Long-Term Safety and Effectiveness of PF-05280014 (a Trastuzumab Biosimilar) Treatment in Patients with HER2-Positive Metastatic Breast Cancer...Randomized patients received intravenous PF-05280014 or trastuzumab-EU, each plus paclitaxel, until objective disease progression. OS...The estimated survival rates (95% CI) at 1 year were 89.4% (85.6–92.2) for the PF-05280014 group and 87.5% (83.5–90.6) for the trastuzumab-EU group.