Relevance of Fc Gamma Receptor Polymorphisms in Cancer Therapy With Monoclonal Antibodies

Hybrid IgE-IgG1 antibodies (IgEG): a new antibody class that combines IgE and IgG functionality

IgG-based anti-cancer therapies have achieved promising clinical outcomes, but, especially for patients with solid tumors, response rates vary. IgE antibodies promote distinct immune responses compared to IgG and have shown anti-tumoral pre-clinical activity and preliminary efficacy and safety profile in clinical testing. To improve potency further, we engineered a hybrid IgE-IgG1 antibody (IgEG), to combine the functions of both isotypes. Two IgEGs were generated with variable regions taken from trastuzumab (Tras IgEG) and from a novel anti-HER2 IgE (26 IgEG). Both IgEGs expressed well in mammalian cells and demonstrated IgE-like stability. IgEGs demonstrated both IgE and IgG1 functionality in vitro. A lack of type I hypersensitivity associated with IgEG incubation with human blood is suggestive of acceptable safety. In vivo, IgEGs exhibited distinct pharmacokinetic profiles and produced anti-tumoral efficacy comparable to IgE. These findings highlight the potential of IgEG as a new therapeutic modality in oncology.

The Evolution of Anti-CD20 Treatment for Multiple Sclerosis: Optimization of Antibody Characteristics and Function

B-cell depletion with CD20-targeted agents is commonly used for treatment of multiple sclerosis (MS), other autoimmune diseases, and certain hematologic malignancies. Initial apparent success with rituximab in MS and neuromyelitis optica spurred development of the anti-CD20 monoclonal antibody (mAb) therapies ocrelizumab, ofatumumab, and ublituximab as well as the anti-CD19 mAb inebilizumab. While each are effective at targeting and depleting B cells, structural differences translate into different mechanisms of action affecting maintenance of B-cell depletion and safety and tolerability. Although the anti-CD20 mAbs differ in degree of human versus mouse sequences as well as target CD20 epitope, these properties do not appear to substantially affect activity or tolerability. In contrast, an antibody-dependent cell-mediated cytotoxicity (ADCC) versus a complement-dependent cytotoxicity mechanism of action as well as subcutaneous versus intravenous administration may provide improved tolerability. Glycoengineering of the mAbs ublituximab and inebilizumab enhances ADCC and can overcome the reduced responses to mAb-mediated B-cell depletion associated with certain genetic polymorphisms. Other strategies for therapeutic targeting of CD20, including brain shuttle antibodies (e.g., RO7121932), bispecific antibodies, chimeric antigen receptor T-cell therapies, and antibody-drug conjugates, are in active clinical development and may be future treatment approaches in MS and other B-cell-mediated autoimmune diseases.

Pancreatic cancer precursor lesions - Can immunotherapy prevent progression into pancreatic ductal adenocarcinoma?

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, with a 5-year survival rate of only 12.5 %. Early detection of PDAC or addressing risk factors for PDAC development are ways to improve outcomes. PDAC can arise from precursor lesions, including pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), and less frequent, mucinous cystic neoplasm (MCN), and other rare precursor variants. High-risk precursor lesions harbor a substantial chance of evolving into PDAC. Such lesions can often be found in resected PDAC specimens adjacent to the cancer. Unfortunately, recognizing precursor lesions that need to be resected is often tricky, and resections frequently end in major surgical interventions. Thus, better ways to handle precursor lesions are desperately needed. We mapped the immune microenvironments (IMEs) of PanINs, IPMNs, and MCNs on a cellular level using multiplex immunofluorescence and computational imaging technology and compared the findings to PDACs and normal pancreatic tissues. We found distinct and potentially targetable mechanisms of immunosuppression between the two main precursor lesions, PanIN and IMPN. Immunosuppression in IPMNs seems partly mediated by programmed cell death protein 1 ligand (PD-L1) expression on antigen-presenting cells (APCs). By contrast, elevated numbers of regulatory T cells (Tregs) seem to be key players in the immunosuppression of PanINs. Thus, treating high-risk IPMNs with anti-PD-1 and high-risk PanINs with agents targeting Tregs, such as anti-lymphocyte associated protein 4 (anti-CTLA-4) antibodies, could reverse their immunosuppressive state. Reversal of immunosuppression will restore immunosurveillance and eventually prevent progression into PDAC. We also review relevant published and ongoing non-surgical treatment approaches for high-risk IPMNs and PanINs.

