il). Accurate and unstrained antibody model structures may in some cases obviate the need for experimental structures in antibody optimization workflows.

Cathepsin D: Removal strategy on protein A chromatography, near real time monitoring and characterisation during monoclonal antibody production

Monoclonal antibody (mAb) fragmentation is a well-known degradation pathway that results in product loss and can significantly impact product quality, efficacy, or even cause immunogenic reactions, thus potentially endangering patients' health. It is recognised that residual proteases present among host cell proteins (HCPs) such as those expressed by Chinese Hamster Ovary (CHO) can induce fragmentation, and failure of their complete removal during downstream processing could cause fragmentation during mAb production and in the final drug product. We identified, using a protease inhibitor screen, an aspartic protease that contributes to proteolytic fragmentation of partially purified mAbs in multiple projects. Subsequent LC-MS analysis indicated that cathepsin D, a typical aspartic protease, was responsible for the observed fragmentation of in-process samples. To address the issue, an alternative chromatography wash was implemented at the capture step and has been demonstrated to be an effective and scalable solution to mitigate the residual cathepsin D associated fragmentation risk. Furthermore, a near real time targeted mass spectrometry method has been developed to proactively monitor the presence of cathepsin D during upstream and downstream process. Our approach demonstrated an emerging HCP mitigation strategy through integrated upstream and downstream involvement and holds great promise for a range of future applications.

On-line glucose monitoring by near infrared spectroscopy during the scale up steps of mammalian cell cultivation process development

NIR spectroscopy is a non-destructive tool for in-situ, on-line bioprocess monitoring. One of its most frequent applications is the determination of metabolites during cultivation, especially glucose. Previous studies have usually investigated the applicability of Near Infrared (NIR) spectroscopy at one bioreactor scale but the effect of scale up was not explored. In this study, the complete scale up from shake flask (1 L) through 20 L, 100 L and 1000 L up to 5000 L bioreactor volume level was monitored with on-line NIR spectroscopy. The differences between runs and scales were examined using principal component analysis. The bioreactor runs were relatively similar regardless of scales but the shake flasks differed strongly from bioreactor runs. The glucose concentration throughout five 5000 L scale bioreactor runs were predicted by partial least squares regression models that were based on pre-processed spectra of bioreactor runs and combinations of them. The model that produced the lowest error of prediction (4.18 mM on a 29 mM concentration range) for all five runs in the prediction set was based on the combination of 20 L and 100 L data. This result demonstrated the capabilities and the limitations of an NIR system for glucose monitoring in mammalian cell cultivations.

Impact of a Heat Shock Protein Impurity on the Immunogenicity of Biotherapeutic Monoclonal Antibodies

Purpose

Anti-drug antibodies can impair the efficacy of therapeutic proteins and, in some circumstances, induce adverse health effects. Immunogenicity can be promoted by aggregation; here we examined the ability of recombinant mouse heat shock protein 70 (rmHSP70) - a common host cell impurity - to modulate the immune responses to aggregates of two therapeutic mAbs in mice.

Methods

Heat and shaking stress methods were used to generate aggregates in the sub-micron size range from two human mAbs, and immunogenicity assessed by intraperitoneal exposure in BALB/c mice.

Results

rmHSP70 was shown to bind preferentially to aggregates of both mAbs, but not to the native, monomeric proteins. Aggregates supplemented with 0.1% rmHSP70 induced significantly enhanced IgG2a antibody responses compared with aggregates alone but the effect was not observed for monomeric mAbs. Dendritic cells pulsed with mAb aggregate showed enhanced IFNγ production on co-culture with T cells in the presence of rmHSP70.

Conclusion

The results indicate a Th1-skewing of the immune response by aggregates and show that murine rmHSP70 selectively modulates the immune response to mAb aggregates, but not monomer. These data suggest that heat shock protein impurities can selectively accumulate by binding to mAb aggregates and thus influence immunogenic responses to therapeutic proteins.

Electronic supplementary material

The online version of this article (10.1007/s11095-019-2586-7) contains supplementary material, which is available to authorized users.

Obtaining and characterization of anti-testis monoclonal antibodies: Invaluable tools toward the identification of testis antigens involved in fertilization

BACKGROUND

Generation and utilization of the specific monoclonal antibodies against testis antigens is reported to identify the antigens that are important in reproductive field.

