Antibody drug conjugates as targeted cancer therapy: past development, present challenges and future opportunities

Understanding the chemistry & pharmacology of antibody-drug conjugates in triple-negative breast cancer with special reference to exatecan derivatives

In the spectrum of breast malignancies, triple-negative breast cancer is the most widely spreading subtype of breast cancer due to a low availability of therapeutic remedies. Recently, antibody-drug conjugates dramatically resolved the landscape for the treatment of triple-negative breast cancer. This review mainly focuses on the chemistry, structure, mechanism of action, and role of antibody-drug conjugates in triple-negative breast cancer. Datopotecan Deruxtecan (Dato-DXd) is a new-generation ADC showing encouraging results for TNBC. In this review, we have also emphasized TROP-2-directed Datopotamab deruxtecan ADCs to treat triple-negative breast cancer, its synthesis, mechanism of action, pharmacokinetics, pharmacodynamics, adverse events, and their ongoing clinical trials.

Advances in conjugate drug delivery System: Opportunities and challenges

Ideal drug delivery system is designed to accurately deliver the drug to its intended site. The development of conjugate drug delivery system introduces a novel pathway to precise drug delivery with advantages over traditional methods. The core of a conjugate drug delivery system comprises a molecule with two functional components, bounded by a linker structure. One component is responsible for delivering or stabilizing the conjugate, while the other is used to provide the therapeutic or diagnostic effects of the bioactivity. Conjugate drug delivery system improves patient health by maintaining the structural stability of drugs in molecular form, delivering therapeutics or diagnostic material to the target site, minimising off-target accumulation and promoting patient compliance. This system includes various types of drug conjugates that modulate drug pharmacokinetics, stability, absorption, and exposure in lesions and healthy tissues. In this review, we focus on the key characteristics and recent advances of various conjugate drug delivery systems and explore their mechanisms. We also point out the current challenges faced by conjugate drug delivery system and look forward to the future prospects.

Anti-Claudin-2 Antibody-Drug Conjugates for the Treatment of Colorectal Cancer Liver Metastasis

We have previously demonstrated that Claudin-2 is required for colorectal cancer (CRC) liver metastasis. The expression of Claudin-2 in primary CRC is associated with poor survival and highly expressed in liver metastases. Claudin-2 also promotes breast cancer liver metastasis by enabling seeding and cancer cell survival. These observations support Claudin-2 as a potential therapeutic target for managing patients with liver metastases. Antibody-drug conjugates (ADC) are promising antitumor therapeutics, which combine the specific targeting ability of monoclonal antibodies with the potent cell killing activity of cytotoxic drugs. Herein, we report the generation of 28 anti-Claudin-2 antibodies for which the binding specificities, cross-reactivity with claudin family members, and cross-species reactivity were assessed by flow cytometry analysis. Multiple drug conjugates were tested, and PNU was selected for conjugation with anti-Claudin-2 antibodies binding either extracellular loop 1 or 2. Anti-Claudin-2 ADCs were efficiently internalized and were effective at killing Claudin-2-expressing CRC cancer cells in vitro. Importantly, PNU-conjugated-anti-Claudin-2 ADCs impaired the development of replacement-type CRC liver metastases in vivo, using established CRC cell lines and patient-derived xenograft (PDX) models of CRC liver metastases. Results suggest that the development of ADCs targeting Claudin-2 is a promising therapeutic strategy for managing patients with CRC liver-metastatic disease who present replacement-type liver metastases.

Ocular adverse events associated with antibody-drug conjugates in oncology: a pharmacovigilance study based on FDA adverse event reporting system (FAERS)

Background

Antibody-drug conjugates (ADCs) have emerged as the focus and hotspots in the cancer field, yet the accompanying ocular toxicity has often been underestimated. We aimed to comprehensively and comparatively analyze the risk of ocular toxicity associated with various ADCs using the FDA Adverse Event Reporting System (FAERS) database.

Methods

Data were extracted from the FAERS database from Q3 2011 to Q3 2023. We analyzed the clinical characteristics of ADCs-related ocular adverse events (AEs). These data were further mined by proportional analysis and Bayesian approach to detect signals of ADCs-induced ocular AEs. Moreover, the time to onset of ocular toxicity was also evaluated.

