Monoclonal Antibodies in Cancer Therapy: Mechanisms, Successes and Limitations

Gene therapy in glioblastoma multiforme: Can it be a role changer?

Glioblastoma multiforme (GBM) is one of the most lethal cancers with a poor prognosis. Over the past century since its initial discovery and medical description, the development of effective treatments for this condition has seen limited progress. Despite numerous efforts, only a handful of drugs have gained approval for its treatment. However, these treatments have not yielded substantial improvements in both overall survival and progression-free survival rates. One reason for this is its unique features such as heterogeneity and difficulty of drug delivery because of two formidable barriers, namely the blood-brain barrier and the tumor-blood barrier. Over the past few years, significant developments in therapeutic approaches have given rise to promising novel and advanced therapies. Target-specific therapies, such as monoclonal antibodies (mAbs) and small molecules, stand as two important examples; however, they have not yielded a significant improvement in survival among GBM patients. Gene therapy, a relatively nascent advanced approach, holds promise as a potential treatment for cancer, particularly GBM. It possesses the potential to address the limitations of previous treatments and even newer advanced therapies like mAbs, owing to its distinct properties. This review aims to elucidate the current status and advancements in gene therapy for GBM treatment, while also presenting its future prospects.

Monoclonal Antibodies and Antibody-drug Conjugates as Emerging Therapeutics for Breast Cancer Treatment

When breast cells divide and multiply out of control, it is called breast cancer. Symptoms include lump formation in the breast, a change in the texture or color of the breast, or a discharge from the nipple. Local or systemic therapy is frequently used to treat breast cancer. Surgical and radiation procedures limited to the affected area are examples of local management. There has been significant worldwide progress in the development of monoclonal antibodies (mAbs) since 1986, when the first therapeutic mAb, Orthoclone OKT3, became commercially available. mAbs can resist the expansion of cancer cells by inducing the destruction of cellular membranes, blocking immune system inhibitors, and preventing the formation of new blood vessels. mAbs can also target growth factor receptors. Understanding the molecular pathways involved in tumor growth and its microenvironment is crucial for developing effective targeted cancer therapeutics. Due to their unique properties, mAbs have a wide range of clinical applications. Antibody-drug conjugates (ADCs) are drugs that improve the therapeutic index by combining an antigen-specific antibody with a payload. This review focuses on the therapeutic applications, mechanistic insights, characteristics, safety aspects, and adverse events of mAbs like trastuzumab, bevacizumab, pertuzumab, ertumaxomab, and atezolizumab in breast cancer treatment. The creation of novel technologies utilizing modified antibodies, such as fragments, conjugates, and multi-specific antibodies, must be a central focus of future studies. This review will help scientists working on developing mAbs to treat cancers more effectively.

Targeting allosteric binding site in methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) to identify natural product inhibitors via structure-based computational approach

Cancer has been viewed as one of the deadliest diseases worldwide. Among various types of cancer, breast cancer is the most common type of cancer in women. Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is a promising druggable target and is overexpressed in cancerous cells, like, breast cancer. We conducted structure-based modeling on the allosteric site of the enzyme. Targeting the allosteric site avoids the problem of drug resistance. Pharmacophore modeling, molecular docking, HYDE assessment, drug-likeness, ADMET predictions, simulations, and free-energy calculations were performed. The RMSD, RMSF, RoG, SASA, and Hydrogen-bonding studies showed that seven candidates displayed stable behaviour. As per the literature, average superimposed simulated structures revealed a similar protein conformational change in the αE'-βf' loop, causing its displacement away from the allosteric site. The MM-PBSA showed tight binding of six compounds with the allosteric pocket. The effect of inhibitors interacting in the allosteric site causes a decrease in the binding energy of J49 (active-site inhibitor), suggesting the effect of allosteric binding. The PCA and FEL analysis revealed the significance of the docked compounds in the stable behaviour of the complexes. The outcome can contribute to the development of potential natural products with drug-like properties that can inhibit the MTHFD2 enzyme.

