Lipid Nanoparticle Delivery System for mRNA Encoding B7H3-redirected Bispecific Antibody Displays Potent Antitumor Effects on Malignant Tumors

B7-H3 in acute myeloid leukemia: From prognostic biomarker to immunotherapeutic target

ABSTRACT

B7-H3 (CD276), an immune checkpoint protein of the B7 family, exhibits significant upregulation in solid tumors and hematologic malignancies, exerting a crucial role in their pathophysiology. The distinct differential expression of B7-H3 between tumors and normal tissues and its multifaceted involvement in tumor pathogenesis position it as a promising therapeutic target for tumors. In the context of acute myeloid leukemia (AML), B7-H3 is prominently overexpressed and closely associated with unfavorable prognoses, yet it has remained understudied. Despite various ongoing clinical trials demonstrating the potential efficacy of immunotherapies targeting B7-H3, the precise underlying mechanisms responsible for B7-H3-mediated proliferation and immune evasion in AML remain enigmatic. In view of this, we comprehensively outline the current research progress concerning B7-H3 in AML, encompassing in-depth discussions on its structural attributes, receptor interactions, expression profiles, and biological significance in normal tissues and AML. Moreover, we delve into the protumor effects of B7-H3 in AML, examine the intricate mechanisms that underlie its function, and discuss the emerging application of B7-H3-targeted therapy in AML treatment. By juxtaposing B7-H3 with other molecules within the B7 family, this review emphasizes the distinctive advantages of B7-H3, not only as a valuable prognostic biomarker but also as a highly promising immunotherapeutic target in AML.

The present and future of bispecific antibodies for cancer therapy

Bispecific antibodies (bsAbs) enable novel mechanisms of action and/or therapeutic applications that cannot be achieved using conventional IgG-based antibodies. Consequently, development of these molecules has garnered substantial interest in the past decade and, as of the end of 2023, 14 bsAbs have been approved: 11 for the treatment of cancer and 3 for non-oncology indications. bsAbs are available in different formats, address different targets and mediate anticancer function via different molecular mechanisms. Here, we provide an overview of recent developments in the field of bsAbs for cancer therapy. We focus on bsAbs that are approved or in clinical development, including bsAb-mediated dual modulators of signalling pathways, tumour-targeted receptor agonists, bsAb-drug conjugates, bispecific T cell, natural killer cell and innate immune cell engagers, and bispecific checkpoint inhibitors and co-stimulators. Finally, we provide an outlook into next-generation bsAbs in earlier stages of development, including trispecifics, bsAb prodrugs, bsAbs that induce degradation of tumour targets and bsAbs acting as cytokine mimetics.

Dual-targeting tigecycline nanoparticles for treating intracranial infections caused by multidrug-resistant Acinetobacter baumannii

Multidrug-resistant (MDR) Acinetobacter baumannii (A. baumannii) is a formidable pathogen responsible for severe intracranial infections post-craniotomy, exhibiting a mortality rate as high as 71%. Tigecycline (TGC), a broad-spectrum antibiotic, emerged as a potential therapeutic agent for MDR A. baumannii infections. Nonetheless, its clinical application was hindered by a short in vivo half-life and limited permeability through the blood-brain barrier (BBB). In this study, we prepared a novel core-shell nanoparticle encapsulating water-soluble tigecycline using a blend of mPEG-PLGA and PLGA materials. This nanoparticle, modified with a dual-targeting peptide Aβ11 and Tween 80 (Aβ11/T80@CSs), was specifically designed to enhance the delivery of tigecycline to the brain for treating A. baumannii-induced intracranial infections. Our findings demonstrated that Aβ11/T80@CSs nanocarriers successfully traversed the BBB and effectively delivered TGC into the cerebrospinal fluid (CSF), leading to a significant therapeutic response in a model of MDR A. baumannii intracranial infection. This study offers initial evidence and a platform for the application of brain-targeted nanocarrier delivery systems, showcasing their potential in administering water-soluble anti-infection drugs for intracranial infection treatments, and suggesting promising avenues for clinical translation.