Results

A total of 1,246 cases of ocular AEs were attributed to ADCs. Ocular toxicity signals were observed in patients treated with belantamab mafodotin, brentuximab vedotin, enfortumab vedotin, mirvetuximab soravtansine, sacituzumab govitecan, trastuzumab deruxtecan, and trastuzumab emtansine. Of these, belantamab mafodotin, trastuzumab emtansine, and mirvetuximab soravtansine, whose payloads are microtubule polymerization inhibitors, were more susceptible to ocular toxicity. The ten most common ADCs-related ocular AEs signals are keratopathy [ROR = 1,273.52, 95% CI (1,129.26-1,436.21)], visual acuity reduced [ROR = 22.83, 95% CI (21.2-24.58)], dry eye [ROR = 9.69, 95% CI (8.81-10.66)], night blindness [ROR = 259.87, 95% CI (228.23-295.89)], vision blurred [ROR = 1.78, 95% CI (1.57-2.02)], photophobia [ROR = 10.45, 95% CI (9.07-12.05)], foreign body sensation in eyes [ROR = 23.35, 95% CI (19.88-27.42)], ocular toxicity [ROR = 144.62, 95% CI (117.3-178.32)], punctate keratitis [ROR = 126.21, 95% CI (101.66-156.69)], eye disorder [ROR = 2.71, 95% CI (2.21-3.32)]. In terms of onset time, sacituzumab govitecan displayed an earlier onset of 21 days, while trastuzumab deruxtecan exhibited the latest onset of 223 days.

Conclusion

ADCs may increase the risk of ocular toxicity in cancer patients, leading to serious mortality. With the widespread application of newly launched ADCs, combining the FAERS data with other data sources is crucial for monitoring the ocular toxicity of ADCs. In addition, novel ocular toxicity signals not documented in product labeling were detected. Further research will be necessary to validate our findings in the future.

Innovations in Biosensor Technologies for Healthcare Diagnostics and Therapeutic Drug Monitoring: Applications, Recent Progress, and Future Research Challenges

This comprehensive review delves into the forefront of biosensor technologies and their critical roles in disease biomarker detection and therapeutic drug monitoring. It provides an in-depth analysis of various biosensor types and applications, including enzymatic sensors, immunosensors, and DNA sensors, elucidating their mechanisms and specific healthcare applications. The review highlights recent innovations such as integrating nanotechnology, developing wearable devices, and trends in miniaturisation, showcasing their transformative potential in healthcare. In addition, it addresses significant sensitivity, specificity, reproducibility, and data security challenges, proposing strategic solutions to overcome these obstacles. It is envisaged that it will inform strategic decision-making, drive technological innovation, and enhance global healthcare outcomes by synthesising multidisciplinary insights.

Antibody-drug conjugates in cancer therapy: mechanisms and clinical studies

Antibody-drug conjugates (ADCs) consist of monoclonal antibodies that target tumor cells and cytotoxic drugs linked through linkers. By leveraging antibodies' targeting properties, ADCs deliver cytotoxic drugs into tumor cells via endocytosis after identifying the tumor antigen. This precise method aims to kill tumor cells selectively while minimizing harm to normal cells, offering safe and effective therapeutic benefits. Recent years have seen significant progress in antitumor treatment with ADC development, providing patients with new and potent treatment options. With over 300 ADCs explored for various tumor indications and some already approved for clinical use, challenges such as resistance due to factors like antigen expression, ADC processing, and payload have emerged. This review aims to outline the history of ADC development, their structure, mechanism of action, recent composition advancements, target selection, completed and ongoing clinical trials, resistance mechanisms, and intervention strategies. Additionally, it will delve into the potential of ADCs with novel markers, linkers, payloads, and innovative action mechanisms to enhance cancer treatment options. The evolution of ADCs has also led to the emergence of combination therapy as a new therapeutic approach to improve drug efficacy.

A native SEC-MS workflow and validation for analyzing drug-to-antibody ratio and drug load distribution in cysteine-linked antibody-drug conjugates

