Ozoralizumab, a Humanized Anti-TNFα NANOBODY® Compound, Exhibits Efficacy Not Only at the Onset of Arthritis in a Human TNF Transgenic Mouse but Also During Secondary Failure of Administration of an Anti-TNFα IgG

BCMA/CD47-directed universal CAR-T cells exhibit excellent antitumor activity in multiple myeloma

BACKGROUND

BCMA-directed autologous chimeric antigen receptor T (CAR-T) cells have shown excellent clinical efficacy in relapsed or refractory multiple myeloma (RRMM), however, the current preparation process for autologous CAR-T cells is complicated and costly. Moreover, the upregulation of CD47 expression has been observed in multiple myeloma, and anti-CD47 antibodies have shown remarkable results in clinical trials. Therefore, we focus on the development of BCMA/CD47-directed universal CAR-T (UCAR-T) cells to improve these limitations.

METHODS

In this study, we employed phage display technology to screen nanobodies against BCMA and CD47 protein, and determined the characterization of nanobodies. Furthermore, we simultaneously disrupted the endogenous TRAC and B2M genes of T cells using CRISPR/Cas9 system to generate TCR and HLA double knock-out T cells, and developed BCMA/CD47-directed UCAR-T cells and detected the antitumor activity in vitro and in vivo.

RESULTS

We obtained fourteen and one specific nanobodies against BCMA and CD47 protein from the immunized VHH library, respectively. BCMA/CD47-directed UCAR-T cells exhibited superior CAR expression (89.13-98.03%), and effectively killing primary human MM cells and MM cell lines. BCMA/CD47-directed UCAR-T cells demonstrated excellent antitumor activity against MM and prolonged the survival of tumor-engrafted NCG mice in vivo.

CONCLUSIONS

This work demonstrated that BCMA/CD47-directed UCAR-T cells exhibited potent antitumor activity against MM in vitro and in vivo, which provides a potential strategy for the development of a novel "off-the-shelf" cellular immunotherapies for the treatment of multiple myeloma.

Functional insights of Tyr37 in framework region 2 directly contributing to the binding affinities and dissociation kinetics in single-domain VHH antibodies

Single-domain VHH antibody is regarded as one of the promising antibody classes for therapeutic and diagnostic applications. VHH antibodies have amino acids in framework region 2 that are distinct from those in conventional antibodies, such as the Val37Phe/Tyr (V37F/Y) substitution. Correlations between the residue type at position 37 and the conformation of the CDR3 in VHH antigen recognition have been previously reported. However, few studies focused on the meaning of harboring two residue types in position 37 of VHH antibodies, and the concrete roles of Y37 have been little to be elucidated. Here, we investigated the functional states of position 37 in co-crystal structures and performed analyses of three model antibodies with either F or Y at position 37. Our analysis indicates that Y at position 37 enhances the dissociation rate, which is highly correlated with drug efficacy. Our findings help to explain the molecular mechanisms that distinguish VHH antibodies from conventional antibodies.

Next generation single-domain antibodies against respiratory zoonotic RNA viruses

The global impact of zoonotic viral outbreaks underscores the pressing need for innovative antiviral strategies, particularly against respiratory zoonotic RNA viruses. These viruses possess a high potential to trigger future epidemics and pandemics due to their high mutation rate, broad host range and efficient spread through airborne transmission. Recent pandemics caused by coronaviruses and influenza A viruses underscore the importance of developing targeted antiviral strategies. Single-domain antibodies (sdAbs), originating from camelids, also known as nanobodies or VHHs (Variable Heavy domain of Heavy chain antibodies), have emerged as promising tools to combat current and impending zoonotic viral threats. Their unique structure, coupled with attributes like robustness, compact size, and cost-effectiveness, positions them as strong alternatives to traditional monoclonal antibodies. This review describes the pivotal role of sdAbs in combating respiratory zoonotic viruses, with a primary focus on enhancing sdAb antiviral potency through optimization techniques and diverse administration strategies. We discuss both the promises and challenges within this dynamically growing field.

Investigational bispecific antibodies for the treatment of rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disorder with a characteristic chronic inflammation of the synovium that may lead to the destruction of the joints in untreated patients. Interestingly, despite the availability of several effective treatments, many patients do not achieve remission or low disease activity or may experience disease relapse.Following the above unmet needs, bispecific antibodies (BsAbs) have emerged as a new approach to improve the disease's treatment. BsAbs are designed to simultaneously target two different proteins involved in RA pathogenesis, leading to enhanced efficacy and reduced side effects compared to traditional monoclonal antibodies (mAbs).

AREAS COVERED

In this review, we discuss the development of BsAbs for RA treatment, including their mechanism of action, efficacy, and safety profile. We also deal with the challenges and future directions in this field.

EXPERT OPINION

BsAbs show promise in preclinical and clinical evaluations for treating RA. Further research is needed to optimize design and dosage and identify ideal patient groups. BsAbs can benefit disease management and improve outcomes of RA patients.

Next-Generation Anti-TNFα Agents: The Example of Ozoralizumab

Biologic therapy involving anti-tumor necrosis factor-α (anti-TNFα) agents has fundamentally changed the management of patients with immune-mediated inflammatory diseases, including rheumatoid arthritis, thus benefiting many patients. Nevertheless, the inability of some patients to achieve low disease activity or clinical remission remains a major concern. To address such concerns, next-generation anti-TNFα agents that differ from the immunoglobulin G-format anti-TNFα agents that have been used to date are being developed using antibody-engineering technology. Their unique design employing novel molecular characteristics affords several advantages, such as early improvement of clinical symptoms, optimization of drug bioavailability, enhancement of tissue penetration, and a reduction in side effects. This holds promise for a new paradigm shift in biologic therapy via the use of next-generation anti-TNFα agents. Ozoralizumab, a next-generation anti-TNFα agent that was recently approved in Japan, comprises a variable region heavy-chain format. It has a completely different structure from conventional therapeutic antibodies, such as a small molecular size, an albumin-binding module, and a unique format that produces an avidity effect. Ozoralizumab exhibited rapid biodistribution into joints, provided attenuation of Fcγ receptor-mediated inflammatory responses, and had a high binding affinity to TNFα in non-clinical studies. In clinical trials, ozoralizumab yielded an early improvement in clinical symptoms, a sustained efficacy for up to 52 weeks, and an acceptable tolerability in patients with rheumatoid arthritis. This review focuses on the results of pre-clinical and clinical trials for ozoralizumab and outlines the progress in next-generation antibody development.

