scholarly journals Fcγ Receptor-Dependent Internalization and Off-Target Cytotoxicity of Antibody-Drug Conjugate Aggregates

2021 ◽  
Author(s):  
Michihiko Aoyama ◽  
Minoru Tada ◽  
Hidetomo Yokoo ◽  
Yosuke Demizu ◽  
Akiko Ishii-Watabe
Keyword(s):  
Cell Lines ◽  
Potential Risk ◽  
Target Cells ◽  
Antibody Drug Conjugate ◽  
Blocking Antibody ◽  
Effector Functions ◽  
Drug Conjugates ◽  
Negative Cell ◽  
Tumor Killing ◽  
Antibody Drug

Abstract Purpose Antibody-drug conjugates (ADCs), which are monoclonal antibodies (mAbs) conjugated with highly toxic payloads, achieve high tumor killing efficacy due to the specific delivery of payloads in accordance with mAbs’ function. On the other hand, the conjugation of payloads often increases the hydrophobicity of mAbs, resulting in reduced stability and increased aggregation. It is considered that mAb aggregates have potential risk for activating Fcγ receptors (FcγRs) on immune cells, and are internalized into cells via FcγRs. Based on the mechanism of action of ADCs, the internalization of ADCs into target-negative cells may cause the off-target toxicity. However, the impacts of aggregation on the safety of ADCs including off-target cytotoxicity have been unclear. In this study, we investigated the cytotoxicity of ADC aggregates in target-negative cells. Methods The ADC aggregates were generated by stirring stress or thermal stress. The off-target cytotoxicity of ADC aggregates was evaluated in several target-negative cell lines, and FcγR-activation properties of ADC aggregates were characterized using a reporter cell assay. Results Aggregation of ADCs enhanced the off-target cytotoxicity in several target-negative cell lines compared with non-stressed ADCs. Notably, ADC aggregates with FcγR-activation properties showed dramatically enhanced cytotoxicity in FcγR-expressing cells. The FcγR-mediated off-target cytotoxicity of ADC aggregates was reduced by using a FcγR-blocking antibody or Fc-engineering for silencing Fc-mediated effector functions. Conclusions These results indicated that FcγRs play an important role for internalization of ADC aggregates into non-target cells, and the aggregation of ADCs increases the potential risk for off-target toxicity.

Axially-substituted silicon phthalocyanine payloads for antibody-drug conjugates

Synlett ◽  
2021 ◽  
Author(s):  
Kazuki Takahashi ◽  
Akira Sugiyama ◽  
Kei Ohkubo ◽  
Toshifumi Tatsumi ◽  
Tatsuhiko Kodama ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
Antibody Drug Conjugate ◽  
Antibody Drug Conjugates ◽  
Drug Conjugate ◽  
Drug Conjugates ◽  
Antibody Drug ◽  
Silicon Phthalocyanine

IR700, a silicon phthalocyanine (SiPc) photosensitizer, is an antibody-drug conjugate payload used clinically. It is, however, the sole SiPc payload to date, possibly due to the difficulty of its synthesis, resulting from its asymmetric phathalocyanine skeleton. Here we report a new axially-substituted SiPc payload with easier synthesis. Trastuzumab conjugated with the SiPc showed light- and antigen-dependent cytotoxicity in HER2-overexpressed cancer cell lines.

scholarly journals Antibody-Drug Conjugate Using Ionized Cys-Linker-MMAE as the Potent Payload Shows Optimal Therapeutic Safety

Cancers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 744
Author(s):  
Yanming Wang ◽  
Lianqi Liu ◽  
Shiyong Fan ◽  
Dian Xiao ◽  
Fei Xie ◽  
...  
Keyword(s):  
Bystander Effect ◽  
Maximum Tolerated Dose ◽  
Target Cells ◽  
High Potency ◽  
Antibody Drug Conjugate ◽  
Normal Tissues ◽  
Drug Conjugates ◽  
Lower Permeability ◽  
Ideal Plasma ◽  
Antibody Drug