The development and optimization of Antibody-Drug Conjugates (ADCs) hinge on enhanced analytical and bioanalytical characterization, particularly in assessing critical quality attributes (CQAs). The ADC's potency is largely determined by the average number of drugs attached to the monoclonal antibody (mAb), known as the drug-to-antibody ratio (DAR). Furthermore, the drug load distribution (DLD) influences the therapeutic window of the ADC, defining the range of dosages effective in treating diseases without causing toxic effects. Among CQAs, DAR and DLD are vital; their control is essential for ensuring manufacturing consistency and product quality. Typically, hydrophobic interaction chromatography (HIC) or reversed-phase liquid chromatography (RPLC) with UV detector have been used to quantitate DAR and DLD in quality control (QC) environment. Recently, Native size-exclusion chromatography-mass spectrometry (nSEC-MS) proves the potential as a platformable quantitative method for characterizing DAR and DLD across various cysteine-linked ADCs in research or early preclinical development. In this work, we established and assessed a streamlined nSEC-MS workflow with a benchtop LC-MS platform, to quantitatively monitor DAR and DLD of different chemotype and drug load level cysteine-linked ADCs. Moreover, to deploy this workflow in QC environment, complete method validation was conducted in three independent laboratories, adhering to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) Q2(R1) guidelines. The results met the predefined analytical target profile (ATP) and performance criteria, encompassing specificity/selectivity, accuracy, precision, linearity, range, quantification/detection limit, and robustness. Finally, the method validation design offers a reference for other nSEC-MS methods that are potentially used to determine the DAR and DLD on cysteine-linker ADCs. To the best of our knowledge, this study is the first reported systematic validation of the nSEC-MS method for detecting DAR and DLD. The results indicated that the co-validated nSEC-MS workflow is suitable for DAR and DLD routine analysis in ADC quality control, release, and stability testing.

Implications of inflammatory cell death-PANoptosis in health and disease

Regulated cell death (RCD) pathways, such as pyroptosis, apoptosis, and necroptosis, are essential for maintaining the body's balance, defending against pathogens, and eliminating abnormal cells that could lead to diseases like cancer. Although these pathways operate through distinct mechanisms, recent genetic and pharmacological studies have shown that they can interact and influence each other. The concept of "PANoptosis" has emerged, highlighting the interplay between pyroptosis, apoptosis, and necroptosis, especially during cellular responses to infections. This article provides a concise overview of PANoptosis and its molecular mechanisms, exploring its implications in various diseases. The review focuses on the extensive interactions among different RCD pathways, emphasizing the role of PANoptosis in infections, cytokine storms, inflammatory diseases, and cancer. Understanding PANoptosis is crucial for developing novel treatments for conditions involving infections, sterile inflammations, and cancer.

Antibody-Drug Conjugates in Urothelial Cancer: From Scientific Rationale to Clinical Development

Antibody-drug conjugates (ADCs) have been a significant advancement in cancer therapy, particularly for urothelial cancer (UC). These innovative treatments, originally developed for hematological malignancies, use target-specific monoclonal antibodies linked to potent cytotoxic agents. This rational drug design efficiently delivers cancer cell-killing agents to cells expressing specific surface proteins, which are abundant in UC owing to their high antigen expression. UC is an ideal candidate for ADC therapy, as it enhances on-target efficacy while mitigating systemic toxicity. In recent years, considerable progress has been made in understanding the biology and mechanisms of tumor progression in UC. However, despite the introduction of immune checkpoint inhibitors, advanced UC is characterized by rapid progression and poor survival rates. Targeted therapies that have been developed include the anti-nectin 4 ADC enfortumab vedotin and the fibroblast growth factor receptor inhibitor erdafitinib. Enfortumab vedotin has shown efficacy in prospective studies in patients with advanced UC, alone and in combination with pembrolizumab. The anti-Trop-2 ADC sacituzumab govitecan has also demonstrated effectiveness in single-armed studies. This review highlights the mechanism of action of ADCs, their application in mono- and combination therapies, primary mechanisms of resistance, and future perspectives for their clinical use in UC treatment. ADCs have proven to be an increasingly vital component of the therapeutic landscape for urothelial carcinoma, filling a gap in the treatment of this progressive disease.

Precision Medicine in Rheumatic Diseases: Unlocking the Potential of Antibody-Drug Conjugates

