Drug Development of Therapeutic Monoclonal Antibodies

Identification of novel PD-1/PD-L1 small molecule inhibitors: virtual screening, synthesis and in vitro characterisation

The PD-1/PD-L1 pathway is considered as one of the most promising immune checkpoints in tumour immunotherapy. However, researchers are faced with the inherent limitations of antibodies, driving them to pursue PD-L1 small molecule inhibitors. Virtual screening followed by experimental validation is a proven approach to discover active compounds. In this study, we employed multistage virtual screening methods to screen multiple compound databases to predict new PD-1/PD-L1 ligands. 35 compounds were proposed by combined analysis of fitness scores, interaction pattern and MM-GBSA binding affinities. Enzymatic assay confirmed that 10 out of 35 ligands were potential PD-L1 inhibitors, with inhibitory rate higher than 50% at the concentration of 30 µM. Among them, ZDS20 was identified as the most effective inhibitor with low micromolar activity (IC50 = 3.27 μM). Altogether, ZDS20 carrying novel scaffold was identified and could serve as a lead for the development of new classes of PD-L1 inhibitors.

Optimizing early phase clinical trial washout periods: a report from the Therapeutic Advances in Childhood Leukemia and Lymphoma consortium

BACKGROUND

The National Cancer Institute (NCI) issued a 2021 memorandum adopting the American Society of Clinical Oncology (ASCO) and Friends of Cancer Research (Friends) task force recommendations to broaden clinical study eligibility criteria. They recommended that washout periods be eliminated for most prior cancer therapy and when required to utilize evidence- and/or rationale-based criteria. The Therapeutic Advances in Childhood Leukemia and Lymphoma (TACL) consortium responded to this guidance.

METHODS

A TACL task force reviewed the consortium's research portfolio, the relevant literature and guidance documents from ASCO-Friends, NCI, and US Food and Drug Administration to make expert consensus and evidence-based recommendations for modernizing, broadening, and codifying TACL-study washout periods while ensuring consistency with pediatric ethics, and federal regulations. TACL's screening log was reviewed to estimate the impact that updated washout periods would have on patient inclusivity and recruitment.

RESULTS

Over a 19-year period, 42 (14.6% of all screened ineligible patients [n = 287]) patients were identified as excluded from TACL early phase studies exclusively because of not meeting washout criteria. An additional 6 (2.1%) did not meet washout and at least 1 other exclusion criterion. A new TACL washout guidance document was developed and then adopted for use. Where washout criteria were not eliminated, rationale- and/or evidenced-based criteria were established with citation.

CONCLUSION

In an effort to reduce unnecessary exclusion from clinical trials, TACL created rationale- and/or evidenced-based washout period standards largely following guidance from the NCI and ASCO-Friends recommendations. These new, expanded eligibility criteria are expected to increase access to TACL clinical trials while maintaining safety and scientific excellence.

Immunogenicity of monoclonal antibody: Causes, consequences, and control strategies

Antibody-based treatment was first used in 1891 for the treatment of diphtheria. Since then, monoclonal antibodies (mAbs) have been developed to treat many diseases such as cancer and act as vaccines. However, murine-derived therapeutic mAbs were found to be highly immunogenic, and caused anti-drug antibodies (ADAs) reaction, reducing their efficacy and causing severe infusion reactions. Fully human, humanised, and chimeric antibodies were then introduced for better therapeutic efficacy. With the introduction of immune response associated with mAbs immunogenicity. This review explores the immunogenicity of mAbs, its mechanism, contributing factors, and its impact on therapeutic efficacy. It also discusses immunogenicity assessment for preclinical studies and strategies for minimising immunogenicity for effective therapeutic treatment in various diseases. Finally, predicting immunogenicity in drug development is essential for selecting top drug candidates. A lot of methods can be implemented by the researchers and developers to reduce the development of ADAs while simultaneously minimising the immunogenicity reaction of mAbs.

Emerging trends and therapeutic applications of monoclonal antibodies

Monoclonal antibodies (mAbs) are being used to prevent, detect, and treat a broad spectrum of malignancies and infectious and autoimmune diseases. Over the past few years, the market for mAbs has grown exponentially. They have become a significant part of many pharmaceutical product lines, and more than 250 therapeutic mAbs are undergoing clinical trials. Ever since the advent of hybridoma technology, antibody-based therapeutics were realized using murine antibodies which further progressed into humanized and fully human antibodies, reducing the risk of immunogenicity. Some of the benefits of using mAbs over conventional drugs include a drastic reduction in the chances of adverse reactions, interactions between drugs, and targeting specific proteins. While antibodies are very efficient, their higher production costs impede the process of commercialization. However, their cost factor has been improved by developing biosimilar antibodies, which are affordable versions of therapeutic antibodies. Along with biosimilars, innovations in antibody engineering have helped to design bio-better antibodies with improved efficacy than the conventional ones. These novel mAb-based therapeutics are set to revolutionize existing drug therapies targeting a wide spectrum of diseases, thereby meeting several unmet medical needs. In the future, mAbs generated by applying next-generation sequencing (NGS) are expected to become a powerful tool in clinical therapeutics. This article describes the methods of mAb production, pre-clinical and clinical development of mAbs, approved indications targeted by mAbs, and novel developments in the field of mAb research.

Discovery of Daclatasvir as a potential PD-L1 inhibitor from drug repurposing

This study employed a drug repositioning strategy to discover novel PD-L1 small molecule inhibitors. 3D-QSAR pharmacophore models were establishedand subsequently validated through various means to select a robust model, Hypo-1, suitable for virtual screening. Hypo1 was used toscreen a library of 7,475 compounds from the Drugbank database, leading to the identification of 283 molecules following molecular docking with PD-L1.19 compounds underwent HTRF assays, with 15 showing varying degrees of inhibition of the PD-1/PD-L1 interaction. Compounds2202,2204,2207, and2208were further confirmed to bind to PD-L1 using SPR experiments. Among them, compound2204(Daclatasvir, KD = 11.4 μM) showeda higher affinity for human PD-L1 than the control compound BMS-1. In the HepG2/Jurkat cell co-culture model, Daclatasvir effectively activated Jurkat cells to kill HepG2 cells. In the mouse H22 hepatocellular tumor model, Daclatasvir significantly inhibited tumor growth (TGI = 53.4 % at a dose of 100 mg/kg). Its anti-tumor effect was more pronounced when combined with Lenvatinib (TGI = 85.1 %). Flow cytometry analysis of splenocytes and tumor cells indicated that Daclatasvir activated the immune system in both models. In summary, Daclatasvir was identified as a novel PD-L1small molecule inhibitor.

Immunological Drug-Drug Interactions Affect the Efficacy and Safety of Immune Checkpoint Inhibitor Therapies

With the rapid expansion in the development and clinical utility of immune checkpoint inhibitors (ICIs) for oncology, the continual evaluation of the safety profile of such agents is imperative. The safety profile of ICIs as monotherapy is dominated by immune-related adverse events, which can be considered as an extension of the mechanism of action of these immunomodulatory drugs. Further to this, an emerging theme is that ICI treatment can significantly impact upon the tolerability of coadministered medications. Numerous reports in literature indicate that ICIs may alter the immunological perception of coadministered drugs, resulting in undesirable reactions to a variety of concomitant medications. These reactions can be severe in manifestation, including hepatotoxicity and Stevens-Johnson Syndrome (SJS)/toxic epidermal necrolysis (TEN), but may also have detrimental impact on malignancy control. To minimize the impact of such drug-drug interactions on patients, it is imperative to identify medications that may cause these reactions, understand the underlying mechanisms, consider the timing and dosing of comedication, and explore alternative medications with comparable efficacies. Improving our understanding of how concomitant medications affect the safety and efficacy of ICIs can allow for potential culprit drugs to be identified/removed/desensitized. This approach will allow the continuation of ICI therapy that may have been discontinued otherwise, thereby improving malignant control and patient and drug development outcomes.

