Therapeutic Antibodies Research Articles

Current Status of Gout Arthritis: Current Approaches to Gout Arthritis Treatment: Nanoparticles Delivery Systems Approach

The deposition of monosodium urate (MSU) crystals within joint spaces produces a painful inflammatory condition known as gout, a specific form of arthritis. The condition calls for a combined curative and preventive management model. A new development in the approach to gout is that of NLRP3-targeted biologic agents, such as monoclonal therapies, to provide more accurate treatment by blocking specific pro-inflammatory cytokines. Nanoparticle drug delivery enhances biological availability and delivery to targets, which may increase therapeutic efficacy and decrease general toxicity. The preventive approach again cannot be ignored, mainly keeping up certain modifications in diet and weight, along with pharmacological therapies to reduce uric acid (UA) levels and to decrease the frequency of acute attacks. The advancement of genetic profiling of patients and biomarker discoveries drives the trend towards building individualized medicine and care, quickly gaining ground as the most effective method of delivering treatments to individual patients, moving away from one-size-fits-all treatments. The following paper aims to provide an updated account of the management of gout with a focus on recent developments, in order to enhance these approaches, the quality of life for patients with gout, and the standard of gout treatment.

A comparison between different chemical fractionation methods for immunoglobulin preparation

ABSTRACT Background Application of antibodies in therapeutics and diagnostics are growing Continually. Herein, we aimed to find the most qualified immunoglobulin (Ig) chemical preparation method. Methods A rabbit was immunized against recombinant SARS-CoV-2 nucleocapsid (NP) and reactive polyclonal antibodies were prepared using the ammonium sulfate (AS), caprylic acid (CA), polyethylene glycol (PEG), and caprylic acid/ammonium sulfate (CA/AS) methods. Different antibody solutions were analyzed by SDS-PAGE and subsequently quantified by ImageJ software for further analysis in terms of Ig purity, Ig recovery, and albumin impurity. Ultimately, the prepared antibodies were assessed via Western blotting and ELISA to evaluate their ability to bind NP. Results Prepared Ig solutions via the CA/AS method had the highest Ig purity (followed by CA, PEG, and AS) and lowest albumin impurity (followed by CA, AS, and PEG). The PEG method had the highest recovery followed by AS, CA, and CA/AS methods. Moreover, antibodies prepared via different methods demonstrated comparable binding capacities to NP in ELISA and Western blotting. Conclusions CA/AS, closely followed by CA, proved to be the most qualified method for the preparation of Ig yielding the highest Ig purity while the PEG method resulted in the highest Ig recovery rate.

Emerging Trends in Neuroblastoma Diagnosis, Therapeutics, and Research.

This review explores the current understanding and recent advancements in neuroblastoma, one of the most common extracranial solid pediatric cancers, accounting for ~ 15% of childhood cancer-related mortality. The hallmarks of NBL, including angiogenesis, metastasis, apoptosis resistance, cell cycle dysregulation, drug resistance, and responses to hypoxia and ROS, underscore its complex biology. The tumor microenvironment's significance in disease progression is acknowledged in this study, along with the pivotal role of cancer stem cells in sustaining tumor growth and heterogeneity. A number of molecular signatures are being studied in order to better understand the disease, with many of them serving as targets for the development of new therapeutics. This includes inhibitor therapies for NBL patients, which notably concentrate on ALK signaling, MDM2, PI3K/Akt/mTOR, Wnt, and RAS-MAPK pathways, along with regulators of epigenetic mechanisms. Additionally, this study offers an extensive understanding of the molecular therapies used, such as monoclonal antibodies and CAR-T therapy, focused on both preclinical and clinical studies. Radiation therapy's evolving role and the promise of stem cell transplantation-mediated interventions underscore the dynamic landscape of NBL treatment. This study has also emphasized the recent progress in the field of diagnosis, encompassing the adoption of artificial intelligence and liquid biopsy as a non-intrusive approach for early detection and ongoing monitoring of NBL. Furthermore, the integration of innovative treatment approaches such as CRISPR-Cas9, and cancer stem cell therapy has also been emphasized in this review.

