From intravenous to subcutaneous pertuzumab/trastuzumab in breast cancer: Clinical and pharmacoeconomic drivers and barriers to switching

Purpose: Patients with HER2+ breast cancer (BC) can receive pertuzumab/trastuzumab (PT) subcutaneous (SC) or intravenous (IV) with similar efficacy. This study explores patients and healthcare professionals (HCPs) perceptions post-PT-SC implementation, alongside a pharmacoeconomic analysis. Methods: This multicentre observational study included semi-structured interviews with HER2+ BC patients (SC or IV) and HCPs from six Lombardy (Italy) BC units plus a pharmacoeconomic analysis of organisational and cost impact. Data were analysed using descriptive statistics and thematic analysis to identify key themes: safety perception, treatment comfort, and trust issues. Results: Among 102 patients, 10.8% received only IV, 12.7% only SC, and 76% both; 3.8% of SC patients discontinued due to side effects. Trust scores were high for oncologists and nurses, positively influencing switching. SC was perceived as quicker (81.4%), less invasive (69.8%) and timesaving (71.2%), with over half (56.9%) perceiving equal safety. Among patients exposed to both, 90.7% preferred SC due to lower invasiveness. SC was perceived to be associated with fewer gastrointestinal side effects but more local reactions. IV-preferring patients cited fear of side effects, reduced efficacy, and lack of HCP recommendation. Most HCPs rated SC as faster and workflow-improving; observation and error risk were not major barriers. Non-drug costs were 63% lower with SC, while total treatment costs were comparable (+1.9%). Conclusion: Both patients and HCPs showed high acceptance of PT-SC, offering clear benefits in time, cost, and workflow efficiency. High trust in oncologists and nurses supported its adoption. Time savings may enhance hospital efficiency and patient experience.