Bispecific Antibody Research Articles

Strategies following failure of CAR-T-cell therapy in non-Hodgkin lymphoma.

Several CD19 CAR-T-cell drugs are approved for safety and efficacy in advanced B-cell cancers with encouraging results. However, primary refractory and relapse are common. We critically analyze long-term data on efficacy of CD19 CAR-T-cell therapies in B-cell non-Hodgkin lymphomas from clinical trials with those of so-called real world data. We identify co-variates associated with efficacy, discuss mechanisms of relapse, summarize the data on the results of post-failure therapy including allotransplants, monoclonal and bi-specific antibodies, antibody-drug conjugates, immune checkpoint-inhibitors and repeat infusions of CAR-T-cells. We conclude, save for allotransplants, there are few data strongly supporting any of these interventions. Most trial are with few heterogeneously-treated subjects with diverse interventions and brief follow-up. Interventions need to be tailored to the cause(s) of CAR-T-cell failure. Prestly, there is not a convincingly safe and effective therapy of people failing initial CAR-T-cell therapy of B-cell non-Hodgkin lymphoma.

A Brief Chronicle of Antibody Research and Technological Advances.

This review briefly traces the historical development of antibody research and related technologies. The path from early perceptions of immunity to the emergence of modern immunotherapy has been marked by pivotal discoveries and technological advances. Early insights into immunity led to the development of vaccination and serotherapy. The elucidation of antibody structure and function paved the way for monoclonal antibody technology and its application in diagnosis and therapy. Breakthroughs in genetic engineering have enabled the production of humanized antibodies and the advances in Fc engineering, thereby increasing therapeutic efficacy. The discovery of immune checkpoints and cytokines revolutionized the treatment of cancer and autoimmune diseases. The field continues to evolve rapidly with the advent of antibody-drug conjugates, bispecific antibodies, and CAR T-cell therapies. As we face global health challenges, antibody research remains at the forefront of medical innovation and offers promising solutions for the future.

EXTH-78. A NOVEL BISPECIFIC S100A4/TFR ANTIBODY TO REPROGRAM THE GLIOMA TUMOR MICROENVIRONMENT AND TARGET GLIOMA STEM CELLS

Abstract GBM (glioblastoma) is the most common and aggressive primary brain tumor in adults. While immunotherapy is a promising treatment modality for GBM, most clinical trials have thus far only provided a modest benefit to GBM patients. We propose that enhancing the efficacy of immunotherapy for GBM requires approaches that increase T cell infiltration and reprogram the myeloid cells to a more pro-inflammatory state. S100A4 is a major regulator of stemness, epithelial-mesenchymal transition, and a critical regulator of immune suppressive myeloid and T cell phenotypes in GBM. Targeting S100A4 in either glioma or stromal cells is sufficient to reprogram the tumor immune landscape and extend survival of glioma bearing mice, indicating that S100A4 is a promising immunotherapy target. We recently developed a S100A4 blocking monoclonal antibody; however, this antibody does not cross the blood brain barrier (BBB) efficiently to confer significant therapeutic benefit, limiting its efficacy in treating GBM. To overcome this challenge, we generated a bispecific S100A4-TfR antibody (BsA) that allows robust BBB penetration, and tested this in a pre-clinical syngeneic, orthotopic mouse model of GBM. Using ELISA, confocal immunofluorescent microscopy, flow cytometry, and bulk RNA sequencing, we report that systemic administration of the S100A4-TfR BsA results in increased immune cell infiltration with a preferential increase in CD4 T cell infiltration, and potent immune remodeling of the tumor microenvironment to a more pro-inflammatory state. Furthermore, the BsA is taken up by glioma cells intracellularly, which is correlated with depletion of intracellular S100A4 and decreased nuclear SOX2 localization, which would reduce stemness of glioma cells. Functionally, in vitro BsA treatment of primary glioma cell cultures shows decreased S100A4 expression, proliferation, and self-renewal. Our results suggest that S100A4-TfR BsA is a novel dual activity inhibitor to simultaneously reprogram the GBM immune landscape and reduce glioma stemness.

A Systematic Workflow for Fragmentation Identification of Therapeutic Antibodies by Liquid Chromatography-Mass Spectrometry.