Potentiating Antibody-Dependent Cellular Cytotoxicity in Triple-Negative Breast Cancer via the Humanized Anti-CD147 Antibody

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive subtype with high metastatic potential, poor prognosis, and the absence of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 (HER2). The lack of these receptors limits the standard treatments, such as hormone therapies and HER2-targeted antibodies like trastuzumab. These challenges highlight the critical need for novel therapeutic strategies. CD147, a transmembrane glycoprotein overexpressed in TNBC, promotes tumor progression, metastasis, and chemoresistance, making it a promising therapeutic target. This study evaluates the antibody-dependent cellular cytotoxicity (ADCC) of HuM6-1B9, a humanized anti-CD147 antibody, against MDA-MB-231 cells, a TNBC model.

METHODS

CFSE-labelled MDA-MB-231 cells were co-cultured with PBMCs as effector cells (E:T ratio 80:1) in the presence of HuM6-1B9 and incubated for 4 h. Cells were then collected and stained with PI, and CFSE+/PI+ dead target cells were analyzed by flow cytometry.

RESULTS

Co-culturing MDA-MB-231 cells with peripheral blood mononuclear cells (PBMCs) in the presence of HuM6-1B9 demonstrated effective ADCC induction without direct cytotoxicity. HuM6-1B9 induced 54.01% cancer cell death via ADCC, significantly outperforming trastuzumab (26.14%) while sparing PBMCs.

CONCLUSION

These findings support HuM6-1B9 as a prospective TNBC therapeutic and warrant further investigation into its clinical potential.

Neutrophils and Neutrophil-Based Drug Delivery Systems in Anti-Cancer Therapy

Neutrophils, the most abundant white blood cells, play a dual role in cancer progression. While they can promote tumor growth, metastasis, and immune suppression, they also exhibit anti-tumorigenic properties by attacking cancer cells and enhancing immune responses. This review explores the complex interplay between neutrophils and the tumor microenvironment (TME), highlighting their ability to switch between pro- and anti-tumor phenotypes based on external stimuli. Pro-tumorigenic neutrophils facilitate tumor growth through mechanisms such as neutrophil extracellular traps (NETs), secretion of pro-inflammatory cytokines, and immune evasion strategies. They contribute to angiogenesis, tumor invasion, and metastasis by releasing vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). Conversely, anti-tumor neutrophils enhance cytotoxicity by generating reactive oxygen species (ROS), promoting antibody-dependent cell-mediated cytotoxicity (ADCC), and activating other immune cells such as cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. Recent advances in neutrophil-based drug delivery systems have harnessed their tumor-homing capabilities to improve targeted therapy. Neutrophil-mimicking nanoparticles and membrane-coated drug carriers offer enhanced drug accumulation in tumors, reduced systemic toxicity, and improved therapeutic outcomes. Additionally, strategies to modulate neutrophil activity, such as inhibiting their immunosuppressive functions or reprogramming them towards an anti-tumor phenotype, are emerging as promising approaches in cancer immunotherapy. Understanding neutrophil plasticity and their interactions with the TME provides new avenues for therapeutic interventions. Targeting neutrophil-mediated mechanisms could enhance existing cancer treatments and lead to the development of novel immunotherapies, ultimately improving patient survival and clinical outcomes.

Fc gamma receptor polymorphisms in antibody therapy: implications for bioassay development to enhance product quality

The effectiveness of therapeutic antibodies is often associated with their Fc-mediated effector functions, such as antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis. These functions rely on interactions between Fc gamma receptors (FcγRs) on immune cells and the Fc region of antibodies. Genetic variations in these receptors, known as FcγR polymorphisms, can influence therapeutic outcomes by altering receptor expression levels, affinity, and function. This review examines the impact of FcγR polymorphisms on antibody therapy, emphasizing their role in developing and optimizing functional bioassays to assess product quality. Understanding these polymorphisms is essential for refining bioassays, which are crucial for accurately characterizing antibody products and ensuring consistency in manufacturing processes.

