Biosimilars, molecules intended to mimic the structure and function of existing pharmaceutical agents, are still in the early stages of being implemented into cancer treatments. Richard Markus, MD, PhD, from Amgen, Los Angeles, CA discusses the intended purpose of biosimilars and talks about why Amgen feel that their new biosimilar of trastuzumab, ABP 980, is an important new addition to the field. This interview was recorded at the European Society for Medical Oncology (ESMO) 2017 conference held in Madrid, Spain.