Fragmentation is a phenomenon ubiquitously observed during research and development of therapeutic antibodies. The clear identification of the cleavage site is vital for comprehending fragmentation mechanisms and optimizing processes. Capillary electrophoresis-sodium dodecyl sulfate (CE-SDS) is now widely used to detect and quantify fragments, while its peak identification is hindered by immature capillary electrophoresis-sodium dodecyl sulfate coupled with mass spectrometry techniques. In this study, we developed a systematic workflow for fragment characterization, which integrated direct identification, fragment enrichment, and fragmentation confirmation using multiple techniques, such as microscale peptide mapping (PM), PM of N-termini labeled sample, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in-gel extraction for molecular weight (MW) and PM measurements. By employing this innovative workflow, we successfully identified the cleavage sites of two therapeutic antibodies. In the first case, through direct liquid chromatography-mass spectrometry (LC-MS) characterization, the cleavages leading to the loss of biological function were identified on the linker of a bispecific antibody. In the second case involving a tetravalent antibody, direct LC-MS analysis failed. However, more sophisticated analysis nailed down the critical cleavage at the LC/HC: G105-R106 site in the CDR3 region of the antibody. Our systematic workflow provides a clear and accessible method for identifying cleavage sites with broad applicability across pharmaceutical laboratories.

Engineered bispecific antibodies with enhanced breadth and potency against SARS-CoV-2 variants and SARS-related coronaviruses.

The concern of COVID-19 persists due to the continuous emergence of variants and the potential spillover of animal coronaviruses. The broad-spectrum neutralizing antibodies play a pivotal role in the prevention and treatment of coronavirus (CoV) infections. Here, we constructed 18 bi-specific antibodies (bsAbs) using 9 antibodies isolated from COVID-19 convalescents and vaccinated individuals, designed as dual variable domain immunoglobulin (DVD-Ig). A bsAb 5-HI showed a high binding capability to the S1 subunit of spike and exhibited breadth and potency against pseudotyped SARS-CoV-2 variants of concerns (VOCs) and SARS-related-CoVs (SARSr-CoVs), with half maximal effective concentration (EC50) of 0.028-3.444 nM and 50% inhibitory concentration (IC50) of 0.008-0.800 nM. In addition, it retained neutralization potency against the peudotyped virus of recently prevalent JN.1 strain (IC50, 12.74 nM). We found that the parental antibodies showed weak or no binding to the receptor binding domain (RBD) of the SARS-CoV, EG.5.1, and JN.1. However, the 5-HI maintained the binding with RBD and prevented the binding between hACE2 and RBD (IC50 for the RBD of SARS-CoV, 1.067 nM; EG.5.1, 0.423 nM; JN.1, 0.223 nM). In neutralization assays with the authentic virus, we found that the5-HI effectively neutralized Omicron variants XBB.1.5 (IC50, 0.308 nM), EG.5.1 (IC50, 0.129 nM), and JN.1 (IC50, 13.692 nM), while its parental antibodies showed weakened or no neutralization. Therefore, the5-HI represents a promising candidate for further development in the treatment and prevention of ongoing evolved SARS-CoV-2 VOCs and other SARSr-CoVs that potentially emerge in the future.

Évaluation en TEP 18F-FDG de la réponse au traitement par CAR T-Cells et anticorps bispécifiques des lymphomes non hodgkiniens agressifs

Refractory or relapsing aggressive non-Hodgkin lymphomas have improved prognosis in the last few years thanks to innovative therapies such as CAR T-cells and bispecific antibodies. During these therapeutic strategies, tumoral response assessment with FDG PET remains of paramount importance. However, due to their mode of action, these treatments can result in delayed responses or in inflammatory events that may hamper interpretation of metabolic imaging. Lugano criteria, relying on the Deauville score, are useful, but it is crucial to be aware of the interpretation pitfalls and to consider all the clinical and biological background of the patient, ideally in a multidisciplinary approach.

Advances in Development of Drug Treatment for Hemophilia with Inhibitors.