Fc-mediated immune stimulating, pro-inflammatory and antitumor effects of anti-HER2 IgE against HER2-expressing and trastuzumab-resistant tumors

BACKGROUND

Anti-human epidermal growth factor receptor 2 (HER2) IgG1-based antibody therapies significantly improve cancer prognosis, yet intrinsic or acquired resistance to fragment antigen-binding (Fab)-mediated direct effects commonly occurs. Most resistant tumors retain antigen expression and therefore remain potentially targetable with anti-HER2 therapies that promote immune-mediated responses. Tumor-antigen-specific IgE class antibodies can mediate powerful immune cell-mediated effects against different cancers and have been shown to activate IgE Fc receptor-expressing monocytes. We previously reported the engineering of a trastuzumab-equivalent anti-HER2 IgE antibody and showed early evidence of Fc-mediated cancer cell-targeting effects. In the present study, we evaluated the anti-tumoral functions of two anti-HER2 IgEs, trastuzumab and pertuzumab IgE.

METHODS

In vitro functionality of the two anti-HER2 antibodies was assessed by HER2 phosphorylation and ligand-independent viability assays, as well as basophil (RBL-SX38) degranulation, antibody-dependent cellular cytotoxicity/antibody-dependent cellular phagocytosis(ADCC/ADCP) assays and primary monocyte stimulation assays. The potential to trigger a hypersensitivity type I reaction was investigated using the basophil activation test (BAT). anti-tumoral efficacy was assessed in two humanized HER2+, trastuzumab-resistant models in vivo. Changes in the tumor microenvironment were assessed by flow cytometry or bulk RNA sequencing.

RESULTS

We demonstrate the anti-tumoral and immunostimulatory functions of two anti-HER2 IgEs derived from variable region sequences of the clinically available trastuzumab and pertuzumab IgG1 antibodies. IgE engagement of monocytes via the Fc region induced tumor cell cytotoxicity and a pro-inflammatory shift with upregulation of immune-stimulatory CD40, CD80 and CD86, and downregulation of scavenger CD163, cell surface molecules. This was accompanied by enhanced pro-inflammatory tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β cytokine production. The absence of basophil activation by anti-HER2 IgEs ex vivo in whole blood points to potentially safe administration in humans. In two trastuzumab-resistant HER2+ tumor xenograft models in immunodeficient mice reconstituted with human immune cells, the trastuzumab-equivalent anti-HER2 IgE restricted tumor growth. Treatment was associated with enriched classical (CD14+CD16-) monocyte and lower alternatively-activated (CD163+CD206+) macrophage infiltration, and higher densities of activated CD4+ (CD127loCD25hi) T cells and favorable effector T cell(Teff) to regulatory T cell (Treg) ratios in tumors.

CONCLUSION

Collectively, anti-HER2 IgE maintains Fab-mediated antitumor activity, induces Fc-mediated effects against HER2-expressing tumor cells, and stimulates remodeling of the immune microenvironment in tumors to promote pro-inflammatory cell phenotypes which could translate to improved outcomes for patients.

Therapeutic antibodies in oncology: an immunopharmacological overview

The biotechnological development of monoclonal antibodies and their immunotherapeutic use in oncology have grown exponentially in the last decade, becoming the first-line therapy for some types of cancer. Their mechanism of action is based on the ability to regulate the immune system or by interacting with targets that are either overexpressed in tumor cells, released into the extracellular milieu or involved in processes that favor tumor growth. In addition, the intrinsic characteristics of each subclass of antibodies provide specific effector functions against the tumor by activating antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and antibody-dependent cellular phagocytosis, among other mechanisms. The rational design and engineering of monoclonal antibodies have improved their pharmacokinetic and pharmacodynamic features, thus optimizing the therapeutic regimens administered to cancer patients and improving their clinical outcomes. The selection of the immunoglobulin G subclass, modifications to its crystallizable region (Fc), and conjugation of radioactive substances or antineoplastic drugs may all improve the antitumor effects of therapeutic antibodies. This review aims to provide insights into the immunological and pharmacological aspects of therapeutic antibodies used in oncology, with a rational approach at molecular modifications that can be introduced into these biological tools, improving their efficacy in the treatment of cancer.

