Additional One-Year Follow-Up Study To Evaluate Safety And Survival In Patients Who Have Completed Neoadjuvant-Adjuvant Treatment With Sb3 (Trastuzumab Biosimilar) Or Reference Trastuzumab In Her2-Positive Early Or Locally Advanced Breast Cancer.

e12631Background: SB3 was approved by the European Commission as a trastuzumab (TRZ) biosimilar. Here, we report safety and survival data with a follow-up of at least 12 treatment-free months after completing 12 months of neoadjuvant-adjuvant therapy. Methods: Patients with HER2 positive early or locally advanced breast cancer were randomly assigned to receive 8 cycles of SB3 or TRZ in neoadjuvant setting concurrently with chemotherapy (4 cycles of docetaxel followed by 4 cycles of 5-fluorouracil/epirubicin/cyclophosphamide). Patients then underwent surgery followed by 10 cycles of adjuvant SB3 or TRZ. After completion of therapy, patients from selected countries were asked for consent to participate in a five-year follow-up study (NCT02771795). Recommended visits were every 6 months for 2 years and annually for the following 3 years. The aim of this study was to observe the incidence of symptomatic congestive heart failure (CHF), asymptomatic significant left ventricular ejection fraction (LVEF) decrease...