In the era of precision medicine, antibody-drug conjugates (ADCs) have emerged as a cutting-edge therapeutic strategy. These innovative compounds combine the precision of monoclonal antibodies with the potent cell-killing or immune-modulating abilities of attached drug payloads. This unique strategy not only reduces off-target toxicity but also enhances the therapeutic effectiveness of drugs. Beyond their well established role in oncology, ADCs are now showing promising potential in addressing the unmet needs in the therapeutics of rheumatic diseases. Rheumatic diseases, a diverse group of chronic autoimmune diseases with varying etiologies, clinical presentations, and prognoses, often demand prolonged pharmacological interventions, creating a pressing need for novel, efficient, and low-risk treatment options. ADCs, with their ability to precisely target the immune components, have emerged as a novel therapeutic strategy in this context. This review will provide an overview of the core components and mechanisms behind ADCs, a summary of the latest clinical trials of ADCs for the treatment of rheumatic diseases, and a discussion of the challenges and future prospects faced by the development of next-generation ADCs. SIGNIFICANCE STATEMENT: There is a lack of efficient and low-risk targeted therapeutics for rheumatic diseases. Antibody-drug conjugates, a class of cutting-edge therapeutic drugs, have emerged as a promising targeted therapeutic strategy for rheumatic disease. Although there is limited literature summarizing the progress of antibody-drug conjugates in the field of rheumatic disease, updating the advancements in this area provides novel insights into the development of novel antirheumatic drugs.

Incidence and Mitigation of Corneal Pseudomicrocysts Induced by Antibody-Drug Conjugates (ADCs)

Purpose of Review

This study is to highlight the incidence of corneal pseudomicrocysts in FDA-approved antibody-drug conjugates (ADCs), and success of preventive therapies for pseudomicrocysts and related ocular surface adverse events (AEs).

Recent Findings

ADCs are an emerging class of selective cancer therapies that consist of a potent cytotoxin connected to a monoclonal antibody (mAb) that targets antigens expressed on malignant cells. Currently, there are 11 FDA-approved ADCs with over 164 in clinical trials. Various AEs have been attributed to ADCs, including ocular surface AEs (keratitis/keratopathy, dry eye, conjunctivitis, blurred vision, corneal pseudomicrocysts). While the severity and prevalence of ADC-induced ocular surface AEs are well reported, the reporting of corneal pseudomicrocysts is limited, complicating the development of therapies to prevent or treat ADC-related ocular surface toxicity.

Summary

Three of 11 FDA-approved ADCs have been implicated with corneal pseudomicrocysts, with incidence ranging from 41 to 100% of patients. Of the six ADCs that reported ocular surface AEs, only three had ocular substudies to investigate the benefit of preventive therapies including topical steroids, vasoconstrictors, and preservative-free lubricants. Current preventive therapies demonstrate limited efficacy at mitigating pseudomicrocysts and other ocular surface AEs.

Expanding the horizons of targeted protein degradation: A non-small molecule perspective

Targeted protein degradation (TPD) represented by proteolysis targeting chimeras (PROTACs) marks a significant stride in drug discovery. A plethora of innovative technologies inspired by PROTAC have not only revolutionized the landscape of TPD but have the potential to unlock functionalities beyond degradation. Non-small-molecule-based approaches play an irreplaceable role in this field. A wide variety of agents spanning a broad chemical spectrum, including peptides, nucleic acids, antibodies, and even vaccines, which not only prove instrumental in overcoming the constraints of conventional small molecule entities but also provided rapidly renewing paradigms. Herein we summarize the burgeoning non-small molecule technological platforms inspired by PROTACs, including three major trajectories, to provide insights for the design strategies based on novel paradigms.

Current Status and Future Perspectives of Antibody-Drug Conjugates in Hormone Receptor-Positive Breast Cancer

Breast cancer is the most common cancer type in women. The vast majority of breast cancer patients have hormone receptor-positive (HR+) tumors. In advanced HR+ breast cancer, the combination of endocrine therapy with cyclin-dependent kinase 4/6 (CDK4/6) inhibitors is considered the standard of care in the front-line setting. Nevertheless, resistance to hormonal therapy and CDK4/6 inhibitors eventually occurs, leading to progression of the disease. Antibody-drug conjugates (ADCs) comprise a promising therapeutic choice with significant efficacy in patients with HR+ breast cancer, which is resistant to endocrine treatment. ADCs typically consist of a cytotoxic payload attached by a linker to a monoclonal antibody that targets a specific tumor-associated antigen, offering the advantage of a more selective delivery of chemotherapy to cancer cells. In this review, we focus on the ADC mechanisms of action, their toxicity profile and therapeutic uses as well as on related biomarkers and future perspectives in advanced HR+ breast cancer.

When will the immune-stimulating antibody conjugates (ISACs) be transferred from bench to bedside?

