POS1178 DRUG DISCONTINUATION IN INFLAMMATORY ARTHRITIS FOLLOWING MANDATORY NON-MEDICAL SWITCHING FROM ORIGINATOR TO BIOSIMILAR IN QUEBEC, CANADA

Le résumé fourni par la source

Background: In April 2022, the Canadian province of Quebec introduced a mandatory non-medical switch to biosimilars for persons on bio-originators to manage healthcare costs. Objectives: To describe real-world experience with biosimilars used for inflammatory arthritis in the context of this policy change. Methods: We used data from three adult clinical registries in Quebec: the RHUMADATA prospective arthritis registry, the Early Undifferentiated Polyarthritis (EUPA) cohort, and the University of Sherbrooke Registry of Advanced Therapies (USRAT). We studied individuals who transitioned from the originator biologics to their equivalent biosimilars – infliximab, etanercept (ETA), adalimumab (ADA), and rituximab– from the time of the non-medical switching policy (April 2021) through May 2023. Baseline characteristics were assessed at the time of biosimilar initiation, including age, sex, underlying condition (ankylosing spondylitis, rheumatoid arthritis, psoriatic arthritis), disease duration, body mass index, alcohol and tobacco use, and quality of life (Health Assessment Questionnaire for RHUMADATA, and the Modified HAQ for EUPA and USRAT). Prior medication history, including other biologics, corticosteroids, and non-biologic immunosuppressants, was also reviewed. Reasons for discontinuation were documented by treating physicians. Discontinuation was estimated using Kaplan-Meier methods. Results: We studied 110 individuals with inflammatory arthritis, most switching to ADA (68%) or ETA (20%) biosimilars. Females were 61% of the cohort, and at biosimilar transition, the mean age was 56.9 years (standard deviation 15.8). Additional baseline characteristics are presented in Table 1. Individuals were followed for a median of 1.5 years (interquartile range 0.5 to 1.9 years). During this time, 16 individuals discontinued their treatment, for a discontinuation rate of 115.7 (95% confidence interval, CI 66.1-187.8) events per 1,000 person-years. As seen in Figure 1, the probability of discontinuation was 11.2% (95% CI: 4.4%-17.6%) by Year 1 and 18.2% % (95% CI: 9.3% to 26.2%) by Year 2. The most common reason for discontinuation was treatment failure in 7 individuals. Conclusion: Among individuals with arthritis who underwent mandatory non-medical switching from bio-originators to biosimilars, about 80% remain on the biosimilar at 2 years. Thus, discontinuation rates appear consistent with those observed among experienced biologic users, suggesting relative stability despite the policy-driven switch. REFERENCES: NIL . Figure 1Kaplan-Meier survival curves showing the probability of discontinuing the biosimilar therapy over follow-up, with shaded areas representing 95% confidence intervals (95% CI). Table 1Baseline characteristics of individuals transitioning from bio-originator to biosimilars.CharacteristicN (%), mean (SD), or median (IQR)Biosimilar, N (%)Adalimumab75 (68.2)Etanercept22 (20.0)Rituximab12 (10.9)Infliximab1 (0.9)Female sex, N (%)67 (60.9)Age in years, mean (standard deviation, SD)56.9 (15.8)Disease duration in years, mean (SD)19.3 (12.6)Body mass index, mean (SD)29.0 (6.6)Current smoker, N (%)18 (16.4)Current alcohol drinker, N (%)21 (19.1)Use of biologic (other than the originator) in the past year, N (%)33 (30.0)Current use of synthetic disease-modifying antirheumatic drugs, N (%)58 (53.2)Health Assessment Questionnaire (HAQ) score, median (interquartile range, IQR, Q1-Q3)1.1 (0.6-1.6)Modified HAQ* score, median (IQR)1.1 (0.9-1.6)*HAQ for the RHUMADATA cohort and Modified HAQ for EUPA cohort and USRAT Acknowledgements: NIL . Disclosure of Interests: Cristiano S Moura: None declared, Luck Lukusa: None declared, Denis Choquette Amgen, AbbVie, CIHR, Novartis, Pfizer, Fresenius Kabi, Eli Lilly, Sandoz, and Tevapharm, Amgen, AbbVie, CIHR, Novartis, Pfizer, Fresenius Kabi, Eli Lilly, Sandoz, and Tevapharm, Amgen, AbbVie, CIHR, Novartis, Pfizer, Fresenius Kabi, Eli Lilly, Sandoz, and Tevapharm, Gilles Boire Janssen; Orimed Pharma; Viatris, Eli Lilly; Janssen; Organon; Orimed Pharma; Otsuka; Pfizer; Sandoz; Teva; Viatris, Biocon Biologics; Pfizer, Nathalie Carrier: None declared, Autumn Neville: None declared, Sasha Bernatsky: None declared. © The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.