Abstract
Breast cancer is the most common cancer in women, with roughly half a million deaths per year worldwide. Among various approaches for breast cancer treatment, chemotherapy is predominantly used for patients at stages II-IV, and monoclonal antibody (mAb) therapy is used for patients with human epidermal growth factor receptor 2 (HER2) overexpression. Integrating the tumor specificity provided by unique mAbs and cytotoxicity of small molecule drugs, antibody-drug conjugates (ADCs) are a series of smart chemotherapeutics that have recently shown great promise in treating a number of cancer types. ADCs are designed to selectively attack and kill cancer cells with minimal toxicity to normal tissues. Ado-Trastuzumab emtansine (T-DM1) was the first and only ADC approved by the US Food and Drug Administration for HER2-positive breast cancer. Following the success of T-DM1, many novel ADCs have been developed, and their anticancer efficacies are currently undergoing preclinical or clinical investigation. The development of ADCs is a rapidly progressing field, and this review aims to summarize the most recent advances in ADCs targeting breast cancer over the past five years (2011-2016). The review highlights compositions and mechanisms of action of these newly developed ADCs and discusses current challenges and future directions of developing new ADCs for improved treatment of breast cancer.
Keywords: Antibody-drug conjugates, breast cancer, drug-antibody ratios, monoclonal antibody, targeted therapy, antigen.