OBJECTIVE

Current study aimed to introduce a hybridoma that producing a specific anti-testis monoclonal antibody to identify the testis antigens that can be important in the reproduction field.

METHODS

To make hybridoma against testis antigens, mice were immunized with testis cell lysate. After cell fusion, resulted hybridomas were screened by indirect ELISA, then cloned by limiting dilution and finally the produced monoclonal antibody were characterized by some of the molecular laboratory techniques such as immunohistochemistry, immunocytochemistry and western blot.

RESULTS

By using hybridoma technique, cell fusion was performed and ten (8A11, 8D6, 8D7, 9F6, 9G11, 10C3, 10B3, 10B2, 10C2 and 10H7) antibodies specific to the testis antigens were produced finally. Among the produced antibodies, 10C3 was found to cross-react with testis, but not detected in other tissues. mAb 10C3 recognized the sperm and testis antigens, specifically the intertestitial tissue of testis, spermatogonia, primary and secondary spermatocyte antigens, so they were most likely the target of generated mAb. Also our mAb could totally detect the mouse sperm antigens and the specific antigens of head and tail of human sperm. In western blotting analysis, mAb 10C3 could recognize the specific protein bands of sperm and testis extracts. Also in this study the testis specific genes that were target of generated mAb, were selected according to the mouse EST profile available at UniGene part of NCBI.

CONCLUSIONS

So this stable anti-testis mAb has a potential for laboratory researches and also for diagnostic procedures in fertilization. Thus it could be exploited as a suitable tool for target-specific diagnosis and research in several diseases.

Therapeutic targeting of angiogenesis molecular pathways in angiogenesis-dependent diseases

Angiogenesis is a critical step in the progression of almost all human malignancies and some other life-threatening diseases. Anti-angiogenic therapy is a novel and effective approach for treatment of angiogenesis-dependent diseases such as cancer, diabetic retinopathy, and age-related macular degeneration. In this article, we will review the main strategies developed for anti-angiogenic therapies beside their clinical applications, the major challenges, and the latest advances in the development of anti-angiogenesis-based targeted therapies.

Frontiers of monoclonal antibodies: Applications in medical practices

With the flourishing of innovation in drug discovery into a new era of personalized therapy, the use of monoclonal antibodies (mAbs) in the treatment of various ailments lies at the forefront. Major improvements in genetic sequencing and biomedical techniques as well as research into mAbs emphasize on determining new targets for advanced therapy while maximizing efficacy for clinical application. However, a balance has to be achieved concerning developing a target with low toxicity combined with high specificity and versatility, to allow a specific antibody to facilitate several biotic effects, ranging from neutralization of virus mechanisms to modulation of immune response and maintaining low global economic cost. Presently, there are approximately 30 mAbs' permitted for therapeutic use with many more being tested in clinical trials. Nevertheless, the heavy cost of mAbs' production, stowage and management as well as the subsequent hindrances to their development are outweighed by mAbs' clinical advantages. Compared to conventional drugs, since mAbs use as pharmacologic iotas have specific physical features and modes of action, they should be considered as a discrete therapeutic category. In this review, the history of mAb generation and the innovative technological applications of mAbs that has advanced in clinical practices is reviewed.

Building blocks for bispecific and trispecific antibodies

Bispecific antibodies (BsAbs), which target two antigens or epitopes, incorporate the specificities and properties of two distinct monoclonal antibodies (mAbs) into a single molecule. As such, BsAbs can elicit synergistic activities and provide the capacity for enhanced therapeutic efficacy and/or safety compared to what can be achieved with conventional monospecific IgGs. There are many building block formats to generate BsAbs and Trispecific antibodies (TsAbs) based on combining the antigen recognition domains of monoclonal antibodies (mAbs). This review describes the many and varied antibody-based building blocks used to achieve multivalency and multispecificity. These diverse building blocks provide opportunities to tailor the design of BsAbs and TsAbs to match the desired applications.

The global role of biotechnology for non communicable disorders

The World Health Organization (WHO) has tagged non-communicable diseases (NCDs) as one of the twenty-first century's major development challenges. NCDs account for over 15 million deaths annually and over 80% of those deaths occur in developing countries and among the poorest populations. Biotechnology presents unique opportunities to improve the early diagnosis and the treatment of NCDs. This review describes the major applications of biotechnology for a better clinical management of NCDs, i.e. the implementation of innovative diagnostic approaches and the production of innovative treatments, including those based on monoclonal antibodies, recombinant proteins, regulatory nucleic acids and cell-based therapies for regenerative medicine. In this context, it also examines the major challenges faced by biotechnology in developing countries.