Stability of Protein Pharmaceuticals: Recent Advances

There have been significant advances in the formulation and stabilization of proteins in the liquid state over the past years since our previous review. Our mechanistic understanding of protein-excipient interactions has increased, allowing one to develop formulations in a more rational fashion. The field has moved towards more complex and challenging formulations, such as high concentration formulations to allow for subcutaneous administration and co-formulation. While much of the published work has focused on mAbs, the principles appear to apply to any therapeutic protein, although mAbs clearly have some distinctive features. In this review, we first discuss chemical degradation reactions. This is followed by a section on physical instability issues. Then, more specific topics are addressed: instability induced by interactions with interfaces, predictive methods for physical stability and interplay between chemical and physical instability. The final parts are devoted to discussions how all the above impacts (co-)formulation strategies, in particular for high protein concentration solutions.'

Recent Advances in Enterovirus A71 Infection and Antiviral Agents

Enterovirus A71 (EV-A71) is one of the major causative agents of hand, foot, and mouth disease (HFMD) that majorly affects children. Most of the time, HFMD is a mild disease but can progress to severe complications, such as meningitis, brain stem encephalitis, acute flaccid paralysis, and even death. HFMD caused by EV-A71 has emerged as an acutely infectious disease of highly pathogenic potential in the Asia-Pacific region. In this review, we introduced the properties and life cycle of EV-A71, and the pathogenesis and the pathophysiology of EV-A71 infection, including tissue tropism and host range of virus infection, the diseases caused by the virus, as well as the genes and host cell immune mechanisms of major diseases caused by enterovirus 71 (EV-A71) infection, such as encephalitis and neurologic pulmonary edema. At the same time, clinicopathologic characteristics of EV-A71 infection were introduced. There is currently no specific medication for EV-A71 infection, highlighting the urgency and significance of developing suitable anti-EV-A71 agents. This overview also summarizes the targets of existing anti-EV-A71 agents, including virus entry, translation, polyprotein processing, replication, assembly and release; interferons; interleukins; the mitogen-activated protein kinase, phosphatidylinositol 3-kinase, and protein kinase B signaling pathways; the oxidative stress pathway; the ubiquitin-proteasome system; and so on. Furthermore, it overviews the effects of natural products, monoclonal antibodies, and RNA interference against EV-A71. It also discusses issues limiting the research of antiviral drugs. This review is a systematic and comprehensive summary of the mechanism and pathological characteristics of EV-A71 infection, the latest progress of existing anti-EV-A71 agents. It would provide better understanding and guidance for the research and application of EV-A71 infection and antiviral inhibitors.

Immunological Assessment of Recent Immunotherapy for Colorectal Cancer

Colorectal cancer (CRC) is the third most prevalent malignancy with increased incidence and mortality rates worldwide. Traditional treatment approaches have attempted to efficiently target CRC; however, they have failed in most cases, owing to the cytotoxicity and non-specificity of these therapies. Therefore, it is essential to develop an effective alternative therapy to improve the clinical outcomes in heterogeneous CRC cases. Immunotherapy has transformed cancer treatment with remarkable efficacy and overcomes the limitations of traditional treatments. With an understanding of the cancer-immunity cycle and tumor microenvironment evolution, current immunotherapy approaches have elicited enhanced antitumor immune responses. In this comprehensive review, we outline the latest advances in immunotherapy targeting CRC and provide insights into antitumor immune responses reported in landmark clinical studies. We focused on highlighting the combination approaches that synergistically induce immune responses and eliminate immunosuppression. This review aimed to understand the limitations and potential of recent immunotherapy clinical studies conducted in the last five years (2019-2023) and to transform this knowledge into a rational design of clinical trials intended for effective antitumor immune responses in CRC.

Novel 4-Arylindolines Containing a Pyrido[3,2-d]pyrimidine Moiety as the Programmed Cell Death-1/Programmed Cell Death-Ligand 1 Interaction Inhibitors for Tumor Immunotherapy

A series of pyrido[3,2-d]pyrimidine-containing 4-arylindolines were identified as potent inhibitors of the programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) interaction by structural optimization of a 4-arylindoline precursor reported previously. Among them, compound N11 was the most promising inhibitor, showing an IC50 value of 6.3 nM against the PD-1/PD-L1 interaction at the biochemical level. In in vitro T-cell tumor co-culture models, N11 significantly promoted T-cell proliferation, activation, and infiltration into tumor spheres, demonstrating that it possessed excellent immunomodulatory activity. In addition, N11 exhibited favorable in vivo antitumor activity in an LLC/PD-L1 tumor-bearing mouse model. Flow cytometry analysis verified that the in vivo antitumor efficacy of N11 was dependent on the activation of the immune microenvironment. These findings suggest that N11 can serve as a new starting point for the future development of small-molecule antitumor immunomodulators targeting the PD-1/PD-L1 axis.

Added Value of Internal Fragments for Top-Down Mass Spectrometry of Intact Monoclonal Antibodies and Antibody-Drug Conjugates

Monoclonal antibodies (mAbs) and antibody-drug conjugates (ADCs) are two of the most important therapeutic drug classes that require extensive characterization, whereas their large size and structural complexity make them challenging to characterize and demand the use of advanced analytical methods. Top-down mass spectrometry (TD-MS) is an emerging technique that minimizes sample preparation and preserves endogenous post-translational modifications (PTMs); however, TD-MS of large proteins suffers from low fragmentation efficiency, limiting the sequence and structure information that can be obtained. Here, we show that including the assignment of internal fragments in native TD-MS of an intact mAb and an ADC can improve their molecular characterization. For the NIST mAb, internal fragments can access the sequence region constrained by disulfide bonds to increase the TD-MS sequence coverage to over 75%. Important PTM information, including intrachain disulfide connectivity and N-glycosylation sites, can be revealed after including internal fragments. For a heterogeneous lysine-linked ADC, we show that assigning internal fragments improves the identification of drug conjugation sites to achieve a coverage of 58% of all putative conjugation sites. This proof-of-principle study demonstrates the potential value of including internal fragments in native TD-MS of intact mAbs and ADCs, and this analytical strategy can be extended to bottom-up and middle-down MS approaches to achieve even more comprehensive characterization of important therapeutic molecules.

Production of monoclonal antibodies for therapeutic purposes: A review

Monoclonal antibodies (mAbs) have been used in the development of immunotherapies that target a variety of diseases, such as cancer, autoimmune diseases, and even viral infections; they play a key role in immunization and are expected after vaccination. However, some conditions do not promote the development of neutralizing antibodies. Production and use of mAbs, generated in biofactories, represent vast potential as aids in immunological responses when the organism cannot produce them on their own, these convey unique specificity by recognizing and targeting specific antigen. Antibodies can be defined as heterotetrametric glycoproteins of symmetric nature, and they participate as effector proteins in humoral responses. Additionally, there are different types of mAbs (murine, chimeric, humanized, human, mAbs as Antibody-drug conjugates and bispecific mAbs) discussed in the present work. When these molecules are produced in vitro as mAbs, several common techniques, such as hybridomas or phage display are used. There are several preferred cell lines that function as biofactories, for the production of mAbs, the selection of which rely on the variation of adaptability, productivity and both phenotypic and genotypic shifts. After the cell expression systems and culture techniques are used, there are diverse specialized downstream processes to achieve desired yield and isolation as well as product quality and characterization. Novel perspectives regarding these protocols represent a potential improvement for mAbs high-scale production.