Synthetic G protein-coupled receptors for programmable sensing and control of cell behavior

Synthetic receptors that mediate antigen-dependent cell responses are transforming therapeutics, drug discovery, and basic research. However, established technologies such as chimeric antigen receptors (CARs) can only detect immobilized antigens, have limited output scope, and lack built-in drug control. Here, we engineer synthetic G protein-coupled receptors (GPCRs) capable of driving a wide range of native or nonnative cellular processes in response to user-defined antigen. We achieve modular antigen gating by engineering and fusing a conditional auto-inhibitory domain onto GPCR scaffolds. Antigen binding to a fused nanobody relieves auto-inhibition and enables receptor activation by drug, thus generating Programmable Antigen-gated G protein-coupled Engineered Receptors (PAGERs). We create PAGERs responsive to more than a dozen biologically and therapeutically important soluble and cell surface antigens, in a single step, from corresponding nanobody binders. Different PAGER scaffolds permit antigen binding to drive transgene expression, real-time fluorescence, or endogenous G protein activation, enabling control of cytosolic Ca 2+ , lipid signaling, cAMP, and neuronal activity. Due to its modular design and generalizability, we expect PAGER to have broad utility in discovery and translational science.

A selection and optimization strategy for single-domain antibodies targeting the PHF6 linear peptide within the tau intrinsically disordered protein

The use of variable domain of the heavy-chain of the heavy-chain-only antibodies (VHHs) as disease-modifying biomolecules in neurodegenerative disorders holds promises, including targeting of aggregation-sensitive proteins. Exploitation of their clinical values depends however on the capacity to deliver VHHs with optimal physico-chemical properties for their specific context of use. We described previously a VHH with high therapeutic potential in a family of neurodegenerative diseases called tauopathies. The activity of this promising parent VHH named Z70 relies on its binding within the central region of the tau protein. Accordingly, we carried out random mutagenesis followed by yeast two-hybrid screening to obtain optimized variants. The VHHs selected from this initial screen targeted the same epitope as VHH Z70 as shown using NMR spectroscopy and had indeed improved binding affinities according to dissociation constant values obtained by surface plasmon resonance spectroscopy. The improved affinities can be partially rationalized based on three-dimensional structures and NMR data of three complexes consisting of an optimized VHH and a peptide containing the tau epitope. Interestingly, the ability of the VHH variants to inhibit tau aggregation and seeding could not be predicted from their affinity alone. We indeed showed that the in vitro and in cellulo VHH stabilities are other limiting key factors to their efficacy. Our results demonstrate that only a complete pipeline of experiments, here described, permits a rational selection of optimized VHH variants, resulting in the selection of VHH variants with higher affinities and/or acting against tau seeding in cell models.

Engineered polyspecific antibodies: A new frontier in the field of immunotherapeutics

The 21st-century beginning remarked with the huge success of monospecific MAbs, however, in the last couple of years, polyspecific MAbs (PsAbs) have been an interesting topic and show promise of being biobetter than monospecific MAbs. Polyspecificity, in which a single antibody serves multiple specific target binding, has been hypothesized to contribute to the development of a highly effective antibody repertoire for immune defence. This polyspecific MAb trend represents an explosion that is gripping the whole pharmaceutical industry. This review is concerned with the current development and quality enforcement of PsAbs. All provided literature on monospecific MAbs and polyspecific MAbs (PsAbs) were searched using various electronic databases such as PubMed, Google Scholar, Web of Science, Elsevier, Springer, ACS, Google Patent and books via the keywords Antibody engineering, Polyspecific antibody, Conventional antibody, non-conventional antibody, and Single domain antibody. In the literature, there are more than 100 different formats to construct PsAb by quadroma technology, chemical conjugation and genetic engineering. Till March 2023, nine PsAb have been approved around the world, and around 330 are in advanced developmental stages, showing the dominancy of PsAb in the growing health sector. Recent advancements in protein engineering techniques and the fusion of non-conventional antibodies have made it possible to create complex PsAbs that demonstrate higher stability and enhanced potency. This marks the most significant achievement for cancer immunotherapy, in which PsAbs have immense promise. It is worth mentioning that seven out of the nine PsAbs have been approved as anti-cancer therapy. As PsAbs continue to acquire prominence, they could pave the way for the development of novel immunotherapies for multiple diseases.

Population Pharmacokinetics of Ozoralizumab in Patients with Rheumatoid Arthritis

Ozoralizumab is a bispecific NANOBODY compound that binds tumor necrosis factor alpha (TNFα) and human serum albumin. Ozoralizumab inhibits the TNFα physiological activity while maintaining long-term plasma retention owing to its human serum albumin-binding ability. A population pharmacokinetic (PK) model was developed using data from 494 Japanese patients with rheumatoid arthritis in Phase II/III and Phase III trials to assess the effects of potential PK covariates. The ozoralizumab PK after subcutaneous administration was described using a 1-compartment model with first-order absorption and first-order elimination processes. A proportional error model was used for inter- and intra-individual variabilities, with covariance set between inter-individual variabilities of the apparent clearance and apparent distribution volume. Body weight, sex, antidrug antibody status, estimated glomerular filtration rate, and concomitant methotrexate use were identified as covariates for apparent clearance, while body weight and sex were covariates for apparent distribution volume in the final model. Body weight had the greatest effect on the PK of ozoralizumab, while the other covariates had minor effects. When administered at 30 mg every 4 weeks, the predicted steady-state plasma trough concentration in a patient weighing 83.2 kg exceeded the trough concentration required to maintain efficacy of ozoralizumab, and the estimated exposure in a patient weighing 42.5 kg did not exceed the mean exposure at 80 mg, a well-tolerated dose, throughout 52 weeks. We developed a population PK model that adequately described the ozoralizumab PK in Japanese patients with rheumatoid arthritis, and none of the evaluated covariates showed clinically relevant effects on the PK of ozoralizumab.

