Immunogenicity of protein therapeutics: The key causes, consequences and challenges

The biological macromolecules constructed Matrigel for cultured organoids in biomedical and tissue engineering

Matrigel is the most commonly used matrix for 3D organoid cultures. Research on the biomaterial basis of Matrigel for organoid cultures is a highly challenging field. Currently, many studies focus on Matrigel-based biological macromolecules or combinations to construct natural Matrigel and synthetic hydrogel scaffolds based on collagen, peptides, polysaccharides, microbial transglutaminase, DNA supramolecules, and polymers for organoid culture. In this review, we discuss the limitations of both natural and synthetic Matrigel, and describe alternative scaffolds that have been employed for organoid cultures. The patient-derived organoids were constructed in different cancer types and limitations of animal-derived organoids based on the hydrogel or Matrigel. The constructed techniques utilizing 3D bioprinting platforms, air-liquid interface (ALI) culture, microfluidic culture, and organ-on-a-chip platform are summarized. Given the potential of organoids for a wide range of therapeutic, tissue engineering and pharmaceutical applications, it is indeed imperative to develop defined and customized hydrogels in addition to Matrigel.

A Multi-Enzyme Nanocascade to Target Disease-Relevant Metabolites

Metabolic processes in living organisms depend on the synergistic actions of enzymes working in proximity and in concert, catalyzing reactions effectively while regulating the formation of metabolites. This enzyme synergy offers promising therapeutic application for diseases such as alcohol intoxication, cancer, and hyperinflammation. Despite their potential, the clinical translation of enzyme cascades is restricted by challenges including poor enzyme stability, short half-life, and a lack of delivery strategies that maintain enzyme proximity. In this study, multi-enzyme nanocascades synthesized are developed through in situ atom transfer radical polymerization using a zwitterionic monomer. This method markedly enhances enzyme stability and proximity, thereby prolonging their circulation half-life after systemic administration. It is demonstrated that the nanocascades of uricase and catalase effectively reduce uric acid levels without excessive hydrogen peroxide production, providing a potential antidote for hyperuricemia. Moreover, in a murine breast cancer model, the nanocascades of glucose oxidase and catalase inhibited tumor progression and enhanced the therapeutic efficacy of doxorubicin. The prolonged circulation and promoted reaction efficacy of these nanocascades underscore their substantial potential in enzyme replacement therapy and the treatment of various diseases.

Cardiovascular adverse events in patients with HER2-positive breast cancer treated with trastuzumab-drug conjugates : a Bayesian disproportional real world study for signal detection leveraging the FDA Adverse Event Reporting System (FAERS)

BACKGROUND

The cardiovascular risk profiles of trastuzumab drug conjugates (T-DCs) in the treatment of Human Epidermal Growth Factor Receptor 2 (HER2)-positive breast cancer are uncertain. This study analyzed real-world adverse events data from the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) to investigate the association between T-DCs and major adverse cardiovascular events (MACE).

METHODS

We searched the FAERS database for reports of cardiovascular adverse events in patients with HER2-positive breast cancer receiving trastuzumab, ado-trastuzumab emtansine (T-DM1), and trastuzumab deruxtecan (T-Dxd). The primary endpoint was MACE and the secondary endpoint was other cardiovascular events.

RESULTS

Between January 2015 and April 2024, out of the 135,226 drug-adverse event pairs analyzed, 8,497 were cardiovascular events, with 4,457 classified as MACE and 4,040 as other cardiovascular events. Trastuzumab reached pharmacovigilance for MACE (ROR = 1.39, 95%CI: 1.30-1.49, IC025 = 0.25), while neither T-DM1 (ROR = 0.78, 95%CI: 0.69-0.88, IC025=-0.51) nor T-Dxd (ROR = 0.63, 95%CI: 0.52-0.76, IC025=-0.93) reached MACE-related pharmacovigilance. Among MACE, stroke linked to T-DM1 (ROR = 1.86, 95%CI: 1.42-2.43, IC025 = 0.35) and T-Dxd (ROR = 2.44, 95%CI: 1.68-3.56, IC025 = 0.57) both reached pharmacovigilance in younger patients (<65 years). Proportionate analysis showed age and weight were the two key factors contributing to the occurrence of T-DCs induced MACE.

CONCLUSION

HER2-positive breast cancer patients receiving T-DCs require additional cardiac monitoring, particularly for stroke in younger patients.

Immunogenicity risk assessment and mitigation for engineered antibody and protein therapeutics

Remarkable progress has been made in recent decades in engineering antibodies and other protein therapeutics, including enhancements to existing functions as well as the advent of novel molecules that confer biological activities previously unknown in nature. These protein therapeutics have brought major benefits to patients across multiple areas of medicine. One major ongoing challenge is that protein therapeutics can elicit unwanted immune responses (immunogenicity) in treated patients, including the generation of anti-drug antibodies. In rare and unpredictable cases, anti-drug antibodies can seriously compromise therapeutic safety and/or efficacy. Systematic deconvolution of this immunogenicity problem is confounded by the complexity of its many contributing factors and the inherent limitations of available experimental and computational methods. Nevertheless, continued progress with the assessment and mitigation of immunogenicity risk at the preclinical stage has the potential to reduce the incidence and severity of clinical immunogenicity events. This Review focuses on identifying key unsolved anti-drug antibody-related challenges and offers some pragmatic approaches towards addressing them. Examples are drawn mainly from antibodies, given that the majority of available clinical data are from this class of protein therapeutics. Plausible and seemingly tractable solutions are in sight for some immunogenicity problems, whereas other challenges will likely require completely new approaches.

Immunogenicity dynamics and covariate effects after satralizumab administration predicted with a hidden Markov model

Immunogenicity is the propensity of a therapeutic protein to generate an immune response to itself. While reporting of antidrug antibodies (ADAs) is increasing, model-based analysis of such data is seldom performed. Model-based characterization of factors affecting the emergence and dissipation of ADAs may inform drug development and/or improve understanding in clinical practice. This analysis aimed to predict ADA dynamics, including the potential influence of individual covariates, following subcutaneous satralizumab administration. Satralizumab is a humanized IgG2 monoclonal recycling IL-6 receptor antagonist antibody approved for treating neuromyelitis optica spectrum disorder (NMOSD). Longitudinal pharmacokinetic (PK) and ADA data from 154 NMOSD patients in two pivotal Phase 3 studies (NCT02028884, NCT02073279) and PK data from one Phase 1 study (SA-001JP) in 72 healthy volunteers were available for this analysis. An existing population PK model was adapted to derive steady-state concentration without ADA for each patient. A mixed hidden Markov model (mHMM) was developed whereby three different states were identified: one absorbing Markov state for non-ADA developer, and two dynamic and inter-connected Markov states-transient ADA negative and positive. Satralizumab exposure and body mass index impacted transition probabilities and, therefore, the likelihood of developing ADAs. In conclusion, the mHMM model was able to describe the time course of ADA development and identify patterns of ADA development in NMOSD patients following treatment with satralizumab, which may allow for the formulation of strategies to reduce the emergence or limit the impact of ADA in the clinical setting.

Mechanism of Action and Pharmacokinetics of Approved Bispecific Antibodies

Bispecific antibodies represent a significant advancement in therapeutic antibody engineering, offering the ability to simultaneously target two distinct antigens. This dual-targeting capability enhances therapeutic efficacy, especially in complex diseases, such as cancer and autoimmune disorders, where drug resistance and incomplete target coverage are prevalent challenges. Bispecific antibodies facilitate immune cell engagement and disrupt multiple signaling pathways, providing a more comprehensive treatment approach than traditional monoclonal antibodies. However, the intricate structure of bispecific antibodies introduces unique pharmacokinetic challenges, including issues related to their absorption, distribution, metabolism, and excretion, which can significantly affect their efficacy and safety. This review provides an in-depth analysis of the structural design, mechanisms of action, and pharmacokinetics of the currently approved bispecific antibodies. It also highlights the engineering innovations that have been implemented to overcome these challenges, such as Fc modifications and advanced dimerization techniques, which enhance the stability and half-life of bispecific antibodies. Significant progress has been made in bispecific antibody technology; however, further research is necessary to broaden their clinical applications, enhance their safety profiles, and optimize their incorporation into combination therapies. Continuous advancements in this field are expected to enable bispecific antibodies to provide more precise and effective therapeutic strategies for a range of complex diseases, ultimately improving patient outcomes and advancing precision medicine.