A Review of the Pharmacokinetic Characteristics of Immune Checkpoint Inhibitors and Their Clinical Impact Factors

Immune checkpoint inhibitors (ICIs) have been shown to be significant in improving the overall survival rate in certain malignancies with poor prognoses. However, only 20-40% of patients achieve long-term benefits, highlighting the relevance of the factors that influence the treatment, which can help clinicians improve their results and guide the development of new immune checkpoint therapies. In this study, the current pharmacokinetic aspects associated with the ICIs and the factors influencing clinical efficacy were characterised, including in terms of drug metabolism, drug clearance, hormonal effects and immunosuppressive effects.

Succinate Buffer in Biologics Products: Real-world Formulation Considerations, Processing Risks and Mitigation Strategies

The succinic acid/succinate system has an excellent buffering capacity at acidic pH values (4.5-6.0), promising to be a buffer of choice for biologics having slightly acidic to basic isoelectric points (pI 6 - 9). However, its prevalence in drug products is limited due to the propensity (risk) of its components to crystallize during freezing and the consequent shift in the pH which might affect the product stability. Most of these previous assessments have been performed under operational conditions that do not simulate typical drug product processing conditions. In this work, we have characterized the physicochemical behavior of succinate formulations under representative pharmaceutical conditions. Our results indicate that the pH increases by ∼ 1.2 units in 25 mM and 250 mM succinate buffers at pharmaceutically relevant freezing conditions. X-ray diffractometry studies revealed selective crystallization of monosodium succinate, which is posed as the causative mechanism. This salt crystallization was not observed in the presence of 2% w/v sucrose, suggesting that this pH shift can be mitigated by including sucrose in the formulation. Additionally, three monoclonal antibodies (mAbs) that represent different IgG subtypes and span a range of pIs (5.9 - 8.8) were formulated with succinate and sucrose and subjected to freeze-thaw, frozen storage and lyophilization. No detrimental impact on quality attributes (QA) such as high molecular weight (HMW) species, turbidity, alteration in protein concentration and sub-visible particles, was observed of any of the mAbs tested. Lastly, drug formulations lyophilized in succinate buffer with sucrose demonstrated acceptable QA profiles upon accelerated kinetic storage stability, supporting the use of succinate buffers in mAb drug products.

AbAgIntPre: A deep learning method for predicting antibody-antigen interactions based on sequence information

Introduction

Antibody-mediated immunity is an essential part of the immune system in vertebrates. The ability to specifically bind to antigens allows antibodies to be widely used in the therapy of cancers and other critical diseases. A key step in antibody therapeutics is the experimental identification of antibody-antigen interactions, which is generally time-consuming, costly, and laborious. Although some computational methods have been proposed to screen potential antibodies, the dependence on 3D structures still limits the application of these methods.

Methods

Here, we developed a deep learning-assisted prediction method (i.e., AbAgIntPre) for fast identification of antibody-antigen interactions that only relies on amino acid sequences. A Siamese-like convolutional neural network architecture was established with the amino acid composition encoding scheme for both antigens and antibodies.

Results and Discussion

The generic model of AbAgIntPre achieved satisfactory performance with the Area Under Curve (AUC) of 0.82 on a high-quality generic independent test dataset. Besides, this approach also showed competitive performance on the more specific SARS-CoV dataset. We expect that AbAgIntPre can serve as an important complement to traditional experimental methods for antibody screening and effectively reduce the workload of antibody design. The web server of AbAgIntPre is freely available at http://www.zzdlab.com/AbAgIntPre.

Covariate analysis of tusamitamab ravtansine, a DM4 anti‐CEACAM5 antibody‐drug conjugate, based on first‐in‐human study

Tusamitamab ravtansine is an anti‐CEACAM5 antibody‐drug conjugate indicated in patients with solid tumors. Based on a previous developed semimechanistic model describing simultaneously pharmacokinetic (PK) of SAR408701, two of its active metabolites: DM4 and methyl‐DM4 and naked antibody, with integration of drug‐to‐antibody data, the main objective of the present analysis was to evaluate covariate’s impact in patients from phase I/II study (n = 254). Demographic and pathophysiologic baseline covariates were explored to explain interindividual variability on each entity PK parameter. Model parameters were estimated with good precision. Five covariates were included in the final PK model: body surface area (BSA), tumor burden, albumin, circulating target, and gender. Comparison of BSA‐adjusted dosing and flat dosing supported the current BSA‐based dosing regimen, to limit under and over exposure in patients with extreme BSA. Overall, this model characterized accurately the PKs of all entities and highlighted sources of PK variability. By integrating mechanistic considerations, this model aimed to improve understanding of the SAR408701 complex disposition while supporting key steps of clinical development.

Knowledge Gaps in the Pharmacokinetics of Therapeutic Proteins in Pediatric Patients

Therapeutic proteins such as monoclonal antibodies and their derivatives, fusions proteins, hormone analogs and enzymes for replacement therapy are an ever-growing mainstay in our pharmacopoeia. While a growing number of these medications are developed for and used in younger and younger pediatric patients, knowledge gaps in the basic understanding of the molecular and physiologic processes governing the disposition of these compounds in the human body and their modulation by age and childhood development are a hindrance to the effective and timely development and clinical use of these compounds, especially in very young pediatric patient populations. This is particularly the case for the widespread lack of information on the ontogeny and age-associated expression and function of receptor systems that are involved in the molecular processes driving the pharmacokinetics of these compounds. This article briefly highlights three receptor systems as examples, the neonatal Fc receptor, the asialoglycoprotein receptor, and the mannose receptor. It furthermore provides suggestions on how these gaps should be addressed and prioritized to provide the field of pediatric clinical pharmacology the urgently needed tools for a more effective development and clinical utilization of this important class of drugs with rapidly evolving importance as cornerstone in pediatric pharmacotherapy.

Folic Acid-Decorated β-Cyclodextrin-Based Poly(ε-caprolactone)-dextran Star Polymer with Disulfide Bond-Linker as Theranostic Nanoparticle for Tumor-Targeted MRI and Chemotherapy

β-cyclodextrin(βCD)-based star polymers have attracted much interest because of their unique structures and potential biomedical and biological applications. Herein, a well-defined folic acid (FA)-conjugated and disulfide bond-linked star polymer ((FA-Dex-SS)-βCD-(PCL)₁₄) was synthesized via a couple reaction between βCD-based 14 arms poly(ε-caprolactone) (βCD-(PCL)₁₄) and disulfide-containing α-alkyne dextran (alkyne-SS-Dex), and acted as theranostic nanoparticles for tumor-targeted MRI and chemotherapy. Theranostic nanoparticles were obtained by loading doxorubicin (DOX), and superparamagnetic iron oxide (SPIO) particles were loaded into the star polymer nanoparticles to obtain ((FA-Dex-SS)-βCD-(PCL)₁₄@DOX-SPIO) theranostic nanoparticles. In vitro drug release studies showed that approximately 100% of the DOX was released from disulfide bond-linked theranostic nanoparticles within 24 h under a reducing environment in the presence of 10.0 mM GSH. DOX and SPIO could be delivered into HepG2 cells efficiently, owing to the folate receptor-mediated endocytosis process of the nanoparticles and glutathione (GSH), which triggered disulfide-bonds cleaving. Moreover, (FA-Dex-SS)-βCD-(PCL)₁₄@DOX-SPIO showed strong MRI contrast enhancement properties. In conclusion, folic acid-decorated reduction-sensitive star polymeric nanoparticles are a potential theranostic nanoparticle candidate for tumor-targeted MRI and chemotherapy.