Refining nanoprobes for monitoring of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a gastrointestinal immune disease that requires clear diagnosis, timely treatment, and lifelong monitoring. The diagnosis and monitoring methods of IBD mainly include endoscopy, imaging examination, and laboratory examination, which are constantly developed to achieve early definite diagnosis and accurate monitoring. In recent years, with the development of nanotechnology, the diagnosis and monitoring methods of IBD have been remarkably enriched. Nanomaterials, characterized by their minuscule dimensions that can be tailored, along with their distinctive optical, magnetic, and biodistribution properties, have emerged as valuable contrast agents for imaging and targeted agents for endoscopy. Through both active and passive targeting mechanisms, nanoparticles accumulate at the site of inflammation, thereby enhancing IBD detection. This review comprehensively outlines the existing IBD detection techniques, expounds upon the utilization of nanoparticles in IBD detection and diagnosis, and offers insights into the future potential of in vitro diagnostics. STATEMENT OF SIGNIFICANCE: Due to their small size and unique physical and chemical properties, nanomaterials are widely used in the biological and medical fields. In the area of oncology and inflammatory disease, an increasing number of nanomaterials are being developed for diagnostics and drug delivery. Here, we focus on inflammatory bowel disease, an autoimmune inflammatory disease that requires early diagnosis and lifelong monitoring. Nanomaterials can be used as contrast agents to visualize areas of inflammation by actively or passively targeting them through the intestinal mucosal epithelium where gaps exist due to inflammation stimulation. In this article, we summarize the utilization of nanoparticles in inflammatory bowel disease detection and diagnosis, and offers insights into the future potential of in vitro diagnostics.

Nanobodies in cytokine‑mediated immunotherapy and immunoimaging (Review)

Cytokines are the main regulators of innate and adaptive immunity, mediating communications between the cells of the immune system and regulating biological functions, including cell motility, differentiation, growth and apoptosis. Cytokines and cytokine receptors have been used in the treatment of tumors and autoimmune diseases, and to intervene in cytokine storms. Indeed, the use of monoclonal antibodies to block cytokine‑receptor interactions, as well as antibody‑cytokine fusion proteins has exhibited immense potential for the treatment of tumors and autoimmune diseases. Compared with these traditional types of antibodies, nanobodies not only maintain a high affinity and specificity, but also have the advantages of high thermal stability, a high capacity for chemical manipulation, low immunogenicity, good tissue permeability, rapid clearance and economic production. Thus, nanobodies have extensive potential for use in the diagnosis and treatment of cytokine‑related diseases. The present review summarizes the application of nanobodies in cytokine‑mediated immunotherapy and immunoimaging.

Promises and challenges of single-domain antibodies to control influenza

The World Health Organization advices the use of a quadrivalent vaccine as prophylaxis against influenza, to prevent severe influenza-associated disease and -mortality, and to keep up with influenza antigenic diversity. Different small molecule antivirals to treat influenza have become available. However, emergence of drug resistant influenza viruses has been observed upon use of these antivirals. An appealing alternative approach to prevent or treat influenza is the use of antibody-based antivirals, such as conventional monoclonal antibodies and single-domain antibodies (sdAbs). The surface of the influenza A and B virion is decorated with hemagglutinin molecules, which act as receptor-binding and membrane fusion proteins and represent the main target of neutralizing antibodies. SdAbs that target influenza A and B hemagglutinin have been described. In addition, sdAbs directed against the influenza A virus neuraminidase have been reported, whereas no sdAbs targeting influenza B neuraminidase have been described to date. SdAbs directed against influenza A matrix protein 2 or its ectodomain have been reported, while no sdAbs have been described targeting the influenza B matrix protein 2. Known for their high specificity, ease of production and formatting, sdAb-based antivirals could be a major leap forward in influenza control.

SARS-CoV-2 Specific Nanobodies Neutralize Different Variants of Concern and Reduce Virus Load in the Brain of h-ACE2 Transgenic Mice

Since the beginning of the COVID-19 pandemic, there has been a significant need to develop antivirals and vaccines to combat the disease. In this work, we developed llama-derived nanobodies (Nbs) directed against the receptor binding domain (RBD) and other domains of the Spike (S) protein of SARS-CoV-2. Most of the Nbs with neutralizing properties were directed to RBD and were able to block S-2P/ACE2 interaction. Three neutralizing Nbs recognized the N-terminal domain (NTD) of the S-2P protein. Intranasal administration of Nbs induced protection ranging from 40% to 80% after challenge with the WA1/2020 strain in k18-hACE2 transgenic mice. Interestingly, protection was associated with a significant reduction in virus replication in nasal turbinates and a reduction in virus load in the brain. Employing pseudovirus neutralization assays, we identified Nbs with neutralizing capacity against the Alpha, Beta, Delta, and Omicron variants, including a Nb capable of neutralizing all variants tested. Furthermore, cocktails of different Nbs performed better than individual Nbs at neutralizing two Omicron variants (B.1.529 and BA.2). Altogether, the data suggest the potential of SARS-CoV-2 specific Nbs for intranasal treatment of COVID-19 encephalitis.

