PRM42 - COST MODEL OF SWITCHING FROM ENBREL TO ETANERCEPT BIOSIMILARS, FOR NON MEDICAL REASONS, IN RHEUMATOID ARTHRITIS PATIENTS IN SPAIN

Abstract

To assess the potential cost offsets of continuing stable Enbrel therapy versus switching to etanercept-biosimilars for non-medical reasons in Rheumatoid Arthritis (RA), from the Spanish National Health System (NHS) perspective. A cohort-based decision tree analysis was developed to compare within a 1-year time-horizon the cost of continuing Enbrel therapy versus switching to etanercept-biosimilars for non-medical reasons in stable RA patients defined as being in remission or with low disease activity for at least 6 months. The model uses as inputs results of a survey of 30 rheumatologists in Spain, and data from the DANBIO Registry. Stable patients in the model can either switch to etanercept-biosimilar for non-medical reasons or stay on Enbrel, according to proportions derived from the DANBIO registry. The non-medical switch is associated with treatment adjustment costs including drug costs (public exfactory prices with mandatory deduction or reference prices), monitoring, hospitalization and other healthcare costs (€2018). Following the first switch for non-medical reasons, patients who have been switched to the etanercept-biosimilar have the option to switch back to Enbrel, or to another etanercept-biosimilar or to a therapy with another mode of action. If after 3-6 months do not respond to the first etanercept-biosimilar. In accordance to proportions from the DANBIO registry, 78.7% of stable patients treated with Enbrel switched to etanercept-biosimilars and 21.3% stayed on Enbrel. After 3 months of treatment, 18.2% of patients switched to etanercept-biosimilars switched to another mode of action (adalimumab, tocilizumab and abatacept, in similar proportion). Using the described patient journey scenario, the annual cost per-patient of switchers was €11,478.90 compared to the annual cost per patient of continuers (with Enbrel) was €10,251.14. This economic model suggests that switching from Enbrel to etanercept-biosimilars leads to higher cost (€1,227.75) than maintaining Enbrel treatment for 1 year using the Spanish NHS perspective.