Antiangiogenic Therapeutic mRNA Delivery Using Lung-Selective Polymeric Nanomedicine for Lung Cancer Treatment

Therapeutic antibodies that block vascular endothelial growth factor (VEGF) show clinical benefits in treating nonsmall cell lung cancers (NSCLCs) by inhibiting tumor angiogenesis. Nonetheless, the therapeutic effects of systemically administered anti-VEGF antibodies are often hindered in NSCLCs because of their limited distribution in the lungs and their adverse effects on normal tissues. These challenges can be overcome by delivering therapeutic antibodies in their mRNA form to lung endothelial cells, a primary target of VEGF-mediated pulmonary angiogenesis, to suppress the NSCLCs. In this study, we synthesized derivatives of poly(β-amino esters) (PBAEs) and prepared nanoparticles to encapsulate the synthetic mRNA encoding bevacizumab, an anti-VEGF antibody used in the clinic. Optimization of nanoparticle formulations resulted in a selective lung transfection after intravenous administration. Notably, the optimized PBAE nanoparticles were distributed in lung endothelial cells, resulting in the secretion of bevacizumab. We analyzed the protein corona on the lung- and spleen-targeting nanoparticles using proteomics and found distinctive features potentially contributing to their organ-selectivity. Lastly, bevacizumab mRNA delivered by the lung-targeting PBAE nanoparticles more significantly inhibited tumor proliferation and angiogenesis than recombinant bevacizumab protein in orthotopic NSCLC mouse models, supporting the therapeutic potential of bevacizumab mRNA therapy and its selective delivery through lung-targeting nanoparticles. Our proof-of-principle results highlight the clinical benefits of nanoparticle-mediated mRNA therapy in anticancer antibody treatment in preclinical models.

Lipid Nanoparticle (LNP) Delivery Carrier-Assisted Targeted Controlled Release mRNA Vaccines in Tumor Immunity

In recent years, lipid nanoparticles (LNPs) have attracted extensive attention in tumor immunotherapy. Targeting immune cells in cancer therapy has become a strategy of great research interest. mRNA vaccines are a potential choice for tumor immunotherapy, due to their ability to directly encode antigen proteins and stimulate a strong immune response. However, the mode of delivery and lack of stability of mRNA are key issues limiting its application. LNPs are an excellent mRNA delivery carrier, and their structural stability and biocompatibility make them an effective means for delivering mRNA to specific targets. This study summarizes the research progress in LNP delivery carrier-assisted targeted controlled release mRNA vaccines in tumor immunity. The role of LNPs in improving mRNA stability, immunogenicity, and targeting is discussed. This review aims to systematically summarize the latest research progress in LNP delivery carrier-assisted targeted controlled release mRNA vaccines in tumor immunity to provide new ideas and strategies for tumor immunotherapy, as well as to provide more effective treatment plans for patients.

A promising target for breast cancer: B7-H3

Breast cancer (BC) is the second-leading factor of mortality for women globally and is brought on by a variety of genetic and environmental causes. The conventional treatments for this disease have limitations, making it difficult to improve the lifespan of breast cancer patients. As a result, extensive research has been conducted over the past decade to find innovative solutions to these challenges. Targeting of the antitumor immune response through the immunomodulatory checkpoint protein B7 family has revolutionized cancer treatment and led to intermittent patient responses. B7-H3 has recently received attention because of its significant demodulation and its immunomodulatory effects in many cancers. Uncontrolled B7-H3 expression and a bad outlook are strongly associated, according to a substantial body of cancer research. Numerous studies have shown that BC has significant B7-H3 expression, and B7-H3 induces an immune evasion phenotype, consequently enhancing the survival, proliferation, metastasis, and drug resistance of BC cells. Thus, an innovative target for immunotherapy against BC may be the B7-H3 checkpoint.In this review, we discuss the structure and regulation of B7-H3 and its double costimulatory/coinhibitory function within the framework of cancer and normal physiology. Then we expound the malignant behavior of B7-H3 in BC and its role in the tumor microenvironment (TME) and finally focus on targeted drugs against B7-H3 that have opened new therapeutic opportunities in BC.

Revolutionizing cancer immunotherapy: unleashing the potential of bispecific antibodies for targeted treatment

Recent progressions in immunotherapy have transformed cancer treatment, providing a promising strategy that activates the immune system of the patient to find and eliminate cancerous cells. Bispecific antibodies, which engage two separate antigens or one antigen with two distinct epitopes, are of tremendous concern in immunotherapy. The bi-targeting idea enabled by bispecific antibodies (BsAbs) is especially attractive from a medical standpoint since most diseases are complex, involving several receptors, ligands, and signaling pathways. Several research look into the processes in which BsAbs identify different cancer targets such angiogenesis, reproduction, metastasis, and immune regulation. By rerouting cells or altering other pathways, the bispecific proteins perform effector activities in addition to those of natural antibodies. This opens up a wide range of clinical applications and helps patients with resistant tumors respond better to medication. Yet, further study is necessary to identify the best conditions where to use these medications for treating tumor, their appropriate combination partners, and methods to reduce toxicity. In this review, we provide insights into the BsAb format classification based on their composition and symmetry, as well as the delivery mode, focus on the action mechanism of the molecule, and discuss the challenges and future perspectives in BsAb development.