Computational design of a chimeric toxin against Claudin-4-expressing cancer cells: molecular modeling, docking and molecular dynamics simulation analysis

Cancer is one of the main reasons of mortality all over the world. Over the time, the major ways for cancer-therapy were based on radiotherapy, chemotherapy and surgery. These methods are not specific enough for that purpose, therefore, new ideas for design of new drugs with higher specificity are considered. Chimeric protein toxins are hybrid proteins consisting of a targeting portion and a toxic one which specifically bind and kill the target cancer cells. The main purpose of this study was designing a recombinant chimeric toxin with biding capability to one of the most key receptors namely claudin-4 which is over-expressed in almost all cancer cells. To design it, we utilized the last 30 C-terminal amino acids of Clostridium perfringens enterotoxin (CPE) as a binding module for claudin-4 and the toxic module which is the A-domain of Shiga toxin from Shigella dysenteriae. Using molecular modeling and docking methods, appropriate binding affinity of the recombinant chimeric toxin to its specific receptor was demonstrated. In the next step, the stability of this interaction was investigated by molecular dynamics simulation. Although partial instability was detected at some time points, however, sufficient stable situation of hydrogens bonds and high binding affinity between the chimeric toxin and receptor were observed in the in silico studies which in turn suggested that this complex could be formed successfully.

Harnessing the immune system against cancer: current immunotherapy approaches and therapeutic targets

Cancer immunotherapy is a rapidly evolving concept that has been given the tag "fifth pillar" of cancer therapy while radiation therapy, chemotherapy, surgery and targeted therapy remain the other four pillars. This involves the stimulation of the immune system to control tumor growth and it specifically targets the neoplastic cells rather than the normal cells. Conventional chemotherapy has many limitations which include drug resistance, recurrence of cancer and severe adverse effects. Immunology has made major treatment breakthroughs for several cancers such as colorectal cancer, prostate cancer, breast cancer, lung cancer, liver cancer, kidney cancer, stomach cancer, acute lymphoblastic leukaemia etc. Currently, therapeutic strategies harnessing the immune system involve Checkpoint inhibitors, Chimeric antigen receptor T cells (CAR T cells), Monoclonal antibodies, Cancer vaccines, Cytokines, Radio-immunotherapy and Oncolytic virus therapy. The molecular characterization of several tumor antigens (TA) indicates that these TA can be utilized as promising candidates in cancer immunotherapy strategies. Here in this review, we highlight and summarize the different categories of emerging cancer immunotherapies along with the immunologically recognized tumor antigens involved in the tumor microenvironment.

The Epithelial-Mesenchymal Transition Influences the Resistance of Oral Squamous Cell Carcinoma to Monoclonal Antibodies via Its Effect on Energy Homeostasis and the Tumor Microenvironment

Oral squamous cell carcinoma (OSCC) is a major type of cancer that accounts for over 90% of all oral cancer cases. Recently developed evidence-based therapeutic regimens for OSCC based on monoclonal antibodies (mAbs), such as cetuximab, pembrolizumab, and nivolumab, have attracted considerable attention worldwide due to their high specificity, low toxicity, and low rates of intolerance. However, the efficacy of those three mAbs remains poor because of the low rate of responders and acquired resistance within a short period of time. The epithelial-mesenchymal transition (EMT) process is fundamental for OSCC growth and metastasis and is also responsible for the poor response to mAbs. During EMT, cancer cells consume abundant energy substrates and create an immunosuppressive tumor microenvironment to support their growth and evade T cells. In this review, we provide an overview of the complex roles of major substrates and signaling pathways involved in the development of therapeutic resistance in OSCC. In addition, we summarize potential therapeutic strategies that may help overcome this resistance. This review aims to help oral oncologists and researchers aiming to manage OSCC and establish new treatment modalities.

Engineering a cell-penetrating hyperstable antibody scFv(Ras) - An extraordinary approach to cancer therapeutics

In the modern pharmaceutical industry, monoclonal antibodies are often used as therapeutic agents. However, they are restricted to cell surface antigens due to their inability to penetrate the outer cell membrane and maintain normal function in the reducing environment. Additionally, it can lead to cytotoxicity since it attacks cancerous cells by mimicking the human immune system. As an alternative, this study modifies the hyperstable single-chain fragment variable(scFv) antibody to eliminate cancer using its linear shape. The scFv(F8) antibody model was modified to recognize human Ras protein by altering residues in the antigen-binding site. Furthermore, a cell-penetrating peptide (CPP) was attached to the scFv(Ras) antibody model to allow entrance to the cell, creating CPP-scFv(Ras). Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE), western blotting, and the binding assay were performed to prove its effectiveness. As a result, CPP-scFv(Ras) was successfully engineered and bound to the antigen, HRas(G12V).

