Biosimilars are gaining much attention as a favorable alternative to the standard drugs used in cancer treatment. Mark Pegram, MD, from the Stanford Women’s Cancer Center, Stanford, CA talks to us at the 2017 European Society for Medical Oncology (ESMO) conference held in Madrid, Spain to explain what biosimilars are and their goals. A recent Phase III clinical trial, REFLECTIONS B327-02 (NCT01989676), compared the efficacy of trastuzumab and a biosimilar in the treatment of HER2-positive first line metastatic breast cancer. Dr Pegram describes the study and talks us through the exciting results, telling us what they signify for the biosimilar tested.