Nano- and Micro-Platforms in Therapeutic Proteins Delivery for Cancer Therapy: Materials and Strategies

Proteins have emerged as promising therapeutics in oncology due to their great specificity. Many treatment strategies are developed based on protein biologics, such as immunotherapy, starvation therapy, and pro-apoptosis therapy, while some protein biologics have entered the clinics. However, clinical translation is severely impeded by instability, short circulation time, poor transmembrane transportation, and immunogenicity. Micro- and nano-particles-based drug delivery platforms are designed to solve those problems and enhance protein therapeutic efficacy. This review first summarizes the different types of therapeutic proteins in clinical and research stages, highlighting their administration limitations. Next, various types of micro- and nano-particles are described to demonstrate how they can overcome those limitations. The potential of micro- and nano-particles are then explored to enhance the therapeutic efficacy of proteins by combinational therapies. Finally, the challenges and future directions of protein biologics carriers are discussed for optimized protein delivery.

In vivo safety evaluation and tracing of arginylglycylaspartic acid-engineered phage nanofiber in murine model

The engineered phage YSY184, mimicking the extracellular matrix nanofiber, effectively promotes stem cell differentiation and angiogenesis. This study evaluated its safety in a mouse model, monitoring weight, immunogenicity, spleen immune responses, and macrophage infiltration. Rapid clearance of YSY184 was observed, with peak tissue presence within three hours, significantly reduced by 24 hours, and negligible after one month. No adverse physiological or pathological effects were detected post-administration, affirming YSY184's safety and underscore its potential for therapeutic use, warranting further clinical exploration.

Half-Life and Clearance of Cardiac Troponin I and Troponin T in Humans

BACKGROUND

Cardiac troponin (cTn) is key in diagnosing myocardial infarction (MI). After MI, the clinically observed half-life of cTn has been reported to be 7 to 20 hours, but this estimate reflects the combined elimination and simultaneous release of cTn from cardiomyocytes. More precise timing of myocardial injuries necessitates separation of these 2 components. We used a novel method for determination of isolated cTn elimination kinetics in humans.

METHODS

Patients with MI were included within 24 hours after revascularization and underwent plasmapheresis to obtain plasma with a high cTn concentration. After at least 3 weeks, patients returned for an autologous plasma retransfusion followed by blood sampling for 8 hours. cTn was measured with 5 different high-sensitivity cTn assays.

RESULTS

Of 25 included patients, 20 participants (mean age, 64.5 years; SD, 8.2 years; 4 women [20%]) received a retransfusion after a median of 5.8 weeks (interquartile range, 5.0-6.9 weeks) after MI. After retransfusion of a median of 620 mL (range, 180-679 mL) autologous plasma, the concentration of cTn in participants' blood increased 4 to 445 times above the upper reference level of the 5 high-sensitivity cTn assays. The median elimination half-life ranged from 134.1 minutes (95% CI, 117.8-168.0) for the Elecsys high-sensitivity cTnT assay to 239.7 minutes (95% CI, 153.7-295.1) for the Vitros high-sensitivity cTnI assay. The median clearance of cTnI ranged from 40.3 mL/min (95% CI, 32.0-44.9) to 52.7 mL/min (95% CI, 42.2-57.8). The clearance of cTnT was 77.0 mL/min (95% CI, 45.2-95.0).

CONCLUSIONS

This novel method showed that the elimination half-life of cTnI and cTnT was 5 to 16 hours shorter than previously reported. This indicates a considerably longer duration of cardiomyocyte cTn release after MI than previously thought. Improved knowledge of timing of myocardial injury may call for changes in the management of MI and other disorders with myocardial injury.

Assessing Immunogenicity in Drug Reviews and Prescribing Information in Japan

Anti-drug antibodies (ADAs) generated in response to biopharmaceuticals can significantly impact pharmacokinetics (PK) and overall drug efficacy. Thus, the ICH M4 guidelines mandate summarizing immunogenicity data from clinical trials in drug approval applications. However, following the approval of the first antibody drug in Japan in 2001, no cross-sectional investigation has focused on immunogenicity during the regulatory review process. Therefore, this study aims to examine the review reports and prescribing information of antibody drugs approved in Japan to identify key points related to immunogenicity evaluation. We conducted a cross-sectional analysis of review reports for antibody drugs approved between June 2001 and July 2022 by the Japanese regulatory authority. Specifically, we evaluated the ADA positivity rate, presence of neutralizing antibodies, antibody titers, and effects of ADA on PK, efficacy, and safety. We also compared this information with that provided in the prescribing information. Our analysis revealed that the ADA positivity rate and its effects on PK, efficacy, and safety were critical aspects of the review process. The emphasis on these factors varied depending on the number of applications and disease area. The information presented in the prescribing information was largely consistent with that discussed in the review reports. Overall, this study provides the first cross-sectional evaluation of immunogenicity considerations in the regulatory review of antibody drugs in Japan. Our findings can contribute to the efficiency of clinical trial planning and preparation of approval applications, to potentially improve the overall drug development process and address the drug loss problem in Japan.

Immunomodulatory activity of ovotransferrin-chlorogenic acid complexes enhanced by high-intensity ultrasound (HIU): A structure-function relationship study

This study investigated the impact of high-intensity ultrasound (HIU) treatment on the physiochemical, conformational, and immunomodulatory activity of the OVT-CA complex, emphasizing the structure-function relationship. HIU treatment reduced particle size, improved dispersion, and increased electronegativity of the complex. It facilitated binding between OVT and CA, achieving a maximum degree of 45.22 mg/g CA grafting and reducing interaction time from 2 h to 15 min. HIU-induced cavitation and shear promoted the exposure of -SH and unfolding of OVT, leading to increased surface hydrophobicity of the complex and transformation of its structure from β-sheet to α-helix. Additionally, CA binds to OVT in the C-lobe region, and HIU treatment modulates the intermolecular forces governing the complex formation, particularly by reinforcing hydrogen bonding, hydrophobic interactions, and introducing electrostatic interactions. Furthermore, HIU treatment increased the immunomodulatory activity of the complex, which was attributed to complex structural changes facilitating enhanced cell membrane affinity, antigen recognition, and B-cell epitope availability. Hierarchical cluster and Pearson correlation analysis confirmed that HIU treatment duration had a greater impact than power on both the structure and activity of the complex, and an optimal HIU treatment duration within 30 min was found to be crucial for activity enhancement. Moreover, structural changes, including ζ-potential, particle size/turbidity, and surface hydrophobicity, were closely correlated with immunomodulatory activity. This study highlights the potential application of HIU in developing protein-polyphenol immunomodulatory agents for public health and food nutrition.

ErpY-like Protein Interaction with Host Thrombin and Fibrinogen Intervenes the Plasma Coagulation through Extrinsic and Intrinsic Pathways

The survival and proliferation of pathogenic Leptospira within a host are complex phenomena that require careful consideration. The ErpY-like lipoprotein, found on the outer membrane surface of Leptospira, plays a crucial role in enhancing the bacterium's pathogenicity. The rErpY-like protein, in its recombinant form, contributes significantly to spirochete virulence by interacting with various host factors, including host complement regulators. This interaction facilitates the bacterium's evasion of the host complement system, thereby augmenting its overall pathogenicity. The rErpY-like protein exhibits a robust binding affinity to soluble fibrinogen, a vital component of the host coagulation system. In this study, we demonstrate that the rErpY-like protein intervenes in the clotting process of the platelet-poor citrated plasma of bovines and humans in a concentration-dependent manner. It significantly reduces clot density, alters the viscoelastic properties of the clot, and diminishes the average clotting rate in plasma. Furthermore, the ErpY-like protein inhibits thrombin-catalyzed fibrin formation in a dose-dependent manner and exhibits saturable binding to thrombin, suggesting its significant role in leptospiral infection. These findings provide compelling evidence for the anticoagulant effect of the ErpY-like lipoprotein and its significant role in leptospiral infection.