Lipid Nanoparticle (LNP) Enables mRNA Delivery for Cancer Therapy

Messenger RNA (mRNA) has received great attention in the prevention and treatment of various diseases due to the success of coronavirus disease 2019 (COVID-19) mRNA vaccines (Comirnaty and Spikevax). To meet the therapeutic purpose, it is required that mRNA must enter the target cells and express sufficient proteins. Therefore, the development of effective delivery systems is necessary and crucial. Lipid nanoparticle (LNP) represents a remarkable vehicle that has indeed accelerated mRNA applications in humans, as several mRNA-based therapies have already been approved or are in clinical trials. In this review, the focus is on mRNA-LNP-mediated anticancer therapy. It summarizes the main development strategies of mRNA-LNP formulations, discusses representative therapeutic approaches in cancer, and points out current challenges and possible future directions of this research field. It is hoped that these delivered messages can help further improve the application of mRNA-LNP technology in cancer therapy.

Scalable multimodal weak anion exchange chromatographic purification for stable mRNA drug substance

Messenger RNA (mRNA) has emerged as a modality with immense therapeutic potential. Recent innovations in production process of mRNA call for procedures to isolate pure mRNA drug substance (DS) with high yield, high capacity, scalability, and compatibility with GMP production systems. Novel RNA modalities, such as circular RNA (circRNA), have further driven the need for non-affinity capture possibilities which are already widely used in the biopharmaceutical industry, for example, in monoclonal antibody processing. The principle that multimodal ion exchange/hydrogen bonding chromatography can be used to separate mRNA from in vitro transcription components has recently been demonstrated. Here, we apply and refine this approach to be suitable for scalable purification of multiple mRNA constructs with sufficient yields, purity, and stability, for use in mRNA production process. Binding capacity of the PrimaS-modified monolithic chromatographic column for mRNA enabled up to 7 mg/mL product isolation in a single chromatographic run, with 98% recovery and room temperature stability of the eGFP mRNA demonstrated for up to 28 days. This approach is independent of construct size or the presence of polyadenylic acid tail and is applicable for capture of a wide variety of RNAs, including mRNA, self-amplifying RNA, circRNA, and with optimization also smaller RNAs such as transfer RNA and others.

B7H3 targeting gold nanocage pH-sensitive conjugates for precise and synergistic chemo-photothermal therapy against NSCLC

BACKGROUND

The combination of drug delivery with immune checkpoint targeting has been extensively studied in cancer therapy. However, the clinical benefit for patients from this strategy is still limited. B7 homolog 3 protein (B7-H3), also known as CD276 (B7-H3/CD276), is a promising therapeutic target for anti-cancer treatment. It is widely overexpressed on the surface of malignant cells and tumor vasculature, and its overexpression is associated with poor prognosis. Herein, we report B7H3 targeting doxorubicin (Dox)-conjugated gold nanocages (B7H3/Dox@GNCs) with pH-responsive drug release as a selective, precise, and synergistic chemotherapy-photothermal therapy agent against non-small-cell lung cancer (NSCLC).

RESULTS

In vitro, B7H3/Dox@GNCs exhibited a responsive release of Dox in the tumor acidic microenvironment. We also demonstrated enhanced intracellular uptake, induced cell cycle arrest, and increased apoptosis in B7H3 overexpressing NSCLC cells. In xenograft tumor models, B7H3/Dox@GNCs exhibited tumor tissue targeting and sustained drug release in response to the acidic environment. Wherein they synchronously destroyed B7H3 positive tumor cells, tumor-associated vasculature, and stromal fibroblasts.

CONCLUSION

This study presents a dual-compartment targeted B7H3 multifunctional gold conjugate system that can precisely control Dox exposure in a spatio-temporal manner without evident toxicity and suggests a general strategy for synergistic therapy against NSCLC.

