biomedicines Review Advances and Limitations of Antibody Drug Conjugates for Cancer Candice Maria Mckertish and Veysel Kayser * Sydney School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia;
[email protected] * Correspondence:
[email protected]; Tel.: +61-2-9351-3391 Abstract: The popularity of antibody drug conjugates (ADCs) has increased in recent years, mainly due to their unrivalled efficacy and specificity over chemotherapy agents. The success of the ADC is partly based on the stability and successful cleavage of selective linkers for the delivery of the payload. The current research focuses on overcoming intrinsic shortcomings that impact the successful devel- opment of ADCs. This review summarizes marketed and recently approved ADCs, compares the features of various linker designs and payloads commonly used for ADC conjugation, and outlines cancer specific ADCs that are currently in late-stage clinical trials for the treatment of cancer. In addition, it addresses the issues surrounding drug resistance and strategies to overcome resistance, the impact of a narrow therapeutic index on treatment outcomes, the impact of drug–antibody ratio (DAR) and hydrophobicity on ADC clearance and protein aggregation. Keywords: antibody drug conjugates; drug resistance; linkers; payloads; therapeutic index; target specific; ADC clearance; protein aggregation Citation: Mckertish, C.M.; Kayser, V. Advances and Limitations of Antibody Drug Conjugates for 1. Introduction Cancer. Biomedicines 2021, 9, 872. Conventional cancer therapy often entails a low therapeutic window and non-specificity https://doi.org/10.3390/ of chemotherapeutic agents that consequently affects normal cells with high mitotic rates biomedicines9080872 and provokes an array of adverse effects, and in some cases leads to drug resistance [1].