Background Adalimumab is a subcutaneous anti-tumour necrosis factor antibody therapy used in the treatment of numerous pathologies related to rheumatology, dermatology and gastroenterology. This drug is on the top ranking of the annual hospital budget. The data exclusivity period on the reference drug (Humira) is close to expiration.

Purpose To analyse the cost of treatment with the biosimilar adalimumab in comparison with its reference drug.

Material and methods All patients treated (September2015–August 2016) with adalimumab were included. Data were obtained from electronic medical records (SAP). The total cost was calculated using the current reference price, €436.06, and separated by clinical department: rheumatology, dermatology and gastroenterology. Considering the same price reduction (30% less than the reference price) for the biosimilar adalimumab than that observed for other biosimilar drugs, we estimated the price of biosimilar adalimumab as €305.24. Cost savings were calculated considering the expected biosimilar adalimumab price for the same period.

Results 326 patients were treated with 5894 doses of adalimumab during the study period. The annual cost was €2 570 137.6. Divided by department: rheumatological pathologies accounted for 53.4% of the cost, followed by gastroenterological pathologies 28.8% and dermatological 17.1%; the cost for other areas accounted for less than 1% of the total cost. The economic impact of switching to a biosimilar could result in annual savings of €771 041.3.

Conclusion As biosimilar therapy has shown similar results to those observed with the reference drug in clinical practise, we consider that the cost savings associated with the use of biosimilars contributes to the sustainability of the National Health System.

No conflict of interest