Pharmacovigilance study of the association between peripheral neuropathy and antibody-drug conjugates using the FDA adverse event reporting system

Antibody-drug conjugates (ADCs) are among the fastest-growing classes of anticancer drugs, making it crucial to evaluate their potential for causing peripheral neuropathy. We analyzed data from the FAERS database (January 1, 2014, to June 30, 2023) using disproportionality and Bayesian methods. We identified 3076 cases of ADC-associated peripheral neuropathy. Our study revealed significant signals for all ADCs (ROR 1.82, 95% CI 1.76-1.89). ADCs with tubulin-binding payloads showed significant peripheral neuropathy signals (ROR 2.31, 95% CI 2.23-2.40), whereas those with DNA-targeting (ROR 0.48, 95% CI 0.39-0.59) and topoisomerase 1 inhibitor (ROR 0.56, 95% CI 0.48-0.66) payloads exhibited non-significant signals. Signals for peripheral sensory neuropathy were 4.83, 2.44, 2.74, and 2.21 (calculated based on IC025) for brentuximab vedotin, trastuzumab emtansine, enfortumab vedotin, and polatuzumab vedotin, while signals for peripheral motor neuropathy were 5.31, 0.34, 2.27, and 0.03, respectively. The median time to onset for all ADCs was 127 days (interquartile range 40-457). Tisotumab vedotin had the highest hospitalization rate at 26.67%, followed by brentuximab vedotin at 25.5%. Trastuzumab emtansine had the highest mortality rate ,with 80 deaths (11.96%) among 669 cases. Based on FAERS database, only ADCs with tubulin-binding payloads exhibited significant peripheral neuropathy signals. Brentuximab vedotin and enfortumab vedotin showed similar profiles for peripheral sensory neuropathy and motor neuropathy. Given the delayed time to onset and potentially poor outcomes, ADC-related peripheral neuropathy warrants significant attention.

A review and outlook on expression of animal proteins in plants

This review delves into the multifaceted technologies, benefits and considerations surrounding the expression of animal proteins in plants, emphasizing its potential role in advancing global nutrition, enhancing sustainability, while being mindful of the safety considerations. As the world's population continues to grow and is projected to reach 9 billion people by 2050, there is a growing need for alternative protein sources that can meet nutritional demands while minimizing environmental impact. Plant expression of animal proteins is a cutting-edge biotechnology approach that allows crops to produce proteins traditionally derived from animals, offering a sustainable and resource-efficient manner of producing these proteins that diversifies protein production and increases food security. In the United States, it will be important for there to be clear guidance in order for these technologies to reach consumers. As consumer demand for sustainable and alternative food sources rise, biotechnologies can offer economic opportunities, making this emerging technology a key player in the market landscape.

Engineering Toxoplasma gondii secretion systems for intracellular delivery of multiple large therapeutic proteins to neurons

Delivering macromolecules across biological barriers such as the blood-brain barrier limits their application in vivo. Previous work has demonstrated that Toxoplasma gondii, a parasite that naturally travels from the human gut to the central nervous system (CNS), can deliver proteins to host cells. Here we engineered T. gondii's endogenous secretion systems, the rhoptries and dense granules, to deliver multiple large (>100 kDa) therapeutic proteins into neurons via translational fusions to toxofilin and GRA16. We demonstrate delivery in cultured cells, brain organoids and in vivo, and probe protein activity using imaging, pull-down assays, scRNA-seq and fluorescent reporters. We demonstrate robust delivery after intraperitoneal administration in mice and characterize 3D distribution throughout the brain. As proof of concept, we demonstrate GRA16-mediated brain delivery of the MeCP2 protein, a putative therapeutic target for Rett syndrome. By characterizing the potential and current limitations of the system, we aim to guide future improvements that will be required for broader application.

Recent Advances in Gene Therapy for Hemophilia: Projecting the Perspectives

One of the well-known X-linked genetic disorders is hemophilia, which could be hemophilia A as a result of a mutation in the F8 (factor VIII) gene or hemophilia B as a result of a mutation in the F9 (factor IX) gene, leading to insufficient levels of the proteins essential for blood coagulation cascade. In patients with severe hemophilia, factor VIII or factor IX activities in the blood plasma are considerably low, estimated to be less than 1%. This is responsible for spontaneous or post-traumatic bleeding episodes, or both, leading to disease complications and death. Current treatment of hemophilia relies on the prevention of bleeding, which consists of expensive lifelong replacement infusion therapy of blood plasma clotting factors, their recombinant versions, or therapy with recombinant monoclonal antibodies. Recently emerged gene therapy approaches may be a potential game changer that could reshape the therapeutic outcomes of hemophilia A or B using a one-off vector in vivo delivery and aim to achieve long-term endogenous expression of factor VIII or IX. This review examines both traditional approaches to the treatment of hemophilia and modern methods, primarily focusing on gene therapy, to update knowledge in this area. Recent technological advances and gene therapeutics in the pipeline are critically reviewed and summarized. We consider gene therapy to be the most promising method as it may overcome the problems associated with more traditional treatments, such as the need for constant and expensive infusions and the presence of an immune response to the antibody drugs used to treat hemophilia.

Suborgan Level Quantitation of Proteins in Tissues Delivered by Polymeric Nanocarriers

Amidst the rapid growth of protein therapeutics as a drug class, there is an increased focus on designing systems to effectively deliver proteins to target organs. Quantitative monitoring of protein distributions in tissues is essential for optimal development of delivery systems; however, existing strategies can have limited accuracy, making it difficult to assess suborgan dosing. Here, we describe a quantitative imaging approach that utilizes metal-coded mass tags and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to quantify the suborgan distributions of proteins in tissues that have been delivered by polymeric nanocarriers. Using this approach, we measure nanomole per gram levels of proteins as delivered by guanidinium-functionalized poly(oxanorborneneimide) (PONI) polymers to various tissues, including the alveolar region of the lung. Due to the multiplexing capability of the LA-ICP-MS imaging, we are also able to simultaneously quantify protein and polymer distributions, obtaining valuable information about the relative excretion pathways of the protein cargo and carrier. This imaging approach will facilitate quantitative correlations between nanocarrier properties and protein cargo biodistributions.

Aerosolization of poly(sulfobetaine) microparticles that encapsulate therapeutic antibodies

Pulmonary delivery of protein therapeutics poses significant challenges that have not been well addressed in the research literature or practice. In fact, there is currently only one commercial protein therapeutic that is delivered through aerosolization and inhalation. In this study, we propose a drug delivery strategy that enables a high-concentration dosage for the pulmonary delivery of antibodies as an aerosolizable solid powder with desired stability. We utilized zwitterionic polymers for their promising properties as drug delivery vehicles and synthesized swellable, biodegradable poly(sulfo-betaine) (pSB) microparticles. The microparticles were loaded with Immunoglobulin G (IgG) as a model antibody. We quantified the microparticle size and morphology, and the particles were found to have an average diameter of 1.6 μm, falling within the optimal range (~1-5 μm) for pulmonary drug delivery. In addition, we quantified the impact of the crosslinker to monomer ratio on particle morphology and drug loading capacity. The results showed that there is a trade-off between desired morphology and drug loading capacity as the crosslinker density increases. In addition, the particles were aerosolized, and our data indicated that the particles remained intact and retained their initial morphology and size after aerosolization. The combination of morphology, particle size, antibody loading capacity, low cytotoxicity, and ease of aerosolization support the potential use of these particles for pulmonary delivery of protein therapeutics.

Preclinical immunogenicity risk assessment of biotherapeutics using CD4 T cell assays

T-cell dependent antibody responses to biotherapeutics remain a challenge to the optimal clinical application of biotherapeutics because of their capacity to impair drug efficacy and their potential to cause safety issues. To minimize this clinical immunogenicity risk, preclinical assays measuring the capacity of biotherapeutics to elicit CD4 T cell response in vitro are commonly used. However, there is considerable variability in assay formats and a general poor understanding of their respective predictive value. In this study, we evaluated the performance of three different CD4 T cell proliferation assays in their capacity to predict clinical immunogenicity: a CD8 T cell depleted peripheral blood mononuclear cells (PBMC) assay and two co-culture-based assays between dendritic cells (DCs) and autologous CD4 T cells with or without restimulation with monocytes. A panel of 10 antibodies with a wide range of clinical immunogenicity was selected. The CD8 T cell depleted PBMC assay predicted the clinical immunogenicity in four of the eight highly immunogenic antibodies included in the panel. Similarly, five antibodies with high clinical immunogenicity triggered a response in the DC: CD4 T cell assay but the responses were of lower magnitude than the ones observed in the PBMC assay. Remarkably, three antibodies with high clinical immunogenicity did not trigger any response in either platform. The addition of a monocyte restimulation step to the DC: CD4 T cell assay did not further improve its predictive value. Overall, these results indicate that there are no CD4 T cell assay formats that can predict the clinical immunogenicity of all biotherapeutics and reinforce the need to combine results from various preclinical assays assessing antigen uptake and presentation to fully mitigate the immunogenicity risk of biotherapeutics.