Improving antibody drug development using bionanotechnology

Monoclonal antibodies are being used to treat a remarkable breadth of human disorders. Nevertheless, there are several key challenges at the earliest stages of antibody drug development that need to be addressed using simple and widely accessible methods, especially related to generating antibodies against membrane proteins and identifying antibody candidates with drug-like biophysical properties (high solubility and low viscosity). Here we highlight key bionanotechnologies for preparing functional and stable membrane proteins in diverse types of lipoparticles that are being used to improve antibody discovery and engineering efforts. We also highlight key bionanotechnologies for high-throughput and ultra-dilute screening of antibody biophysical properties during antibody discovery and optimization that are being used for identifying antibodies with superior combinations of in vitro (formulation) and in vivo (half-life) properties.

Pharmacokinetic Modeling and Predictive Performance: Practical Considerations for Therapeutic Monoclonal Antibodies

Population pharmacokinetic (PopPK) model parameter estimation and predictive performance depend on the data adequacy for model building. PopPK models of therapeutic monoclonal antibodies (mAbs) may not be well supported by commonly used sparse sampling in late-stage development because of the slow absorption (days) and long half-life (weeks) of mAbs, affecting accuracy of predicted exposure metrics which are often used to support drug development. A case study was presented for a representative mAb to compare the predictive performance of two established PopPK models from their respective data. Differences in datasets for model building (including sample size, sampling schedule and route of administration), model structure and parameters, and key derived exposure metrics were compared, and the resulting differences in model prediction were elaborated. With the majority of the data used for developing models being trough concentration (C_trough) data, both models projected similar C_trough and area under the concentration-time curve (AUC) but different peak concentrations (C_max) at steady state following the same subcutaneous dose regimen. Our case study supports the importance of appropriate sampling schemes for PopPK model development and exposure metric estimation. We recommend collecting proper random pharmacokinetic samples, in addition to troughs, to allow adequate characterization of PopPK models for mAbs. Selecting the informative model and relevant pharmacokinetic metrics could be critical in driving drug development decision-making, especially in simulation-based exposure matching to inform doses in special populations such as pediatrics.

Immune Checkpoint and Anti-Angiogenic Antibodies for the Treatment of Non-Small Cell Lung Cancer in the European Union and United States

Several types of antibodies (Abs) are currently used in non-small cell lung cancer (NSCLC). Anti-angiogenic and immune checkpoint inhibitor (ICI) Abs are the most frequent treatments used alone or with chemotherapy in metastatic NSCLC, for the front line and beyond. Considering the many therapeutic options for locally advanced and metastatic lung cancer and differences in use according to geographic area, we present here a comprehensive review of the marketed ICI and anti-angiogenic Abs approved in the European Union (EU) and the US to treat locally advanced and metastatic NSCLC patients. We briefly describe the different molecules and their development in thoracic oncology and compare pharmacokinetic data, processing decision algorithms and marketing authorizations by the EMA and US Food and Drug Administration (FDA).

Pediatric Dose Selection for Therapeutic Proteins

In selecting optimal dosing regimens in support of the clinical use of monoclonal antibodies and other therapeutic proteins in pediatric indications, the unique pharmacokinetic properties of this class of biologics, as well as the underlying physiologic and pathophysiologic processes and their modulation by childhood growth and development, needs to be appreciated. During drug development, first-in-pediatric dose selection is a capstone event in the pediatric investigation plan that relies heavily on extrapolation of pharmacokinetic and pharmacodynamic data from adult to pediatric populations. It is facilitated by combinations of pharmacometric approaches, including allometry, physiologically based pharmacokinetic modeling, and population pharmacokinetic analyses, although data on reliability and qualification of some of these tools in the context of therapeutic proteins are still limited but emerging. Presented data suggest nonlinear relationships between body weight and both clearance and volume of distribution for therapeutic proteins in pediatric populations, with allometric exponents of 0.75 and 0.8, respectively. For newborns and infants (<1 year), even higher nonlinearity seems to occur. Translation of the quantitative characterization of the pediatric pharmacokinetics of therapeutic proteins into dosing regimens for the drug label requires compromising between precision dosing and clinical practicability, with tiered dosing algorithms based on size or age strata being the currently most frequently applied methodology.

T cell mediated hypersensitivity to previously tolerated iodinated contrast media precipitated by introduction of atezolizumab

Many adverse reactions associated with immune checkpoint inhibitor (ICI) treatments are immunologically driven and may necessitate discontinuation of the ICI. Herein, we present a patient who had been administered the radio contrast media amidotrizoate multiple times without issue but who then developed a Stevens-Johnson syndrome reaction after coadministration of atezolizumab. Causality was confirmed by a positive re-challenge with amidotrizoate and laboratory investigations that implicated T cells. Importantly, the introduction of atezolizumab appears to have altered the immunologic response to amidotrizoate in terms of the tolerance–elicitation continuum. Proof of concept studies demonstrated enhancement of recall responses to a surrogate antigen panel following in-vitro (healthy donors) and in-vivo (ICI patients) administrations of ICIs. Our findings highlight the importance of considering all concomitant medications in patients on ICIs who develop immune-mediated adverse reactions. In the event of some immune-related adverse reactions, it may be critical to identify the culprit antigen-forming entity that the ICIs have altered the perception of rather than simply attribute causality to the ICI itself in order to optimize both patient safety and treatment of malignancies.

Which factors matter the most? Revisiting and dissecting antibody therapeutic doses

Factors such as antibody clearance and target affinity can influence antibodies' effective doses for specific indications. However, these factors vary considerably across antibody classes, precluding direct and quantitative comparisons. Here, we apply a dimensionless metric, the therapeutic exposure affinity ratio (TEAR), which normalizes the therapeutic doses by antibody bioavailability, systemic clearance and target-binding property to enable direct and quantitative comparisons of therapeutic doses. Using TEAR, we revisited and dissected the doses of up to 60 approved antibodies. We failed to detect a significant influence of target baselines, turnovers or anatomical locations on antibody therapeutic doses, challenging the traditional perceptions. We highlight the importance of antibodies' modes of action for therapeutic doses and dose selections; antibodies that work through neutralizing soluble targets show higher TEARs than those working through other mechanisms. Overall, our analysis provides insights into the factors that influence antibody doses, and the factors that are crucial for antibodies' pharmacological effects.

