AB0218 NON MEDICAL SWITCH FROM ADALIMUMAB ORIGINATOR TO THE BIOSIMILAR GP2017 IN PATIENTS AFFECTED BY CHRONIC ARTHRITIS

Abstract

Background: The non-medical switch (NMS) from originator drugs to biosimilars is a possible strategy adopted by rheumatologists in order to control the expansion of pharmaceutic costs for the treatment fo patients affected by chronic arthritis. To date, few real life data on the switch from adalimumab (ADA) originator to its biosimilars are available. Objective(s): We aimed to evaluate efficacy and safety in a single-Centre cohort of patients affected by chronic arthritis who switched from ADA originator to the biosimilar GP2017. Method(s): Patients affected by rheumatoid arthritis (RA), psoriatic arthritis (PA) and axial spondyloarthritis (axSpA) already on therapy with ADA originator in remission or low disease activity for at least 6 months were switched to GP2017 (March-June 2020). 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. Result(s): 88 patients were enrolled (M/F 36/52; mean age 55.8 +/- 12 years; 25 RA, 32 PA, 31 axSpA, mean duration of therapy 6.3 +/- 3.8 years). No statistically significant difference was observed in median DAS28-PCR/CDAI/SDAI values at the baseline and after 6 months [1.03 (0.96-3.43) vs. 1.21 (0-3.7) / 0 (0-15) vs. 0 (0-17) / 0 (0-15) vs. 0.5 (0-17.5)], DAPSA [0 (0-12.2) vs. 0 (0-15)] and BASDAI [0 (0-4.3) vs. 0 (0-6.4)]. The retention rate was 93.2%. 6/88 patients (6.8%) switched back to the originator. The causes of discontinuation were: disease reactivation in a single case (1.1%), subjective reasons/ nocebo effect in 5/88 cases (5.7%), including: general malaise and transient increased of blood pressure (n.1), dizziness, paraesthesia, arthralgia, headache (n.1), itch sine materia (n.1) and subjective worsening without objective disease flare (n.2). Conclusion(s): This is the first real life study showing that the NMS from ADA originator to GP2017 represents a safe practice that maintains the efficacy of the current treatment. However, a few cases of switchback were described, mainly attributed to nocebo effect [1].