Immunostimulatory antibody conjugates (ISACs) as a promising new generation of targeted therapeutic antibody-drug conjugates (ADCs), that not only activate innate immunity but also stimulate adaptive immunity, providing a dual therapeutic effect to eliminate tumor cells. However, several ISACs are still in the early stages of clinical development or have already failed. Therefore, it is crucial to design ISACs more effectively to overcome their limitations, including high toxicity, strong immunogenicity, long development time, and poor pharmacokinetics. This review aims to summarize the composition and function of ISACs, incorporating current design considerations and ongoing clinical trials. Additionally, the review delves into the current issues with ISACs and potential solutions, such as adjusting the drug-antibody ratio (DAR) to improve the bioavailability of ISACs. By leveraging the affinity and bioavailability-enhancing properties of bispecific antibodies, the utility between antibodies and immunostimulatory agents can be balanced. Commonly used immunostimulatory agents may induce systemic immune reactions, and BTK (Bruton's tyrosine kinase) inhibitors can regulate immunogenicity. Finally, the concept of grafting ADC's therapeutic principles is simple, but the combination of payload, linker, and targeted functional molecules is not a simple permutation and combination problem. The development of conjugate drugs faces more complex pharmacological and toxicological issues. Standing on the shoulders of ADC, the development and application scenarios of ISAC are endowed with broader space.

Engineered polyspecific antibodies: A new frontier in the field of immunotherapeutics

The 21st-century beginning remarked with the huge success of monospecific MAbs, however, in the last couple of years, polyspecific MAbs (PsAbs) have been an interesting topic and show promise of being biobetter than monospecific MAbs. Polyspecificity, in which a single antibody serves multiple specific target binding, has been hypothesized to contribute to the development of a highly effective antibody repertoire for immune defence. This polyspecific MAb trend represents an explosion that is gripping the whole pharmaceutical industry. This review is concerned with the current development and quality enforcement of PsAbs. All provided literature on monospecific MAbs and polyspecific MAbs (PsAbs) were searched using various electronic databases such as PubMed, Google Scholar, Web of Science, Elsevier, Springer, ACS, Google Patent and books via the keywords Antibody engineering, Polyspecific antibody, Conventional antibody, non-conventional antibody, and Single domain antibody. In the literature, there are more than 100 different formats to construct PsAb by quadroma technology, chemical conjugation and genetic engineering. Till March 2023, nine PsAb have been approved around the world, and around 330 are in advanced developmental stages, showing the dominancy of PsAb in the growing health sector. Recent advancements in protein engineering techniques and the fusion of non-conventional antibodies have made it possible to create complex PsAbs that demonstrate higher stability and enhanced potency. This marks the most significant achievement for cancer immunotherapy, in which PsAbs have immense promise. It is worth mentioning that seven out of the nine PsAbs have been approved as anti-cancer therapy. As PsAbs continue to acquire prominence, they could pave the way for the development of novel immunotherapies for multiple diseases.

Diverse drug delivery systems for the enhancement of cancer immunotherapy: an overview

Despite the clear benefits demonstrated by immunotherapy, there is still an inevitable off-target effect resulting in serious adverse immune reactions. In recent years, the research and development of Drug Delivery System (DDS) has received increased prominence. In decades of development, DDS has demonstrated the ability to deliver drugs in a precisely targeted manner to mitigate side effects and has the advantages of flexible control of drug release, improved pharmacokinetics, and drug distribution. Therefore, we consider that combining cancer immunotherapy with DDS can enhance the anti-tumor ability. In this paper, we provide an overview of the latest drug delivery strategies in cancer immunotherapy and briefly introduce the characteristics of DDS based on nano-carriers (liposomes, polymer nano-micelles, mesoporous silica, extracellular vesicles, etc.) and coupling technology (ADCs, PDCs and targeted protein degradation). Our aim is to show readers a variety of drug delivery platforms under different immune mechanisms, and analyze their advantages and limitations, to provide more superior and accurate targeting strategies for cancer immunotherapy.

Anticancer activities of natural antimicrobial peptides from animals

Cancer is the most common cause of human death worldwide, posing a serious threat to human health and having a negative impact on the economy. In the past few decades, significant progress has been made in anticancer therapies, but traditional anticancer therapies, including radiation therapy, surgery, chemotherapy, molecular targeted therapy, immunotherapy and antibody-drug conjugates (ADCs), have serious side effects, low specificity, and the emergence of drug resistance. Therefore, there is an urgent need to develop new treatment methods to improve efficacy and reduce side effects. Antimicrobial peptides (AMPs) exist in the innate immune system of various organisms. As the most promising alternatives to traditional drugs for treating cancers, some AMPs also have been proven to possess anticancer activities, which are defined as anticancer peptides (ACPs). These peptides have the advantages of being able to specifically target cancer cells and have less toxicity to normal tissues. More and more studies have found that marine and terrestrial animals contain a large amount of ACPs. In this article, we introduced the animal derived AMPs with anti-cancer activity, and summarized the types of tumor cells inhibited by ACPs, the mechanisms by which they exert anti-tumor effects and clinical applications of ACPs.