Electron Transfer Dissociation Parameter Optimization Using Design of Experiments Increases Sequence Coverage of Monoclonal Antibodies

Middle-down analysis of monoclonal antibodies (mAbs) by tandem mass spectrometry (MS²) can provide detailed insight into their primary structure with minimal sample preparation. The middle-down approach uses an enzyme to cleave mAbs into Fc/2, LC, and Fd subunits that are then analyzed by reversed phase liquid chromatography tandem mass spectrometry (RPLC-MS²). As maximum sequence coverage is desired to obtain meaningful structural information at the subunit level, a host of dissociation methods have been developed, and sometimes combined, to bolster fragmentation and increase the number of identified fragments. Here, we present a design of experiments (DOE) approach to optimize MS² parameters, in particular those that may influence electron transfer dissociation (ETD) efficiency to increase the sequence coverage of antibody subunits. Applying this approach to the NIST monoclonal antibody standard (NISTmAb) using three RPLC-MS² runs resulted in high sequence coverages of 67%, 67%, and 52% for Fc/2, LC, and Fd subunits, respectively. In addition, we apply this DOE strategy to model the parameters required to maximize the number of fragments produced in "low", "medium", and "high" mass ranges, which ultimately resulted in even higher sequence coverages of NISTmAb subunits (75%, 78%, and 64% for Fc/2, LC, and Fd subunits, respectively). The DOE approach provides high sequence coverage percentages utilizing only one fragmentation method, ETD, and could be extended to other state-of-the-art techniques that combine multiple fragmentation mechanisms to increase coverage.

Recent advance of peptide-based molecules and nonpeptidic small-molecules modulating PD-1/PD-L1 protein-protein interaction or targeting PD-L1 protein degradation

Tumor immunotherapy has made great progress in recent years. In the tumor microenvironment, the binding of PD-1 and its ligand PD-L1 can promote tumor immune escape and tumor survival. Clinical studies have indicated that antibodies blocking PD-1 and PD-L1 have reliable effects on many advanced malignant tumors. However, no small-molecule inhibitors have been approved so far, indicating that the development of marketable small-molecules PD-1/PD-L1 targeted therapy drugs is a challenging process. Small-molecule inhibitors can overcome the limitations of monoclonal antibodies, including poor oral bioavailability, high cost, poor tissue and tumor penetration and long half-life, which prompt researchers to turn their attention to the development of peptide molecules and small-molecule inhibitors modulating PD-1/PD-L1 to overcome some disadvantages of monoclonal antibodies or targeting PD-L1 protein degradation as potential alternatives or supplements. In this review, we will focus on the peptide-based and nonpeptidic molecules against PD-1/PD-L1 base on the structural classification. More importantly, we also focus on the latest research progress of small-molecules mediated PD-L1 degradation mechanism.

Recent Advances in Monoclonal Antibody Therapy for Colorectal Cancers

Colorectal cancer (CRC) is one of the leading causes of cancer deaths worldwide. Recent advances in recombinant DNA technology have led to the development of numerous therapeutic antibodies as major sources of blockbuster drugs for CRC therapy. Simultaneously, increasing numbers of therapeutic targets in CRC have been identified. In this review, we first highlight the physiological and pathophysiological roles and signaling mechanisms of currently known and emerging therapeutic targets, including growth factors and their receptors as well as immune checkpoint proteins, in CRC. Additionally, we discuss the current status of monoclonal antibodies in clinical development and approved by US Food and Drug Administration for CRC therapy.

Galcanezumab for the prevention of migraine

Migraine is a common and disabling disorder affecting approximately 1.02 billion people worldwide. Calcitonin gene-related peptide (CGRP) has been identified as playing an important role in the pathophysiology of migraine and several migraine-specific therapies targeting the CGRP ligand or its receptor have been approved since 2018 for the acute and preventive treatment of migraine. This review focuses on the pharmacology, clinical efficacy and safety/tolerability of galcanezumab, an anti-CGRP monoclonal antibody approved for the prevention of migraine.

From cell line development to the formulated drug product: The art of manufacturing therapeutic monoclonal antibodies

Therapeutic monoclonal antibodies and related products have steadily grown to become the dominant product class within the biopharmaceutical market. Production of antibodies requires special precautions to ensure safety and efficacy of the product. In particular, minimizing antibody product heterogeneity is crucial as drug substance variants may impair the activity, efficacy, safety, and pharmacokinetic properties of an antibody, consequently resulting in the failure of a product in pre-clinical and clinical development. This review will cover the manufacturing and formulation challenges and advances of therapeutic monoclonal antibodies, focusing on improved processes to minimize variants and ensure batch-to-batch consistency. Processes put in place by regulatory agencies, such as Quality-by-Design (QbD) and current Good Manufacturing Practices (cGMP), and how their implementation has aided drug development in pharmaceutical companies will be reviewed. Advances in formulation and considerations on the intended use of a therapeutic antibody, including the route of administration and patient compliance, will be discussed.

Conformational Ensembles of Antibodies Determine Their Hydrophobicity

A major challenge in the development of antibody biotherapeutics is their tendency to aggregate. One root cause for aggregation is exposure of hydrophobic surface regions to the solvent. Many current techniques predict the relative aggregation propensity of antibodies via precalculated scales for the hydrophobicity or aggregation propensity of single amino acids. However, those scales cannot describe the nonadditive effects of a residue’s surrounding on its hydrophobicity. Therefore, they are inherently limited in their ability to describe the impact of subtle differences in molecular structure on the overall hydrophobicity. Here, we introduce a physics-based approach to describe hydrophobicity in terms of the hydration free energy using grid inhomogeneous solvation theory (GIST). We apply this method to assess the effects of starting structures, conformational sampling, and protonation states on the hydrophobicity of antibodies. Our results reveal that high-quality starting structures, i.e., crystal structures, are crucial for the prediction of hydrophobicity and that conformational sampling can compensate errors introduced by the starting structure. On the other hand, sampling of protonation states only leads to good results when combined with high-quality structures, whereas it can even be detrimental otherwise. We conclude by pointing out that a single static homology model may not be adequate for predicting hydrophobicity.

Metabolism and Distribution of Novel Tumor Targeting Drugs In Vivo

BACKGROUND

As a new tumor therapy, targeted therapy is becoming a hot topic due to its high efficiency and low toxicity. Drug effects of targeted tumor drugs are closely related to pharmacokinetics, so it is important to understand their distribution and metabolism in vivo.

METHODS

A systematic review of the literature on the metabolism and distribution of targeted drugs over the past 20 years was conducted, and the pharmacokinetic parameters of approved targeted drugs were summarized in combination with the FDA's drug instructions. Targeting drugs are divided into two categories: small molecule inhibitors and monoclonal antibodies. Novel targeting drugs and their mechanisms of action, which have been developed in recent years, are summarized. The distribution and metabolic processes of each drug in the human body are reviewed.

RESULTS

In this review, we found that the distribution and metabolism of small molecule kinase inhibitors (TKI) and monoclonal antibodies (mAb) showed different characteristics based on the differences of action mechanism and molecular characteristics. TKI absorbed rapidly (Tmax ≈ 1-4 h) and distributed in large amounts (Vd > 100 L). It was mainly oxidized and reduced by cytochrome P450 CYP3A4. However, due to the large molecular diameter, mAb was distributed to tissues slowly, and the volume of distribution was usually very low (Vd < 10 L). It was mainly hydrolyzed and metabolized into peptides and amino acids by protease hydrolysis. In addition, some of the latest drugs are still in clinical trials, and the in vivo process still needs further study.

