Optimizing the safety of antibody-drug conjugates for patients with solid tumours

Over the past 5 years, improvements in the design of antibody-drug conjugates (ADCs) have enabled major advances that have reshaped the treatment of several advanced-stage solid tumours. Considering the intended rationale behind the design of ADCs, which is to achieve targeted delivery of cytotoxic molecules by linking them to antibodies targeting tumour-specific antigens, ADCs would be expected to be less toxic than conventional chemotherapy. However, most ADCs are still burdened by off-target toxicities that resemble those of the cytotoxic payload as well as on-target toxicities and other poorly understood and potentially life-threatening adverse effects. Given the rapid expansion in the clinical indications of ADCs, including use in curative settings and various combinations, extensive efforts are ongoing to improve their safety. Approaches currently being pursued include clinical trials optimizing the dose and treatment schedule, modifications of each ADC component, identification of predictive biomarkers for toxicities, and the development of innovative diagnostic tools. In this Review, we describe the determinants of the toxicities of ADCs in patients with solid tumours, highlighting key strategies that are expected to improve tolerability and enable improvements in the treatment outcomes of patients with advanced-stage and those with early stage cancers in the years to come. Advances in technology have enabled the development of several novel antibody-drug conjugates (ADCs) with encouraging clinical activity in patients with advanced-stage solid tumours. Indications for these therapies are expanding rapidly to earlier lines of therapy. Nonetheless, the toxicities of these various agents are not trivial and can be fatal, even in patients with early stage disease. In this Review, the authors summarize the toxicities of ADCs in patients with solid tumours both as monotherapies and in combination with other agents and discuss various ongoing research efforts attempting to optimize the therapeutic index of these agents.

Automated summary

Improvements in the design of antibody-drug conjugates (ADCs) have reshaped the treatment of advanced-stage solid tumours, but toxicities of ADCs are still a concern. Ongoing efforts are being made to enhance the safety of ADCs, including optimizing dose and treatment schedule, modifying ADC components, identifying predictive biomarkers for toxicities, and developing innovative diagnostic tools.