Real-world clinical scenarios during introduction of trastuzumab biosimilar for HER2-positive breast cancer in the European Union.

Abstract

Aim: Trastuzumab-anns is an intravenously administered biosimilar to trastuzumab approved by the EMA and USFDA for treatment of HER2+ early and metastatic breast cancer as well as metastatic gastric cancer. Lack of real-world characterization of biosimilar use has hindered uptake. Methods: This observational chart review characterizes 488 patients who received trastuzumab-anns in EU clinical practice settings. Results: Approximately 2/3rds of patients initiated trastuzumab-anns in adjuvant and neoadjuvant settings and most were naive new starters (70%). 30%were switchers from another trastuzumab, among whom 48% switched from trastuzumab iv. reference product. Common reasons for trastuzumab-anns discontinuation were a switch to another biosimilar product (34.8%, n=85) or to trastuzumab reference product (15.6%, n=38). Conclusion: Trastuzumab-anns was widely used in various treatment settings for HER2+ breast cancer.