Circular RNA vaccine in disease prevention and treatment

CircRNAs are a class of single-stranded RNAs with covalently linked head-to-tail topology. In the decades since its initial discovery, their biogenesis, regulation, and function have rapidly disclosed, permitting a better understanding and adoption of them as new tools for medical applications. With the development of biotechnology and molecular medicine, artificial circRNAs have been engineered as a novel class of vaccines for disease treatment and prevention. Unlike the linear mRNA vaccine which applications were limited by its instability, inefficiency, and innate immunogenicity, circRNA vaccine which incorporate internal ribosome entry sites (IRESs) and open reading frame (ORF) provides an improved approach to RNA-based vaccination with safety, stability, simplicity of manufacture, and scalability. However, circRNA vaccines are at an early stage, and their optimization, delivery and applications require further development and evaluation. In this review, we comprehensively describe circRNA vaccine, including their history and superiority. We also summarize and discuss the current methodological research for circRNA vaccine preparation, including their design, synthesis, and purification. Finally, we highlight the delivery options of circRNA vaccine and its potential applications in diseases treatment and prevention. Considering their unique high stability, low immunogenicity, protein/peptide-coding capacity and special closed-loop construction, circRNA vaccine, and circRNA-based therapeutic platforms may have superior application prospects in a broad range of diseases.

Lipid nanoparticle-based mRNA delivery systems for cancer immunotherapy

Cancer immunotherapy, which harnesses the power of the immune system, has shown immense promise in the fight against malignancies. Messenger RNA (mRNA) stands as a versatile instrument in this context, with its capacity to encode tumor-associated antigens (TAAs), immune cell receptors, cytokines, and antibodies. Nevertheless, the inherent structural instability of mRNA requires the development of effective delivery systems. Lipid nanoparticles (LNPs) have emerged as significant candidates for mRNA delivery in cancer immunotherapy, providing both protection to the mRNA and enhanced intracellular delivery efficiency. In this review, we offer a comprehensive summary of the recent advancements in LNP-based mRNA delivery systems, with a focus on strategies for optimizing the design and delivery of mRNA-encoded therapeutics in cancer treatment. Furthermore, we delve into the challenges encountered in this field and contemplate future perspectives, aiming to improve the safety and efficacy of LNP-based mRNA cancer immunotherapies.

Delivery platforms for broadly neutralizing antibodies

PURPOSE OF REVIEW

Passive administration of broadly neutralizing antibodies (bNAbs) is being evaluated as a therapeutic approach to prevent or treat HIV infections. However, a number of challenges face the widespread implementation of passive transfer for HIV. To reduce the need of recurrent administrations of bNAbs, gene-based delivery approaches have been developed which overcome the limitations of passive transfer.

RECENT FINDINGS

The use of DNA and mRNA for the delivery of bNAbs has made significant progress. DNA-encoded monoclonal antibodies (DMAbs) have shown great promise in animal models of disease and the underlying DNA-based technology is now being tested in vaccine trials for a variety of indications. The COVID-19 pandemic greatly accelerated the development of mRNA-based technology to induce protective immunity. These advances are now being successfully applied to the delivery of monoclonal antibodies using mRNA in animal models. Delivery of bNAbs using viral vectors, primarily adeno-associated virus (AAV), has shown great promise in preclinical animal models and more recently in human studies. Most recently, advances in genome editing techniques have led to engineering of monoclonal antibody expression from B cells. These efforts aim to turn B cells into a source of evolving antibodies that can improve through repeated exposure to the respective antigen.

SUMMARY

The use of these different platforms for antibody delivery has been demonstrated across a wide range of animal models and disease indications, including HIV. Although each approach has unique strengths and weaknesses, additional advances in efficiency of gene delivery and reduced immunogenicity will be necessary to drive widespread implementation of these technologies. Considering the mounting clinical evidence of the potential of bNAbs for HIV treatment and prevention, overcoming the remaining technical challenges for gene-based bNAb delivery represents a relatively straightforward path towards practical interventions against HIV infection.

Recent Advances in Site-Specific Lipid Nanoparticles for mRNA Delivery

The success of mRNA vaccines during the COVID-19 pandemic has greatly accelerated the development of mRNA therapy. mRNA is a negatively charged nucleic acid that serves as a template for protein synthesis in the ribosome. Despite its utility, the instability of mRNA requires suitable carriers for in vivo delivery. Lipid nanoparticles (LNPs) are employed to protect mRNA from degradation and enhance its intracellular delivery. To further optimize the therapeutic efficacy of mRNA, site-specific LNPs have been developed. Through local or systemic administration, these site-specific LNPs can accumulate in specific organs, tissues, or cells, allowing for the intracellular delivery of mRNA to specific cells and enabling the exertion of local or systemic therapeutic effects. This not only improves the efficiency of mRNA therapy but also reduces off-target adverse effects. In this review, we summarize recent site-specific mRNA delivery strategies, including different organ- or tissue-specific LNP after local injection, and organ-specific or cell-specific LNP after intravenous injection. We also provide an outlook on the prospects of mRNA therapy.