Antibody-drug conjugates: Principles and clinical results in breast cancer treatment

2018 ◽  
Vol 39 (4) ◽  
pp. 490-495
Author(s):  
Nguyen Phuong Loan ◽  
Duong Hong Quan

Antibody-drug conjugates (ADCs) are consisted of the combination of highly specific monoclonal antibodies (mAbs) with conventional cytotoxic agents to particular cancer types. The use of mAbs that are specific to tumor cell-surface proteins allows highly selective accumulation of cytotoxic agents as ADCs at the tumor tissue, that is not achievable with conventional cytotoxic agents alone. Designing of effective ADCs for cancer treatment requires identification of an appropriate target, a mAb against the target, potent cytotoxic agents and conjugation of the mAb to cytotoxic agents. Until now, three ADCs including Gemtuzumab ozogamicin, Brentuximab and trastuzumab emtansine have received an FDA approval so far. These three ADCs have shown improved efficacy and safety data compared with standard chemotherapy for the treatment of patients of acute myeloid leukemia, advanced lymphoma and breast cancer, respectively. Moreover, several promising ADCs are now in the latter-phase of clinical testing. Thus, with special focusing on these new anti-cancer drugs, this review briefly describes the principles of ADCs including their structure and mechanism of action, and summarizes their clinical performance in breast cancer. Citation: Nguyen Phuong Loan, Duong Hong Quan, 2017. Antibody-drug conjugates: Principles and clinical results in breast cancer treatment. Tap chi Sinh hoc, 39(4): 489-493. DOI: 10.15625/0866-7160/v39n4.9327.*Corresponding author: [email protected] 15 March 2017, accepted 12 December 2017

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2898
Author(s):  
Chiara Corti ◽  
Federica Giugliano ◽  
Eleonora Nicolò ◽  
Liliana Ascione ◽  
Giuseppe Curigliano

Metastatic breast cancer (BC) is currently an incurable disease. Besides endocrine therapy and targeted agents, chemotherapy is often used in the treatment of this disease. However, lack of tumor specificity and toxicity associated with dose exposure limit the manageability of cytotoxic agents. Antibody–drug conjugates (ADCs) are a relatively new class of anticancer drugs. By merging the selectivity of monoclonal antibodies with the cytotoxic properties of chemotherapy, they improve the therapeutic index of antineoplastic agents. Three core components characterize ADCs: the antibody, directed to a target antigen; the payload, typically a cytotoxic agent; a linker, connecting the antibody to the payload. The most studied target antigen is HER2 with some agents, such as trastuzumab deruxtecan, showing activity not only in HER2-positive, but also in HER2-low BC patients, possibly due to a bystander effect. This property to provide a cytotoxic impact also against off-target cancer cells may overcome the intratumoral heterogeneity of some target antigens. Other cancer-associated antigens represent a strategy for the development of ADCs against triple-negative BC, as shown by the recent approval of sacituzumab govitecan. In this review, we discuss the current landscape of ADC development for the treatment of BC, as well as the possible limitations of this treatment.


Author(s):  
Anthony W. Tolcher

In 2019, an important inflection point occurred when the U.S. Food and Drug Administration approved three new antibody-drug conjugates (ADCs) for the treatment of malignancies, including urothelial cancer (enfortumab vedotin-ejfv), diffuse large B-cell lymphoma (polatuzumab vedotin-piiq), and HER2 breast cancer (fam-trastuzumab deruxtecan-nxki), and expanded the indication for ado-trastuzumab emtansine to early breast cancer. This near doubling in the number of approved ADCs within 1 year validates the ADC platform and represents a successful evolution over the past 30 years. ADCs were born in an era when systemic therapy for cancer was largely cytotoxic chemotherapy. Many of the investigational cytotoxic agents were determined to be too toxic for oral and intravenous use. The agents were especially potent, with inhibitory concentrations that inhibited 50% of cells in the nanomolar and picomolar range but had poor therapeutic indexes when administered systemically. Now, over the last 30 years, we have seen an evolution of the many aspects of this complex platform with better antigen target selection, more sophisticated chemistry for the linkers, a growing diversity of payloads from cytotoxic chemotherapy to targeted therapies and immunostimulants, and, with the recent series of regulatory approvals, a buoyed sense of optimism for the technology. Nonetheless, we have not fully realized the full potential of this platform. In this review, the many components of ADCs will be discussed, the difficulties encountered will be highlighted, the innovative strategies that are being used to improve them will be assessed, and the direction that the field is going will be considered.


2021 ◽  
Vol 9 (8) ◽  
Author(s):  
Mony Ung ◽  
Jean Lacaze ◽  
Eleonora Maio ◽  
Florence Dalenc

Antibody–drug conjugates (ADCs) are a new class of anticancer agents that combine cytotoxic agents attached by a linker to a monoclonal antibody. These engineered drugs can selectively deliver a cytotoxic payload to targeted cancer cells and the local microenvironment (bystander effect), thereby increasing activity and reducing off-target toxicity. The association of ADCs with other anti-cancer therapies is therefore promising. Trastuzumab-emtansine was the first approved ADC in breast cancer (BC), specifically for the management of human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer. New ADCs are in development in BC. Some have shown meaningful clinical benefit and have been recently approved, such as trastuzumab deruxtecan in HER2-positive trastuzumab emtansine (T-DM1) pretreated BC and Trop-2 guided sacituzumab govitecan in triple-negative BC. Trastuzumab deruxtecan also has potential clinical activity in HER2-low BC thanks to a bystander effect. In this article, we review the ADCs under development in advanced BC.


Author(s):  
Frederik Marmé

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.


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