Background and Importance Breast cancer is one of the tumours with the highest incidence in Spain, and its pharmacological treatment generates a huge economic impact. Clinical trials are essential for evaluating the efficacy and safety of new therapies, and also provide a financial benefit to the public health system.

Aim and Objectives The aim of this research is to calculate the saving costs in drugs, derived from the participation of breast cancer patients in clinical trials (based on the drug free support provided by the sponsor of each study).

Material and Methods A retrospective analysis was made of all breast cancer clinical trials initiated in our hospital since January 2020, and all patients included in these trials were selected. The data collected were: trial phase, investigational drug, number of subjects enrolled and number of treatment cycles received. The Oncology Department was contacted to discuss the therapeutic alternative of choice and its theoretical duration if the patient had not participated in the clinical trial. The cost of each option was calculated using the acquisition price of the drug (laboratory sale price – discount + 4% VAT). Information was obtained from the database of the clinical trials unit.

Results Since 2020, 8 breast cancer clinical trials (2 phase II and 6 phase III), were initiated in our hospital. Were included 10 subjects, receiving a total of 106 treatment cycles. The investigational medical products studied were: trastuzumab and conjugates, pertuzumab, atezolizumab, olaparib, alpelisib and palbociclib. The overall cost saving was €198.775,32. The trial with the highest cost impact offers a saving of €8.269,48 per cycle of each enrolled patient. The drug with highest avoided cost was pemetrexed (€32.890,54).

Conclusion and Relevance Clinical trials in breast cancer patients, in addition to offering the possibility of access to new therapeutic alternatives, represent a considerable economic saving and a significant reduction in pharmaceutical costs. It is important to improve patient recruitment in these types of studies.

Conflict of Interest No conflict of interest