LAUSR

In the last decades, new biologic drugs were introduced for the treatment of chronic inflammatory arthropathies, progressively leading to a relevant increase of medical costs. However, the introduction of biosimilars (biologic molecules similar to branded drugs with expired patent) permitted to optimize the financial resources. The non-medical switch (NMS) is the switch from a biologic originator to a biosimilar agent for economic reasons only, on the basis of the substantial equivalence as regards efficacy and safety between originator and biosimilar drugs.In literature, several evidences from clinical trials and registry studies showed that the switch from etanercept originator to biosimilar SB4 was safe [1]. Instead no sufficient data may be found regarding the biosimilar GP2015.We aimed to evaluate efficacy, safety, and retention rate in a series of patients with chronic arthritis treated with etanercept originator who underwent to NMS towards the ETN biosimilar GP2015.From March to June 2020, all patient referred in our Centre affected by rheumatoid arthritis (RA), psoriatic arthritis (PA) and axial spondyloarthritis (axSpA) treated with etanercept originator and in remission/low disease activity for at least 6 months underwent to NMS. Data on disease activity (DAS28-PCR/CDAI/SDAI; DAPSA; BASDAI), eventual adverse events and causes of withdrawal of therapy were collected at 2, 4 and 6 months after the switch.We recruited 71 consecutive patients (M/F: 24/47; mean age 55,8± 11,1 years; 39 RA; 15 PA; 17 axSpA; mean duration therapy 7.3±3.8 years). Disease activity was unchanged for almost all patients after 6 months from the switch (median ΔDAS28-PCR/CDAI/SDAI: 0,1/0/0,5; median ΔDAPSA: 0; median ΔBASDAI: 0) Moreover, the 6-month retention rate was 97.2%. Only 2 patients (2.8%) switched back to the originator due to loss of efficacy in one case and adverse events in the second case (paraesthesia, headache, dizziness and worsening of arthralgia).Our study confirmed that the NMS from ETN originator to GP2015 represents a safe practice that maintains the efficacy of the current treatment.[1]Glintborg B, AG, Omerovic E, et Al. To switch or not to switch: results of a nationwide guideline of mandatory switching from originator to biosimilar etanercept. One-year treatment outcomes in 2061 patients with inflammatory arthritis from the DANBIO registry. Ann Rheum Dis 2019; 78:192–200.None declared