A Comprehensive Analysis of Biopharmaceutical Products Listed in the FDA's Purple Book

Although biopharmaceuticals constitute around 10% of the drug landscape, eight of the ten top-selling products were biopharmaceuticals in 2023. This study did a comprehensive analysis of the FDA's Purple Book database. Firstly, our research uncovered market trends and provided insights into biologics distributions. According to the investigation, although biotechnology has advanced and legislative shifts have made the approval process faster, there are still challenges to overcome, such as molecular instability and formulation design. Moreover, our research comprehensively analyzed biological formulations, pointing out significant strategies regarding administration routes, dosage forms, product packaging, and excipients. In conjunction with biologics, the widespread integration of innovative delivery strategies will be implemented to confront the evolving challenges in healthcare and meet an expanding array of treatment needs.

Microgels for bioprinting: recent advancements and challenges

Microgels have become a popular and powerful structural unit in the bioprinting field due to their advanced properties, ranging from the tiny size and well-connected hydrogel (nutrient) network to special rheological properties. Different microgels can be fabricated by a variety of fabrication methods including bulk crushing, auxiliary dripping, multiphase emulsion, and lithography technology. Traditionally, microgels can encapsulate specific cells and are used for in vitro disease models and in vivo organ regeneration. Furthermore, microgels can serve as a drug carrier to realize controlled release of drug molecules. Apart from being used as an independent application unit, recently, these microgels are widely applied as a specific bioink component in 3D bioprinting for in situ tissue repair or building special 3D structures. In this review, we introduce different methods used to generate microgels and the microgel-based bioink for bioprinting. Besides, the further tendency of microgel development in future is introduced and predicted to provide guidance for related researchers in exploring more effective ways to fabricate microgels and more potential bioprinting application cases as multifunctional bioink components.

Biomaterials for Protein Delivery: Opportunities and Challenges to Clinical Translation

The development of biomaterials for protein delivery is an emerging field that spans materials science, bioengineering, and medicine. In this review, we highlight the immense potential of protein-delivering biomaterials as therapeutic options and discuss the multifaceted challenges inherent to the field. We address current advancements and approaches in protein delivery that leverage stimuli-responsive materials, harness advanced fabrication techniques like 3D printing, and integrate nanotechnologies for greater targeting and improved stability, efficacy, and tolerability profiles. We also discuss the demand for highly complex delivery systems to maintain structural integrity and functionality of the protein payload. Finally, we discuss barriers to clinical translation, such as biocompatibility, immunogenicity, achieving reliable controlled release, efficient and targeted delivery, stability issues, scalability of production, and navigating the regulatory landscape for such materials. Overall, this review summarizes insights from a survey of the current literature and sheds light on the interplay between innovation and the practical implementation of biomaterials for protein delivery.

Engineering Antigen-Specific Tolerance to an Artificial Protein Hydrogel

Artificial protein hydrogels are an emerging class of biomaterials with numerous prospective applications in tissue engineering and regenerative medicine. These materials are likely to be immunogenic due to their frequent incorporation of novel amino acid sequence domains, which often serve a functional role within the material itself. We engineered injectable "self" and "nonself" artificial protein hydrogels, which were predicted to have divergent immune outcomes in vivo on the basis of their primary amino acid sequence. Following implantation in mouse, the nonself gels raised significantly higher antigel antibody titers than the corresponding self gels. Prophylactic administration of a fusion antibody targeting the nonself hydrogel epitopes to DEC-205, an endocytic receptor involved in Treg induction, fully suppressed the elevated antibody titer against the nonself gels. These results suggest that the clinical immune response to artificial protein biomaterials, including those that contain highly antigenic sequence domains, can be tuned through the induction of antigen-specific tolerance.

Applications of Flow Cytometry in Drug Discovery and Translational Research

Flow cytometry is a mainstay technique in cell biology research, where it is used for phenotypic analysis of mixed cell populations. Quantitative approaches have unlocked a deeper value of flow cytometry in drug discovery research. As the number of drug modalities and druggable mechanisms increases, there is an increasing drive to identify meaningful biomarkers, evaluate the relationship between pharmacokinetics and pharmacodynamics (PK/PD), and translate these insights into the evaluation of patients enrolled in early clinical trials. In this review, we discuss emerging roles for flow cytometry in the translational setting that supports the transition and evaluation of novel compounds in the clinic.

Toward reproducible tumor organoid culture: focusing on primary liver cancer

Organoids present substantial potential for pushing forward preclinical research and personalized medicine by accurately recapitulating tissue and tumor heterogeneity in vitro. However, the lack of standardized protocols for cancer organoid culture has hindered reproducibility. This paper comprehensively reviews the current challenges associated with cancer organoid culture and highlights recent multidisciplinary advancements in the field with a specific focus on standardizing liver cancer organoid culture. We discuss the non-standardized aspects, including tissue sources, processing techniques, medium formulations, and matrix materials, that contribute to technical variability. Furthermore, we emphasize the need to establish reproducible platforms that accurately preserve the genetic, proteomic, morphological, and pharmacotypic features of the parent tumor. At the end of each section, our focus shifts to organoid culture standardization in primary liver cancer. By addressing these challenges, we can enhance the reproducibility and clinical translation of cancer organoid systems, enabling their potential applications in precision medicine, drug screening, and preclinical research.

The strain-dependent cytostatic activity of Lactococcus lactis on CRC cell lines is mediated through the release of arginine deiminase

BACKGROUND

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers, posing a serious public health challenge that necessitates the development of new therapeutics, therapies, and prevention methods. Among the various therapeutic approaches, interventions involving lactic acid bacteria (LAB) as probiotics and postbiotics have emerged as promising candidates for treating and preventing CRC. While human-isolated LAB strains are considered highly favorable, those sourced from environmental reservoirs such as dairy and fermented foods are also being recognized as potential sources for future therapeutics.

RESULTS

In this study, we present a novel and therapeutically promising strain, Lactococcus lactis ssp. lactis Lc4, isolated from dairy sources. Lc4 demonstrated the ability to release the cytostatic agent - arginine deiminase (ADI) - into the post-cultivation supernatant when cultured under conditions mimicking the human gut environment. Released arginine deiminase was able to significantly reduce the growth of HT-29 and HCT116 cells due to the depletion of arginine, which led to decreased levels of c-Myc, reduced phosphorylation of p70-S6 kinase, and cell cycle arrest. The ADI release and cytostatic properties were strain-dependent, as was evident from comparison to other L. lactis ssp. lactis strains.

CONCLUSION

For the first time, we unveil the anti-proliferative properties of the L. lactis cell-free supernatant (CFS), which are independent of bacteriocins or other small molecules. We demonstrate that ADI, derived from a dairy-Generally Recognized As Safe (GRAS) strain of L. lactis, exhibits anti-proliferative activity on cell lines with different levels of argininosuccinate synthetase 1 (ASS1) expression. A unique feature of the Lc4 strain is also its capability to release ADI into the extracellular space. Taken together, we showcase L. lactis ADI and the Lc4 strain as promising, potential therapeutic agents with broad applicability.

Antibody-Drug Conjugate Overview: a State-of-the-art Manufacturing Process and Control Strategy

Antibody-drug conjugates (ADCs) comprise an antibody, linker, and drug, which direct their highly potent small molecule drugs to target tumor cells via specific binding between the antibody and surface antigens. The antibody, linker, and drug should be properly designed or selected to achieve the desired efficacy while minimizing off-target toxicity. With a unique and complex structure, there is inherent heterogeneity introduced by product-related variations and the manufacturing process. Here this review primarily covers recent key advances in ADC history, clinical development status, molecule design, manufacturing processes, and quality control. The manufacturing process, especially the conjugation process, should be carefully developed, characterized, validated, and controlled throughout its lifecycle. Quality control is another key element to ensure product quality and patient safety. A patient-centric strategy has been well recognized and adopted by the pharmaceutical industry for therapeutic proteins, and has been successfully implemented for ADCs as well, to ensure that ADC products maintain their quality until the end of their shelf life. Deep product understanding and process knowledge defines attribute testing strategies (ATS). Quality by design (QbD) is a powerful approach for process and product development, and for defining an overall control strategy. Finally, we summarize the current challenges on ADC development and provide some perspectives that may help to give related directions and trigger more cross-functional research to surmount those challenges.