Monomethyl auristatin E (MMAE) is the most popular and widely used cytotoxin in the development of antibody-drug conjugates (ADCs). However, current MMAE-based ADCs are all constructed using cleavable linkers, and this design concept still has insurmountable drawbacks. Their potential instabilities and lipophilic MMAE-induced “bystander effect” inevitably increase the toxicity to normal tissues. Herein, we overturn previous negative views of MMAE-based ADCs with non-cleavable linkers and propose using ionized L-Cysteine (Cys)-linker-MMAE as a novel payload, which can ingeniously enrich and enter tumor cells through receptor-mediated endocytosis of antibodies while its lower permeability helps to avoid further off-target toxicity. We demonstrate that Cys-linker-MMAE maintains high potency similar to free MMAE at the tubulin molecular level and can also be efficiently released in target cells. As a result, the preferred ADC (mil40-15) not only exhibits ideal plasma stability and maintains potent cytotoxicity as MMAE (IC50: 10−11 M), but also shows improved safety with lower bystander toxicity (IC50: 10−9 M), its maximum tolerated dose approaching the level of the naked antibody (160 mg/kg). This study indicated that Cys-linker-MMAE has the potential as a potent payload for ADCs, which is expected to provide novel strategies for the development of MMAE-based ADCs.

scholarly journals Generation of Antibody-Drug Conjugate Resistant Models

Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4631
Author(s):  
Lucía Gandullo-Sánchez ◽  
Alberto Ocaña ◽  
Atanasio Pandiella
Keyword(s):  
Cell Lines ◽  
Resistance Mechanisms ◽  
Continuous Treatment ◽  
Antibody Drug Conjugate ◽  
Primary Resistance ◽  
Secondary Resistance ◽  
Drug Conjugates ◽  
Tumoral Cells ◽  
Late Stages ◽  
Antibody Drug

In the last 20 years, antibody-drug conjugates (ADCs) have been incorporated into the oncology clinic as treatments for several types of cancer. So far, the Food and Drug Administration (FDA) has approved 11 ADCs and other ADCs are in the late stages of clinical development. Despite the efficacy of this type of drug, the tumors of some patients may result in resistance to ADCs. Due to this, it is essential not only to comprehend resistance mechanisms but also to develop strategies to overcome resistance to ADCs. To reach these goals, the generation and use of preclinical models to study those mechanisms of resistance are critical. Some cells or patient tumors may result in primary resistance to the action of an ADC, even if they express the antigen against which the ADC is directed. Isolated primary tumoral cells, cell lines, or patient explants (patient-derived xenografts) with these characteristics can be used to study primary resistance. The most common method to generate models of secondary resistance is to treat cancer cell lines or tumors with an ADC. Two strategies, either continuous treatment with the ADC or intermittent treatment, have successfully been used to develop those resistance models.

Computational Approaches in Antibody-drug Conjugate Optimization for Targeted Cancer Therapy

2018 ◽  
Vol 18 (13) ◽  
pp. 1091-1109 ◽  
Author(s):  
Rita Melo ◽  
Agostinho Lemos ◽  
Antonio J. Preto ◽  
Jose G. Almeida ◽  
Joao D.G. Correia ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Coarse Grained ◽  
Cytotoxic Agent ◽  
Target Cells ◽  
Antibody Drug Conjugate ◽  
Drug Conjugate ◽  
Cross Correlation Analysis ◽  
Traditional Therapies ◽  
Modular Structures ◽  
Antibody Drug