Design and engineering of bispecific antibodies: insights and practical considerations

Bispecific antibodies (bsAbs) have attracted significant attention due to their dual binding activity, which permits simultaneous targeting of antigens and synergistic binding effects beyond what can be obtained even with combinations of conventional monospecific antibodies. Despite the tremendous therapeutic potential, the design and construction of bsAbs are often hampered by practical issues arising from the increased structural complexity as compared to conventional monospecific antibodies. The issues are diverse in nature, spanning from decreased biophysical stability from fusion of exogenous antigen-binding domains to antibody chain mispairing leading to formation of antibody-related impurities that are very difficult to remove. The added complexity requires judicious design considerations as well as extensive molecular engineering to ensure formation of high quality bsAbs with the intended mode of action and favorable drug-like qualities. In this review, we highlight and summarize some of the key considerations in design of bsAbs as well as state-of-the-art engineering principles that can be applied in efficient construction of bsAbs with diverse molecular formats.

A novel single domain bispecific antibody targeting VEGF and TNF-α ameliorates rheumatoid arthritis

Anti-TNF-α therapy fails in 30% of patients, where TNF-α may not be the key causative factor in these patients. We developed a bispecific single-domain antibody block TNF-α and VEGF (V5-3).The experiments showed that V5-3 effectively activated proliferation and migration of RA-FLS and HUVEC, tube-forming role of HUVEC, and expression of inflammatory factors in vitro. Besides, the experiments indicated that the anti-RA activity of V5-3 was superior to Anbainuo in vivo. Application of V5-3 reduced the expression of inflammatory factors, extent of synovial inflammation and angiogenesis and attenuated the severity of autoimmune arthritis in collagen-induced arthritis (CIA) mice. Mechanistically, V5-3 suppressed p65, AKT and VEGFR2 phosphorylation, as well as production of TNF-α and VEGF in joint tissues. These results demonstrated that V5-3 displayed a superior effect of anti-RA, may be a new therapy to overcome the limitations of anti-TNF-α monoclonal antibody.

Protein-Based Nanocarriers and Nanotherapeutics for Infection and Inflammation

Infectious and inflammatory diseases are one of the leading causes of death globally. The status quo has become more prominent with the onset of the coronavirus disease 2019 (COVID-19) pandemic. To combat these potential crises, proteins have been proven as highly efficacious drugs, drug targets, and biomarkers. On the other hand, advancements in nanotechnology have aided efficient and sustained drug delivery due to their nano-dimension-acquired advantages. Combining both strategies together, the protein nanoplatforms are equipped with the advantageous intrinsic properties of proteins as well as nanoformulations, eloquently changing the field of nanomedicine. Proteins can act as carriers, therapeutics, diagnostics, and theranostics in their nanoform as fusion proteins or as composites with other organic/inorganic materials. Protein-based nanoplatforms have been extensively explored to target the major infectious and inflammatory diseases of clinical concern. The current review comprehensively deliberated proteins as nanocarriers for drugs and nanotherapeutics for inflammatory and infectious agents, with special emphasis on cancer and viral diseases. A plethora of proteins from diverse organisms have aided in the synthesis of protein-based nanoformulations. The current study specifically presented the proteins of human and pathogenic origin to dwell upon the field of protein nanotechnology, emphasizing their pharmacological advantages. Further, the successful clinical translation and current bottlenecks of the protein-based nanoformulations associated with the infection-inflammation paradigm have also been discussed comprehensively. SIGNIFICANCE STATEMENT: This review discusses the plethora of promising protein-based nanocarriers and nanotherapeutics explored for infectious and inflammatory ailments, with particular emphasis on protein nanoparticles of human and pathogenic origin with reference to the advantages, ADME (absorption, distribution, metabolism, and excretion parameters), and current bottlenecks in development of protein-based nanotherapeutic interventions.

A pivotal decade for bispecific antibodies?

Bispecific antibodies (bsAbs) are a class of antibodies that can mediate novel mechanisms of action compared to monospecific monoclonal antibodies (mAbs). Since the discovery of mAbs and their adoption as therapeutic agents in the 1980s and 1990s, the development of bsAbs has held substantial appeal. Nevertheless, only three bsAbs (catumaxomab, blinatumomab, emicizumab) were approved through the end of 2020. However, since then, 11 bsAbs received regulatory agency approvals, of which nine (amivantamab, tebentafusp, mosunetuzumab, cadonilimab, teclistamab, glofitamab, epcoritamab, talquetamab, elranatamab) were approved for the treatment of cancer and two (faricimab, ozoralizumab) in non-oncology indications. Notably, of the 13 currently approved bsAbs, two, emicizumab and faricimab, have achieved blockbuster status, showing the promise of this novel class of therapeutics. In the 2020s, the approval of additional bsAbs can be expected in hematological malignancies, solid tumors and non-oncology indications, establishing bsAbs as essential part of the therapeutic armamentarium.

TROP2-directed nanobody-drug conjugate elicited potent antitumor effect in pancreatic cancer

BACKGROUND

Pancreatic cancer is a highly aggressive malignancy with limited treatment options and a poor prognosis. Trophoblast cell surface antigen 2 (TROP2), a cell surface antigen overexpressed in the tumors of more than half of pancreatic cancer patients, has been identified as a potential target for antibody-drug conjugates (ADCs). Almost all reported TROP2-targeted ADCs are of the IgG type and have been poorly studied in pancreatic cancer. Here, we aimed to develop a novel nanobody-drug conjugate (NDC) targeting TROP2 for the treatment of pancreatic cancer.

RESULTS

In this study, we developed a novel TROP2-targeted NDC, HuNbTROP2-HSA-MMAE, for the treatment of TROP2-positive pancreatic cancer. HuNbTROP2-HSA-MMAE is characterized by the use of nanobodies against TROP2 and human serum albumin (HSA) and has a drug-antibody ratio of 1. HuNbTROP2-HSA-MMAE exhibited specific binding to TROP2 and was internalized into tumor cells with high endocytosis efficiency within 5 h, followed by intracellular translocation to lysosomes and release of MMAE to induce cell apoptosis in TROP2-positive pancreatic cancer cells through the caspase-3/9 pathway. In a xenograft model of pancreatic cancer, doses of 0.2 mg/kg and 1 mg/kg HuNbTROP2-HSA-MMAE demonstrated significant antitumor effects, and a dose of 5 mg/kg even eradicated the tumor.

