Ab0429 eight-month follow-up of the non-medical switch from etanercept bio-originator to gp-2015 or sb4 etanercept biosimilars in patients with chronic inflammatory arthropathies: a monocentric observational study

Background After the expiration of bio-originators’ licenses, the development of less expensive biosimilars has prompted the switch to these drugs. Data on the switch from etanercept (ETA) bio-originators to biosimilars are reassuring [1-2] but still limited. Objectives This observational study evaluated the real-life effectiveness of a non-medical switch from ETA bio-originator to GP-2015 or SB4 biosimilars in our cohort of patients with inflammatory chronic arthritis. Methods We enrolled consecutive adult patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS) classified according to standard criteria switched from ETA bio-originator to GP-2015 or SB4 biosimilars for administrative/economic reasons. The date of the switch was the baseline (T0). Patients were reassessed after 4 (T4) and 8 months (T8). At T0, T4, and T8, data on demographic and clinical/laboratory features were registered. Patient-reported outcomes (PROs), such as visual analog scale (VAS 0-10) for pain and global assessment (PGA) and functional status by Health Assessment Questionnaire (HAQ) were used, together with disease-specific scores (DAS28-CRP for RA, DAPSA for PsA, ASDAS-CRP and BASDAI for AS). We assessed the same data at the time of early discontinuation for inefficacy (loss or lack of efficacy – LoE or LaE) or adverse events (AEs). Results One hundred and twelve patients switched from ETA bio-originator to GP-2015 [45 RA, F:M=33:12, median age 67 years (IQR 24), median disease duration 214 months (IQR 180), median exposure to bio-originator 126 months (IQR 97); 48 PsA, F:M=18:30, median age 59 years (IQR 18), median disease duration 168 months (IQR 120), median exposure to bio-originator 120 months (IQR 96); 19 AS, F:M=7:12, median age 55 years (IQR 16), median disease duration 162 months (IQR 245), median exposure to bio-originator 132 months (IQR 82)]. No differences were found in the clinical and laboratory parameters compared to T0 in RA and PsA, while AS patients showed an improvement of BASDAI at T8 compared to T4 (p=0.0273). Interestingly, at T8 RA patients experienced a worsening in the HAQ (p=0.0313) with respect to T0 (figure 1A) and PsA patients had a worsening of VAS pain compared to T4 (p=0.0371) (figure 1B). Four (8.8%) RA patients discontinued GP-2015 at T4 due to AEs (1 for recurrent infection of upper airways, 1 for injection site reaction, 1 for skin cancer, 1 for breast cancer). One (2%) PsA patient discontinued GP-2015 at T4 due to AE (oral ulcers). Twenty-eight patients switched from ETA bio-originator to SB4 [14 RA, F:M=13:1, median age 63.5 years (IQR 33), median disease duration 144 months (IQR 206), median exposure to bio-originator 84 months (IQR 96); 11 PsA, F:M=6:5, median age 54 years (IQR 12), median disease duration 205 months (IQR 198), median exposure to bio-originator 177 months (IQR 164); 3 AS, F:M=0:3; median age 56 years, median disease duration 210 months, median exposure to bio-originator 120 months]. An improvement of DAPSA at T4 compared to T0 was observed in PsA patients (p=0.0469). At T8, no differences were found compared to T0. One (9%) PsA patient experienced LoE at T4. Conclusion Our data indicate that the switch to GP-2015 or SB4 ETA biosimilars from ETA bio-originator does not bear clinical and laboratory differences in patients with chronic arthropathies. The worse outcome in PROs, which we also observed in the adalimumab bio-originator to biosimilar switch (3), does not reflect a worsening of disease activity indexes and could indicate a possible nocebo response. References [1] Ditto MC et al. Sci Rep 2020 [2] Jaworski J et al. Arthritis Res Ther 2019 [3] Scrivo R et al. Clin Exp Rheumatol 2022 Figure 1. - Change in the HAQ in RA patients switching from ETA bio-originator to GP-2015 (A); change in the pain VAS score (0-10) in PsA patients switching from ETA bio-originator to GP-2015 (B) Data are shown as Tukey boxplots; lines represent the median level with 25 th -75 th percentile; dots represent outliers. Acknowledgements: NIL. Disclosure of Interests None Declared.