Therapeutic Antibodies in Breast Cancer

The discovery of HER2 and development of trastuzumab pioneered the field of targeted therapy in breast cancer. Hoping to emulate the same clinical success, pharmaceutical companies have developed several antibodies against newly identified membrane-bound targets. Unfortunately, none of these agents has yet matched the thousands of lives saved by trastuzumab. In this article we review the most advanced therapeutic antibodies in breast cancer. While acknowledging their unquestionable benefit, we emphasize the need to better understand their biology and mechanisms of action in order to optimize their use in defined patient populations.