CONCLUSION

HuNbTROP2-HSA-MMAE has desirable affinity, internalization efficiency and antitumor activity. It holds significant promise as a potential therapeutic option for the treatment of TROP2-positive pancreatic cancer.

Role of Albumin as a Targeted Drug Carrier in the Management of Rheumatoid Arthritis: A Comprehensive Review

An endogenous transporter protein called albumin interacts with the Fc receptor to provide it with multiple substrate-binding domains, cell membrane receptor activation, and an extended circulating half-life. Albumin has the remarkable ability to bind with receptors viz. secreted protein acidic and rich in cysteine (SPARC) and scavenger protein-A (SR-A) that are overexpressed during rheumatoid arthritis (RA), enabling active targeting of the disease site instead of requiring specialized substrates to be added to the nanocarrier. RA, a chronic autoimmune illness, is characterized by the presence of a severe inflammatory response. RA patients have low serum albumin concentration, which signifies the high uptake of albumin at the inflammatory sites, giving a rationale to use albumin as a drug carrier for RA therapy. Albumin has the capacity for both passive and active targeting. It is an abundantly available protein in the bloodstream showing excellent cellular compatibility, degradability in biological tissues, nonantigenicity, and safety. There are three strategies of albumin mediated drug delivery as encapsulating therapeutics in albumin nanoparticles, chemically conjugating drugs with functional proteins, and albumin itself which is used as a targeting ligand to deliver drugs specifically to cells or tissues that express albumin-binding receptors. In the current review, an attempt has been made to highlight the significant evidence of albumin as a drug delivery carrier for the safe and effective management of RA. Evidence has been provided in the form of recent research advances, clinical trials, and patents. Additionally, this review will outline the prospective for the potential utilization of albumin as a drug vehicle for RA and suggest possible future avenues to provide the perspective for subsequent studies.

Bispecific soluble cytokine receptor-nanobody fusions inhibit Interleukin (IL-)6 trans-signaling and IL-12/23 or tumor necrosis factor (TNF) signaling

At least 0.5% of people in the Western world develop inflammatory bowel disease (IBD). While antibodies that block tumor necrosis factor (TNF) α and Interleukin (IL-)23 have been approved for the treatment of IBD, IL-6 antibodies failed in the phase II clinical trial due to non-tolerable side effects. However, two clinical phase II studies suggest that inhibiting IL-6/soluble IL-6R (sIL-6R)-induced trans-signaling via the cytokine receptor gp130 benefit IBD patients with fewer adverse events. Here we develop inhibitors targeting a combination of IL-6/sIL-6R and TNF or IL-12/IL-23 signaling, named cs130-TNFVHHFc and cs130-IL-12/23VHHFc. Surface plasmon resonance experiments showed that recombinant cs130-TNFVHHFc and cs130-IL-12/23VHHFc bind with high affinity to IL-6/sIL-6R complexes and human TNFα (hTNFα) or IL-12/IL-23, respectively. Immunoprecipitation experiments have verified the higher ordered complex formation of the inhibitors with IL-6/sIL-6R and IL-12. We demonstrated that cs130-TNFVHHFc and cs130-IL-12/23VHHFc block IL-6/sIL-6R trans-signaling-induced proliferation and STAT3 phosphorylation of Ba/F3-gp130 cells, as well as hTNFα- or IL-23-induced signaling, respectively. In conclusion, cs130-TNFVHHFc and cs130-IL-12/23VHHFc represent a class of dimeric and bispecific chimeric cytokine inhibitors that consist of a soluble cytokine receptor fused to anti-cytokine nanobodies.

Bispecific Antibodies in Lung Cancer: A State-of-the-Art Review

Bispecific antibodies have emerged as a promising class of therapeutics in the field of oncology, offering an innovative approach to target cancer cells while sparing healthy tissues. These antibodies are designed to bind two different antigens, enabling them to bridge immune cells with cancer cells, resulting in enhanced tumor cell killing and improved treatment responses. This review article summarizes the current landscape of bispecific antibodies in lung cancer, including their mechanisms of action, clinical development, and potential applications in other solid tumor malignancies. Additionally, the challenges and opportunities associated with their use in the clinic are discussed, along with future directions for research and development in this exciting area of cancer immunotherapy.

The role of inflammation in autoimmune disease: a therapeutic target

Autoimmune diseases (AIDs) are immune disorders whose incidence and prevalence are increasing year by year. AIDs are produced by the immune system's misidentification of self-antigens, seemingly caused by excessive immune function, but in fact they are the result of reduced accuracy due to the decline in immune system function, which cannot clearly identify foreign invaders and self-antigens, thus issuing false attacks, and eventually leading to disease. The occurrence of AIDs is often accompanied by the emergence of inflammation, and inflammatory mediators (inflammatory factors, inflammasomes) play an important role in the pathogenesis of AIDs, which mediate the immune process by affecting innate cells (such as macrophages) and adaptive cells (such as T and B cells), and ultimately promote the occurrence of autoimmune responses, so targeting inflammatory mediators/pathways is one of emerging the treatment strategies of AIDs. This review will briefly describe the role of inflammation in the pathogenesis of different AIDs, and give a rough introduction to inhibitors targeting inflammatory factors, hoping to have reference significance for subsequent treatment options for AIDs.

