Economic Evaluation of Ready-to-Dilute Thiotepa (Tepylute®): Institutional Cost Offsets and Time Savings Compared to Lyophilized Thiotepa in a United States Hospital Pharmacy

Orlaith Ryan,1 Maurice Clancy,1 Alanna MacDonald,2 Laura Pastor,2 Megan Bourque2 1Shorla Oncology, Clonmel, Co., Tipperary, Ireland; 2Value and Evidence Department, EVERSANA, Burlington, ON, CanadaCorrespondence: Orlaith Ryan, Shorla Oncology, Questum Acceleration Centre Ballingarrane Science and Technology Park, Clonmel, Co., Tipperary, E91 V329, Ireland, Tel +353 87 950 9534, Email [email protected]: Thiotepa is an intravenous alkylating agent used with other chemotherapy drugs to treat several forms of cancers. Preparation of thiotepa requires reconstitution of powder in sterile water, followed by dilution of the solution with sodium chloride 0.9% solution for injection. The reconstitution of lyophilized powdered drug formulations may pose challenges as it can increase the risk of preparation errors, leading to wastage or potential clinical consequences, and extend preparation time compared to ready-to-dilute formulations; one study found that 15% of thiotepa doses were made out-of-tolerance. Tepylute® is a ready-to-dilute formulation of thiotepa and has been approved by the United States Food and Drug Administration for the treatment of breast and ovarian adenocarcinoma. The objective of this study was to explore the economic impact to a hospital pharmacy of using ready-to-dilute Tepylute® versus a lyophilized powdered formulation of thiotepa.Patients and Methods: A cost offset model was created in Microsoft Excel™, the analysis compared a current scenario (thiotepa: 100% market share) with a future scenario (Tepylute®: 100% market share) for a hospital pharmacy treating 96 cancer patients annually. Costs (2024 USD) included drug acquisition, compounding time, drug wastage, and clinical consequences due to reconstitution errors. Incremental costs, cost offsets, and pharmacy time saved were evaluated.Results: For a hypothetical hospital pharmacy, use of Tepylute® versus a lyophilized powdered formulation of thiotepa resulted in savings of $339,777 over 1-year ($3539 per patient), primarily from reduced drug acquisition costs, as well as a reduction in drug wastage, clinical consequences due to reconstitution errors, and compounding time. Results were consistent across sensitivity and scenario analyses.Conclusion: Modeled results demonstrate that ready-to-dilute Tepylute® may save time, reduce acquisition and preparation costs, and lower clinical risks from preparation errors. This study is among the first to quantify potential savings from switching to a ready-to-dilute formulation.Keywords: costs and cost analysis, pharmacy administration, drug costs, thiotepa, cost savings, drug compounding