Trastuzumab emtansine is the standard second-line treatment following horizontal blockade in first line of advanced HER-2 positive breast cancer: A plant that has still to grow

From 2001 until now, treatment of HER-2 expressing breast cancer is radically changed. The cardinal role of HER-2 antigen [1] and the power of blocking HER-2 signalling by trastuzumab [2] have been increasingly recognized as the bricks on which a robust therapeutic strategy could be built. In fact, Cleopatra study in first-line [3], Emilia in second line [4] and Th3resa [5] in third line are only confirmative of this statement. The novel antibody pertuzumab, added to the trastuzumab in the triplet of Cleopatra study, significantly increases overall survival and progression-free survival as never before [3]. Trastuzumabado-emtansine (TDM-1) is an anti-HER2 antibody-drug conjugate (ADC). TDM-1 was pharmacologically developed on the solid axis of trastuzumab because the chemotherapeutic emtansine is too toxic to be used alone. This means that HER-2 pathway remains the way to arrive to tumor but the machine was empowered by a chemotherapeutic able to enhance the killing cell rate.