TNF and TNF receptors as therapeutic targets for rheumatic diseases and beyond

The cytokine TNF signals via two distinct receptors, TNF receptor 1 (TNFR1) and TNFR2, and is a central mediator of various immune-mediated diseases. Indeed, TNF-neutralizing biologic drugs have been in clinical use for the treatment of many inflammatory pathological conditions, including various rheumatic diseases, for decades. TNF has pleiotropic effects and can both promote and inhibit pro-inflammatory processes. The integrated net effect of TNF in vivo is a result of cytotoxic TNFR1 signalling and the stimulation of pro-inflammatory processes mediated by TNFR1 and TNFR2 and also TNFR2-mediated anti-inflammatory and tissue-protective activities. Inhibition of the beneficial activities of TNFR2 might explain why TNF-neutralizing drugs, although highly effective in some diseases, have limited benefit in the treatment of other TNF-associated pathological conditions (such as graft-versus-host disease) or even worsen the pathological condition (such as multiple sclerosis). Receptor-specific biologic drugs have the potential to tip the balance from TNFR1-mediated activities to TNFR2-mediated activities and enable the treatment of diseases that do not respond to current TNF inhibitors. Accordingly, a variety of reagents have been developed that either selectively inhibit TNFR1 or selectively activate TNFR2. Several of these reagents have shown promise in preclinical studies and are now in, or approaching, clinical trials.

Efficacy and safety of anti-TNF multivalent NANOBODY® compound 'ozoralizumab' without methotrexate co-administration in patients with active rheumatoid arthritis: A 52-week result of phase III, randomised, open-label trial (NATSUZORA trial)

OBJECTIVES

The aim is to assess the efficacy and safety of a 52-week subcutaneous ozoralizumab treatment at 30 and 80 mg without methotrexate (MTX) in active rheumatoid arthritis.

METHODS

This randomised, open-label, multicentre phase III trial randomly allocated 140 patients in 2:1 ratio as subcutaneous ozoralizumab at 30 or 80 mg every 4 weeks for 52 weeks without MTX.

RESULTS

Both groups administered ozoralizumab at 30 and 80 mg showed good clinical improvement. The American College of Rheumatology response rates were high at Week 24 and maintained through 52 weeks. The ozoralizumab groups also showed good improvement in other end points, and improvements observed from Week 1 were maintained through 52 weeks. Improvements in many efficacy assessments were similar between doses. No deaths were reported, and serious adverse events occurred in a total of 20 patients in the ozoralizumab groups. Increased antidrug antibodies were observed in approximately 40% of patients in the ozoralizumab groups, and 27.7% of the patients in the 30 mg group were neutralising antibody-positive.

CONCLUSIONS

Ozoralizumab, at 30 and 80 mg, demonstrated significant therapeutic effects without MTX, and the efficacy was maintained for 52 weeks with active rheumatoid arthritis. Ozoralizumab showed an acceptable tolerability profile over 52 weeks.

Efficacy and safety of the anti-TNF multivalent NANOBODY® compound ozoralizumab in patients with rheumatoid arthritis and an inadequate response to methotrexate: A 52-week result of a Phase II/III study (OHZORA trial)

OBJECTIVE

To assess the efficacy and safety through a 52-week treatment with subcutaneous ozoralizumab at 30 or 80 mg in patients with active rheumatoid arthritis despite methotrexate therapy.

METHODS

This multicentre, randomized, placebo-controlled, double-blind, parallel-group confirmatory trial included a 24-week double-blind treatment period followed by a 28-week open-label treatment period. The double-blind treatment period randomized 381 (2:2:1) patients to placebo and ozoralizumab at 30 or 80 mg, and patients receiving placebo were re-randomized (1:1) to ozoralizumab at 30 or 80 mg in the open-label period.

RESULTS

The ozoralizumab groups showed good clinical improvement, with high American College of Rheumatology response rates at 52 weeks, as well as good improvements in other endpoints, which were observed from Day 3 and maintained through Week 52. Furthermore, the ozoralizumab groups showed a high remission rate in clinical and functional remission at Week 52. Serious adverse events occurred in a total of 23 patients in the ozoralizumab groups, without differences in incidence between doses.

CONCLUSIONS

Ozoralizumab demonstrated significant therapeutic effects and efficacy, which was maintained for 52 weeks. The safety profile was consistent with the evaluated results in interim analysis at Week 24, and ozoralizumab was well-tolerated up to Week 52.

Potential Promises and Perils of Human Biological Treatments for Immunotherapy in Veterinary Oncology

The emergence of immunotherapy for the treatment of human cancers has heralded a new era in oncology, one that is making its way into the veterinary clinic. As the immune system of many animal species commonly seen by veterinarians is similar to humans, there is great hope for the translation of human therapies into veterinary oncology. The simplest approach for veterinarians would be to adopt existing reagents that have been developed for human medicine, due to the potential of reduced cost and the time it takes to develop a new drug. However, this strategy may not always prove to be effective and safe with regard to certain drug platforms. Here, we review current therapeutic strategies that could exploit human reagents in veterinary medicine and also those therapies which may prove detrimental when human-specific biological molecules are used in veterinary oncology. In keeping with a One Health framework, we also discuss the potential use of single-domain antibodies (sdAbs) derived from camelid species (also known as Nanobodies™) for therapies targeting multiple veterinary animal patients without the need for species-specific reformulation. Such reagents would not only benefit the health of our veterinary species but could also guide human medicine by studying the effects of outbred animals that develop spontaneous tumors, a more relevant model of human diseases compared to traditional laboratory rodent models.

Shark VNAR phage display libraries: An alternative source for therapeutic and diagnostic recombinant antibody fragments

The development of recombinant antibody fragments as promising alternatives to full-length immunoglobulins offers vast opportunities for biomedicine. Antibody fragments have important advantages compared with conventional monoclonal antibodies that make them attractive for the biotech industry: superior stability and solubility, reduced immunogenicity, higher specificity and affinity, capacity to target the hidden epitope and cross the blood-brain barrier, the ability to refold after heat denaturation and inexpensive and easy large-scale production. Different antibody formats such as antigen-binding fragments (Fab), single-chain fragment variable (scFv) consisting of the antigen-binding domains of Ig heavy (VH) and light (VL) chain regions connected by a flexible peptide linker, single-domain antibody fragments (sdAbs) like camelid heavy-chain variable domains (VHHs) and shark variable new antigen receptor (VNARs), and bispecific antibodies (bsAbs) are currently being evaluated as diagnostics or therapeutics in preclinical studies and clinical trials. In the present review, we summarize and discuss studies on VNARs, the smallest recombinant antibody fragment, obtained after the screening of different types of phage display antibody libraries. Results published until March 2023 are discussed.