Nivolumab, Pomalidomide, and Elotuzumab Combination Regimens for Treatment of Relapsed and Refractory Multiple Myeloma: Results from the Phase 3 CheckMate 602 Study

BACKGROUND

Preclinical studies suggest that combining nivolumab, a programmed death-1 (PD-1) immune checkpoint inhibitor, with pomalidomide/dexamethasone (Pd) with or without elotuzumab, an antisignaling lymphocytic activation molecule F7 monoclonal antibody, may improve multiple myeloma (MM) treatment efficacy.

PATIENTS AND METHODS

The phase 3 CheckMate 602 study (NCT02726581) assessed the efficacy and safety of nivolumab plus pomalidomide/dexamethasone (NPd) and NPd plus elotuzumab (NE-Pd). Eligible patients (aged ≥ 18 years) had measurable MM after ≥ 2 prior lines of therapy, that included an immunomodulatory drug (IMiD) and proteasome inhibitor (PI), each for ≥ 2 consecutive cycles, alone or combined, and were refractory to their last line of therapy. Patients were randomized 3:3:1 to receive NPd, Pd, or NE-Pd. The primary endpoint was progression-free survival (PFS); overall response rate (ORR) was a key secondary endpoint.

RESULTS

At a median follow-up of 16.8 months, PFS was similar between treatment arms (Pd, 7.3 months [95% CI, 6.5-8.4]; NPd, 8.4 months [95% CI, 5.8-12.1]; NE-Pd, 6.3 months [95% CI, 2.4-11.1]). ORR was similar in the Pd (55%), NPd (48%), and NE-Pd (42%) arms. Nivolumab-containing arms were associated with a less favorable safety profile versus Pd, including a higher rate of thrombocytopenia (NPd, 25.0%; NE-Pd, 16.7%; Pd, 15.7%), any-grade immune-mediated adverse events (NPd, 13.9%; NE-Pd, 16.7%; Pd, 2.9%), and adverse events leading to discontinuation (NPd, 25.0%; NE-Pd, 33.3%; Pd, 18.6%). No new safety signals were identified.

CONCLUSION

CheckMate 602 did not demonstrate clinical benefit of nivolumab (+/- elotuzumab) plus Pd versus Pd for patients with relapsed/refractory MM (RRMM).

Current development of Fc gamma receptors (FcγRs) in diagnostics: a review

The ability of the immune system to fight against pathogens relies on the intricate collaboration between antibodies and Fc gamma receptors (FcγRs). These receptors are a group of transmembrane glycoprotein molecules, which can specifically detect and bind to the Fc portion of immunoglobulin G (IgG) molecules. They are distributed on a diverse array of immune cells, forming a strong defence system to eliminate invading threats. FcγRs have gained increasing attention as potential biomarkers for various diseases in recent years due to their ability to reflect immune dysregulation and disease pathogenesis. Increasing lines of evidence have shed new light on the remarkable association of FcγRs polymorphisms with the susceptibility of autoimmune diseases such as systemic lupus erythematosus (SLE) and lupus nephritis. Several studies have also reported the application of FcγR as a novel biomarker for the diagnosis of infection and cancer. Due to the surge in interest and concern regarding the potential of FcγRs as promising diagnostic biomarkers, this review, thereby, serves to provide a comprehensive overview of the structural characteristics, functional roles, and expression patterns of FcγRs, with a particular focus on their evolving role as diagnostic and prognostic biomarkers.

