Biologic therapy of breast cancer: focus on co-inhibition of endocrine and angiogenesis pathways

There remains a high unmet need for effective treatments for metastatic breast cancer. In recent years there have been many advances in the understanding of biological basis of cancer. Several cellular pathways have been identified that play crucial roles in causing or maintaining the cancer phenotype. Many new agents that target these pathways have entered the clinic or are being investigated. In order to improve the therapeutic efficacy seen with single-agent regimens, rational combinations of targeted agents are being evaluated in ongoing trials. The optimal sequencing and combination of agents has yet to be established. Endocrine and vascular endothelial growth factor pathways are the two most prominent pathways active in breast cancer cells and inhibition of either of these is associated with clinical benefit. Here we discuss the rationale for simultaneously targeting these pathways and highlight ongoing clinical trials.