Evolution of Therapeutic Antibodies, Influenza Virus Biology, Influenza, and Influenza Immunotherapy

This narrative review article summarizes past and current technologies for generating antibodies for passive immunization/immunotherapy. Contemporary DNA and protein technologies have facilitated the development of engineered therapeutic monoclonal antibodies in a variety of formats according to the required effector functions. Chimeric, humanized, and human monoclonal antibodies to antigenic/epitopic myriads with less immunogenicity than animal-derived antibodies in human recipients can be produced in vitro. Immunotherapy with ready-to-use antibodies has gained wide acceptance as a powerful treatment against both infectious and noninfectious diseases. Influenza, a highly contagious disease, precipitates annual epidemics and occasional pandemics, resulting in high health and economic burden worldwide. Currently available drugs are becoming less and less effective against this rapidly mutating virus. Alternative treatment strategies are needed, particularly for individuals at high risk for severe morbidity. In a setting where vaccines are not yet protective or available, human antibodies that are broadly effective against various influenza subtypes could be highly efficacious in lowering morbidity and mortality and controlling unprecedented epidemic/pandemic. Prototypes of human single-chain antibodies to several conserved proteins of influenza virus with no Fc portion (hence, no ADE effect in recipients) are available. These antibodies have high potential as a novel, safe, and effective anti-influenza agent.

Ultrasensitive NIR-SERRS Probes with Multiplexed Ratiometric Quantification for In Vivo Antibody Leads Validation

Immunotargeting ability of antibodies may show significant difference between in vitro and in vivo. To select antibody leads with high affinity and specificity, it is necessary to perform in vivo validation of antibody candidates following in vitro antibody screening. Herein, a robust in vivo validation of anti-tetraspanin-8 antibody candidates against human colon cancer using ratiometric quantification method is reported. The validation is performed on a single mouse and analyzed by multiplexed surface-enhanced Raman scattering using ultrasensitive and near infrared (NIR)-active surface-enhanced resonance Raman scattering nanoprobes (NIR-SERRS dots). The NIR-SERRS dots are composed of NIR-active labels and Au/Ag hollow-shell assembled silica nanospheres. A 93% of NIR-SERRS dots is detectable at a single-particle level and signal intensity is 100-fold stronger than that from nonresonant molecule-labeled spherical Au NPs (80 nm). The result of SERRS-based antibody validation is comparable to that of the conventional method using single-photon-emission computed tomography. The NIR-SERRS-based strategy is an alternate validation method which provides cost-effective and accurate multiplexing measurements for antibody-based drug development.

Polyester-Based Nanoparticles for the Encapsulation of Monoclonal Antibodies

Aliphatic polyesters have been widely explored for biomedical applications (e.g., drug delivery systems, biomedical devices, and tissue engineering). Recently, polyesters have been used in nanoparticle formulations for the controlled release of monoclonal antibodies (mAbs) for the enhanced efficacy of antibody-based therapy. Polyester-based nanoparticles for mAb delivery provide decreased antibody dosage, increased antibody stability and protection and longer therapeutic action, ultimately translating to an increased therapeutic index. Additionally, nanoencapsulation holds the potential for the selective cellular recognition and internalization of mAbs, in the disease context when intracellular organelles and molecules (e.g., enzymes, transcription factors and oncogenic proteins) are the preferred target. We present here a detailed method to prepare mAb-loaded polyester-based nanoparticles and the various techniques to characterize the resulting nanoparticles and mAb structure. Finally, we highlight different biological approaches to assess the in vitro bioactivity of the antibody upon nanoparticle release.