Cancer has become one of the main leading causes of morbidity and mortality worldwide. One of the critical drawbacks of current cancer therapeutics has been the lack of the target-selectivity, as these drugs should have an effect exclusively on cancer cells while not perturbing healthy ones. In addition, their mechanism of action should be sufficiently fast to avoid the invasion of neighbouring healthy tissues by cancer cells. The use of conventional chemotherapeutic agents and other traditional therapies, such as surgery and radiotherapy, leads to off-target interactions with serious side effects. In this respect, recently developed target-selective Antibody-Drug Conjugates (ADCs) are more effective than traditional therapies, presumably due to their modular structures that combine many chemical properties simultaneously. In particular, ADCs are made up of three different units: a highly selective Monoclonal antibody (Mab) which is developed against a tumour-associated antigen, the payload (cytotoxic agent), and the linker. The latter should be stable in circulation while allowing the release of the cytotoxic agent in target cells. The modular nature of these drugs provides a platform to manipulate and improve selectivity and the toxicity of these molecules independently from each other. This in turn leads to generation of second- and third-generation ADCs, which have been more effective than the previous ones in terms of either selectivity or toxicity or both. Development of ADCs with improved efficacy requires knowledge at the atomic level regarding the structure and dynamics of the molecule. As such, we reviewed all the most recent computational methods used to attain all-atom description of the structure, energetics and dynamics of these systems. In particular, this includes homology modelling, molecular docking and refinement, atomistic and coarse-grained molecular dynamics simulations, principal component and cross-correlation analysis. The full characterization of the structure-activity relationship devoted to ADCs is critical for antibody-drug conjugate research and development.

scholarly journals Systematic identification of engineered methionines and oxaziridines for efficient, stable, and site-specific antibody bioconjugation

2019 ◽  
Author(s):  
Susanna K. Elledge ◽  
Hai L. Tran ◽  
Alec H. Christian ◽  
Veronica Steri ◽  
Byron Hann ◽  
...  
Keyword(s):  
Specific Antibody ◽  
Xenograft Model ◽  
Antibody Engineering ◽  
Antibody Drug Conjugate ◽  
Site Specific ◽  
Drug Conjugates ◽  
Mouse Xenograft Model ◽  
Random Modification ◽  
The Stability ◽  
Antibody Drug

AbstractChemical modification of antibodies is one of the most important bioconjugations utilized by biologists and biotechnology. To date, the field has been dominated by random modification of lysines or more site-specific labeling of cysteines, each with attendant challenges. Recently we have developed oxaziridine chemistry for highly selective and efficient sulfimide modification of methionine called redox-activated chemical tagging (ReACT). Here, we systematically scanned methionines throughout one of the most popular antibody scaffolds, trastuzumab, for antibody engineering and drug conjugation. We tested the expression, reactivities, and stabilities of 123 single engineered methionines distributed over the surface of the antibody when reacted with oxaziridine. We found uniformly high expression for these mutants and generally good reaction efficiencies with the panel of oxaziridines. Remarkably, the stability to hydrolysis of the sulfimide varied more than ten-fold depending on temperature and the site of the engineered methionine. Interestingly, the most stable and reactive sites were those that were partially buried, likely because of their reduced access to water. There was also a ten-fold variation in stability depending on the nature of the oxaziridine, which we determined was inversely correlated with the electrophilic nature of the sulfimide. Importantly, the stabilities of the best analogs and antibody drug conjugate potencies were comparable to those reported for cysteine-maleimide modifications of trastuzumab. We also found our antibody drug conjugates to be potent in a breast cancer mouse xenograft model. These studies provide a roadmap for broad application of ReACT for efficient, stable, and site-specific antibody and protein bioconjugation.

scholarly journals Targeted Fluorogenic Cyanine Carbamates Enable In Vivo Analysis of Antibody-Drug Conjugate Linker Chemistry

2021 ◽  
Author(s):  
Syed Usama ◽  
Sierra Marker ◽  
Donald Caldwell ◽  
Nimit Patel ◽  
Yang Feng ◽  
...  
Keyword(s):  
Near Infrared ◽  
Antibody Drug Conjugate ◽  
Drug Conjugates ◽  
Lysosomal Accumulation ◽  
Cellular Signal ◽  
In Vivo Analysis ◽  
Cellular Permeability ◽  
Therapeutic Platform ◽  
Antibody Drug

