Evaluation of cost and infusion-related reactions among intravenous trastuzumab, subcutaneous trastuzumab, and trastuzumab biosimilars at an academic medical center

Introduction Trastuzumab is a vital treatment option for human epidermal growth factor 2 positive breast cancer. Since 2017, there have been 5 trastuzumab biosimilars approved for use. Despite hypotheses of infusion-related reactions among intravenous trastuzumab, subcutaneous trastuzumab, and trastuzumab biosimilars, there is minimal available literature comparing these agents. This evaluation will compare the rate of infusion-related reactions among these agents, evaluate our institution's utilization, and compare acquisition costs to determine if there is a potential cost savings by utilizing specific agents as our formulary preferred medication. Methods We retrospectively analyzed medical records to identify the incidence of infusion-related reaction after administration of intravenous or subcutaneous trastuzumab or trastuzumab biosimilars. Additionally, we conducted a cost analysis to identify potential cost savings by switching to an alternative institutional preferred agent. Infusion chair time was calculated to identify chair time savings with subcutaneous administration. Results There were 183 patients included in this study. Seven patients (3.8%) experienced an infusion-related reaction. The most utilized agent within our cohort was intravenous trastuzumab. During our study period, 181 patients received intravenous infusions, which could allow for substantial infusion chair savings by switching to trastuzumab/hyaluronidase, the subcutaneous formulation. Beyond the chair time, direct drug cost savings were also identified when comparing the costs of each of the evaluated medications. Conclusion Subcutaneous trastuzumab or trastuzumab biosimilars do not pose a greater risk of infusion-related reactions compared to intravenous trastuzumab and may offer more affordable treatment options for breast cancer patients who qualify for trastuzumab therapy.