Real-world data indicate treatment adherence was highest among patients who had prior infliximab exposure but no prior infliximab biosimilar use.
At the American College of Rheumatology Convergence 2020 meeting, researchers presented a report on medication adherence among infliximab biosimilar users compared with infliximab reference users in a large national administrative database.
Patients were identified using the national administrative Truven Health MarketScan database. Eligible patients were aged ≥18 years, had ≥1 administration or pharmacy claims for infliximab reference or biosimilar for any of its indications, and had continuous full coverage from 2014 to 2018. Based on their prior use of infliximab and its biosimilars, 4 patient subgroups were identified: infliximab biosimilar–naïve users (no prior use of infliximab biosimilars with past use of infliximab), infliximab biosimilar–prevalent users (no prior use of infliximab but with prior use of infliximab biosimilar), infliximab reference–naïve users (no prior use of infliximab reference without past use of infliximab biosimilar), and infliximab reference–prevalent users (prior use of reference infliximab).
The identified patients were categorized into the 4 predefined cohorts; 96 patients were infliximab biosimilar–naïve users, 223 patients were infliximab biosimilar–prevalent users, 2149 patients were infliximab reference–naïve users, and 10,970 patients were infliximab reference–prevalent users. The mean age among the study population was 45 years and 60% of patients were female; demographic characteristics and biologic use prior to the index date were similar across the 4 cohorts.
Among the 4 cohorts, the infliximab reference–prevalent users had the highest adherence at 12 or 18 months of follow-up, and adherence patterns were similar among the infliximab biosimilar–naïve, infliximab biosimilar–prevalent, and infliximab reference–naïve cohorts. In the infliximab reference–prevalent cohort, 73% of patients at 12 months and 64% of patients at 18 months achieved >80% treatment adherence. Among patients who had ≥12 months of follow-up, >80% treatment adherence was achieved by 43% of infliximab biosimilar–naïve users, 41.5% of infliximab biosimilar–prevalent users, and 52% of infliximab reference–naïve users; among patients who had ≥18 months of follow-up, 48%, 36%, 41%, and 64% of patients, respectively, continued to be adherent.
The findings of this large, national administrative data analysis indicate that treatment adherence was highest among infliximab reference–prevalent users.
Alanaeme J, et al. Arthritis Rheumatol. 2020;72(suppl 10):Abstract 819.