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

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. 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. 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. 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.