Increasing the melting temperature of VHH with the in silico free energy score

VHH, the antigen-binding fragment of a heavy chain-only antibody, is a useful component of antibody-based therapeutics. Thermal stability, represented by the melting temperature (Tm), is one of the key factors affecting the developability of antibody-based therapeutics. In this study, we examined whether the in silico free energy score dStability can be used to design mutants with improved Tm compared to the anti-lysozyme VHH, D3-L11. After verifying that exhaustive mutagenesis was inefficient for improving Tm, we performed a two-round rational approach that combined dStability calculations with a small number of experiments. This method improved the Tm by more than 5 °C in several single mutants including A79I. It reduced the affinity for the antigen by less than 1.6-fold. We speculate that stabilization of A79I required exquisite compatibility among neighboring residues to fill in the internal cavity in the protein. Given that we identified only one mutation that could simultaneously improve Tm and almost maintain affinity, we concluded that achieving both is extremely difficult, even with single mutations that are not located in the paratope. Therefore, we recommend using a variety of approaches when trying to achieve such a feat. Our method will be a useful complementary approach to other existing methods.

Polyspecificity - An emerging trend in the development of clinical antibodies

The essence of the growth and development of therapeutic conventional monoclonal antibodies (MAbs) for the treatment of various disorders is the aptitude of MAbs to precisely bind a target antigen and neutralise or promote its activity. However, the conventional antibodies are monoclonal i.e., both paratopes bind to the same epitope. But most of the pathophysiological conditions are multifaceted, hence targeting/blocking/inhibition of more than one epitope/antigen is more promising than one epitope/antigen. Polyspecific antibodies (PsAbs) have the potential to concurrently bind to more than one target and are the next-generation antibodies that augment efficacy in both clinical and non-clinical contexts. Thus, the trend of engineering and developing various formats of PsAbs is emerging. In this review, we have briefly discussed the importance of antibody polyspecificity and PsAbs approved for clinical use. Subsequently, we have discussed the role of TNF-α and IL-23 in inflammatory diseases and stressed the need for developing anti-TNF-α and anti-IL-23 bispecific antibodies.

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

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

Personalized medicine in rheumatoid arthritis: Combining biomarkers and patient preferences to guide therapeutic decisions

The last few decades have seen major therapeutic advancements in rheumatoid arthritis (RA) therapeutics. New disease-modifying antirheumatic drugs (DMARDs) have continued to emerge, creating more choices for people. However, no therapeutic works for all patients. Each has its own inherent benefits, risks, costs, dosing, and monitoring considerations. In parallel, there has been a focus on personalized medicine initiatives that tailor therapeutic decisions to patients based on their unique characteristics or biomarkers. Personalized effect estimates require an understanding of a patient's baseline probability of response to treatment and data on the comparative effectiveness of the available treatments. However, even if accurate risk prediction models are available, trade-offs often still need to be made between treatments. In this paper, we review the history of RA therapeutics and progress that has been made toward personalized risk predictive models for DMARDs, outlining where knowledge gaps still exist. We further review why patient preferences play a key role in a holistic view of personalized medicine and how this links with shared decision-making. We argue that a "preference misdiagnosis" may be equally important as a medical misdiagnosis but is often overlooked.

Unique structure of ozoralizumab, a trivalent anti-TNFα NANOBODY® compound, offers the potential advantage of mitigating the risk of immune complex-induced inflammation

Biologics have become an important component of treatment strategies for a variety of diseases, but the immunogenicity of large immune complexes (ICs) and aggregates of biologics may increase risk of adverse events is a concern for biologics and it remains unclear whether large ICs consisting of intrinsic antigen and therapeutic antibodies are actually involved in acute local inflammation such as injection site reaction (ISR). Ozoralizumab is a trivalent, bispecific NANOBODY^® compound that differs structurally from IgGs. Treatment with ozoralizumab has been shown to provide beneficial effects in the treatment of rheumatoid arthritis (RA) comparable to those obtained with other TNFα inhibitors. Very few ISRs (2%) have been reported after ozoralizumab administration, and the drug has been shown to have acceptable safety and tolerability. In this study, in order to elucidate the mechanism underlying the reduced incidence of ISRs associated with ozoralizumab administration, we investigated the stoichiometry of two TNFα inhibitors (ozoralizumab and adalimumab, an anti-TNFα IgG) ICs and the induction by these drugs of Fcγ receptor (FcγR)-mediated immune responses on neutrophils. Ozoralizumab-TNFα ICs are smaller than adalimumab-TNFα ICs and lack an Fc portion, thus mitigating FcγR-mediated immune responses on neutrophils. We also developed a model of anti-TNFα antibody-TNFα IC-induced subcutaneous inflammation and found that ozoralizumab-TNFα ICs do not induce any significant inflammation at injection sites. The results of our studies suggest that ozoralizumab is a promising candidate for the treatment of RA that entails a lower risk of the IC-mediated immune cell activation that leads to unwanted immune responses.

Ozoralizumab: First Approval

Ozoralizumab (Nanozora^®), a trivalent anti-tumour necrosis factor alpha (TNFα) NANOBODY^Ⓡ compound, has been developed by Taisho Pharmaceutical Co. Ltd (under license from Ablynx, an affiliate of Sanofi) for the treatment of rheumatoid arthritis (RA). In September 2022, ozoralizumab was approved in Japan for the treatment of RA that is inadequately managed by current available treatments. This article summarizes the milestones in the development of ozoralizumab leading to this first approval.

Phase II/III Results of a Trial of Anti-Tumor Necrosis Factor Multivalent NANOBODY Compound Ozoralizumab in Patients With Rheumatoid Arthritis

OBJECTIVE

To assess the efficacy and safety of subcutaneous administration of 30 mg or 80 mg of ozoralizumab plus methotrexate (MTX) in patients with rheumatoid arthritis (RA) whose disease remained active despite MTX therapy.