Reducing Immunogenicity by Design: Approaches to Minimize Immunogenicity of Monoclonal Antibodies

Monoclonal antibodies (mAbs) have transformed therapeutic strategies for various diseases. Their high specificity to target antigens makes them ideal therapeutic agents for certain diseases. However, a challenge to their application in clinical practice is their potential risk to induce unwanted immune response, termed immunogenicity. This challenge drives the continued efforts to deimmunize these protein therapeutics while maintaining their pharmacokinetic properties and therapeutic efficacy. Because mAbs hold a central position in therapeutic strategies against an array of diseases, the importance of conducting comprehensive immunogenicity risk assessment during the drug development process cannot be overstated. Such assessment necessitates the employment of in silico, in vitro, and in vivo strategies to evaluate the immunogenicity risk of mAbs. Understanding the intricacies of the mechanisms that drive mAb immunogenicity is crucial to improving their therapeutic efficacy and safety and developing the most effective strategies to determine and mitigate their immunogenic risk. This review highlights recent advances in immunogenicity prediction strategies, with a focus on protein engineering strategies used throughout development to reduce immunogenicity.

Colon-targeted S100A8/A9-specific peptide systems ameliorate colitis and colitis-associated colorectal cancer in mouse models

The link between chronic inflammation and cancer development is well acknowledged. Inflammatory bowel disease including ulcerative colitis and Crohn's disease frequently promotes colon cancer development. Thus, control of intestinal inflammation is a therapeutic strategy to prevent and manage colitis-associated colorectal cancer (CRC). Recently, gut mucosal damage-associated molecular patterns S100A8 and S100A9, acting via interactions with their pattern recognition receptors (PRRs), especially TLR4 and RAGE, have emerged as key players in the pathogenesis of colonic inflammation. We found elevated serum levels of S100A8 and S100A9 in both colitis and colitis-associated CRC mouse models along with significant increases in their binding with PRR, TLR4, and RAGE. In this study we developed a dual PRR-inhibiting peptide system (rCT-S100A8/A9) that consisted of TLR4- and RAGE-inhibiting motifs derived from S100A8 and S100A9, and conjugated with a CT peptide (TWYKIAFQRNRK) for colon-specific delivery. In human monocyte THP-1 and mouse BMDMs, S100A8/A9-derived peptide comprising TLR4- and RAGE-interacting motif (0.01, 0.1, 1 μM) dose-dependently inhibited the binding of S100 to TLR4 or RAGE, and effectively inhibited NLRP3 inflammasome activation. We demonstrated that rCT-S100A8/A9 had appropriate drug-like properties including in vitro stabilities and PK properties as well as pharmacological activities. In mouse models of DSS-induced acute and chronic colitis, injection of rCT-S100A8/A9 (50 μg·kg-1·d-1, i.p. for certain consecutive days) significantly increased the survival rates and alleviated the pathological injuries of the colon. In AOM/DSS-induced colitis-associated colorectal cancer (CAC) mouse model, injection of rCT-S100A8/A9 (50 μg·kg-1·d-1, i.p.) increased the body weight, decreased tumor burden in the distal colon, and significantly alleviated histological colonic damage. In mice bearing oxaliplatin-resistant CRC xenografts, injection of rCT-S100A8/A9 (20 μg/kg, i.p., every 3 days for 24-30 days) significantly inhibited the tumor growth with reduced EMT-associated markers in tumor tissues. Our results demonstrate that targeting the S100-PRR axis improves colonic inflammation and thus highlight this axis as a potential therapeutic target for colitis and CRC.

AbImmPred: An immunogenicity prediction method for therapeutic antibodies using AntiBERTy-based sequence features

Due to the unnecessary immune responses induced by therapeutic antibodies in clinical applications, immunogenicity is an important factor to be considered in the development of antibody therapeutics. To a certain extent, there is a lag in using wet-lab experiments to test the immunogenicity in the development process of antibody therapeutics. Developing a computational method to predict the immunogenicity at once the antibody sequence is designed, is of great significance for the screening in the early stage and reducing the risk of antibody therapeutics development. In this study, a computational immunogenicity prediction method was proposed on the basis of AntiBERTy-based features of amino sequences in the antibody variable region. The AntiBERTy-based sequence features were first calculated using the AntiBERTy pre-trained model. Principal component analysis (PCA) was then applied to reduce the extracted feature to two dimensions to obtain the final features. AutoGluon was then used to train multiple machine learning models and the best one, the weighted ensemble model, was obtained through 5-fold cross-validation on the collected data. The data contains 199 commercial therapeutic antibodies, of which 177 samples were used for model training and 5-fold cross-validation, and the remaining 22 samples were used as an independent test dataset to evaluate the performance of the constructed model and compare it with other prediction methods. Test results show that the proposed method outperforms the comparison method with 0.7273 accuracy on the independent test dataset, which is 9.09% higher than the comparison method. The corresponding web server is available through the official website of GenScript Co., Ltd., https://www.genscript.com/tools/antibody-immunogenicity.

Recombinant IFN-γ1b Treatment in a Patient with Inherited IFN-γ Deficiency

PURPOSE

Inborn errors of IFN-γ immunity underlie Mendelian susceptibility to mycobacterial disease (MSMD). Twenty-two genes with products involved in the production of, or response to, IFN-γ and variants of which underlie MSMD have been identified. However, pathogenic variants of IFNG encoding a defective IFN-γ have been described in only two siblings, who both underwent hematopoietic stem cell transplantation (HCST).

METHODS

We characterized a new patient with MSMD by genetic, immunological, and clinical means. Therapeutic decisions were taken on the basis of these findings.

RESULTS

The patient was born to consanguineous Turkish parents and developed bacillus Calmette-Guérin (BCG) disease following vaccination at birth. Whole-exome sequencing revealed a homozygous private IFNG variant (c.224 T > C, p.F75S). Upon overexpression in recipient cells or constitutive expression in the patient's cells, the mutant IFN-γ was produced within the cells but was not correctly folded or secreted. The patient was treated for 6 months with two or three antimycobacterial drugs only and then for 30 months with subcutaneous recombinant IFN-γ1b plus two antimycobacterial drugs. Treatment with IFN-γ1b finally normalized all biological parameters. The patient presented no recurrence of mycobacterial disease or other related infectious diseases. The treatment was well tolerated, without the production of detectable autoantibodies against IFN-γ.

CONCLUSION

We describe a patient with a new form of autosomal recessive IFN-γ deficiency, with intracellular, but not extracellular IFN-γ. IFN-γ1b treatment appears to have been beneficial in this patient, with no recurrence of mycobacterial infection over a period of more than 30 months. This targeted treatment provides an alternative to HCST in patients with complete IFN-γ deficiency or at least an option to better control mycobacterial infection prior to HCST.

Biophysical and biochemical characterization of a recombinant Lyme disease vaccine antigen, CspZ-YA

Lyme disease, caused by Lyme Borrelia spirochetes, is the most common vector-borne illness in the United States. Despite its global significance, with an estimated 14.5 % seroprevalence, there is currently no licensed vaccine. Previously, we demonstrated that CspZ-YA protein conferred protection against Lyme Borrelia infection, making it a promising vaccine candidate. However, such a protein was tagged with hexahistidine, and thus not preferred for vaccine development; furthermore, the formulation to stabilize the protein was understudied. In this work, we developed a two-step purification process for tag-free E. coli-expressed recombinant CspZ-YA. We further utilized various bioassays to analyze the protein and determine the suitable buffer system for long-term storage and formulation as a vaccine immunogen. The results indicated that a buffer with a pH between 6.5 and 8.5 stabilized CspZ-YA by reducing its surface hydrophobicity and colloidal interactions. Additionally, low pH values induced a change in local spatial conformation and resulted in a decrease in α-helix content. Lastly, an optimal salinity of 22-400 mM at pH 7.5 was found to be important for its stability. Collectively, this study provides a fundamental biochemical and biophysical understanding and insights into the ideal stabilizing conditions to produce CspZ-YA recombinant protein for use in vaccine formulation and development.

Characterization of anti-drug antibody dynamics using a bivariate mixed hidden-markov model by nonlinear-mixed effects approach

Biological therapies may act as immunogenic triggers leading to the formation of anti-drug antibodies (ADAs). Population pharmacokinetic (PK) models can be used to characterize the relationship between ADA and drug disposition but often rely on the ADA bioassay results, which may not be sufficiently sensitive to inform on this characterization.In this work, a methodology that could help to further elucidate the underlying ADA production and impact on the drug disposition was explored. A mixed hidden-Markov model (MHMM) was developed to characterize the underlying (hidden) formation of ADA against the biologic, using certolizumab pegol (CZP), as a test drug. CZP is a PEGylated Fc free TNF-inhibitor used in the treatment of rheumatoid arthritis and other chronic inflammatory diseases.The bivariate MHMM used information from plasma drug concentrations and ADA measurements, from six clinical studies (n = 845), that were correlated through a bivariate Gaussian function to infer about two hidden states; production and no-production of ADA influencing PK. Estimation of inter-individual variability was not supported in this case. Parameters associated with the observed part of the model were reasonably well estimated while parameters associated with the hidden part were less precise. Individual state sequences obtained using a Viterbi algorithm suggested that the model was able to determine the start of ADA production for each individual, being a more assay-independent methodology than traditional population PK. The model serves as a basis for identification of covariates influencing the ADA formation, and thus has the potential to identify aspects that minimize its impact on PK and/or efficacy.