Keeping Myeloma in Check: The Past, Present and Future of Immunotherapy in Multiple Myeloma

Multiple myeloma is an incurable disease of malignant plasma cells and an ideal target for modern immune therapy. The unique plasma cell biology maintained in multiple myeloma, coupled with its hematological nature and unique bone marrow microenvironment, provide an opportunity to design specifically targeted immunotherapies that selectively kill transformed cells with limited on-target off-tumor effects. Broadly defined, immune therapy is the utilization of the immune system and immune agents to treat a disease. In the context of multiple myeloma, immune therapy can be subdivided into four main categories: immune modulatory imide drugs, targeted antibodies, adoptive cell transfer therapies, and vaccines. In recent years, advances in all four of these categories have led to improved therapies with enhanced antitumor activity and specificity. In IMiDs, modified chemical structures have been developed that improve drug potency while reducing dose limiting side effects. Targeted antibody therapies have resulted from the development of new selectively expressed targets as well as the development of antibody drug conjugates and bispecific antibodies. Adoptive cell therapies, particularly CAR-T therapies, have been enhanced through improvements in the manufacturing process, as well as through the development of CAR constructs that enhance CAR-T activation and provide protection from a suppressive immune microenvironment. This review will first cover in-class breakthrough therapies for each of these categories, as well as therapies currently utilized in the clinic. Additionally, this review will explore up and coming therapeutics in the preclinical and clinical trial stage.

Insights from IgE Immune Surveillance in Allergy and Cancer for Anti-Tumour IgE Treatments

IgE, the predominant antibody class of the allergic response, is known for its roles in protecting against parasites; however, a growing body of evidence indicates a significant role for IgE and its associated effector cells in tumour immunosurveillance, highlighted by the field of AllergoOncology and the successes of the first-in-class IgE cancer therapeutic MOv18. Supporting this concept, substantial epidemiological data ascribe potential roles for IgE, allergy, and atopy in protecting against specific tumour types, with a corresponding increased cancer risk associated with IgE immunodeficiency. Here, we consider how epidemiological data in combination with functional data reveals a complex interplay of IgE and allergy with cancer, which cannot be explained solely by one of the existing conventional hypotheses. We furthermore discuss how, in turn, such data may be used to inform future therapeutic approaches, including the clinical management of different patient groups. With epidemiological findings highlighting several high-risk cancer types protected against by high IgE levels, it is possible that use of IgE-based therapeutics for a range of malignant indications may offer efficacy to complement that of established IgG-class antibodies.

Molecules and Mechanisms to Overcome Oxidative Stress Inducing Cardiovascular Disease in Cancer Patients

Reactive oxygen species (ROS) are molecules involved in signal transduction pathways with both beneficial and detrimental effects on human cells. ROS are generated by many cellular processes including mitochondrial respiration, metabolism and enzymatic activities. In physiological conditions, ROS levels are well-balanced by antioxidative detoxification systems. In contrast, in pathological conditions such as cardiovascular, neurological and cancer diseases, ROS production exceeds the antioxidative detoxification capacity of cells, leading to cellular damages and death. In this review, we will first describe the biology and mechanisms of ROS mediated oxidative stress in cardiovascular disease. Second, we will review the role of oxidative stress mediated by oncological treatments in inducing cardiovascular disease. Lastly, we will discuss the strategies that potentially counteract the oxidative stress in order to fight the onset and progression of cardiovascular disease, including that induced by oncological treatments.

Plant-Produced Monoclonal Antibody as Immunotherapy for Cancer

Plant-based products have expanded to include cancer immunotherapy, which has made great strides over recent years. Plants are considered inexpensive and facile production platforms for recombinant monoclonal antibody (mAb) due to the latest advancements and diversification of transgenic techniques. Current human biologics, including those based on mAbs produced by fermentation technologies using primarily mammalian cell cultures, have been replaced by plant-produced mAbs, which are cost effective, more scalable, speedy, versatile, and safer. Moreover, the use of animals for antibody production is always a question of ethical unambiguity, and the suitability of animal models for predicting the immunogenicity of therapeutic mAbs in humans and transposition of the immunogenic potential of therapeutic antibodies in animals to the human situation has no scientific rationale. Quite a few plant-based mAbs are approved for the treatment of cancer, ranging from tumors to hematological malignancies. This review focuses on the cutting-edge approaches for using plant-derived mAbs to suppress or prevent cancers. It also discusses the avenues taken to prevent infection by oncogenic viruses, solid tumors, lymphomas, and other cancerous conditions using mAbs. The review emphasizes the use of a plant-derived monoclonal antibody as a premier platform to combat cancer.

Cancer immunotherapy: dawn of the death of cancer?

Cancer is one of the proficient evaders of the immune system which claims millions of lives every year. Developing therapeutics against cancer is extremely challenging as cancer involves aberrations in self, most of which are not detected by the immune system. Conventional therapeutics like chemotherapy, radiotherapy are not only toxic but they significantly lower the quality of life. Immunotherapy, which gained momentum in the 20th century, is emerging as one of the alternatives to the conventional therapies and is relatively less harmful but more costly. This review explores the modern advances in an array of such therapies and try to compare them along with a limited analysis of concerns associated with them.