Camelid Single-Domain Antibodies: Historical Perspective and Future Outlook

Tremendous effort has been expended over the past two and a half decades to understand many aspects of camelid heavy chain antibodies, from their biology, evolution, and immunogenetics to their potential applications in various fields of research and medicine. In this article, I present a historical perspective on the development of camelid single-domain antibodies (sdAbs or V_HHs, also widely known as nanobodies) since their discovery and discuss the advantages and disadvantages of these unique molecules in various areas of research, industry, and medicine. Commercialization of camelid sdAbs exploded in 2001 with a flurry of patents issued to the Vrije Universiteit Brussel (VUB) and later taken on by the Vlaams Interuniversitair Instituut voor Biotechnologie (VIB) and, after 2002, the VIB-founded spin-off company, Ablynx. While entrepreneurial spirit has certainly catalyzed the exploration of nanobodies as marketable products, IP restrictions may be partially responsible for the relatively long time span between the discovery of these biomolecules and their entry into the pharmaceutical market. It is now anticipated that the first V_HH-based antibody drug, Caplacizumab, a bivalent anti-vWF antibody for treating rare blood clotting disorders, may be approved and commercialized in 2018 or shortly thereafter. This elusive first approval, along with the expiry of key patents, may substantially alter the scientific and biomedical landscape surrounding camelid sdAbs and pave the way for their emergence as mainstream biotherapeutics.

Qualitative and quantitative characterization of protein biotherapeutics with liquid chromatography mass spectrometry

In the last decade, the advancement of liquid chromatography mass spectrometry (LC/MS) techniques has enabled their broad application in protein characterization, both quantitatively and qualitatively. Owing to certain important merits of LC/MS techniques (e.g., high selectivity, flexibility, and rapid method development), LC/MS assays are often deemed as preferable alternatives to conventional methods (e.g., ligand-binding assays) for the analysis of protein biotherapeutics. At the discovery and development stages, LC/MS is generally employed for two purposes absolute quantification of protein biotherapeutics in biological samples and qualitative characterization of proteins. For absolute quantification of a target protein in bio-matrices, recent work has led to improvements in the efficiency of LC/MS method development, sample treatment, enrichment and digestion, and high-performance low-flow-LC separation. These advances have enhanced analytical sensitivity, specificity, and robustness. As to qualitative analysis, a range of techniques have been developed to characterize intramolecular disulfide bonds, glycosylation, charge variants, primary sequence heterogeneity, and the drug-to-antibody ratio of antibody drug conjugate (ADC), which has enabled a refined ability to assess product quality. In this review, we will focus on the discussion of technical challenges and strategies of LC/MS-based quantification and characterization of biotherapeutics, with the emphasis on the analysis of antibody-based biotherapeutics such as monoclonal antibodies (mAbs) and ADCs. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 36:734-754, 2017.

The Use of a 2,2'-Azobis (2-Amidinopropane) Dihydrochloride Stress Model as an Indicator of Oxidation Susceptibility for Monoclonal Antibodies

Protein oxidation is a major pathway for degradation of biologic drug products. Past literature reports have suggested that 2,2-azobis (2-amidinopropane) dihydrochloride (AAPH), a free radical generator that produces alkoxyl and alkyl peroxyl radicals, is a useful model reagent stress for assessing the oxidative susceptibility of proteins. Here, we expand the applications of the AAPH model by pairing it with a rapid peptide map method to enable site-specific studies of oxidative susceptibility of monoclonal antibodies and their derivatives for comparison between formats, the evaluation of formulation components, and comparisons across the stress models. Comparing the free radical-induced oxidation model by AAPH with a light-induced oxidation model suggests that light-sensitive residues represent a subset of AAPH-sensitive residues and therefore AAPH can be used as a preliminary screen to highlight molecules that need further assessment by light models. In sum, these studies demonstrate that AAPH stress can be used in multiple ways to evaluate labile residues and oxidation sensitivity as it pertains to developability and manufacturability.

Evolving patterns in a collaboration network of global R&D on monoclonal antibodies

We investigated the evolution process of collaborative inter-organizational network of the research and development (R&D) on monoclonal antibody (mAb) over the past 30 y. The annual detection of the collaboration network provides dynamics on network structures and relationship changes among different organizations. Our research showed continuous growth of the network's scale and complexity due to the constant entry of new organizations and the forging of new partnering relationships. The evolving topological features reveal a core-periphery structure that became clearer over time and an increasing heterogeneity within the collaborative mAb R&D network. As measured by the number of network participants, dedicated biotechnology firms (DBFs) were the dominant organization form in the field of mAb development, but their average centrality was reduced during the period of 2004-2009, when pharmaceutical companies took over the positions of DBFs. Along with the network evolution, 2 waves of substitution on the leading positions were driven by technological innovations and mergers and acquisitions (M&A). In addition, this study analyzed organizational-level behaviors to help understand the evolution of network structures over the field of mAb development across the different technologically innovative or economic contexts.

