Pharmaco-economic assessment of subcutaneous compared to intravenous trastuzumab in HER2-positive breast cancer patients: A single institution experience.

e19409 Background: Traditionally, trastuzumab is given through intravenous (IV) administration. Recently, subcutaneous (SC) trastuzumab formulation has been developed showing similar efficacy and safety with shorter administration time. This study aims to assess the pharmaco-economics of SC compared to IV trastuzumab in patients with HER2-positive breast cancer treated in a single institution in Saudi Arabia. Methods: We checked the average number of trastuzumab doses, both IV and SC, given per year in King Abdullah Medical City, Saudi Arabia. One-year pharmaco-economic analysis of either trastuzumab forms were performed separately. This analysis included direct medication price based on hospital purchasing in addition to costs of drug preparation kits, nursing administration utilities and staff working time, based on average duration of drug preparation/ administration in chemotherapy unit records. IV trastuzumab dose was calculated based on an average body weight of 80 kg. Results: On average, the total number of trastuzumab doses, both IV and SC, were 1000 doses per year. We calculated the overall cost of 1000 doses of IV compared to SC trastuzumab separately. The average costs of one dose of IV and SC trastuzumab were 2,099 and 1,619 USD, respectively. This is translated to 2,099,000 and 1,619,000 USD per year for IV and SC trastuzumab, respectively. Other costs of trastuzumab administration were 24,933 and 2,666 USD per year of IV and SC trastuzumab, respectively. IV and SC trastuzumab administration needed 2,000 and 83 working hours per year, respectively, resulting in 1,917 saving in nursing working hours per year. This is translated to 18,106 USD saving per year based on average nursing salary. IV and SC trastuzumab pharmacy preparation needed 333 and 33 working hours per year, respectively, corresponding to annual saving of 300 hours in pharmacist- working time and 10,106 USD of pharmacist salary. The overall cost of IV trastuzumab per year was 2,153,667 compared to 1,623,236 USD for SC trastuzumab which corresponds to 2,153 and 1,623 USD per dose for IV and SC trastuzumab, respectively. This is translated to 24.6% overall cost reduction with the SC formulation. Conclusions: SC trastuzumab is associated with favorable pharmaco-economic profile with considerable cost saving compared to the IV counterpart. This is coupled with significant reduction of administration time and improved convenience.