Clinicopathological and prognostic significance and molecular mechanisms governing uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Although UM and cutaneous melanoma are derived from melanocytes, UM differs clinically and biologically from its more common skin counterparts. More than half of primary UMs metastasize. However, there is currently no effective treatment for metastatic UM. Therefore, studying mutations related to the metastasis, growth, proliferation, and survival of UM can help researchers understand its pathogenesis and metastatic mechanism, thereby leading to a more effective treatment. In addition, we provide an overview of the recent basic and clinical studies to provide a strong foundation for developing novel anti-carcinogenesis targets for future interventions.

A Proposed Treatment Approach to Treat Lethal Mutating Cancers

A proposed treatment using dual-peptide ligand masks, that are functional extensions to existing analogous mammalian immune system structures, to bind to cancer cell surface proteins and stop mutating cancers that could evade presently used engineered immune cell therapies. One treatment injects the dual-peptide ligand masks into the blood stream of patients, and another treatment injects the dual-peptide ligand masks into localized cancers to bind to cancer cell surface proteins. The mammalian immune system has long used analogous, but more complex structures called pentraxins to physically link various types of pathogens to immune cells for neutralization. This treatment approach offers potential advantages in increased binding adaptability to mutations in the surface proteins of cancer cells, and potentially lower treatment cost compared to engineered immune cell treatments against cancer, especially against mutating cancer cells, even compared to extremely specific and costly monoclonal antibody treatments or engineered T cell treatments.

Safety-Related Regulatory Actions and Risk Factors for Anticancer Drugs in Japan

INTRODUCTION

The approval of anticancer drugs in Japan has increased to meet high medical demand. To maximize the benefits of anticancer drugs, adverse drug reactions (ADRs) must be properly managed. However, in some cases, clinically significant safety issues are detected after launch, and safety-related regulatory actions (SRRAs) are implemented.

OBJECTIVES

We aimed to determine the characteristics of SRRAs for anticancer drugs approved in Japan and to identify factors related to the drug development and regulatory approval process associated with the occurrence of an SRRA.

METHODS

We defined an SRRA as the issuance of a 'Yellow Letter', 'Blue Letter', or an official notification by the Ministry of Health, Labor and Welfare. Anticancer drugs approved in Japan as new active ingredients from April 2004 to July 2016 were analyzed using publicly available information. The Kaplan-Meier survival curve was plotted to estimate the probability of the occurrence of an SRRA, and the Cox proportional hazards model was used to identify risk factors associated with the occurrence of an SRRA. Independent variables were selected using backward/forward stepwise selection according to Akaike's Information Criterion.

RESULTS

An SRRA was implemented for 38 of 63 anticancer drugs. Approximately 70% of SRRAs occurred within 2 years after approval, and the median time between approval and the occurrence of an SRRA was 1.6 years (interquartile range 0.94-2.4). No Yellow Letter was issued during the follow-up period; however, one Blue Letter was issued for 'acute lung injury and interstitial pneumonia' for sorafenib. According to official notifications, 'clinically significant adverse reactions' was the most revised section of package inserts (62%). The probability of an SRRA at the 1-, 2- and 3-year follow-up was 15.9% (95% confidence interval [CI] 6.4-24.4%), 41.3% (95% CI 27.8-52.3%), and 56.8% (95% CI 41.8-68.0%), respectively. Monoclonal antibodies were associated with a low risk of occurrence of an SRRA (hazard ratio [HR] 0.29, p = 0.019), while the large number of patients in pivotal studies (per 100 patients) was associated with a high risk of occurrence (HR 1.07, p = 0.012).

CONCLUSIONS

The high-risk period for the occurrence of an SRRA for anticancer drugs in Japan was within 2 years after approval. Among the factors related to the drug development and regulatory approval process, anticancer drugs in the form of non-monoclonal antibodies, and whose pivotal studies included a large number of patients, were more likely to be associated with an SRRA. Postmarketing follow-up should therefore be carefully performed, especially in the first 2 years after approval and for non-monoclonal antibody anticancer drugs. Moreover, postmarketing follow-up is crucial, even if large-scale pivotal studies for regulatory approval have already been performed.

The Pivotal Roles of the Epithelial Membrane Protein Family in Cancer Invasiveness and Metastasis

The members of the family of epithelial membrane proteins (EMPs), EMP1, EMP2, and EMP3, possess four putative transmembrane domain structures and are composed of approximately 160 amino acid residues. EMPs are encoded by the growth arrest-specific 3 (GAS3)/peripheral myelin protein 22 kDa (PMP22) gene family. The GAS3/PMP22 family members play roles in cell migration, growth, and differentiation. Evidence indicates an association of these molecules with cancer progression and metastasis. Each EMP has pro- and anti-metastatic functions that are likely involved in the complex mechanisms of cancer progression. We have recently demonstrated that the upregulation of EMP1 expression facilitates cancer cell migration and invasion through the activation of a small GTPase, Rac1. The inoculation of prostate cancer cells overexpressing EMP1 into nude mice leads to metastasis to the lymph nodes and lungs, indicating that EMP1 contributes to metastasis. Pro-metastatic properties of EMP2 and EMP3 have also been proposed. Thus, targeting EMPs may provide new insights into their clinical utility. Here, we highlight the important aspects of EMPs in cancer biology, particularly invasiveness and metastasis, and describe recent therapeutic approaches.

Pharmacogenetics of anticancer monoclonal antibodies

Pharmacogenetics is the study of therapeutic and adverse responses to drugs based on an individual’s genetic background. Monoclonal antibodies (mAbs) are a rapidly evolving field in cancer therapy, however a number of newly developed and highly effective mAbs (e.g., anti-CTLA-4 and anti-PD-1) possess pharmacogenomic profiles that remain largely undefined. Since the first chemotherapeutic mAb Rituximab was approved in 1997 by the US Food and Drug Administration for cancer treatment, a broad number of other mAbs have been successfully developed and implemented into oncological practice. Nowadays, mAbs are considered as one of the most promising new approaches for cancer treatment. The efficacy of mAb treatment can however be significantly affected by genetic background, where genes responsible for antibody presentation and metabolism, for example, can seriously affect patient outcome. This review will focus on current anticancer mAb treatments, patient genetics that shape their efficacy, and the molecular pathways that bridge the two.

Drug discovery of anticancer drugs targeting methylenetetrahydrofolate dehydrogenase 2

Many anticancer drugs have serious adverse effects; therefore, it is necessary to target features specific to cancer cells to minimize the effects on healthy cells. Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) was reported to be specifically enhanced in cancer. We confirmed the validity of MTHFD2 as a drug discovery target using clinical data. In addition, we performed in silico screening to design an anticancer drug specifically targeting MTHFD2. Analysis of the clinical data indicated that MTHFD2 was enhanced in most cancers compared with normal tissues, and affected the prognosis in cancer patients. Candidate compounds for MTHFD2 inhibitors were identified using in silico drug discovery techniques, and the important interactions for MTHFD2 binding were determined. In addition, these candidate compounds decreased levels of MTHFD2 metabolites in cancer cells. The findings of the present study may help to develop anticancer drugs targeting MTHFD2, with a view to minimizing the adverse effects of anticancer drugs.

Conservation of oncofetal antigens on human embryonic stem cells enables discovery of monoclonal antibodies against cancer

Monoclonal antibodies (mAbs) are used as targeted therapies against cancers. These mAbs kill cancer cells via various mechanisms of actions. In this study, human embryonic stem cells (hESCs) was used as the immunogen to generate a panel of antibodies. From this panel of mAbs, A19 was found to bind both hESC and various cancer cell lines. The antigen target of A19 was identified as Erbb-2 and glycan analysis showed that A19 binds to a N-glycan epitope on the antigen. A19 was elucidated to internalize into cancer cells following binding to Erbb-2 and hence developed as an antibody-drug conjugate (ADC). Using ADC as the mechanism of action, A19 was able to kill cancer cells in vitro and delayed the onset of tumour formation in mice xenograft model. When compared to Herceptin, A19 binds to different isoforms of Erbb-2 and does not compete with Herceptin for the same epitope. Hence, A19 has the potential to be developed as an alternative targeted therapeutic agent for cancers expressing Erbb-2.

Challenges and new frontiers in analytical characterization of antibody-drug conjugates

Antibody-drug conjugates (ADCs) are a growing class of biotherapeutics in which a potent small molecule is linked to an antibody. ADCs are highly complex and structurally heterogeneous, typically containing numerous product-related species. One of the most impactful steps in ADC development is the identification of critical quality attributes to determine product characteristics that may affect safety and efficacy. However, due to the additional complexity of ADCs relative to the parent antibodies, establishing a solid understanding of the major quality attributes and determining their criticality are a major undertaking in ADC development. Here, we review the development challenges, especially for reliable detection of quality attributes, citing literature and new data from our laboratories, highlight recent improvements in major analytical techniques for ADC characterization and control, and discuss newer techniques, such as two-dimensional liquid chromatography, that have potential to be included in analytical control strategies.