Cost minimization analysis of subcutaneous trastuzumab versus intravenous biosimilar trastuzumab: policy recommendations for breast cancer treatment in Malaysia.

Purpose: Current clinical practice recommends switching innovator intravenous trastuzumab (IV-TZM_i) to subcutaneous trastuzumab (SC-TZM) to save healthcare resources. However, with the availability of biosimilar intravenous trastuzumab (IV-TZM_b), there is a need to re-evaluate the recommendation. Hence, this study aims to compare the cost and resource use of SC-TZM and IV-TZM_b in a Malaysian public healthcare facility.

Methods: This activity-based costing study consists of (1) a retrospective medical record abstraction to determine patient details to estimate drug costs and (2) a time-motion study to quantify personnel time, patient time, and consumables used. The total cost of both SC-TZM and IV-TZM_b were then compared using a cost-minimization approach, while differences were explored using an independent t-test. A sensitivity analysis was also conducted to determine the impact of uncertainties in the analysis.

Results: The mean total cost of SC-TZM and IV-TZM_b was USD 13,693 and USD 5,624 per patient respectively. The cost difference was primarily contributed by savings in drug cost of IV-TZM_b, a reduction of USD 8,546 (SD = 134), p < 0.001 compared to SC-TZM. Interestingly, SC-TZM had a significantly lower cost than IV-TZM_b for both the consumable and personnel cost, a reduction by USD 300 (SD = 17.6); p < 0.001 and USD 176 (SD = 7.3); p < 0.001 respectively. The sensitivity analysis demonstrated that the total cost difference between the formulation was mainly driven by drug costs.

Conclusion: The study evidenced that IV-TZM_b was a more economically viable option in Malaysian public healthcare currently compared to SC-TZM.