Abstract 2901: Gastric cancer antibody fragment drug-conjugates (FDCs): From concept to clinical development

2020 ◽  
Author(s):  
Mahendra P. Deonarain ◽  
Gokhan Yahioglu ◽  
ioanna Stamati ◽  
Bryan Edwards ◽  
Soraya Diez-Posada ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Antibody Fragment ◽  
Clinical Development ◽  
Drug Conjugates

Antibody-Drug-Conjugates for Breast Cancer

2021 ◽  
Author(s):  
Frederik Marmé
Keyword(s):  
Breast Cancer ◽  
Bystander Effect ◽  
Systemic Exposure ◽  
Clinical Development ◽  
Therapeutic Window ◽  
Target Cells ◽  
Magic Bullet ◽  
Antibody Drug Conjugates ◽  
Drug Conjugates ◽  
Antibody Drug

Background Despite the advances that have been made to improve conventional chemotherapies, their use is limited by a narrow therapeutic window based on off-target toxicities. Antibody-drug-conjugates (ADCs) are composed of an antibody and a toxic payload covalently coupled by a chemical linker. They constitute an elegant means to tackle the limitations of conventional chemotherapeutics by selectively delivering a highly toxic payload directly to target cells and thereby increasing efficacy of the delivered cytotoxic but at the same time limiting systemic exposure and toxicities. As such they appear inspired by Paul Ehrlich´s concept of a “magic bullet”, which he envisioned as drugs that go directly to their target to attack pathogens but remain harmless in healthy tissues. Summary The concept of conjugating drugs to antibodies via chemical linkers is not new. As early as in the 1960s researchers started to investigate such ADCs in animal models and first clinical trials based on mouse antibodies began in the 1980s. Although the concept appears relatively straightforward, ADCs are highly complex molecules, and it took several decades of research and development until the first ADC became approved by the FDA in 2000 and the second followed not until 11 years later. The development of an effective ADC is highly demanding, and each individual component of an ADC must be optimized: the target, the antibody, the linker and its conjugation chemistry as well as the cytotoxic payload. Today there are 9 approved ADCs overall and 3 for breast cancer. So, the pace of development seems to pick up with over 100 candidates in various stages of clinical development. Many ADCs of the newest generation are optimized to elicit a so-called bystander effect, to increase efficacy and tackle heterogneous antigen expression. This approach requires a balancing of efficacy and systemic toxicity. Hence, ADCs based on their complex biology cause relevant toxicities, which are characteristic for each specific compound and may include hematologic toxicities, elevated transaminases, gastrointestinal events, pneumonitis but also ocular toxicities as well as others many physicians may initially not be very familiar with. Management of the side effects will be key to the successful clinical use of these potent drugs. Key Messages This review focusses on the clinical experience with ADCs approved in breast cancer as well as promising candidates in late-stage clinical development. We will discuss the mode of action, biology, and composition of ADCs and how each of these crucial components influences their properties and efficacy.

scholarly journals Antibody–Drug Conjugates for Cancer Therapy

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4764
Author(s):  
Umbreen Hafeez ◽  
Sagun Parakh ◽  
Hui K. Gan ◽  
Andrew M. Scott
Keyword(s):  
Monoclonal Antibody ◽  
Molecular Imaging ◽  
Cancer Therapy ◽  
Normal Tissue ◽  
Clinical Development ◽  
Antibody Drug Conjugates ◽  
Drug Conjugates ◽  
Novel Drugs ◽  
Antibody Drug

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.

Cancer-targeting Antibody–Drug Conjugates: Site-specific Conjugation of Doxorubicin to Anti-EGFR 528 Fab' through a Polyethylene Glycol Linker

2011 ◽  
Vol 64 (6) ◽  
pp. 779 ◽  
Author(s):  
Lisa P. T. Hong ◽  
Judith A. Scoble ◽  
Larissa Doughty ◽  
Gregory Coia ◽  
Charlotte C. Williams
Keyword(s):  
Polyethylene Glycol ◽  
Growth Factor Receptor ◽  
Antibody Fragment ◽  
Aqueous Solubility ◽  
Cancer Targeting ◽  
Antibody Activity ◽  
Antibody Drug Conjugates ◽  
Drug Conjugates ◽  
Epidermal Growth ◽  
Antibody Drug

Antibody–drug conjugates have been prepared to examine the effect that attaching small-molecule drugs to an antibody fragment has on antibody activity. The anticancer drug doxorubicin was covalently attached through a polyethylene glycol linker to a cancer-targeting, anti-epidermal growth factor receptor antibody fragment (Fab′). The reactivity of maleimide was compared with a substituted maleimide derivative (citraconimide) in conjugation reactions with cysteine residues on a Fab′. Introduction of polyethylene glycol increased aqueous solubility of the cytotoxic drug, which led to an improvement in overall yield of the conjugation reaction with the antibody fragment. Antibody–drug conjugates prepared retained activity of the parent antibody, as determined by antigen binding experiments measured by surface plasmon resonance.

scholarly journals Dual site-specific chemoenzymatic antibody fragment conjugation using CRISPR-based hybridoma engineering

2020 ◽  
Author(s):  
Camille M. Le Gall ◽  
Johan M.S. van der Schoot ◽  
Iván Ramos-Tomillero ◽  
Melek Parlak Khalily ◽  
Floris J. van Dalen ◽  
...  
Keyword(s):  
Antibody Fragment ◽  
Therapeutic Index ◽  
Stable Cell Line ◽  
Hybridoma Cells ◽  
Target Cells ◽  
Site Specific ◽  
Drug Conjugates ◽  
High Yields ◽  
A Site

I.AbstractFunctionalized antibodies and antibody fragments have found applications in the fields of biomedical imaging, theragnostics, and antibody-drug conjugates (ADC). Antibody functionalization is classically achieved by coupling payloads onto lysine or cysteine residues. However, such stochastic strategies typically lead to heterogenous products, bearing a varying number of payloads. This affects bioconjugate efficacy and stability, as well as its in vivo biodistribution, and therapeutic index, while potentially obstructing the binding sites and leading to off-target toxicity. In addition, therapeutic and theragnostic approaches benefit from the possibility to deliver more than one type of cargo to target cells, further challenging stochastic labelling strategies. Thus, bioconjugation methods to reproducibly obtain defined homogenous conjugates bearing multiple different cargo molecules, without compromising target affinity, are in demand. Here, we describe a straightforward CRISPR/Cas9-based strategy to rapidly engineer hybridoma cells to secrete Fab’ fragments bearing two distinct site-specific labelling motifs, which can be separately modified by two different sortase A mutants. We show that sequential genetic editing of the heavy chain (HC) and light chain (LC) loci enables the generation of a stable cell line that secretes a dual tagged Fab’ molecule (DTFab’), which can be easily isolated in high yields. To demonstrate feasibility, we functionalized the DTFab’ with two distinct cargos in a site-specific manner. This technology platform will be valuable in the development of multimodal imaging agents, theragnostics, and next-generation ADCs.

scholarly journals An in silico method to assess antibody fragment polyreactivity

2022 ◽  
Author(s):  
Edward P Harvey ◽  
Jung-Eun Shin ◽  
Meredith A Skiba ◽  
Genevieve R Nemeth ◽  
Joseph D Hurley ◽  
...  
Keyword(s):  
Protein Sequence ◽  
Specific Binding ◽  
Antibody Fragment ◽  
Therapeutic Agents ◽  
Clinical Development ◽  
Biological Research ◽  
Type I ◽  
Polyreactive Antibodies ◽  
Quantitative Scoring ◽  
Machine Learning Models