CONCLUSION

According to the summary of the research progress of the existing targeting drugs, it is found that they have high specificity, but there are still deficiencies in drug resistance and safety. Therefore, the development of safer and more effective targeted drugs is the future research direction. Meanwhile, this study also provides a theoretical basis for clinical accurate drug delivery.

Increased Induction Infliximab Clearance Predicts Early Antidrug Antibody Detection

Treatment of patients with biologics such as infliximab may trigger development of antidrug antibodies, which are associated with faster drug clearance, reduced treatment efficacy, and increased risk of infusion‐related reactions. The aim of this study was to identify predictors of baseline infliximab clearance and early antidrug antibody formation. Pharmacokinetic and pharmacokinetic/pharmacodynamic models for infliximab were developed using 21 178 observations from 859 patients from the PLANETRA (ClinicalTrials.gov identifier: NCT01217086) and PLANETAS (NCT01220518) studies in rheumatoid arthritis and ankylosing spondylitis, respectively, to address the specified aims. Infliximab pharmacokinetics were well described by a 2‐compartment model with linear mean estimated baseline clearance of 0.26 L/day. Alongside increased body weight, serum C‐reactive protein, and antidrug antibody concentrations and decreased serum albumin, elevated serum glucose levels predicted higher clearance. In patients with rheumatoid arthritis, baseline infliximab clearance and body weight were the only identified predictors of early antidrug antibody detection. The odds ratio for antidrug antibody detection for each 0.1 L/day increase in baseline infliximab clearance was 1.78 (95% confidence interval, 1.50–2.12); for each 10‐kg increase in body weight, this was 1.19 (1.06–1.33). Here we describe increased serum glucose levels as a novel independent predictor of baseline infliximab clearance. Estimates of baseline infliximab clearance should be incorporated to guide dosing modifications and/or antidrug antibody prophylaxis in clinical practice.

Effect of age on pharmacokinetics, efficacy, and safety of galcanezumab treatment in adult patients with migraine: results from six phase 2 and phase 3 randomized clinical trials

Background

Migraine clinical profile may change with age, making it necessary to verify that migraine treatments are equally safe and effective in older patients. These analyses evaluated the effects of patient age on the pharmacokinetics (PK), efficacy, and safety of galcanezumab for prevention of migraine.

Methods

Analyses included efficacy data from three double-blind phase 3 clinical trials: two 6-month studies in episodic migraine (EVOLVE-1, EVOLVE-2: N = 1773) and one 3-month study in chronic migraine (REGAIN:N = 1113). Patients were randomized 2:1:1 to placebo, galcanezumab 120 mg, or galcanezumab 240 mg. Safety and PK data included additional phase 2 and phase 3 trials for a larger sample size of patients > 60 years (range = 18–65 for all studies). Subgroup analyses assessed efficacy measures, adverse event (AE) occurrence, and cardiovascular measurement changes by patient age group. Galcanezumab PK were evaluated using a population analysis approach, where age was examined as a potential covariate on apparent clearance (CL/F) and apparent volume of distribution (V/F) of galcanezumab.

Results

Numbers of baseline monthly migraine headache days were similar across age groups. There were no statistically significant treatment-by-age group interactions for any efficacy measures, except in episodic migraine studies where older patients appeared to have a larger reduction than younger patients in the number of monthly migraine headache days with acute medication use. Age (18–65) had a minimal effect on CL/F, and no effect on V/F. Galcanezumab-treated patients ≥60 years experienced no clinically meaningful increases in blood pressure and no increased frequency in treatment-emergent AEs, discontinuations due to AEs, serious adverse events (SAEs) overall, or cardiovascular SAEs, compared to age-matched placebo-treated patients.

Conclusions

Age (up to 65 years) does not affect efficacy in migraine prevention and has no clinically meaningful influence on galcanezumab PK to warrant dose adjustment. Furthermore, older galcanezumab-treated patients experienced no increases in frequency of AEs or increases in blood pressure compared with age-matched placebo-treated patients.

Trial registrations

EVOLVE-1 (NCT02614183, registered 23 November 2015), EVOLVE-2 (NCT02614196, 23 November 2015), REGAIN (NCT02614261, 23 November 2015), ART-01 (NCT01625988, 20 June 2012, ), I5Q-MC-CGAB (NCT02163993, 12 June 2014, ), I5Q-MC-CGAJ (NCT02614287, 23 November 2015, ), all retrospectively registered.

Pharmacokinetics and Clinical Pharmacology of Monoclonal Antibodies in Pediatric Patients

Monoclonal antibodies (mAbs) and their derivatives are increasingly used in pediatric pharmacotherapy, and the number of antibody-based drug products with approved pediatric indications is continuously growing. In most instances, pediatric use is being pursued after the efficacy and safety of novel antibody medications have been established in adult indications. The pediatric extrapolation exercise that is frequently used in this context to bridge efficacy and safety from adults to children is oftentimes challenged through uncertainties and knowledge gaps in how to reliably extrapolate pharmacokinetics and clinical pharmacology of mAbs to different pediatric age groups, and how to derive age-appropriate dosing regimens that strike a balance between precision dosing and practicability. The article highlights some of the pharmacokinetic and clinical pharmacology challenges with regard to therapeutic use of mAbs and antibody derivatives in children, including immunogenicity events. Although considering body size-based differences in drug disposition can account for many of the perceived and actual differences in the distribution and elimination of antibody-based therapeutics between children and adults, increasing evidence suggests potential or actual age-associated differences beyond size differences, especially for young pediatric patients such as newborns and infants. To overcome age-associated differences in antibody disposition, various different dosing approaches have been applied to ensure safe and efficacious antibody exposure for pediatric populations of different ages. The development of such dosing regimens and the associated pathway to pediatric indication approval is illustrated in more detail for two antibody-based biologics, the fusion protein abatacept and the mAb tocilizumab.

Why recombinant antibodies - benefits and applications

Antibodies (Abs) are ubiquitous reagents for biological and biochemical research and are rapidly expanding into new therapeutic areas. They are one of the most important probes for determining how proteins function under normal and pathophysiological conditions. Abs are required for the quantification of targets, detection of temporal and spatial patterns of protein expression in cells and tissues, and identification of interacting partners and their biological activities. Their remarkable specificity and unique binding properties can facilitate three-dimensional structure determination using X-ray crystallography and electron cryomicroscopy. While hybridoma technology that involves animal immunization is often productive, many antigen targets do not generate useful Abs. This is particularly true if unique states of the target or critical non-immunogenic target sequences need to be recognized by the Abs. By using the methods of recombinant antibody generation, identification, and engineering, these 'hybridoma-refractory' antigens can be readily targeted. Specific, reproducible, and renewable recombinant Abs are proving to be invaluable reagents in applications ranging from biological discovery to structure determination of challenging macromolecules.