Decoding the molecular interplay of CD20 and therapeutic antibodies with fast volumetric nanoscopy.

Elucidating the interaction between membrane proteins and antibodies requires whole-cell imaging at high spatiotemporal resolution. Lattice light-sheet (LLS) microscopy offers fast volumetric imaging but suffers from limited spatial resolution. DNA-based point accumulation for imaging in nanoscale topography (DNA-PAINT) achieves molecular resolution but is restricted to two-dimensional imaging owing to long acquisition times. We have developed two-dye imager (TDI) probes that enable ~15-fold faster imaging. Combining TDI-DNA-PAINT and LLS microscopy on immunological B cells revealed the oligomeric states and interaction of endogenous CD20 with the therapeutic monoclonal antibodies (mAbs) rituximab, ofatumumab, and obinutuzumab. Our results demonstrate that CD20 is abundantly expressed on microvilli that bind mAbs, which leads to an antibody concentration-dependent B cell polarization and stabilization of microvilli protrusions. These findings could aid rational design of improved immunotherapies targeting tumor-associated antigens.

Advanced Polymeric Nanoparticles for Cancer Immunotherapy: Materials Engineering, Immunotherapeutic Mechanism and Clinical Translation.

Cancer immunotherapy, which leverages immune system components to treat malignancies, has emerged as a cornerstone of contemporary therapeutic strategies. Yet, critical concerns about the efficacy and safety of cancer immunotherapies remain formidable. Nanotechnology, especially polymeric nanoparticles (PNPs), offers unparalleled flexibility in manipulation-from the chemical composition and physical properties to the precision control of nanoassemblies. PNPs provide an optimal platform to amplify the potency and minimize systematic toxicity in a broad spectrum of immunotherapeutic modalities. In this comprehensive review, the basics of polymer chemistry, and state-of-the-art designs of PNPs from a physicochemical standpoint for cancer immunotherapy, encompassing therapeutic cancer vaccines, in situ vaccination, adoptive T-cell therapies, tumor-infiltrating immune cell-targeted therapies, therapeutic antibodies, and cytokine therapies are delineated. Each immunotherapy necessitates distinctively tailored design strategies in polymeric nanoplatforms. The extensive applications of PNPs, and investigation of their mechanisms of action for enhanced efficacy are particularly focused on. The safety profiles of PNPs and clinical research progress are discussed. Additionally, forthcoming developments and emergent trends of polymeric nano-immunotherapeutics poised to transform cancer treatment paradigms into clinics are explored.

Host cell lectins ASGR1 and DC-SIGN jointly with TMEM106B confer ACE2 independence and imdevimab resistance to SARS-CoV-2 pseudovirus with spike mutation E484D.

The naturally occurring mutation E484D in the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can render viral entry ACE2 independent and imdevimab resistant. Here, we investigated whether the cellular proteins ASGR1, DC-SIGN, and TMEM106B, which interact with the viral S protein, can contribute to these processes. Employing S protein-pseudotyped particles, we found that expression of ASGR1 or DC-SIGN jointly with TMEM106B allowed for robust entry of mutant E484D into otherwise non-susceptible cells, while this effect was not observed upon separate expression of the single proteins and upon infection with SARS-CoV-2 wild type (WT). Furthermore, expression of ASGR1 or DC-SIGN conferred ACE2 independence and imdevimab resistance to entry of mutant E484D but not WT, and entry under those conditions was dependent on endogenous TMEM106B. These results suggest that engagement of certain cellular lectins can direct SARS-CoV-2 mutant E484D to an ACE2-independent, TMEM106B-dependent entry pathway that is not inhibited by imdevimab.IMPORTANCEThe interaction of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein with the ACE2 receptor determines the viral cell tropism and is the key target of the neutralizing antibody response. Here, we show that SARS-CoV-2 with a single, naturally occurring mutation in the spike protein, E484D, can use the cellular lectins ASGR1 and DC-SIGN in conjunction with TMEM106B for ACE2-independent entry and evasion of therapeutic antibodies. These results suggest that engagement of cellular lectins might modulate target cell choice of SARS-CoV-2 and might allow evasion of certain neutralizing antibodies.