METHODS

In this multicenter, double-blind, parallel-group, placebo-controlled phase II/III trial, 381 patients were randomized to receive placebo, ozoralizumab 30 mg, or ozoralizumab 80 mg, plus MTX subcutaneously injected every 4 weeks for 24 weeks. The primary end points were the response rates based on the American College of Rheumatology 20% improvement criteria (ACR20) at week 16 and change in the Sharp/van der Heijde score (ΔSHS) from baseline to week 24.

RESULTS

The proportion of patients with an ACR20 response at week 16 was significantly higher (P < 0.001) in both ozoralizumab groups (79.6% for 30 mg, 75.3% for 80 mg), compared with placebo (37.3%); these improvements were observed from the first week of treatment. The proportion of the patients with structural nonprogression (ΔSHS ≤0) was significantly higher in both ozoralizumab groups than in the placebo group. For some secondary end points, significantly greater improvements were observed starting from as early as day 3. Serious adverse events occurred in 4 patients in the ozoralizumab 30-mg group and 5 patients in the ozoralizumab 80-mg group.

CONCLUSION

In patients with active RA who received ozoralizumab in combination with MTX, the signs and symptoms of RA were significantly reduced as compared with the outcomes in those receiving placebo. Ozoralizumab demonstrated acceptable tolerability with no new safety signals when compared with other antibodies against tumor necrosis factor.

A novel anti-TNF-α drug ozoralizumab rapidly distributes to inflamed joint tissues in a mouse model of collagen induced arthritis

In clinical studies, the next-generation anti-tumor necrosis factor-alpha (TNF-α) single domain antibody ozoralizumab showed high clinical efficacy shortly after the subcutaneous injection. To elucidate the mechanism underlying the rapid onset of the effects of ozoralizumab, we compared the biodistribution kinetics of ozoralizumab and adalimumab after subcutaneous injection in an animal model of arthritis. Alexa Fluor 680-labeled ozoralizumab and adalimumab were administered by subcutaneous injection once (2 mg/kg) at five weeks after induction of collagen-induced arthritis (CIA) in an animal arthritis model. The time-course of changes in the fluorescence intensities of the two compounds in the paws and serum were evaluated. The paws of the CIA mice were harvested at four and eight hours after the injection for fluorescence microscopy. Biofluorescence imaging revealed better distribution of ozoralizumab to the joint tissues than of adalimumab, as early as at four hours after the injection. Fluorescence microscopy revealed a greater fluorescence intensity of ozoralizumab in the joint tissues than that of adalimumab at eight hours after the injection. Ozoralizumab showed a significantly higher absorption rate constant as compared with adalimumab. These results indicate that ozoralizumab enters the systemic circulation more rapidly and is distributed to the target tissues earlier and at higher levels than conventional IgG antibodies. Our investigation provides new insight into the mechanism underlying the rapid onset of the effects of ozoralizumab in clinical practice.

Immunotherapeutic progress and application of bispecific antibody in cancer

Bispecific antibodies (bsAbs) are artificial antibodies with two distinct antigen-binding sites that can bind to different antigens or different epitopes on the same antigen. Based on a variety of technology platforms currently developed, bsAbs can exhibit different formats and mechanisms of action. The upgrading of antibody technology has promoted the development of bsAbs, which has been effectively used in the treatment of tumors. So far, 7 bsAbs have been approved for marketing in the world, and more than 200 bsAbs are in clinical and preclinical research stages. Here, we summarize the development process of bsAbs, application in tumor treatment and look forward to the challenges in future development.

Selection of single domain anti-transferrin receptor antibodies for blood-brain barrier transcytosis using a neurotensin based assay and histological assessment of target engagement in a mouse model of Alzheimer's related amyloid-beta pathology

The blood-brain barrier (BBB) presents a major obstacle in developing specific diagnostic imaging agents for many neurological disorders. In this study we aimed to generate single domain anti-mouse transferrin receptor antibodies (anti-mTfR VHHs) to mediate BBB transcytosis as components of novel MRI molecular contrast imaging agents. Anti-mTfR VHHs were produced by immunizing a llama with mTfR, generation of a VHH phage display library, immunopanning, and in vitro characterization of candidates. Site directed mutagenesis was used to generate additional variants. VHH fusions with neurotensin (NT) allowed rapid, hypothermia-based screening for VHH-mediated BBB transcytosis in wild-type mice. One anti-mTfR VHH variant was fused with an anti-amyloid-beta (Aβ) VHH dimer and labeled with fluorescent dye for direct assessment of in vivo target engagement in a mouse model of AD-related Aβ plaque pathology. An anti-mTfR VHH called M1 and variants had binding affinities to mTfR of <1nM to 1.52nM. The affinity of the VHH binding to mTfR correlated with the efficiency of the VHH-NT induced hypothermia effects after intravenous injection of 600 nmol/kg body weight, ranging from undetectable for nonbinding mutants to -6°C for the best mutants. The anti-mTfR VHH variant M1P96H with the strongest hypothermia effect was fused to the anti-Aβ VHH dimer and labeled with Alexa647; the dye-labeled VHH fusion construct still bound both mTfR and Aβ plaques at concentrations as low as 0.22 nM. However, after intravenous injection at 600 nmol/kg body weight into APP/PS1 transgenic mice, there was no detectible labeling of plaques above control levels. Thus, NT-induced hypothermia did not correlate with direct target engagement in cortex, likely because the concentration required for NT-induced hypothermia was lower than the concentration required to produce in situ labeling. These findings reveal an important dissociation between NT-induced hypothermia, presumably mediated by hypothalamus, and direct engagement with Aβ-plaques in cortex. Additional methods to assess anti-mTfR VHH BBB transcytosis will need to be developed for anti-mTfR VHH screening and the development of novel MRI molecular contrast agents.

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

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