Patients with hemophilia A and B who have inhibitors face limited treatment options, because replacement therapy with clotting factor VIII or IX concentrates is ineffective, particularly for patients with high-titer inhibitors. Current mainstay therapies include immune tolerance induction (through frequent injections of clotting factor VIII or IX concentrates) to eradicate inhibitors and bypassing agents (such as recombinant activated clotting factor VII and activated prothrombin complex concentrates) for the prevention and treatment of bleeding episodes. The use of these agents typically requires intravenous injections and sometimes hospitalization, which can be burdensome for patients. More recently, emicizumab, a bispecific antibody that mimics the function of activated clotting factor VIII, has demonstrated favorable efficacy for prophylaxis in patients with hemophilia A and inhibitors, representing a promising new therapeutic strategy. Ongoing research aims to discover and develop easy-to-use nonfactor agents for managing hemophilia with inhibitors. This review summarizes the current understanding of the pathophysiology of inhibitor development in hemophilia, outlines existing treatment options, and discusses advancements in novel therapeutic biologics, including a recombinant activated clotting factor VII variant (marzeptacog alfa), a new bispecific antibody (Mim8), antitissue factor pathway inhibitor antibodies (concizumab and marstacimab), and small interfering RNA targeting antithrombin (fitusiran). All of these agents are administered subcutaneously, with some offering the convenience of less frequent dosing (e.g., weekly or monthly). These potential drug candidates may provide significant benefits for the prophylaxis or treatment of bleeding disorders in patients with hemophilia and inhibitors.

A B7-H3–Targeted CD28 Bispecific Antibody Enhances the Activity of Anti–PD-1 and CD3 T-cell Engager Immunotherapies

Abstract T-cell activation is a multistep process requiring T-cell receptor engagement by peptide–MHC complexes (Signal 1) coupled with CD28-mediated costimulation (Signal 2). Tumors typically lack expression of CD28 ligands, so tumor-specific Signal 1 (e.g., neoepitope presentation) without costimulation may be ineffective or even induce T-cell anergy. We designed the bispecific antibody XmAb808 to co-engage the tumor-associated antigen B7-H3 with CD28 to promote T-cell costimulation within the tumor microenvironment. XmAb808 costimulation was measured by its ability to activate and expand T cells and enhance T cell–mediated cancer cell killing in cocultures of human peripheral blood mononuclear cells and cancer cells and in mice engrafted with human peripheral blood mononuclear cells and tumor xenografts. XmAb808 avidly bound cancer cells and stimulated IL2 and IFNγ secretion from T cells cocultured with cancer cells engineered to deliver Signal 1 to T cells via a surface-expressed anti-CD3 antibody. XmAb808 enhanced expression of the antiapoptotic factor Bcl-xL and CD25, promoting survival and IL2-dependent expansion of T cells coupled with increased T cell–mediated cytotoxicity in vitro. XmAb808 combined with an EpCAM×CD3 bispecific antibody to enhance target cell killing through IL2-dependent expansion of CD25+ T cells. This combination also suppressed pancreatic tumor xenograft growth in mice. Furthermore, XmAb808 combined with an anti–programmed cell death protein 1 antibody to suppress breast tumor xenograft growth in mice. XmAb808 as monotherapy and in combination with an anti–programmed cell death protein 1 antibody is currently in clinical development in patients with advanced solid tumors. Our results suggest that XmAb808 may also combine with tumor antigen–targeted anti-CD3 (Signal 1) T-cell engagers.

A bispecific CD40 agonistic antibody allowing for antibody-peptide conjugate formation to enable cancer-specific peptide delivery, resulting in improved T Cell proliferation and anti-tumor immunity in mice

Current antibody-based immunotherapy depends on tumor antigen shedding for proper T cell priming. Here we select a novel human CD40 agonistic drug candidate and generate a bispecific antibody, herein named BiA9*2_HF, that allows for rapid antibody-peptide conjugate formation. The format is designed to facilitate peptide antigen delivery to CD40 expressing cells combined with simultaneous CD40 agonistic activity. In vivo, the selected bispecific antibody BiA9*2_HF loaded with peptide cargos induces improved antigen-specific proliferation of CD8+ (10-15 fold) and CD4+ T cells (2-7 fold) over control in draining lymph nodes. In both virus-induced and neoantigen-based mouse tumor models, BiA9*2_HF demonstrates therapeutic efficacy and elevated safety profile, with complete tumor clearance, as well as measured abscopal impact on tumor growth. The BiA9*2_HF drug candidate can thus be utilized to tailor immunotherapeutics for cancer patients.