Antibodies are essential biological research tools and important therapeutic agents, but some exhibit non-specific binding to off-target proteins and other biomolecules. Such polyreactive antibodies compromise screening pipelines, lead to incorrect and irreproducible experimental results, and are generally intractable for clinical development. We designed a set of experiments using a diverse naive synthetic camelid antibody fragment ('nanobody') library to enable machine learning models to accurately assess polyreactivity from protein sequence (AUC > 0.8). Moreover, our models provide quantitative scoring metrics that predict the effect of amino acid substitutions on polyreactivity. We experimentally tested our model's performance on three independent nanobody scaffolds, where over 90% of predicted substitutions successfully reduced polyreactivity. Importantly, the model allowed us to diminish the polyreactivity of an angiotensin II type I receptor antagonist nanobody, without compromising its pharmacological properties. We provide a companion web-server that provides a straightforward means of predicting polyreactivity and polyreactivity-reducing mutations for any given nanobody sequence.

scholarly journals Salmonella and cancer: from pathogens to therapeutics.

2013 ◽  
Vol 60 (3) ◽  
Author(s):  
Paulina Chorobik ◽  
Dominik Czaplicki ◽  
Karolina Ossysek ◽  
Joanna Bereta
Keyword(s):  
Clinical Trial ◽  
Cancer Therapy ◽  
Phase I ◽  
Tumor Biology ◽  
Specific Treatment ◽  
Antibody Fragment ◽  
Cancer Therapeutics ◽  
Clinical Development ◽  
Bacterial Strains ◽  
Site Specific

Bacterial cancer therapy is a concept more than 100 years old - yet, all things considered, it is still in early development. While the use of many passive therapeutics is hindered by the complexity of tumor biology, bacteria offer unique features that can overcome these limitations. Microbial metabolism, motility and sensitivity can lead to site-specific treatment, highly focused on the tumor and safe to other tissues. Activation of tumor-specific immunity is another important mechanism of such therapies. Several bacterial strains have been evaluated as cancer therapeutics so far, Salmonella Typhimurium being one of the most promising. S. Typhimurium and its derivatives have been used both as direct tumoricidal agents and as cancer vaccine vectors. VNP20009, an attenuated mutant of S. Typhimurium, shows significant native toxicity against murine tumors and was studied in a first-in-man phase I clinical trial for toxicity and anticancer activity. While proved to be safe in cancer patients, insufficient tumor colonization of VNP20009 was identified as a major limitation for further clinical development. Antibody-fragment-based targeting of cancer cells is one of the few approaches proposed to overcome this drawback.

What Can We Learn about Antibody-Drug Conjugates from the T-DM1 Experience?

2015 ◽  
pp. e117-e125 ◽  
Author(s):  
Francisco J. Esteva ◽  
Kathy D. Miller ◽  
Beverly A. Teicher
Keyword(s):  
Small Molecule ◽  
Antibody Fragment ◽  
Cytotoxic Agents ◽  
Specific Cell ◽  
Malignant Cells ◽  
Antibody Drug Conjugates ◽  
Drug Conjugates ◽  
Protein Toxin ◽  
Antibody Conjugates ◽  
Antibody Drug

Antibody conjugates are a diverse class of therapeutics that consist of a cytotoxic agent linked covalently to an antibody or antibody fragment directed toward a specific cell surface target expressed by tumor cells. The notion that antibodies directed toward targets on the surface of malignant cells could be used for drug delivery is not new. The history of antibody conjugates has been marked by hurdles identified and overcome. Early conjugates used mouse antibodies, drugs that either were not sufficiently potent, were immunogenic (proteins), or were too toxic, and linkers that were not sufficiently stable in circulation. Four main avenues have been explored using antibodies to target cytotoxic agents to malignant cells: antibody-protein toxin (or antibody fragment–protein toxin fusion) conjugates, antibody-chelated radionuclide conjugates, antibody-small molecule conjugates, and antibody-enzyme conjugates administered along with small molecule prodrugs that require metabolism by the conjugated enzyme to release the activated species. Technology is continuing to evolve regarding the protein and small molecule components, and it is likely that single chemical entities soon will be the norm for antibody-drug conjugates. Only antibody-radionuclide conjugates and antibody-drug conjugates have reached the regulatory approval stage, and there are more than 40 antibody conjugates in clinical trials. The time may have come for this technology to become a major contributor to improving treatment for patients with cancer.

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