Evaluating the expression profile and stability of different UCOE containing vector combinations in mAb-producing CHO cells

Background

As the demand for monoclonal antibodies (mAb) increases, more efficient expression methods are required for their manufacturing process. Transcriptional gene silencing is a common phenomenon in recombinant cell lines which leads to expression reduction and instability. There are reports on improved antibody expression in ubiquitous chromatin opening element (UCOE) containing both heavy and light chain gene constructs. Here we investigate the impact of having these elements as part of the light chain, heavy chain or both genes during cell line development. In this regard, non-UCOE and UCOE vectors were constructed and stable Chinese hamster ovary (CHO) cell pools were generated by different vector combinations.

Results

Expression analysis revealed that all UCOE cell pools had higher antibody yields compared to non-UCOE cells, Moreover the most optimal expression was obtained by cells containing just the UCOE on heavy chain. In terms of stability, it was shown that the high level of expression was kept consistence for more than four months in these cells whereas the expression titers were reduced in the other UCOE pools.

Conclusions

In conclusion, UCOE significantly enhanced the level and stability of antibody expression and the use of this element with heavy chain provided more stable cell lines with higher production level.

Immunotoxin: A new tool for cancer therapy

Cancer is one of the main reasons of death in the most countries and in Iran. Immunotherapy quickly became one of the best methods of cancer treatment, along with chemotherapy and radiation. “Immunotoxin Therapy” is a promising way of cancer therapy that is mentioned in this field. Immunotoxins are made from a toxin attaching to an antibody target proteins present on cancer cells. The first-generation immunotoxins were made of a full-length toxin attached to whole monoclonal antibodies. But, these immunotoxins could bind to normal cells. DAB389IL2 was the first immunotoxin approved by the Food and Drug Administration. Current trends and researches are ongoing on finding proteins that in combination with immunotoxins have minimal immunogenicity and the most potency for target cell killing.

Computer-Aided Antibody Design: An Overview

The use of monoclonal antibody as the next generation protein therapeutics with remarkable success has surged the development of antibody engineering to design molecules for optimizing affinity, better efficacy, greater safety and therapeutic function. Therefore, computational methods have become increasingly important to generate hypotheses, interpret and guide experimental works. In this chapter, we discussed the overall antibody design by computational approches.

A Combinatory Antibody-Antigen Microarray Assay for High-Content Screening of Single-Chain Fragment Variable Clones from Recombinant Libraries

We have developed a combinatory antibody–antigen microarray for direct screening of multiple single-chain fragment variable (scFv) clones with no need for pre-purification or enrichment before screening. The straightforward workflow allows for early selection of binders to predefined peptide and glycopeptide targets. A capture antibody is contact printed on microarray slides, side by side with the antigens of interest. A large number of scFv clones, in supernatants, are printed on top of the capture antibody and the antigen in a “spot-on-spot” print. The printed scFv clones, which bind to the capture antibody, are detected using biotinylated antigen, while the binding of scFv clones to the printed antigen is detected through a mouse anti-tag antibody. Two different analyses are thus performed on the same slide, generating two kinds of information: one on the ability of an individual scFv clone to bind to the soluble form of the antigen, which may favour selection for higher affinity rather than avidity, while the other allows the identification of large numbers of clones, simultaneously, due to the binding of scFv clones to densely presented antigens, thus providing an overall increased hit rate. The functionality of the new screening approach was illustrated through the generation of antibodies against peptides from the chaperone complex Ku70/Ku80 and the GalNAcα-serine/threonine epitope on the IgA1 alpha chain hinge region. In total, 659 scFv clones were screened with a hit rate of approximately 20%. This approach allowed the identification of functional antibodies in both cases, illustrating the usefulness and capacity of this combinatory microarray screening technique for efficient analysis and validation of antibodies at an early stage of antibody generation.

