4CPS-091 Cost saving impact from choosing intravenous or subcutaneous daratumumab based on weight patient for the treatment of multiple myeloma

<h3>Background and Importance</h3> Daratumumab is a monoclonal antibody that specifically targets the CD38 antigen expressed on myeloma cells. Its introduction in subcutaneous form offers faster and more convenient administration, significantly reducing infusion time as well as a lower risk of infusion-related reactions. However, it is important to analyse which patients it is efficient to use it in. <h3>Aim and Objectives</h3> The aim of this study was to evaluate the cost saving impact depending on the choice of subcutaneous or intravenous daratumumab in the treatment of multiple myeloma in a tertiary hospital. <h3>Material and Methods</h3> Observational, retrospective study of patients treated with daratumumab between January 2022 and December 2023 in a tertiary hospital. Variables collected: demographics (sex and age), number of patients, weight and economic data (price of intravenous daratumumab and subcutaneous daratumumab). Variables studied: total cost of patients treated in our hospital with subcutaneous daratumumab and total cost if intravenous or subcutaneous administration had been adapted based on weight. <h3>Results</h3> 57 patients were included in this study, mean age of 70.98 ± 11.66. 38.6% (n=22) of them were men. The average weight was 66.8 ± 13.26 kilograms (kg). Intravenous daratumumab has a dosage of 16 milligrams (mg) per kg of weight and subcutaneous daratumumab has a fixed-dose of 1800 mg. In our hospital, the price of one daratumumab-400 mg vial is €967.61 (2.42 €/mg), €241.85 for one daratumumab-100mg vial (2.42 €/mg) and €2902.85 for one daratumumab-1800 mg vial for subcutaneous injection (1.61 €/mg). All our patients received subcutaneous daratumumab, which represents a total cost of €2,696,747.65. If the dosage had been based on the patient‘s weight (over 75 kg, subcutaneous daratumumab and under 75 kg, intravenous daratumumab), the total cost would have been €2,327,533.04, which represents a cost saving of 13.69% (€369,214.61). <h3>Conclusion and Relevance</h3> This study demonstrates that subcutaneous daratumumab administration in patients with multiple myeloma results in significant economic savings in patients weighing more than 75 kg. Consideration of weight in selecting the route of administration is a strategy that could reduce costs by 13.69%. Therefore, it is critical to balance economic efficiency with patient safety and comfort, especially in cases where subcutaneous administration is feasible and preferable. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest