Antibody-Drug Conjugates for Cancer Therapy Hafeez, Umbreen; Parakh, Sagun; Gan, Hui K ...
Molecules (Basel, Switzerland),
10/2020, Letnik:
25, Številka:
20
Journal Article
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Antibody-drug conjugates (ADCs) are novel drugs that exploit the specificity of a monoclonal antibody (mAb) to reach target antigens expressed on cancer cells for the delivery of a potent cytotoxic ...payload. ADCs provide a unique opportunity to deliver drugs to tumor cells while minimizing toxicity to normal tissue, achieving wider therapeutic windows and enhanced pharmacokinetic/pharmacodynamic properties. To date, nine ADCs have been approved by the FDA and more than 80 ADCs are under clinical development worldwide. In this paper, we provide an overview of the biology and chemistry of each component of ADC design. We briefly discuss the clinical experience with approved ADCs and the various pathways involved in ADC resistance. We conclude with perspectives about the future development of the next generations of ADCs, including the role of molecular imaging in drug development.
The epidermal growth factor receptor (EGFR) is overexpressed in a variety of human epithelial tumors, often as a consequence of gene amplification. Tumors with EGFR gene amplification frequently ...contain EGFR gene rearrangements, with the most common extracellular domain mutation being EGFRvIII. This mutation leads to a deletion of exons 2–7 of the EGFR gene and renders the mutant receptor incapable of binding any known ligand. Despite this, EGFRvIII displays low‐level constitutive signaling that is augmented by reduced internalization and downregulation. Aberrant EGFRvIII signaling has been shown to be important in driving tumor progression and often correlates with poor prognosis. It is clear that EGFRvIII is expressed in a considerable proportion of patients with glioblastoma multiforme (GBM). The presence of EGFRvIII in other tumor types, however, remains controversial. In this review, we critically analyze the evidence for the expression of EGFRvIII in a range of tumor types and discuss recent findings pertinent to its function and biology in GBM.
Tumors with EGFR gene amplification frequently contain EGFR gene rearrangements, with the most common extracellular domain mutation being EGFRvIII. This EGFR deletion mutation is incapable of binding ligand, yet EGFRvIII displays low‐level constitutive signaling augmented by reduced internalization. We analyze the evidence for EGFRvIII expression in different tumor types and discuss recent findings regarding its tumorigenic properties in brain cancer.
•Monoclonal antibodies are effective treatment for various cancers and autoimmune diseases.•Immune checkpoint therapy in cancer has emerged as a potent therapeutic approach.•Autoimmune disease ...control with monoclonal antibodies is highly successful.•Resistance mechanisms have emerged as a major issue in therapeutic efficacy.
Since Nobel laureate Paul Ehrlich proposed the concept of magic bullet in 1906, Köhler and Milstein discovered Hybridoma technology in 1975, and Greg Winter pioneered the technique to humanize monoclonal antibodies in 1988, monoclonal antibodies have been successfully developed to treat medical illnesses. Monoclonal antibodies are effective treatments for inhibition of alloimmune reactivity, haematological malignancies, solid organ malignancies, viral illnesses and are also used as antiplatelet therapy. Their successful use in cancer and autoimmune diseases in humans have made them one of the fastest growing classes of new drugs approved for these indications in last few decades. This review focuses on the role of monoclonal antibodies as an immunomodulatory therapy against cancer and autoimmune diseases, the strategies used to enhance efficacy, and how resistance mechanisms are being addressed to improve therapeutic outcomes for patients.
Radioimmunoconjugates consist of a monoclonal antibody (mAb) linked to a radionuclide. Radioimmunoconjugates as theranostics tools have been in development with success, particularly in hematological ...malignancies, leading to approval by the US Food and Drug Administration (FDA) for the treatment of non-Hodgkin's lymphoma. Radioimmunotherapy (RIT) allows for reduced toxicity compared to conventional radiation therapy and enhances the efficacy of mAbs. In addition, using radiolabeled mAbs with imaging methods provides critical information on the pharmacokinetics and pharmacodynamics of therapeutic agents with direct relevance to the optimization of the dose and dosing schedule, real-time antigen quantitation, antigen heterogeneity, and dynamic antigen changes. All of these parameters are critical in predicting treatment responses and identifying patients who are most likely to benefit from treatment. Historically, RITs have been less effective in solid tumors; however, several strategies are being investigated to improve their therapeutic index, including targeting patients with minimal disease burden; using pre-targeting strategies, newer radionuclides, and improved labeling techniques; and using combined modalities and locoregional application. This review provides an overview of the radiolabeled intact antibodies currently in clinical use and those in development.
Glioblastomas are high-grade brain tumours with a poor prognosis and, currently, few available therapeutic options. This lack of effective treatments has been linked to diverse factors, including ...target selection, tumour heterogeneity and poor penetrance of therapeutic agents through the blood-brain barrier and into tumours. Therapies using monoclonal antibodies, alone or linked to cytotoxic payloads, have proved beneficial for patients with different solid tumours; these approaches are currently being explored in patients with glioblastoma. In this Review, we summarise clinical data regarding antibody-drug conjugates (ADCs) against a variety of targets in glioblastoma, and compare the efficacy and toxicity of targeting EGFR with ADCs versus naked antibodies in order to illustrate key aspects of the use of ADCs in this malignancy. Finally, we discuss the complex challenges related to the biology and mutational changes of glioblastoma that can affect the use of ADC-based therapies in patients with this disease, and highlight potential strategies to improve efficacy.
Abstract Glioblastoma multiforme (GBM) is the most common brain tumour and has the worst prognosis. Epidermal growth factor receptor (EGFR) gene amplification, mutation and re-arrangement (all of ...which enhance tumour growth, survival, progression and resistance to therapy) are frequently observed in primary GBM. The most common EGFR variant in GBM, the EGFRvIII, is characterised by a deletion of 267 amino acids in the extracellular domain, leading to a receptor which is unable to bind ligand yet is constitutively active. Together with its impaired internalisation and degradation, the EGFRvIII enhances the tumourigenic potential of GBM by activating and sustaining mitogenic, anti-apoptotic and pro-invasive signalling pathways. This EGFRvIII-mediated enhanced tumourigenicity combined with the lack of EGFRvIII expression in normal tissue makes it an ideal candidate for targeted therapy. This review summarizes the current knowledge about the role of EGFRvIII in GBM and discusses therapeutic agents targeting EGFRvIII that are being evaluated as treatments for GBM.
Purpose
This review compares reirradiation (reRT), systemic therapy and combination therapy (reRT & systemic therapy) with regards to overall survival (OS), progression-free survival (PFS), adverse ...effects (AEs) and quality of life (QoL) in patients with recurrent high-grade glioma (rHGG).
Methods
A search was performed on PubMed, Scopus, Embase and CENTRAL. Studies reporting OS, PFS, AEs and/or QoL and encompassing the following groups were included; reirradiation vs systemic therapy, combination therapy vs systemic therapy, combination therapy vs reRT, and bevacizumab-based combination therapy vs reRT with/without non-bevacizumab-based systemic therapy. Meta-analyses were performed utilising a random effects model. Certainty of evidence was assessed using GRADE.
Results
Thirty-one studies (three randomised, twenty-eight non-randomised) comprising 2084 participants were included. In the combination therapy vs systemic therapy group, combination therapy improved PFS (HR 0.57 (95% CI 0.41–0.79); low certainty) and OS (HR 0.73 (95% CI 0.56–0.95); low certainty) and there was no difference in grade 3 + AEs (RR 1.03 (95% CI 0.57–1.86); very low certainty). In the combination therapy vs reRT group, combination therapy improved PFS (HR 0.52 (95% CI 0.38–0.72); low certainty) and OS (HR 0.69 (95% CI 0.52–0.93); low certainty). In the bevacizumab-based combination therapy vs reRT with/without non-bevacizumab-based systemic therapy group, adding bevacizumab improved PFS (HR 0.46 (95% CI 0.27–0.77); low certainty) and OS (HR 0.42 (95% CI 0.24–0.72; low certainty) and reduced radionecrosis (RR 0.17 (95% CI 0.06–0.48); low certainty).
Conclusions
Combination therapy may improve OS and PFS with acceptable toxicities in patients with rHGG compared to reRT or systemic therapy alone. Particularly, combining bevacizumab with reRT prophylactically reduces radionecrosis.
Registration
: CRD42022291741.
The Consolidated Standards of Reporting Trials (CONSORT) guidance was extended in 2004 to provide a set of 10 specific and comprehensive guidelines regarding adverse event (AE) reporting in ...randomized clinical trials (RCTs). Limited data exist regarding adherence to these guidelines in publications of oncology RCTs.
All phase III RCTs published between 2007 and 2011 were reviewed using a 16-point AE reporting quality score (AERQS) based on the 2004 CONSORT extension. Multivariable linear regression was used to identify features associated with improved reporting quality.
A total of 325 RCTs were reviewed. The mean AERQS was 10.1 on a 16-point scale. The most common items that were poorly reported were the methodology of AE collection (adequately reported in only 10% of studies), the description of AE characteristics leading to withdrawals (15%), and whether AEs are attributed to trial interventions (38%). Even when reported, the methods of AE collection and analysis were highly heterogeneous. The multivariable regression model revealed that industry funding, intercontinental trials, and trials in the metastatic setting were predictors of higher AERQS. The quality of AE reporting did not improve significantly over time and was not better among articles published in journals with a high impact factor.
Our findings show that some methodologic aspects of AE collection and analysis were poorly reported. Given the importance of AEs in evaluating new treatments, authors should be encouraged to adhere to the 2004 CONSORT guidelines regarding AE reporting.
Epidermal growth factor receptor (EGFR) and its most common extracellular mutant, EGFRvIII, are important therapeutic targets in multiple cancer types. A number of monoclonal antibodies and ...small-molecule inhibitors against these receptors are now used for anticancer treatments. New insights into the structure and function of these receptors illustrate how they can be targeted in novel ways, with expected improvements in the therapeutic efficacy. Monoclonal antibody 806 (mAb806) is an antibody that targets a conformationally exposed epitope of wild-type EGFR when it is overexpressed on tumor cells or in the presence of oncogenic mutations such as EGFRvIII. The mechanism of action of mAb806, which allows for EGFR inhibition without normal tissue toxicity, creates opportunities for combination therapy and strongly suggests mAb806 will be a superior targeted delivery system for antitumor agents. Targeting of the epitope for mAb806 also appears to be an improved strategy to inhibit tumors that express EGFRvIII. This concept of conformational epitope targeting by antibodies reflects an underlying interplay between the structure and biology of different conformational forms of the EGFR family.
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