Selective depletion of tumor-infiltrating regulatory T cells with BAY 3375968, a novel Fc-optimized anti-CCR8 antibody

Regulatory T cells (Tregs) are known to facilitate tumor progression by suppressing CD8+ T cells within the tumor microenvironment (TME), thereby also hampering the effectiveness of immune checkpoint inhibitors (ICIs). While systemic depletion of Tregs can enhance antitumor immunity, it also triggers undesirable autoimmune responses. Therefore, there is a need for therapeutic agents that selectively target Tregs within the TME without affecting systemic Tregs. In this study, as shown also by others, the chemokine (C-C motif) receptor 8 (CCR8) was found to be predominantly expressed on Tregs within the TME of both humans and mice, representing a unique target for selective depletion of tumor-residing Tregs. Based on this, we developed BAY 3375968, a novel anti-human CCR8 antibody, along with respective surrogate anti-mouse CCR8 antibodies, and demonstrated their in vitro mode-of-action through induction of potent antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP) activities. In vivo, anti-mouse CCR8 antibodies effectively depleted Tregs within the TME primarily via ADCP, leading to increased CD8+ T cell infiltration and subsequent tumor growth inhibition across various cancer models. This monotherapeutic efficacy was significantly enhanced in combination with ICIs. Collectively, these findings suggest that CCR8 targeting represents a promising strategy for Treg depletion in cancer therapies. BAY 3375968 is currently under investigation in a Phase I clinical trial (NCT05537740).

Targeting Innate Immunity in Glioma Therapy

Currently, there is a lack of effective therapies for the majority of glioblastomas (GBMs), the most common and malignant primary brain tumor. While immunotherapies have shown promise in treating various types of cancers, they have had limited success in improving the overall survival of GBM patients. Therefore, advancing GBM treatment requires a deeper understanding of the molecular and cellular mechanisms that cause resistance to immunotherapy. Further insights into the innate immune response are crucial for developing more potent treatments for brain tumors. Our review provides a brief overview of innate immunity. In addition, we provide a discussion of current therapies aimed at boosting the innate immunity in gliomas. These approaches encompass strategies to activate Toll-like receptors, induce stress responses, enhance the innate immune response, leverage interferon type-I therapy, therapeutic antibodies, immune checkpoint antibodies, natural killer (NK) cells, and oncolytic virotherapy, and manipulate the microbiome. Both preclinical and clinical studies indicate that a better understanding of the mechanisms governing the innate immune response in GBM could enhance immunotherapy and reinforce the effects of chemotherapy and radiotherapy. Consequently, a more comprehensive understanding of the innate immune response against cancer should lead to better prognoses and increased overall survival for GBM patients.

Advances in artificial intelligence to predict cancer immunotherapy efficacy

Tumor immunotherapy, particularly the use of immune checkpoint inhibitors, has yielded impressive clinical benefits. Therefore, it is critical to accurately screen individuals for immunotherapy sensitivity and forecast its efficacy. With the application of artificial intelligence (AI) in the medical field in recent years, an increasing number of studies have indicated that the efficacy of immunotherapy can be better anticipated with the help of AI technology to reach precision medicine. This article focuses on the current prediction models based on information from histopathological slides, imaging-omics, genomics, and proteomics, and reviews their research progress and applications. Furthermore, we also discuss the existing challenges encountered by AI in the field of immunotherapy, as well as the future directions that need to be improved, to provide a point of reference for the early implementation of AI-assisted diagnosis and treatment systems in the future.

Neutrophils as immune effector cells in antibody therapy in cancer

Tumor-targeting monoclonal antibodies are available for a number of cancer cell types (over)expressing the corresponding tumor antigens. Such antibodies can limit tumor progression by different mechanisms, including direct growth inhibition and immune-mediated mechanisms, in particular complement-dependent cytotoxicity, antibody-dependent cellular phagocytosis, and antibody-dependent cellular cytotoxicity (ADCC). ADCC can be mediated by various types of immune cells, including neutrophils, the most abundant leukocyte in circulation. Neutrophils express a number of Fc receptors, including Fcγ- and Fcα-receptors, and can therefore kill tumor cells opsonized with either IgG or IgA antibodies. In recent years, important insights have been obtained with respect to the mechanism(s) by which neutrophils engage and kill antibody-opsonized cancer cells and these findings are reviewed here. In addition, we consider a number of additional ways in which neutrophils may affect cancer progression, in particular by regulating adaptive anti-cancer immunity.