Population Pharmacokinetics of Galcanezumab, an Anti-CGRP Antibody, Following Subcutaneous Dosing to Healthy Individuals and Patients With Migraine

Galcanezumab is a humanized immunoglobulin G (IgG) monoclonal antibody (mAb) indicated for the prevention of migraine that binds to calcitonin gene‐related peptide. A population pharmacokinetic (PK) analysis was performed to characterize galcanezumab PK using data pooled from 7 clinical studies. Clinical studies included healthy individuals and patients with episodic or chronic migraine who were administered between 5 and 300 mg galcanezumab. The PK data were analyzed using nonlinear mixed‐effects modeling. Galcanezumab concentration‐time data were described with a 1‐compartment model with first‐order absorption following subcutaneous administration and linear elimination. At the median body weight of 74 kg, the estimated population apparent clearance (CL/F) was 0.00785 L/h (34% IIV), the apparent volume of distribution was 7.33 L (34% IIV), and half‐life was 27 days. Patient body weight was found to have a modest effect of CL/F, with median galcanezumab concentrations being lower in the heaviest patients compared to the lightest patients, but this outcome was determined not to be clinically relevant in the context of model‐estimated random variability. Dosing adjusted for body weight is not warranted in adults. Age, sex, race/ethnicity, immunogenicity, renal/hepatic markers, and injection‐site location did not affect galcanezumab PK. In conclusion, galcanezumab exhibits PK parameters typical for an IgG mAb administered subcutaneously. The population PK model developed in this study demonstrates that galcanezumab exhibits linear PK that was not influenced in a clinically relevant manner by the patient factors evaluated.

A new era for migraine: Pharmacokinetic and pharmacodynamic insights into monoclonal antibodies with a focus on galcanezumab, an anti-CGRP antibody

PURPOSE

To review pharmacokinetic and pharmacodynamic characteristics of antibodies that bind to soluble ligands within the framework of calcitonin gene-related peptide antibodies.

OVERVIEW

Calcitonin gene-related peptide has been implicated in the pathophysiology of migraine. Galcanezumab is an antibody that binds to the ligand calcitonin gene-related peptide. Other antibodies that target calcitonin gene-related peptide include eptinezumab and fremanezumab. To understand how antibodies can affect the extent and duration of free ligand concentrations, it is important to consider the dose and pharmacokinetics of an antibody, and the kinetics of the ligand and antibody-ligand complex. Insights regarding the pharmacokinetic/pharmacodynamic properties of galcanezumab as a probe antibody drug and calcitonin gene-related peptide as its binding ligand regarding its clinical outcomes are provided.

DISCUSSION

Antibodies are administered parenterally because oral absorption is limited by gastrointestinal degradation and inefficient diffusion through the epithelium. The systemic absorption of antibodies following intramuscular or subcutaneous administration most likely occurs via convective transport through lymphatic vessels into blood. The majority of antibody elimination occurs via intracellular catabolism into peptides and amino acids following endocytosis. Binding of ligand to an antibody reduces the free ligand that is available to interact with the receptor and efficacy is driven by the magnitude and duration of the reduction in free ligand concentration. A galcanezumab pharmacokinetic/pharmacodynamic model shows that galcanezumab decreases free calcitonin gene-related peptide concentrations in a dose- and time-dependent manner and continues to suppress free calcitonin gene-related peptide with repeated dosing. The model provides evidence for a mechanistic linkage to galcanezumab therapeutic effects for the preventive treatment of migraine.

Evaluation of covariate effects on pharmacokinetics of monoclonal antibodies in oncology

AIMS

The development of monoclonal antibodies (mAbs) requires an understanding of the interindividual variability (IIV) in pharmacokinetics (PK) at the population level facilitated by population PK (PopPK) modelling. However, there is no clear rationale for selecting which covariates to screen during PopPK model development. Here, we compare the effect of covariates on PK parameters for mAbs in oncology and identify the most commonly used covariates affecting PK parameters.

METHODS

All 25 mAbs approved for therapeutic use in oncology until December 2017 by the Food and Drug Administration and the European Medicines Agency were selected for study. Literature searches revealed 23 available PopPK models for these mAbs. To understand the magnitude and types of covariate effect on PK parameters, all covariates included in the final PopPK model for each mAb were summarized.

RESULTS

The most commonly identified covariates were baseline body weight (BW; 17 mAbs), baseline serum albumin (8 mAbs), and sex (7 mAbs) on clearance; and BW (16 mAbs) and sex (12 mAbs) on central volume of distribution. A reduced PopPK model was developed for nivolumab and ipilimumab using these covariates, and the percentage of explained IIV from the reduced model (20.3% and 16.8%, respectively) was compared with that from the full model (24.5% and 27.9%, respectively).

CONCLUSIONS

This analysis provides a uniform platform for selecting covariates and suggests that the effect of BW, albumin and sex should be included during the development of PopPK models for mAbs in oncology. The reduced model was able to explain IIV to a similar extent as the full model.

Population Pharmacokinetic Modeling and Exposure-Response Assessment for the Antibody-Drug Conjugate Brentuximab Vedotin in Hodgkin's Lymphoma in the Phase III ECHELON-1 Study

The efficacy of the CD30‐directed antibody‐drug conjugate (ADC) brentuximab vedotin was established in combination with chemotherapy as frontline treatment for advanced classical Hodgkin's lymphoma in the randomized phase III ECHELON‐1 study. Population pharmacokinetic (PK) and exposure–response models were developed to quantify sources of PK variability and relationships between exposure and safety/efficacy end points in ECHELON‐1. The influence of patient‐specific factors on the PK of the ADC and the microtubule‐disrupting payload monomethyl auristatin E (MMAE) was investigated; none of the significant covariates had a clinically relevant impact. Exposure–response analyses evaluated relationships between time‐averaged area under the curve (AUC; ADC, MMAE) and efficacy end points (ADC) or safety parameters (ADC, MMAE). Exposure–efficacy analyses supported consistent treatment benefit with brentuximab vedotin across observed exposure ranges. Exposure‐safety analyses supported the recommended brentuximab vedotin starting dose (1.2 mg/kg every 2 weeks), and effective management of peripheral neuropathy and neutropenia with dose modification/reduction and febrile neutropenia with granulocyte colony‐stimulating factor primary prophylaxis.

Exploring the dark genome: implications for precision medicine

The increase in the number of both patients and healthcare practitioners who grew up using the Internet and computers (so-called "digital natives") is likely to impact the practice of precision medicine, and requires novel platforms for data integration and mining, as well as contextualized information retrieval. The "Illuminating the Druggable Genome Knowledge Management Center" (IDG KMC) quantifies data availability from a wide range of chemical, biological, and clinical resources, and has developed platforms that can be used to navigate understudied proteins (the "dark genome"), and their potential contribution to specific pathologies. Using the "Target Importance and Novelty Explorer" (TIN-X) highlights the role of LRRC10 (a dark gene) in dilated cardiomyopathy. Combining mouse and human phenotype data leads to increased strength of evidence, which is discussed for four additional dark genes: SLX4IP and its role in glucose metabolism, the role of HSF2BP in coronary artery disease, the involvement of ELFN1 in attention-deficit hyperactivity disorder and the role of VPS13D in mouse neural tube development and its confirmed role in childhood onset movement disorders. The workflow and tools described here are aimed at guiding further experimental research, particularly within the context of precision medicine.

Monoclonal antibodies for severe asthma: Pharmacokinetic profiles

Several monoclonal antibodies (mAbs) (omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab) are currently approved for the treatment of severe asthma. They have complex pharmacokinetic profiles. These profiles are unique in that they are dependent on their structure as well as can be markedly influenced by the biology of their target antigen, but their general behaviour can still be considered a class property, similar to their endogenous IgG counterpart. They cannot be administered by oral route, have a slow distribution into tissue, are metabolized to peptides and amino acids in several tissues but are protected from degradation by binding to protective receptors (the FcRn), which explains their long elimination half-lives. Their clearance is nonlinear because of the saturation of the target-mediated elimination. Also anti-drug antibody (ADA) response and off-target binding, as well as their glycosylation pattern, can influence the pharmacokinetics of mAbs.