Applicability of predictive toxicology methods for monoclonal antibody therapeutics: status Quo and scope

Biopharmaceuticals, monoclonal antibody (mAb)-based therapeutics in particular, have positively impacted millions of lives. MAbs and related therapeutics are highly desirable from a biopharmaceutical perspective as they are highly target specific and well tolerated within the human system. Nevertheless, several mAbs have been discontinued or withdrawn based either on their inability to demonstrate efficacy and/or due to adverse effects. Approved monoclonal antibodies and derived therapeutics have been associated with adverse effects such as immunogenicity, cytokine release syndrome, progressive multifocal leukoencephalopathy, intravascular haemolysis, cardiac arrhythmias, abnormal liver function, gastrointestinal perforation, bronchospasm, intraocular inflammation, urticaria, nephritis, neuropathy, birth defects, fever and cough to name a few. The advances made in this field are also impeded by a lack of progress in bioprocess development strategies as well as increasing costs owing to attrition, wherein the lack of efficacy and safety accounts for nearly 60 % of all factors contributing to attrition. This reiterates the need for smarter preclinical development using quality by design-based approaches encompassing carefully designed predictive models during early stages of drug development. Different in vitro and in silico methods are extensively used for predicting biological activity as well as toxicity during small molecule drug development; however, their full potential has not been utilized for biological drug development. The scope of in vitro and in silico tools in early developmental stages of monoclonal antibody-based therapeutics production and how it contributes to lower attrition rates leading to faster development of potential drug candidates has been evaluated. The applicability of computational toxicology approaches in this context as well as the pitfalls and promises of extending such techniques to biopharmaceutical development has been highlighted.

Research and development of therapeutic mAbs: An analysis based on pipeline projects

As the subject of active research and development (R&D) in recent decades, monoclonal antibodies have emerged among the major classes of therapeutic agents for treatment of many human diseases, especially cancers, infections, and immunological disorders. This article surveys the landscape of R&D projects of therapeutic monoclonal antibodies (mAbs), which are mostly used for disease immunotherapy, from a number of perspectives, including therapeutic indications, development phases, participants, and citation of related patents. The results of this research can be used as a reference resource for pharmaceutical researchers, investors, and policymakers in the field of therapeutic mAbs.

Glypican-3 Targeting Immunotoxins for the Treatment of Liver Cancer

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer, yet no effective therapeutics exist. This review provides an overview of the recent development of recombinant immunotoxins for the treatment of glypican-3 (GPC3) expressing HCC. GPC3 is a cell surface heparan sulfate proteoglycan that is overexpressed in HCC, but is absent from normal adult human tissues. Treatment of HCC with anti-GPC3 immunotoxins represents a new therapeutic option. Using phage display and hybridoma technologies, three high affinity antibodies (HN3, HS20 and YP7) have been generated against GPC3. Two of these antibodies (HN3 and HS20) have demonstrated the ability to inhibit Wnt/Yap signaling, leading to a reduction in liver cancer cell proliferation. By combining the HN3 antibody capable of inhibiting Wnt/Yap signaling with the protein synthesis inhibitory domain of the Pseudomonas exotoxin, a recombinant immunotoxin that exhibits a dual inhibitory mechanism was generated. This immunotoxin was found to be highly effective in the treatment of human HCCs in mouse xenograft models. Engineering of the toxin fragment to reduce the level of immunogenicity is currently being explored. The development of immunotoxins provides opportunities for novel liver cancer therapies.

Farewell to Animal Testing: Innovations on Human Intestinal Microphysiological Systems

The human intestine is a dynamic organ where the complex host-microbe interactions that orchestrate intestinal homeostasis occur. Major contributing factors associated with intestinal health and diseases include metabolically-active gut microbiota, intestinal epithelium, immune components, and rhythmical bowel movement known as peristalsis. Human intestinal disease models have been developed; however, a considerable number of existing models often fail to reproducibly predict human intestinal pathophysiology in response to biological and chemical perturbations or clinical interventions. Intestinal organoid models have provided promising cytodifferentiation and regeneration, but the lack of luminal flow and physical bowel movements seriously hamper mimicking complex host-microbe crosstalk. Here, we discuss recent advances of human intestinal microphysiological systems, such as the biomimetic human "Gut-on-a-Chip" that can employ key intestinal components, such as villus epithelium, gut microbiota, and immune components under peristalsis-like motions and flow, to reconstitute the transmural 3D lumen-capillary tissue interface. By encompassing cutting-edge tools in microfluidics, tissue engineering, and clinical microbiology, gut-on-a-chip has been leveraged not only to recapitulate organ-level intestinal functions, but also emulate the pathophysiology of intestinal disorders, such as chronic inflammation. Finally, we provide potential perspectives of the next generation microphysiological systems as a personalized platform to validate the efficacy, safety, metabolism, and therapeutic responses of new drug compounds in the preclinical stage.