Antibody-drug conjugates (ADCs) are a rapidly emerging therapeutic platform. The chemical linker between the antibody and the drug payload plays an essential role in the efficacy and tolerability of these agents. New methods that quantitively assess cleavage efficiency in complex tissue settings could provide valuable insights into the ADC design process. Here we report the development of a near-infrared (NIR) optical imaging approach that measures the site and extent of linker cleavage in mouse models. This approach is enabled by a superior variant of our recently devised cyanine carbamate (CyBam) platform. We identify a novel tertiary amine-containing norcyanine, the product of CyBam cleavage, that exhibits dramatically in-creased cellular signal due to improved cellular permeability and lysosomal accumulation. The resulting cyanine lysosome-targeting carbamates (CyLBams) are ~50X brighter in cells, and we find this strategy is essential for high-contrast in vivo targeted imaging. Finally, we compare a panel of several common ADC linkers across two antibodies and tumor models. These studies indicate that cathepsin-cleavable linkers provide dramatically higher tumor activation relative to hindered or non-hindered disulfides – an observation that is only apparent with in vivo imaging. This strategy enables quantitative comparisons of cleavable linker chemistries in complex tissue settings with implications across the drug delivery landscape.

The role of enfortumab vedotin and sacituzumab govitecan in treatment of advanced bladder cancer

2021 ◽  
Author(s):  
Kirollos S Hanna ◽  
Samantha Larson ◽  
Jenny Nguyen ◽  
Jenna Boudreau ◽  
Jennifer Bulin ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Immune Checkpoint ◽  
Checkpoint Inhibitors ◽  
Second Line ◽  
Antibody Drug Conjugate ◽  
Drug Conjugates ◽  
Advanced Bladder Cancer ◽  
Checkpoint Inhibitor Therapy ◽  
Antibody Drug

Abstract Disclaimer In an effort to expedite the publication of articles pandemic, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose The treatment landscape of advanced bladder cancer continues to evolve with novel therapeutics approved in recent years and many in the pipeline. Here we review the role of the novel agents enfortumab vedotin and sacituzumab govitecan in treatment of advanced disease. Summary Patients with advanced bladder cancer often first receive platinum-based therapy, while immune checkpoint inhibitors offer a maintenance option following cytotoxic chemotherapy or a second-line option. Despite various first- and second-line options, patients with significant comorbidities and treatment-related adverse events will experience disease progression requiring alternative treatment. Enfortumab vedotin and sacituzumab govitecan are novel antibody-drug conjugates approved in patients with advanced bladder cancer following platinum-based and immune checkpoint inhibitor therapy. Following platinum-based therapy and immunotherapy in patients with advanced bladder cancer, enfortumab vedotin, targeting Nectin-4, improves overall survival while sacituzumab govitecan, targeting Trop-2, is associated with a 27% response rate. With these new approaches to disease management, however, it remains critical to understand safety, efficacy, and operational considerations to optimize outcomes. Conclusion When selecting an antibody-drug conjugate to treat patients with bladder cancer, it is important to note the adverse event profile of each agent to optimize outcomes and safety for patients.

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.

Targeting CD30 in Hodgkin Lymphoma: Antibody-Drug Conjugates Make a Difference

2012 ◽  
pp. 162-166 ◽  
Author(s):  
Catherine S. M. Diefenbach ◽  
John P. Leonard
Keyword(s):  
Hodgkin Lymphoma ◽  
Large Cell ◽  
Brentuximab Vedotin ◽  
Antibody Drug Conjugate ◽  
Lymphoid Malignancies ◽  
Drug Conjugates ◽  
First Line Therapy ◽  
Resistant Disease ◽  
Relapsed Disease ◽  
Antibody Drug

Overview: CD30 expression is characteristic of the malignant Reed-Sternberg cell in Hodgkin lymphoma (HL) and several other lymphoid malignancies, such as anaplastic large-cell lymphoma (ALCL). Although unconjugated anti-CD30 antibodies have had minimal therapeutic activity in patients with HL as single agents, the CD30-directed antibody-drug conjugate (ADC) brentuximab vedotin has demonstrated activity that has resulted in its recent regulatory approval for the treatment of patients with relapsed HL and ALCL. Approximately 75% of patients with recurrent HL achieve objective responses, with the principal toxicity being peripheral neuropathy. Ongoing studies are evaluating treatment with this agent as part of first-line therapy, for patients with relapsed disease, and for patients with resistant disease and limited other options. Brentuximab vedotin demonstrates the therapeutic value of antibody-drug conjugation and serves as a model of how a novel, targeted approach can be employed to potentially further improve outcomes in settings where curative chemotherapeutic regimens are already available.

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