The differential non-covalent binding of epicatechin and chlorogenic acid to ovotransferrin and the enhancing efficiency of immunomodulatory activity

Seeking safe and environmentally friendly natural immunomodulators is a pressing requirement of humanity. This study investigated the differential binding characteristics of two polar polyphenols (PP), namely epicatechin (EC) and chlorogenic acid (CA), to ovotransferrin (OVT), and explored the relationship between structural transformations and immunomodulatory activity of OVT-PP complexes. Results showed that CA exhibited a stronger affinity for OVT than EC, mainly driven by hydrogen bonds and van der Waals forces. Complexation-induced conformational variations in OVT, including static fluorescence quenching, increased microenvironment polarity surrounding tryptophan and tyrosine residues, and the transition from disordered α-helix to stable β-sheet. Furthermore, the structural conformation transformation of OVT-PP complexes facilitated the enhancement of immunomodulatory activity, with the OVT-CA (10:2) complex demonstrating the best immunomodulatory activity. Principal component analysis (PCA) and Pearson correlation analysis revealed the immunomodulatory activities of the OVT-PP complexes were influenced by surface hydrophobicity (negatively correlated), β-sheet percentage and polyphenol binding constants. It could be inferred that PP complexation increased the surface polarity of OVT, consequently enhancing its immunomodulatory activity by promoting cell membrane affinity and antigen recognition. This study provides valuable guidance for effectively utilizing polyphenol-protein complexes in enhancing immunomodulatory activity.

A review on the use of extracellular vesicles for the delivery of drugs and biological therapeutics

INTRODUCTION

Exosomes, a type of extracellular vesicles, are effective tools for delivering small-molecule drugs and biological therapeutics into cells and tissues. Surface modifications with targeting ligands ensure precise delivery to specific cells, minimizing accumulation in healthy organs and reducing the side effects. This is a rapidly growing area in drug delivery research and this review aims to comprehensively discuss the recent advances in the field.

AREA COVERED

Recent studies have presented compelling evidence supporting the application of exosomes as efficient delivery vehicles that escape endosome trapping, achieving effective in vivo delivery in animal models. This review provides a systemic discussion on the exosome-based delivery technology, with topics covering exosome purification, surface modification, and targeted delivery of various cargos ranging from siRNAs, miRNAs, and proteins, to small molecule drugs.

EXPERT OPINION

Exosome-based gene and drug delivery has low toxicity and low immunogenicity. Surface modifications of the exosomes can effectively avoid endosome trapping and increase delivery efficiency. This exciting technology can be applied to improve the treatments for a wide variety of diseases.

Mitigation of Anti-Drug Antibody Production for Augmenting Anticancer Efficacy of Therapeutic Protein via Co-Injection of Nano-Rapamycin

The induction of anti-drug antibody (ADA) is a formidable challenge for protein-based therapy. Trichosanthin (TCS) as a class of ribosome-inactivating proteins is widely studied in tumor treatment. However, the immunogenicity can induce the formation of ADA, which can cause hypersensitivity reactions and neutralize the efficacy of TCS, thus limiting its clinical application in cancer therapy. Here, a promising solution to this issue is presented by co-administration of the rapamycin nanoparticles and TCS. PEGylated rapamycin amphiphilic molecule is designed and synthesized as a prodrug and a delivery carrier, which can self-assemble into a nanoparticle system with encapsulation of free rapamycin, a hydrophobic drug. It is found that co-injection of the PEGylated rapamycin nanoparticles and TCS could mitigate the formation of anti-TCS antibody via inducing durable immunological tolerance. Importantly, the combination of TCS and the rapamycin nanoparticles has an enhanced effect on inhibit the growth of breast cancer. This work provides a promising approach for protein toxin-based anticancer therapy and for promoting the clinical translation.

Therapeutic Fusion Proteins

Therapeutic fusion proteins are a class of hybrid constructs that combine distinct biomolecules into a single platform with the additive effects of the components. The ability to fuse two unrelated proteins provides a means to localize mechanisms to better treat a range of diseases. Fusion proteins can be designed to impart diverse functions, including increasing half-life, providing targeting, and enabling sustained signaling. Of these, half-life extenders, which are fused to a therapeutic protein to increase exposure, are the most established group of fusion proteins, with many clinical successes. Rapid advances in antibody and antibody-derivative technology have enabled the fusion of targeting domains with therapeutic proteins. An emerging group of therapeutic fusion proteins has two separate active functions. Although most research for therapeutic fusion proteins focuses on cancer, prior successes provide a foundation for studies into other diseases as well. The exponential emergence of biopharmaceuticals gives precedence for increased research into therapeutic fusion proteins for a multitude of diseases.

Characterization and root cause analysis of immunogenicity to pasotuxizumab (AMG 212), a prostate-specific membrane antigen-targeting bispecific T-cell engager therapy

Introduction

In oncology, anti-drug antibody (ADA) development that significantly curtails response durability has not historically risen to a level of concern. The relevance and attention ascribed to ADAs in oncology clinical studies have therefore been limited, and the extant literature on this subject scarce. In recent years, T cell engagers have gained preeminence within the prolific field of cancer immunotherapy. These drugs whose mode of action is expected to potently stimulate anti-tumor immunity, may potentially induce ADAs as an unintended corollary due to an overall augmentation of the immune response. ADA formation is therefore emerging as an important determinant in the successful clinical development of such biologics.

Methods

Here we describe the immunogenicity and its impact observed to pasotuxizumab (AMG 212), a prostate-specific membrane antigen (PSMA)-targeting bispecific T cell engager (BiTE®) molecule in NCT01723475, a first-in-human (FIH), multicenter, dose-escalation study in patients with metastatic castration-resistant prostate cancer (mCRPC). To explain the disparity in ADA incidence observed between the SC and CIV arms of the study, we interrogated other patient and product-specific factors that may have explained the difference beyond the route of administration.

Results

Treatment-emergent ADAs (TE-ADA) developed in all subjects treated with at least 1 cycle of AMG 212 in the subcutaneous (SC) arm. These ADAs were neutralizing and resulted in profound exposure loss that was associated with contemporaneous reversal of initial Prostate Surface Antigen (PSA) responses, curtailing durability of PSA response in patients. Pivoting from SC to a continuous intravenous (CIV) administration route remarkably yielded no subjects developing ADA to AMG 212. Through a series of stepwise functional assays, our investigation revealed that alongside a more historically immunogenic route of administration, non-tolerant T cell epitopes within the AMG 212 amino acid sequence were likely driving the high-titer, sustained ADA response observed in the SC arm.

Discussion

These mechanistic insights into the AMG 212 ADA response underscore the importance of performing preclinical immunogenicity risk evaluation as well as advocate for continuous iteration to better our biologics.

Impact of local drug delivery and natural agents as new target strategies against periodontitis: new challenges for personalized therapeutic approach

Periodontitis is a persistent inflammation of the soft tissue around the teeth that affects 60% of the population in the globe. The self-maintenance of the inflammatory process can cause periodontal damage from the alveolar bone resorption to tooth loss in order to contrast the effects of periodontitis, the main therapy used is scaling and root planing (SRP). At the same time, studying the physiopathology of periodontitis has shown the possibility of using a local drug delivery system as an adjunctive therapy. Using local drug delivery devices in conjunction with SRP therapy for periodontitis is a potential tool since it increases drug efficacy and minimizes negative effects by managing drug release. This review emphasized how the use of local drug delivery agents and natural agents could be promising adjuvants for the treatment of periodontitis patients affected or not by cardiovascular disease, diabetes, and other system problems. Moreover, the review evidences the current issues and new ideas that can inspire potential later study for both basic research and clinical practice for a tailored approach.