Simultaneous Blockade of CD209 and CD209L by Monoclonal Antibody Does Not Provide Sufficient Protection Against Multiple Viral Infections InVivo.

Many virus species, including Ebola virus, Marburg virus, SARS-CoV-2, dengue virus (DENV) and Zika virus (ZIKV), exploit CD209 and CD209L as alternative or attachment receptors for viral cis- or trans-infection. Thus, CD209 and CD209L may be critical targets for the development of therapeutic monoclonal blocking antibody drugs to disrupt the infection process caused by multiple viruses. Here, we produced a human chimeric monoclonal blocking antibody that simultaneously blocks CD209 and CD209L, namely 7-H7-B1. We show that 7-H7-B1 effectively blocks multiple pseudotyped or live viral infections invitro, including SARS-CoV, SARS-CoV-2, Ebola virus, Marburg virus, ZIKV and DENV infections. However, the 7-H7-B1 mAb does not provide favourable protection against Zaire Ebola virus or ZIKV infection in hCD209 knock-in mice invivo. Thus, our findings indicate that although CD209 and CD209L are critical for multiple viral infections invitro, they may play only a partial role in viral infections invivo.

Microsporidiosis in Patients with Autoimmune Diseases Undergoing Monoclonal Antibody Associated Therapy.

We present Enterocytozoon bieneusi infection in four patients with autoimmune diseases undergoing prolonged monoclonal antibody therapies. Two patients suffered from inflammatory bowel disease and received anti-TNF therapies, whereas two other patients suffered from systemic lupus erythematosus with renal involvement and received anti-CD20 or anti-BLyS protein therapies. Three out of four patients consulted for diarrhea with abdominal pain without intestinal inflammation or bleeding at the time of sampling. The fourth patient did not declare intestinal troubles. Microsporidia genotype detected in this study were S9, C, Wildboard3 with one patient harboring 2 genotypes S6 and EBCMAP-038. Management of microsporidia infection included albendazole and reduction of immunosuppression treatment, but no specific treatment was implemented in two other patients. In conclusion, microsporidia infection occurs in patients with autoimmune diseases undergoing prolonged monoclonal antibody therapies. Diagnosis should be carefully assessed in this population and a thorough benefit-risk analysis is essential prior to initiating therapeutic interventions.

Potentiating CD20 monoclonal antibody therapy by targeting complement C3 fragment covalently deposited on lymphoma cells.

Monoclonal antibodies (mAbs) improve survival of patients with mature B-cell malignancies. Fcγ-receptor dependent effector mechanisms kill tumor cells but can promote antigen loss through trogocytosis, contributing to treatment failures. Cell-bound mAbs trigger the complement cascade to deposit C3 activation fragments and lyse cells. Within 24 hours after ofatumumab administration to patients with chronic lymphocytic leukemia (CLL), circulating tumor cells had lost CD20 and were opsonized with C3d. We hypothesized that C3d provides a target to eliminate residual CD20 negative tumor cells. To test this hypothesis, we generated C8xi, a mouse/human chimeric IgG1 that reacts with human but not mouse C3d. C8xi was effective in a patient-derived xenograft model against CD20 negative, C3d opsonized CLL cells from patients treated with ofatumumab. We also generated rabbit mAbs, two of which were chosen because they bound mouse and human C3d with low nanomolar affinity but were minimally cross-reactive with full-length C3. Anti-C3d rabbit/human chimeric IgG1 in combination with ofatumumab or rituximab prolonged survival of xenografted mice that model three different types of non-Hodgkin lymphoma (NHL). For example, in a diffuse large B-cell lymphoma model (SU-DHL-6), median survival with single-agent CD20 mAb was 114 days but was not reached for mAb combination treatment (P=.008). In another NHL model (SU-DHL-4), single-agent and combination mAb therapy eradicated lymphoma in most mice. In long-term survivors from both cohorts, there was no evidence of adverse effects. We propose that C3d mAbs combined with complement fixing CD20 mAbs can deliver a one-two punch and increase efficacy of mAb-based therapy.