Comparing biologicals and small molecule drug therapies for chronic respiratory diseases: An EAACI Taskforce on Immunopharmacology position paper

Chronic airway diseases such as asthma and chronic obstructive pulmonary disease (COPD), together with their comorbidities, bear a significant burden on public health. Increased appreciation of molecular networks underlying inflammatory airway disease needs to be translated into new therapies for distinct phenotypes not controlled by current treatment regimens. On the other hand, development of new safe and effective therapies for such respiratory diseases is an arduous and expensive process. Antibody-based (biological) therapies are successful in treating certain respiratory conditions not controlled by standard therapies such as severe allergic and refractory eosinophilic severe asthma, while in other inflammatory respiratory diseases, such as COPD, biologicals are having a more limited impact. Small molecule drug (SMD)-based therapies represent an active field in pharmaceutical research and development. SMDs expand biologicals' therapeutic targets by reaching the intracellular compartment by delivery as either an oral or topically based formulation, offering both convenience and lower costs. Aim of this review was to compare and contrast the distinct pharmacological properties and clinical applications of SMDs- and antibody-based treatment strategies, their limitations and challenges, in order to highlight how they should be integrated for their optimal utilization and to fill the critical gaps in current treatment for these chronic inflammatory respiratory diseases.

How the discovery of rituximab impacted the treatment of B-cell non-Hodgkin's lymphomas

Non-Hodgkin's lymphoma (NHL) is the sixth-most common cancer in the UK, accounting for around 13,700 new cases every year. Until the late 1990s, treatment relied on intensive chemotherapy, such as CHOP (cyclophosphamide-doxorubicin HCl-vincristine [Oncovin]-prednisone). The use of standard CHOP therapy and its variations had resulted in poor five-year survival rates (as low as 26%), particularly in patients with aggressive NHL. Rituximab (Rituxan) was the first chimeric (mouse/human) monoclonal antibody approved for the treatment of NHL. It was approved by the US Food and Drug Administration in 1997 for indolent forms of NHL. It subsequently received EU approval in June 1998, and was licensed under the trade name Mabthera (Roche, Basel, Switzerland). It then went on to be approved for the first-line treatment of aggressive forms of NHL, such as diffuse large B-cell lymphoma (to be used in combination with CHOP or other anthracycline-based chemotherapy) in 2006. It is directed against the CD20 protein, an antigen found on the surface of B-cell lymphomas. With minimal toxicity, activity as a single-agent (for indolent forms of NHL) and safety when combined with chemotherapy (for aggressive forms), it represents great progress in this field. Here, we analyze how this antibody therapeutic was developed from basic molecular and cellular considerations through to preclinical and clinical evaluations and how it came to be a first-line treatment for NHL, and we discuss the impacts the advent of rituximab had on treatment outcomes for patients with DLBCL compared with the pre-rituximab era.

Use of Population Pharmacokinetic Analyses Among FDA-Approved Biologics

Biologics, especially monoclonal antibodies, are increasingly important in the pharmaceutical marketplace. Population pharmacokinetic (PK) analyses could be useful to guide the need for dose adjustments among special populations, yet it is unknown how commonly such analyses are performed during biologics development. We summarized the characteristics of population PK models of biologics and examined their role in informing the drug labels. To do so, we extracted relevant characteristics of 86 biologics approved by the U.S. Food and Drug Administration's Center for Drug Evaluation and Research between 2003 and 2017. Ninety-four percent of monoclonal antibodies (51 of 54 biologics), 75% of fusion proteins with Fc receptor (6 of 8 biologics), and 33% of other proteins (8 of 24 biologics) included population PK analyses. Of these analyses, approximately half (45%) used a 2-compartment model with linear clearance as the base model structure. Body size was the most frequently included covariate in the final models (included in 94% of the 64 biologics in which covariate analysis was performed), although age (11%), sex (35%), race (26%), and renal function (27%) were also included in some models. In 70% to 90% of cases in which the effect of these covariates was examined, information regarding the effect of these on PK was included in the label. These results suggest that population PK analyses provide important information about the impact of intrinsic factors on the PK in the label of biologics by the U.S. Food and Drug Administration.

An approved in vitro approach to preclinical safety and efficacy evaluation of engineered T cell receptor anti-CD3 bispecific (ImmTAC) molecules

Robust preclinical testing is essential to predict clinical safety and efficacy and provide data to determine safe dose for first-in-man studies. There are a growing number of examples where the preclinical development of drugs failed to adequately predict clinical adverse events in part due to their assessment with inappropriate preclinical models. Preclinical investigations of T cell receptor (TCR)-based immunotherapies prove particularly challenging as these biologics are human-specific and thus the conventional testing in animal models is inadequate. As these molecules harness the full force of the immune system, and demonstrate tremendous potency, we set out to design a preclinical package that would ensure adequate evaluation of these therapeutics. Immune Mobilising Monoclonal TCR Against Cancer (ImmTAC) molecules are bi-specific biologics formed of an affinity-enhanced TCR fused to an anti-CD3 effector function. ImmTAC molecules are designed to activate human T lymphocytes and target peptides within the context of a human leukocyte antigen (HLA), thus require an intact human immune system and peptidome for suitable preclinical screening. Here we draw upon the preclinical testing of four ImmTAC molecules, including IMCgp100, the first ImmTAC molecule to reach the clinic, to present our comprehensive, informative and robust approach to in vitro preclinical efficacy and safety screening. This package comprises a broad range of cellular and molecular assays using human tissues and cultured cells to test efficacy, safety and specificity, and hence predict human responses in clinical trials. We propose that this entirely in vitro package offers a potential model to be applied to screening other TCR-based biologics.

Linear pharmacokinetic parameters for monoclonal antibodies are similar within a species and across different pharmacological targets: A comparison between human, cynomolgus monkey and hFcRn Tg32 transgenic mouse using a population-modeling approach

The linear pharmacokinetics (PK) of therapeutic monoclonal antibodies (mAbs) can be considered a class property with values that are similar to endogenous IgG. Knowledge of these parameters across species could be used to avoid unnecessary in vivo PK studies and to enable early PK predictions and pharmacokinetic/pharmacodynamic (PK/PD) simulations. In this work, population-pharmacokinetic (popPK) modeling was used to determine a single set of ‘typical’ popPK parameters describing the linear PK of mAbs in human, cynomolgus monkey and transgenic mice expressing the human neonatal Fc receptor (hFcRn Tg32), using a rich dataset of 27 mAbs. Non-linear PK was excluded from the datasets and a 2-compartment model was applied to describe mAb disposition. Typical human popPK estimates compared well with data from comparator mAbs with linear PK in the clinic. Outliers with higher than typical clearance were found to have non-specific interactions in an affinity-capture self-interaction nanoparticle spectroscopy assay, offering a potential tool to screen out these mAbs at an early stage. Translational strategies were investigated for prediction of human linear PK of mAbs, including use of typical human popPK parameters and allometric exponents from cynomolgus monkey and Tg32 mouse. Each method gave good prediction of human PK with parameters predicted within 2-fold. These strategies offer alternative options to the use of cynomolgus monkeys for human PK predictions of linear mAbs, based on in silico methods (typical human popPK parameters) or using a rodent species (Tg32 mouse), and call into question the value of completing extensive in vivo preclinical PK to inform linear mAb PK.