Efficacy and safety of a single switch from etanercept originator to etanercept biosimilar in a cohort of inflammatory arthritis

AntiTNF-α biosimilars are broadly available for the treatment of inflammatory arthritis. There are a lot of data concerning the maintenance of clinical efficacy after switching from originators to biosimilars; therefore, such a transition is increasingly encouraged both in the US and Europe. However, there are reports about flares and adverse events (AE) as a non-medical switch remains controversial due to ethical and clinical implications (efficacy, safety, tolerability). The aim of our work was to evaluate the disease activity trend after switching from etanercept originator (oETA-Enbrel) to its biosimilar (bETA-SP4/Benepali) in a cohort of patients in Turin, Piedmont, Italy. In this area, the switch to biosimilars is stalwartly encouraged. We switched 87 patients who were in a clinical state of stability from oETA to bETA: 48 patients were affected by Rheumatoid Arthritis (RA),26 by Psoriatic Arthritis (PsA) and 13 by Ankylosing Spondylitis (AS).We evaluated VAS-pain, Global-Health, CRP, number of swollen and tender joints, Disease Activity Score on 28 joints (DAS28) for RA, Disease Activity in Psoriatic Arthritis (DAPSA) for PsA, Health Assessment Questionnaire (HAQ) and Health Assessment Questionnaire for the spondyloarthropathies (HAQ-S),Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) for AS patients. 11/85 patients (12.6%) stopped treatment after switching to biosimilar etanercept. No difference was found between oETA and bETA in terms of efficacy. However, some arthritis flare and AE were reported. Our data regarding maintenance of efficacy and percentage of discontinuation were in line with the existing literature.