Cross-reactive sarbecovirus antibodies induced by mosaic RBD-nanoparticles.

Therapeutic monoclonal antibodies (mAbs) against SARS-CoV-2 become obsolete as spike substitutions reduce antibody binding. To induce antibodies against conserved receptor-binding domain (RBD) regions for protection against SARS-CoV-2 variants of concern and zoonotic sarbecoviruses, we developed mosaic-8b RBD-nanoparticles presenting eight sarbecovirus RBDs arranged randomly on a 60-mer nanoparticle. Mosaic-8b immunizations protected animals from challenges from viruses whose RBDs were matched or mismatched to those on nanoparticles. Here, we describe neutralizing mAbs from mosaic-8b-immunized rabbits, some on par with Pemgarda (the only currently FDA-approved therapeutic mAb). Deep mutational scanning, in vitro selection of spike resistance mutations, and cryo-EM structures of spike-antibody complexes demonstrated targeting of conserved epitopes. Rabbit mAbs included critical D-gene segment features in common with human anti-RBD mAbs, despite rabbit genomes lacking an equivalent human D-gene segment. Thus, mosaic RBD-nanoparticle immunization coupled with multiplexed screening represent an efficient way to generate and select therapeutic pan-sarbecovirus and pan-SARS-2 variant mAbs.

Protein concentration and analyzing charge variants in a co-formulation comprising three monoclonal antibodies: A cation-exchange chromatography approach.

In the realm of therapeutic antibodies, co-formulations comprising two or more monoclonal antibodies (mAbs) have emerged as a promising strategy, offering enhanced treatment efficacy, improved efficiency, and prolonged intellectual property protection. These advantages have sparked significant interest among both patients and pharmaceutical companies. However, the quantification and analysis of individual mAbs within such co-formulations pose a substantial challenge due to their similar physicochemical properties. To address this challenge, we introduce a pH gradient cation exchange chromatography (CEX) method designed to effectively separate three mAbs that share significant similarities in molecular weight, structure, and isoelectric points (pIs) etc. This versatile approach not only facilitates the accurate quantification of each mAb's concentration and their respective ratios within the co-formulation, but also allows for the comprehensive characterization of all charge variants present. In the case of a co-formulation containing three antibodies, the developed CEX method demonstrated superior performance compared to other techniques. The method's robustness was further underscored by its qualification parameters, including acceptable precision (RSD≤3%), accuracy (95%-115% recovery), and linearity (R2>0.99) across a range of 10 to 30μg load for each mAb. Moreover, the method has been successfully applied in stability studies to quantitatively analyze individual mAb concentrations within co-formulations, marking a significant advancement in the field. Through this work, we contribute a crucial analytical insight into mAb co-formulations, especially those comprising three or more molecules, underscoring its considerable potential to propel the field of biotherapeutic co-formulations forward.

Key considerations for combination therapy in Alzheimer's clinical trials: Perspectives from an expert advisory board convened by the Alzheimer's drug discovery foundation.

There is growing consensus in the Alzheimer's community that combination therapy will be needed to maximize therapeutic benefits through the course of the disease. However, combination therapy raises complex questions and decisions for study sponsors, from preclinical research through clinical trial design to regulatory, statistical, and operational considerations. In January 2024, the Alzheimer's Drug Discovery Foundation convened an expert advisory board to discuss the key considerations in each of these areas. Experts agreed on the need to prioritize a combination therapy approach that encompasses a wide range of targets associated with aging and the underlying biology of Alzheimer's disease. Progress in combination therapy could be accelerated by leveraging preclinical research and Phase 1 and 2A trials to identify the most promising combinations for further development, exploring repurposed agents with available preclinical and clinical data, building collaborations across sectors to support operational challenges, and planning for the likely impact of anti-amyloid beta-protein monoclonal antibody therapies on future clinical trial designs.

