Safety profile of subcutaneous trastuzumab in patients with HER2-positive early breast cancer: The French HERmione non-interventional prospective study

Objectives: HERmione study was conducted to assess, in human epidermal growth factor receptor 2 (HER2)-positive early breast cancer (eBC), the safety profile of subcutaneous (SC) formulation of trastuzumab in real-life in France. Materials and methods: This prospective, non-interventional study included 511 patients planned to be treated in both neoadjuvant and adjuvant settings with a follow-up of 12 months maximum in 101 sites. The safety analyses concerned 505 patients. Primary endpoint was the description of systemic safety and local tolerability of the SC trastuzumab. Results: The median age of patients was 58 years. Over the study, 2449 adverse events (AEs) occurred in 422 (83.6%) patients (asthenia, arthralgia, radiation skin injury, myalgia, hot flush and diarrhea in ≥10% of patients): 92 AEs (3.8%) were grade ≥3 (radiation skin injury in 1.8% of patients and febrile neutropenia in 1.4% of patients), 76 (3.1%) were serious (mainly febrile neutropenia in 1.4% of patients) and 336 (13.7%) were treatment-related (mainly injection site pain in 9.1% of patients). Congestive Heart Failure occurred in 58 (11.5%) patients and was related to treatment in 4.6% of patients. Only 34 AEs (1.4%) in 27 (5.4%) patients led to permanent treatment discontinuation. One death was assessed as not treatment-related. Quality of life (QoL) analyses showed no deterioration of global health status. Conclusion: The HERmione study showed that, in a real-life setting, the safety of SC trastuzumab administered in HER2-positive eBC patients is consistent with data reported from previous clinical trials, without new safety concerns or QoL deterioration.