T Cells from CLL Patients on Venetoclax Mount Potent Cytotoxic Responses in Combination with Epcoritamab, a CD20/CD3 Bispecific Antibody

T Cells from CLL Patients on Venetoclax Mount Potent Cytotoxic Responses in Combination with Epcoritamab, a CD20/CD3 Bispecific Antibody

Risk of Infections in Multiple Myeloma Patients Treated with Bispecific Antibodies

Risk of Infections in Multiple Myeloma Patients Treated with Bispecific Antibodies

Activity of CAR-T Cells and Bispecific Antibodies in Multiple Myeloma with Extramedullary Involvement

Activity of CAR-T Cells and Bispecific Antibodies in Multiple Myeloma with Extramedullary Involvement

Automated Body Composition Analyses Reveal Significant Associations with Mortality in Myeloma Patients Following Immunotherapy with Bispecific Antibodies

Automated Body Composition Analyses Reveal Significant Associations with Mortality in Myeloma Patients Following Immunotherapy with Bispecific Antibodies

Risk Factors for Severe Infection in Patients Receiving Bispecific Antibody Therapies for Lymphoma

Risk Factors for Severe Infection in Patients Receiving Bispecific Antibody Therapies for Lymphoma

Forimtamig, a novel GPRC5D-targeting T-cell bispecific antibody with a 2+1 format, for the treatment of multiple myeloma

AbstractDespite several approved therapies, multiple myeloma (MM) remains an incurable disease with high unmet medical need. “Off-the-shelf” T-cell bispecific antibodies (TCBs) targeting B-cell maturation antigen (BCMA) and G protein–coupled receptor class C group 5 member D (GPRC5D) have demonstrated high objective response rates in heavily pretreated patients with MM; however, primary resistance, short duration of response, and relapse driven by antigen shift frequently occur. Although GPRC5D represents the most selective target in MM, recent findings indicate antigen loss occurs more frequently than with BCMA. Thus, anti-GPRC5D immunotherapies must hit hard during a short period of time. Here, we characterize forimtamig, a novel GPRC5D-targeting TCB with 2+1 format. Bivalent binding of forimtamig to GPRC5D confers higher affinity than classical 1+1 TCB formats correlating with formation of more stable immunological synapses and higher potency in tumor cell killing and T-cell activation. Using an orthotopic mouse model of MM, forimtamig recruited T effector cells to the bone marrow and induced rapid tumor killing even after the introduction of step-up dosing to mitigate cytokine release. Combination of forimtamig with standard-of-care agents including anti-CD38 antibodies, immunomodulatory drugs, and proteasome inhibitors improved depth and duration of response. The combination of forimtamig with novel therapeutic agents including BCMA TCB and cereblon E3 ligase modulatory drugs was potent and prevented occurrence of GPRC5D -negative tumor relapse. Forimtamig is currently being evaluated in phase 1 clinical trials in patients with relapsed and refractory MM for monotherapy and in combination treatments. This trial was registered at www.ClinicalTrials.gov as #NCT04557150.

Targeting Intracellular Mutant NPM1 in Acute Myeloid Leukemia with a Novel Peptide-MHC-Specific T-Cell Bispecific Antibody

Targeting Intracellular Mutant NPM1 in Acute Myeloid Leukemia with a Novel Peptide-MHC-Specific T-Cell Bispecific Antibody

Infection Risk and Efficacy of Anti-BCMA Bispecific Antibodies in Multiple Myeloma: A Real-World Propensity Score-Matched Study

Infection Risk and Efficacy of Anti-BCMA Bispecific Antibodies in Multiple Myeloma: A Real-World Propensity Score-Matched Study

Efficacy of Anti-BCMA CAR-T Cell Therapies in Multiple Myeloma Patients with Prior Exposure to Bispecific Antibodies- Results from a Retrospective Multi-Center Registry Analysis

Efficacy of Anti-BCMA CAR-T Cell Therapies in Multiple Myeloma Patients with Prior Exposure to Bispecific Antibodies- Results from a Retrospective Multi-Center Registry Analysis

CAR-T Therapy Versus Bispecific Antibodies in Relapsed Refractory Multiple Myeloma: Systematic Review and Metanalysis of Toxicity and Response

CAR-T Therapy Versus Bispecific Antibodies in Relapsed Refractory Multiple Myeloma: Systematic Review and Metanalysis of Toxicity and Response

Dose Escalation of ISB 1442, a Novel CD38 Biparatopic x CD47 Bispecific Antibody, in Patients with Relapsed / Refractory Multiple Myeloma

Dose Escalation of ISB 1442, a Novel CD38 Biparatopic x CD47 Bispecific Antibody, in Patients with Relapsed / Refractory Multiple Myeloma