Computational-aided rational mutation design of pertuzumab to overcome active HER2 mutation S310F through antibody–drug conjugates

Recurrent missense mutations in the human epidermal growth factor receptor 2 (HER2) have been identified across various human cancers. Among these mutations, the active S310F mutation in the HER2 extracellular domain stands out as not only oncogenic but also confers resistance to pertuzumab, an antibody drug widely used in clinical cancer therapy, by impeding its binding. In this study, we have successfully employed computational-aided rational design to undertake directed evolution of pertuzumab, resulting in the creation of an evolved pertuzumab variant named Ptz-SA. This variant, with only two mutations (T30S/D31A) located on its heavy chain, effectively reinstates binding to the mutated antigen, at the expense of a 35-fold reduction in binding affinity to HER2 (S310F) compared to the wild-type pair. Subsequently, Ptz-SA demonstrates potent killing capacity through antigen-dependent cytotoxicity. Moreover, upon engineering Ptz-SA into antibody-drug conjugates, such as Ptz-SA-MMAE, it manifests notable in vitro and in vivo antitumor efficacy by efficiently delivering cytotoxic payload into tumor cells expressing HER2 (S310F). Cryoelectron microscopy studies elucidate the molecular mechanism underlying the restored binding ability of Ptz-SA toward the S310F mutation. The steric hindrance induced by the S310F mutation is efficiently circumvented by the T30S and D31A mutations, which provides adequate space to accommodate the larger phenylalanine. Additionally, Ptz-SA also exhibits binding capacity to HER2 (S310Y), another mutation occurring at the S310 site of HER2 with high frequency. The computational-aided evolution of pertuzumab provides an alternative strategy for overcoming point mutation-mediated resistance to therapeutic antibodies.

Efficacy of anti-CD19 CAR-T therapy after bispecific monoclonal antibody (CD19/CD3) therapy in a patient with relapsed Ph-positive acute lymphoblastic leukemia with a massive extramedullary component

Introduction. Patients with relapsed/refractory (r/r) Ph-positive acute lymphoblastic leukemia (ALL) have a poor prognosis and limited treatment options. New promising immunotherapies using CAR T cells or monoclonal antibodies (blinatumomab, inotuzumab/ozogamicin) in combination with tyrosine kinase inhibitors are being used for this group of patients. However, long-term results have not been studied when relapse or refractoriness develops after the use of one of these methods.Aim: to present a clinical observation of the use of anti-CD19 CAR T therapy after blinatumomab therapy in a patient with a relapsed course of Ph-positive acute lymphoblastic leukemia.Main findings. A 28-year-old patient was first diagnosed with Ph-positive B-ALL (transcript p210) in 2014. In the 1st line of treatment he was treated with therapy according to the protocol ‘ALL-2009’ with imatinib and allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, 2 months later the first molecular relapse was detected, and imatinib was replaced by dasatinib. In November 2016, a second relapse was diagnosed. In 2017, a third relapse with testicular involvement and T315I mutation was diagnosed, and therapy with ponatinib was initiated. In 2022, a 4th medullary relapse developed, and therapy with blinatumomab (5 courses) in combination with ponatinib was performed. After the 5th course of therapy, the appearance of leukaemides was noted, and asciminib was added to the therapy. However, no clinical effect was noted. The patient was treated with anti-CD19 CAR T therapy. A complete response to CAR T-cell therapy was confirmed on day 28 after CAR T administration. Further follow-up, over the course of one year, demonstrated stable clinical response and persistence of CD3-positive CAR T-cells. This case report of anti-CD19 CAR T cell therapy in a patient with CD19-positive combined relapse with massive extramedullary component after blinatumomab therapy demonstrated long-term efficacy with a 1-year follow-up.

Engineering antibodies with cancer‐associated binding sites

AbstractCancer immunotherapy has appeared as a prospective therapeutic modality. Therapeutic antibodies induced in an in vitro expression system act as “targeting missiles” against tumor‐associated binding sites, and subsequently, immune system attack on tumors is restored or boosted. These antibody regimens are engineered towards enhanced Fc efficacy, humanization, and fragmentation to specifically recognize and bind to effective tumor‐associated targets. The challenge lies in obtaining efficient therapeutic regimens with low response rates, acquisition of resistance, and immune‐related undesirable effects of artificially designed therapeutic antibodies, which is crucial for enhancing clinical efficacy. This review provides an in‐depth introduction to antibodies that perform direct/indirect roles in cancer treatment by binding to immune checkpoints, co‐stimulatory receptors, and extracellular membrane receptors. It also discusses how antibodies kill tumors and modulate microenvironment of tumor through these targets. The classification of expression systems for antibody production is summarized to guide appropriate selection based on different specificities. Understanding antibody sources, ongoing evaluation of engineered antibodies, and tumor‐associated antigen research pave the way for designing appropriate antibody‐based immunotherapy regimens.