Antibody-drug conjugates in cancer therapy: innovations, challenges, and future directions

The emergence of antibody-drug conjugates (ADCs) as a potential therapeutic avenue in cancer treatment has garnered significant attention. By combining the selective specificity of monoclonal antibodies with the cytotoxicity of drug molecules, ADCs aim to increase the therapeutic index, selectively targeting cancer cells while minimizing systemic toxicity. Various ADCs have been licensed for clinical usage, with ongoing research paving the way for additional options. However, the manufacture of ADCs faces several challenges. These include identifying suitable target antigens, enhancing antibodies, linkers, and payloads, and managing resistance mechanisms and side effects. This review focuses on the strategies to overcome these hurdles, such as site-specific conjugation techniques, novel antibody formats, and combination therapy. Our focus lies on current advancements in antibody engineering, linker technology, and cytotoxic payloads while addressing the challenges associated with ADC development. Furthermore, we explore the future potential of personalized medicine, leveraging individual patients' molecular profiles, to propel ADC treatments forward. As our understanding of the molecular mechanisms driving cancer progression continues to expand, we anticipate the development of new ADCs that offer more effective and personalized therapeutic options for cancer patients.

Ex vivo mass spectrometry-based biodistribution analysis of an antibody-Resiquimod conjugate bearing a protease-cleavable and acid-labile linker

Immune-stimulating antibody conjugates (ISACs) equipped with imidazoquinoline (IMD) payloads can stimulate endogenous immune cells to kill cancer cells, ultimately inducing long-lasting anticancer effects. A novel ISAC was designed, featuring the IMD Resiquimod (R848), a tumor-targeting antibody specific for Carbonic Anhydrase IX (CAIX) and the protease-cleavable Val-Cit-PABC linker. In vitro stability analysis showed not only R848 release in the presence of the protease Cathepsin B but also under acidic conditions. The ex vivo mass spectrometry-based biodistribution data confirmed the low stability of the linker-drug connection while highlighting the selective accumulation of the IgG in tumors and its long circulatory half-life.

Targeted therapies in bladder cancer: signaling pathways, applications, and challenges

Bladder cancer (BC) is one of the most prevalent malignancies in men. Understanding molecular characteristics via studying signaling pathways has made tremendous breakthroughs in BC therapies. Thus, targeted therapies including immune checkpoint inhibitors (ICIs), antibody-drug conjugates (ADCs), and tyrosine kinase inhibitor (TKI) have markedly improved advanced BC outcomes over the last few years. However, the considerable patients still progress after a period of treatment with current therapeutic regimens. Therefore, it is crucial to guide future drug development to improve BC survival, based on the molecular characteristics of BC and clinical outcomes of existing drugs. In this perspective, we summarize the applications and benefits of these targeted drugs and highlight our understanding of mechanisms of low response rates and immune escape of ICIs, ADCs toxicity, and TKI resistance. We also discuss potential solutions to these problems. In addition, we underscore the future drug development of targeting metabolic reprogramming and cancer stem cells (CSCs) with a deep understanding of their signaling pathways features. We expect that finding biomarkers, developing novo drugs and designing clinical trials with precisely selected patients and rationalized drugs will dramatically improve the quality of life and survival of patients with advanced BC.

Antibody-Drug Conjugates and Ocular Toxicity

Antibody-drug conjugates (ADCs) are a growing class of chemotherapeutic agents for the purpose of treating cancers that often have relapsed or failed first- and second-line treatments. ADCs are composed of extremely potent cytotoxins with a variety of side effects, one of the most significant being ocular toxicity. The available literature describes these toxicities as varying in severity and in incidence, although with disparate methods of evaluation and management. Some of the most common toxicities include microcyst-like epithelial keratopathy and dry eye. We discuss proposed mechanisms of ocular toxicity and describe the reports that mention these toxicities. We focus on ADCs with the most published literature and the most significant effects on ocular tissue. We propose areas for further investigation and possible ideas of future management. We provide a comprehensive look at the reports of ADCs in current literature to better inform clinicians on an expanding drug class.