ERBB2 and breast carcinoma: In the primary analysis of the prospective, randomized, multicenter phase 3 TROIKA study, HD201, a trastuzumab biosimilar, was shown to be equivalent to the referent trastuzumab in patients with ERBB2-positive early breast cancer (EBC) based on the primary endpoints of locally assessed total pathologic complete response (tpCR) [1].