Effectiveness of switching strategies in CGRP monoclonal antibody therapy for migraine: A retrospective cohort study.

To evaluate the effectiveness of first switching between monoclonal antibodies (mAbs) targeting calcitonin gene-related peptide (CGRP) or its receptor in the treatment of migraine. Although mAbs targeting CGRP or its receptor have emerged as a leading treatment for migraine prevention, a proportion of patients do not respond. While switching between these antibodies is a common clinical practice in such cases, the effectiveness remains a subject of study. We conducted a retrospective cohort study at a tertiary headache center, analyzing data from clinical records of patients treated with anti-CGRP mAbs from January 2020 to March 2024. Baseline was defined as the monthly headache days (MHDs) in the 3 months prior to the start of the second mAb. The primary endpoint was the change in MHDs at month 3 and month 6 following the switch. Additionally, we evaluated response rates in both periods. Subgroup analyses were conducted based on changes in mechanism of action. Finally, we assessed the influence of the number of doses of the first mAb and the inter-treatment interval. Out of 1244 initially identified patients, 185 were included in the month-3 analysis and 123 in the month-6 evaluation. The median MHDs decreased from 27.0 (interquartile range [IQR] 16.1, 30.0; range 5.0, 30.7) at baseline to 21.0 (IQR 10.0, 30.0; range 0.0, 30.0; p < 0.001) at month 3, and to 20.0 (IQR 10.0, 30.0; range 0.0, 31.0; p < 0.001) at month 6. Subgroup analyses revealed no significant differences in MHDs between maintaining the same target or changing it (baseline: 28.0 [IQR 16.2, 30.0; range 5.0, 31.0] vs. 27.0 [IQR 6.0, 31.0; range 6.0, 31.0]; month 3: 23.0 [IQR 10.0, 30.0; range 0.0, 31.0] vs. 19.0 [IQR 11.0, 30.0; range 1.0, 31.0], p = 0.144; month 6: 24.0 [IQR 11.0, 30.0; range 0.0, 31.0] vs. 17.0 [IQR 10.0, 30.0; range 3.0, 31.0], p = 0.170). There was no association between a ≥50% reduction in MHDs and the number of previous doses of the first mAb (odds ratio [OR] 1.0; 95% confidence interval [CI] 1.0, 1.1; p = 0.189) or the inter-treatment interval (OR 1.0; 95% CI 0.9, 1.1; p = 0.914). Switching between anti-CGRP mAbs resulted in a reduction in MHDs, with no significant differences based on the mechanism of action. Factors such as the number of doses of the first mAb and the inter-treatment interval did not appear to predict a ≥50% reduction in MHDs at month 3. Our findings support the viability of switching as an effective treatment option for patients with migraine who do not respond to initial mAb therapy.

Targets and mechanisms of neutralizing monoclonal antibodies against Dengue virus

Dengue fever is a mosquito-borne disease prevalent in tropical and subtropical regions, with its prevalence expanding due to increased global travel. The dengue virus, the causative agent of dengue fever, often co-circulates in the form of four distinct serotypes. Cross-reactive antibodies generated during a primary infection pose a significant risk during secondary infections with different serotypes, and fully protective vaccines and antiviral drugs are yet to be developed. Over the past decade, advances in antibody technology have led to the isolation of numerous monoclonal antibodies against dengue virus, with their neutralizing epitopes elucidated through structure-based analyses. This review highlights the key epitopes associated with neutralizing antibodies against dengue virus and discusses their potential applications in vaccine design and therapeutic antibody development. This review helps systematically summarize the progress in dengue virus neutralizing antibody research, providing a theoretical foundation and technical guidance for the development of novel vaccines and antibody therapeutics.