Biosimilars in rare diseases: a focus on paroxysmal nocturnal hemoglobinuria

Biologics, a class of medicines grown in and purified from genetically engineered cell cultures, have transformed the management of many cancers and rare diseases, such as paroxysmal nocturnal hemoglobinuria. As prescription drug spending has increased and exclusivity periods have expired, manufacturers have developed biosimilars-biologics that may be more affordable and highly similar to a licensed biological therapeutic, with no clinically meaningful differences in terms of safety or efficacy. With biosimilars gaining regulatory approval around the globe and broadening patient access to biologics, this review aims to help rare disease healthcare providers familiarize themselves with biosimilars, understand their development and regulatory approval process, and address practical considerations that may facilitate their use.

Discovery of a Non-competitive TNFR1 Antagonist Affibody with Picomolar Monovalent Potency That Does Not Affect TNFR2 Function

Tumor necrosis factor (TNF) is a key regulator of immune responses and plays a significant role in the initiation and maintenance of inflammation. Upregulation of TNF expression leads to several inflammatory diseases, such as Crohn's, ulcerative colitis, and rheumatoid arthritis. Despite the clinical success of anti-TNF treatments, the use of these therapies is limited because they can induce adverse side effects through inhibition of TNF biological activity, including blockade of TNF-induced immunosuppressive function of TNFR2. Using yeast display, we identified a synthetic affibody ligand (ABYTNFR1-1) with high binding affinity and specificity for TNFR1. Functional assays showed that the lead affibody potently inhibits TNF-induced NF-κB activation (IC50 of 0.23 nM) and, crucially, does not block the TNFR2 function. Additionally, ABYTNFR1-1 acts non-competitively─it does not block TNF binding or inhibit receptor-receptor interactions in pre-ligand-assembled dimers─thereby enhancing inhibitory robustness. The mechanism, monovalent potency, and affibody scaffold give this lead molecule uniquely strong potential as a therapeutic candidate for inflammatory diseases.

Impact of Stress on the Immunogenic Potential of Adalimumab

Monoclonal antibodies against tumor necrosis factor-alpha (TNFα) are widely used for treatment of inflammatory diseases. However, despite the inhibitory effect this class of drugs has on the immune system, anti-drug antibodies are often formed with continuous use. Particles formed during stress conditions, which can be used to simulate storage and handling conditions of commercial antibodies, have previously been associated with the formation of anti-drug antibodies. This study investigates the relationship between particles, oligomerization, folding and chemical degradation on the in vitro cytokine response toward the TNFα inhibitor adalimumab. Adalimumab aggregates generated using stir and heat stress were fractionated into distinct sub-populations, and their structure and immunogenic potential were evaluated. A chemically degraded sample of adalimumab was included to compare particle composition with the milder accelerated heat and stir stressed conditions. Particles from stressed adalimumab samples induced elevated cytokine levels and CD4+ T cell proliferation in vitro compared to non-stressed samples. Samples enriched with both submicron and subvisible particles of adalimumab induced the strongest cytokine release and the strongest CD4+ T cell proliferation despite maintaining some TNFα inhibitory functionality. Samples that were stressed and subsequently purified of subvisible and submicron particles did not elicit a significantly higher cytokine response or show increased CD4+ T cell proliferation compared to a non-stressed sample. Oxidation-induced chemical modifications in adalimumab, mainly in Met, His, Trp, and Tyr, were not found to be sufficient in absence of particle formation to induce increased CD4+ T cell proliferation or cytokine release despite less decreased TNFα inhibitory activity of adalimumab. These observations provide further evidence that particles do indeed potentiate the immunogenic potential of adalimumab.

Amphiphilic Cell-Penetrating Peptides Containing Arginine and Hydrophobic Residues as Protein Delivery Agents

The entry of proteins through the cell membrane is challenging, thus limiting their use as potential therapeutics. Seven cell-penetrating peptides, designed in our laboratory, were evaluated for the delivery of proteins. Fmoc solid-phase peptide synthesis was utilized for the synthesis of seven cyclic or hybrid cyclic-linear amphiphilic peptides composed of hydrophobic (tryptophan (W) or 3,3-diphenylalanine (Dip) and positively-charged arginine (R) residues, such as [WR]₄, [WR]₉, [WWRR]₄, [WWRR]₅, [(RW)₅K](RW)₅, [R₅K]W₇, and [DipR]₅. Confocal microscopy was used to screen the peptides as a protein delivery system of model cargo proteins, green and red fluorescein proteins (GFP and RFP). Based on the confocal microscopy results, [WR]₉ and [DipR]₅ were found to be more efficient among all the peptides and were selected for further studies. [WR]₉ (1-10 µM) + protein (GFP and RFP) physical mixture did not show high cytotoxicity (>90% viability) in triple-negative breast cancer cells (MDA-MB-231) after 24 h, while [DipR]₅ (1-10 µM) physical mixture with GFP exhibited more than 81% cell viability. Confocal microscopy images revealed internalization of GFP and RFP in MDA-MB-231 cells using [WR]₉ (2-10 μM) and [DipR]₅ (1-10 µM). Fluorescence-activated cell sorting (FACS) analysis indicated that the cellular uptake of GFP was concentration-dependent in the presence of [WR]₉ in MDA-MB-231 cells after 3 h of incubation at 37 °C. The concentration-dependent uptake of GFP and RFP was also observed in the presence of [DipR₅] in SK-OV-3 and MDA-MB-231 cells after 3 h of incubation at 37 °C. FACS analysis indicated that the cellular uptake of GFP in the presence of [WR]₉ was partially decreased by methyl-β-cyclodextrin and nystatin as endocytosis inhibitors after 3 h of incubation in MDA-MB-231 cells, whereas nystatin and chlorpromazine as endocytosis inhibitors slightly reduced the uptake of GFP in the presence of [DipR]₅ after 3 h of incubation in MDA-MB-231. [WR]₉ was able to deliver therapeutically relevant proteins (Histone H2A) at different concentrations. These results provide insight into the use of amphiphilic cyclic peptides in the delivery of protein-related therapeutics.

Toward the Development of Epigenome Editing-Based Therapeutics: Potentials and Challenges

The advancement in epigenetics research over the past several decades has led to the potential application of epigenome-editing technologies for the treatment of various diseases. In particular, epigenome editing is potentially useful in the treatment of genetic and other related diseases, including rare imprinted diseases, as it can regulate the expression of the epigenome of the target region, and thereby the causative gene, with minimal or no modification of the genomic DNA. Various efforts are underway to successfully apply epigenome editing in vivo, such as improving target specificity, enzymatic activity, and drug delivery for the development of reliable therapeutics. In this review, we introduce the latest findings, summarize the current limitations and future challenges in the practical application of epigenome editing for disease therapy, and introduce important factors to consider, such as chromatin plasticity, for a more effective epigenome editing-based therapy.

Proteins and their functionalization for finding therapeutic avenues in cancer: Current status and future prospective

Despite the remarkable advancement in the health care sector, cancer remains the second most fatal disease globally. The existing conventional cancer treatments primarily include chemotherapy, which has been associated with little to severe side effects, and radiotherapy, which is usually expensive. To overcome these problems, target-specific nanocarriers have been explored for delivering chemo drugs. However, recent reports on using a few proteins having anticancer activity and further use of them as drug carriers have generated tremendous attention for furthering the research towards cancer therapy. Biomolecules, especially proteins, have emerged as suitable alternatives in cancer treatment due to multiple favourable properties including biocompatibility, biodegradability, and structural flexibility for easy surface functionalization. Several in vitro and in vivo studies have reported that various proteins derived from animal, plant, and bacterial species, demonstrated strong cytotoxic and antiproliferative properties against malignant cells in native and their different structural conformations. Moreover, surface tunable properties of these proteins help to bind a range of anticancer drugs and target ligands, thus making them efficient delivery agents in cancer therapy. Here, we discuss various proteins obtained from common exogenous sources and how they transform into effective anticancer agents. We also comprehensively discuss the tumor-killing mechanisms of different dietary proteins such as bovine α-lactalbumin, hen egg-white lysozyme, and their conjugates. We also articulate how protein nanostructures can be used as carriers for delivering cancer drugs and theranostics, and strategies to be adopted for improving their in vivo delivery and targeting. We further discuss the FDA-approved protein-based anticancer formulations along with those in different phases of clinical trials.

