Introduction: Cancer treatment has evolved significantly with the introduction of biologic agents, especially in the breast cancer (BC) area. The use of trastuzumab for HER2 amplified BCsignificantly improves survival in both metastatic and early stage disease. Although the efficacy of biologics is undeniable, their high costs increased the expenses of cancer care, becoming a problem to health-care systems, mainly in low and middle-income, but also for high-income countries. In an attempt to lower the costs and allow a greater access of biologics to cancer patients, biosimilars are rapidly being developed as an alternative to the reference biologics. Areas covered: A literature review based on the MEDLINE/PubMed search about biosimilars allied with the FDA and EMA's latest statements of this topic were conducted to summarize the development and the use of currently available biosimilars for BC, with a focus on trastuzumab. Expert opinion: Biosimilars are drugs that have similar efficacy and safety profile to those of the original biological product with equivalent immunogenicity and, as these agents hold the potential to improve patient´s access to monoclonal antibodies because their production costs are estimated to be 20-30% lower compared to the reference product, they are progressively being incorporated into clinical practice.
Keywords: Biologic agents; HER2 amplified breast cancer; biosimilars; trastuzumab.