POS0601 DIFFERENCES IN DRUG SURVIVAL BETWEEN ORIGINATOR AND BIOSIMILAR PRODUCTS AMONG FIRST USERS OF EACH MOLECULE

Background: Biosimilar products of biological disease-modifying antirheumatic drugs (bDMARDs) entered the Swedish market in 2015, with regulatory approvals based on head to trials limited duration. Longer-term comparative drug survival, clinical practice, remains less well documented. Objectives: To compare survival between biosimilars and their originator among first starters etanercept, infliximab, adalimumab rituximab. Methods: Data from Rheumatology Quality register (SRQ) was used identify follow patients who started a ever treatment etanercept since April 2015 (originator=ETA,biosimilar= SB4), infliximab March 2014 (originator=IFX,biosimilar= CT-P13), January 2018 (originator=ADA biosimilars=SB5, ABP501), or rituximab (originator=RIT,biosimilar= GP2013), through December 31 st , 2019, date discontinuation drug, death. Discontinuation defined as lack effectiveness adverse events, while other reasons for interruption (including non-medical switch) were considered censoring events. Descriptive characteristics collected SRQ tabulated. Hazard ratios (HR) estimated using Cox regression, each analyzed separately, adjusted age,sex,indication,line treatment,disease duration,year start,region concomitant use csDMARD. Results: 9274 etanercept(49% 3609 infliximab(64% 3117 adalimumab(27% SB5, 14% ABP 501), 763 rituximab(39% Table 1. Patients starting CT-P13 GP2013 likely be biologics-naïve compared those product. Initiators SB5,ABP501 more likely,and likely,to csDMARDs products. ETA SB4 similar. The introduction biosimilar typically followed by decrease uptake originator, but change pricing later led reversal this pattern (Figure 1). For IFX,ADA,and RIT, similar its biosimilar(s). ETA,risk somewhat lower than originator(adjusted HR:0.87,95% confidence interval:0.79-0.95), descriptive vs. molecule, until 2019. Etanercept Infliximab Adalimumab Rituximab Originator SB5 501 N 4721 4553 1308 2301 1834 852 431 465 298 1289 1236 582 878 399 139 80 57 26 Adjusted hazard ratios* Ref 0.87 (0.79-0.95) 1.14 (0.99-1.31) 1.02 (0.83-1.26) 1.16 (0.88-1.52) 1.12 (0.68-1.85) Age, mean years (std ) 51 (16) (15) 49 48 52 59 60 Female, % 67% 65% 61% 64% 62% 75% 76% RA, 46% 48% 39% 35% 33% 42% 43% Bionaïve, 72% 69% 45% 52% 53% 38% Disease duration, 11 (12) (11) 12 (13) 14 (19) 15 DAS28, 4.0 (1.3) (1.4) 4.1 3.7 3.8 4.5 4.7 Concomitant csDMARDs, 47% 57% 37% 49% 36% Abbreviations: RA=rheumatoid arthritis. csDMARDs=conventional synthetic DMARD, std=standard deviation. Figure Number starts during follow-up time, molecule Conclusion: Despite identical indications therapeutic positioning, there are some differences baseline start ADA, IFX RIT biosimilars. There no possible exception although observed difference should interpreted light unmeasured residual channeling. Disclosure Interests: Daniela Di Giuseppe: None declared, Hannah Bower: Bénédicte Delcoigne: Thomas Frisell: Katerina Chatzidionysiou Consultant of: Eli Lilly, AbbVie Pfizer, Ulf Lindström: Christopher Sjowall: Elisabet Lindqvist: Johan Askling Grant/research support from: Abbvie, Astra-Zeneca, BMS, MSD, Roche, Samsung Bioepis, Sanofi, UCB,