The establishment of B cell-deficient Igh-J KO mouse model by gene editing and efficacy evaluation

Over the last few years, immunotherapy has made significant progress in treating various cancers with therapeutic antibodies. However, therapeutic antibodies have been validated for inducing an unintended immune response in human and animal models, which leads to the emergence of anti-drug antibodies (ADAs) and affects their effectiveness and safety. In preclinical research, ADAs production by B cells may accelerate antibody metabolism and result in missing potential candidate molecules. Thus, it is urgent to develop preclinical models that remove only B cells without affecting the function of T and NK cells. Rearrangement of immunoglobulin heavy chain J gene fragment (Igh-J) is the first link in B cell development, and immunotherapies are currently leaning toward combination treatments with PD-1/PD-L1 antibodies, here we created humanized PD-1, PD-L1 and Igh-J knockout (hPD-1/hPD-L1, Igh-J KO) mice and validated by using the reported high immunogenicity drug M7824 (a protein designed to simultaneously block PD-L1 and TGF-β pathways, poorly anti-tumor efficacy in immunocompetent mice). Phenotypic analysis revealed that human PD-1 and PD-L1 were detectable in hPD-1/hPD-L1, Igh-J KO mice, but not mouse IgM and IgD. Igh-J KO depleted B cells while increased the percentage of other immune cell types. Meanwhile, the humanization of PD-1/PD-L1 and Igh-J KO had neither effect on the overall development, differentiation, or distribution of T cell subtypes, nor on the activation of NK and T cells, indicating that mice can be used for T and NK-related immunotherapies. Furthermore, M7824 treatment of these B cell-deficient mice inhibited tumor growth significantly, with higher M7824 analog concentrations and lower ADA-positive rates. These findings demonstrate that Igh-J KO mice are an effective and stable preclinical model for testing drugs based on T and NK cells with high immunogenicity in vivo.

Method validation of a bridging immunoassay in combination with acid-dissociation and bead treatment for detection of anti-drug antibody

Anti-drug antibody (ADA) positivity is correlated with disease relapse risk when treated with monoclonal antibody (mAb) therapeutics. ADA evaluation can assist with interpreting pharmacokinetic, pharmacological, and toxicology results. Here, we established an ADA assay based on two steps of acid dissociation combined with a bridging immunoassay to provide a comprehensive validation strategy. The three-tiered sample analysis process included screening, confirmation, and titration assays using therapeutic HLX26 (targeting lymphocyte activation gene-3 [LAG-3]) as an example. The cut points were determined by testing 50 individual normal human serum samples, including screening cut point (SCP) (SNR: 1.08), confirmatory cut point (CCP) (% inhibition: 12.65), and titration cut point (TCP) (sample-to-noise ratio [SNR]: 1.17). The assay sensitivity, low positive control (LPC), and high positive control (HPC) titer acceptable range were also set up as 33.0 ng/mL, 41.0 ng/mL, and 320-1280, respectively. After full validation, both the intra-assay and inter-assay precision testing passed with coefficient of variations (CVs) < 20%. The assay enabled excellent drug tolerance up to 768.0 μg/mL at the HPC level and 291.0 μg/mL at the LPC level, while the tolerance of target interference was up to 74.0 ng/mL of soluble LAG3. Moreover, no false-positive results were observed in the presence of 5% hemolyzed serum samples and 150 mg/dL of triglyceride in the serum samples, no hook effect was observed, and the stability performed normally under room temperature for 24 h, 2-8 °C for 7 d, and six freeze/thaw cycles. In summary, this ADA assay is feasible and could be used for evaluating the immunogenicity of HLX26 in clinical trials.

Immunogenicity With Ranibizumab Biosimilar SB11 (Byooviz) and Reference Product Lucentis and Association With Efficacy, Safety, and Pharmacokinetics: A Post Hoc Analysis of a Phase 3 Randomized Clinical Trial

Importance

SB11 and reference ranibizumab (RBZ) are monoclonal anti-vascular endothelial growth factor (VEGF)-A antibodies approved for the treatment of neovascular age-related macular degeneration (nAMD) and other retinal diseases. The association of ranibizumab immunogenicity and treatment outcomes in patients with nAMD is unclear but relevant regarding concerns about immunogenicity of anti-VEGF biological products.

Objective

To examine the association of immunogenicity to ranibizumab products (SB11 and RBZ) with efficacy, safety, and pharmacokinetics.

Design, Setting, and Participants

This was a post hoc analysis of a randomized, double-masked, parallel-group phase 3 equivalence study with participants from 75 centers in 9 countries conducted from March 14, 2018, to December 9, 2019. Included were participants 50 years or older with nAMD and active subfoveal choroidal neovascularization lesions.

Interventions

Intravitreal injection of SB11 or RBZ, 0.5 mg, every 4 weeks through week 48.

Main Outcomes and Measures

Serum antidrug antibodies (ADAs) were analyzed during the study period until week 52 to measure immunogenicity. Analyses were performed on immunogenicity (overall ADA positivity) with best-corrected visual acuity (BCVA) and central subfield thickness (CST). Adverse events associated with intraocular inflammation (IOI) and serum ranibizumab levels were compared between overall ADA-positive and ADA-negative participants.

Results

A total of 705 participants (mean [SD] age, 74.1 [8.5] years; 403 female individuals [57.2%]) were included in the study. The overall incidence of ADA-positivity was 32 of 657 (4.9%) at week 52. The least-squares mean (SE) differences between overall ADA-positive and ADA-negative participants up to week 52 for BCVA and CST, respectively, were 1.6 (2.2) letters (95% CI, -2.7 to 5.8; P = .46) and 3 (13) μm (95% CI, -23 to 29; P = .83). IOI-related events occurred in 1 of 32 overall ADA-positive participants (3.1%) and 4 of 620 overall ADA-negative participants (0.6%). Mean (SD) serum ranibizumab concentrations over time were slightly lower in overall ADA-positive participants compared with those of ADA-negative participants, with a maximum value of 1389.3 (875.4) pg/mL at week 16 vs 1665.4 (1124.0) pg/mL at week 36, respectively.

Conclusions and Relevance

Results of this post hoc analysis of an equivalence trial suggest that immunogenicity was not associated with efficacy and safety of SB11 and RBZ in participants with nAMD. With a low overall ADA incidence, no clear association was identified between overall ADA positivity and pharmacokinetics. These findings support the biosimilarity of SB11 and RBZ, with no safety concern identified for SB11 vs RBZ associated with immunogenicity.

Trial Registration

ClinicalTrials.gov Identifier: NCT03150589.

Mechanisms of ADC Toxicity and Strategies to Increase ADC Tolerability

Anti-cancer antibody-drug conjugates (ADCs) aim to expand the therapeutic index of traditional chemotherapy by employing the targeting specificity of monoclonal antibodies (mAbs) to increase the efficiency of the delivery of potent cytotoxic agents to malignant cells. In the past three years, the number of ADCs approved by the Food and Drug Administration (FDA) has tripled. Although several ADCs have demonstrated sufficient efficacy and safety to warrant FDA approval, the clinical use of all ADCs leads to substantial toxicity in treated patients, and many ADCs have failed during clinical development due to their unacceptable toxicity profiles. Analysis of the clinical data has demonstrated that dose-limiting toxicities (DLTs) are often shared by different ADCs that deliver the same cytotoxic payload, independent of the antigen that is targeted and/or the type of cancer that is treated. DLTs are commonly associated with cells and tissues that do not express the targeted antigen (i.e., off-target toxicity), and often limit ADC dosage to levels below those required for optimal anti-cancer effects. In this manuscript, we review the fundamental mechanisms contributing to ADC toxicity, we summarize common ADC treatment-related adverse events, and we discuss several approaches to mitigating ADC toxicity.

PITHA: A Webtool to Predict Immunogenicity for Humanized and Fully Human Therapeutic Antibodies

Immunogenicity is an important concern to therapeutic antibodies during antibody design and development. Based on the co-crystal structures of idiotypic antibodies and their antibodies, one can see that anti-idiotypic antibodies usually bind the complementarity-determining regions (CDR) of idiotypic antibodies. Sequence and structural features, such as cavity volume at the CDR region and hydrophobicity of CDR-H3 loop region, were identified for distinguishing immunogenic antibodies from non-immunogenic antibodies. These features were integrated together with a machine learning platform to predict immunogenicity for humanized and fully human therapeutic antibodies (PITHA). This method achieved an accuracy of 83% in a leave-one-out experiment for 29 therapeutic antibodies with available crystal structures. The web server of this method is accessible at http://mabmedicine.com/PITHA or http://sysbio.unl.edu/PITHA . This method, as a step of computer-aided antibody design, helps evaluate the safety of new therapeutic antibody, which can save time and money during the therapeutic antibody development.