Rat as a Predictive Model for Human Clearance and Bioavailability of Monoclonal Antibodies

Background: The prediction of human clearance (CL) and subcutaneous (SC) bioavailability is a critical aspect of monoclonal antibody (mAb) selection for clinical development. While monkeys are a well-accepted model for predicting human CL, other preclinical species have been less-thoroughly explored. Unlike CL, predicting the bioavailability of SC administered mAbs in humans remains challenging as contributing factors are not well understood, and preclinical models have not been systematically evaluated. Methods: Non-clinical and clinical pharmacokinetic (PK) parameters were mined from public and internal sources for rats, cynomolgus monkeys, and humans. Intravenous (IV) and SC PK was determined in Sprague Dawley rats for fourteen mAbs without existing PK data. Together, we obtained cross-species data for 25 mAbs to evaluate CL and SC bioavailability relationships among rats, monkeys, and humans. Results: Rat and monkey CL significantly correlated with human CL and supported the use of species-specific exponents for body-weight-based allometric scaling. Notably, rat SC bioavailability significantly correlated with human SC bioavailability, while monkey SC bioavailability did not. Bioavailability also correlated with clearance. Conclusions: The rat model enables an early assessment of mAb PK properties, allowing discrimination among molecules in the discovery pipeline and prediction of human PK. Importantly, rat SC bioavailability significantly correlated with human SC bioavailability, which has not been observed with other species. Rats are cost-effective and efficient relative to monkeys and provide a valuable tool for pharmacokinetic predictions in therapeutic antibody discovery.

A shorter linker in the bispecific antibody RmAb158-scFv8D3 improves TfR-mediated blood-brain barrier transcytosis in vitro.

Transferrin Receptor (TfR)-mediated transcytosis across the blood-brain barrier (BBB) enables the uptake of bispecific therapeutic antibodies into the brain. At therapeutically relevant concentrations, bivalent binding to TfR appears to reduce the transcytosis efficiency by receptor crosslinking. In this study, we aimed to improve BBB transcytosis of symmetric antibodies through minimizing their ability to cause TfR crosslinking. We created variants of the previously published RmAb158-scFv8D3, where the linker length between RmAb158 and the mTfR-targeting scFv8D3 was adjusted. We investigated the effect of the linker length on the antibodies' binding kinetics to mTfR using ELISA and LigandTracer assays, and their ability to transcytose across BBB endothelial cells (In-Cell BBB-Trans assay). We show that even a direct fusion without a linker does not alter the antibodies' apparent affinities to mTfR indicating their valency is unlikely affected by the linker length. However, the shortest linker variants demonstrated BBB transcytosis levels comparable to that of the monovalent control at a high antibody concentration and showed an almost two-fold higher level of BBB transcytosis compared to the longer-linker variants at the high concentration. Our new RmAb158-scFv8D3 short-linker variants are examples of symmetric, therapeutic antibodies with improved TfR-binding characteristics to facilitate more efficient brain uptake. We hypothesize that bivalent binding to TfR as such does not negatively affect BBB transcytosis in vitro, but a very short distance between TfR-targeting domains lowers the probability of receptor crosslinking. This study provides valuable insights into antibody-TfR interaction kinetics, contributing to future development of TfR-targeting antibody-based treatments for brain diseases.

About adverse events of targeted therapy for polypous rhinosinusitis

At the present time, usage of monoclonal antibodies is the most progressive method of pathogenetic therapy of polypous rhinosinusitis. The innovation of targeted therapy is based on the inhibition of key cytokines IL-4, IL-13 involved in pathogenetic remodeling of the mucous membrane of nasal cavity and paranasal sinuses at the stages of emerging T2 inflammation. At the same time, certain issues remain unresolved, concerning administration of monoclonal antibodies for treatment of nasal polyposes. We provide a brief historical review of publications devoted to efficiency analysis of biological therapy. In this context, registration of adverse events upon usage of targeted monoclonal antibody therapy becomes extremely valuable, along with prediction of long-term treatment results and assessment of immune status of the patients.