Changes in the use patterns of bDMARDs in patients with rheumatic diseases over the past 13 years.

The better understanding of the safety of biologic DMARDs (bDMARDs), as well as the emergence of new bDMARDs against different therapeutic targets and biosimilars have likely influenced the use patterns of these compounds over time. The aim of this study is to assess changes in demographic characteristics, disease activity and treatment patterns in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), or ankylosing spondylitis (AS) who started a first- or second-line biologic between 2007 and mid-2020. Patients diagnosed with RA, PsA or AS included in the BIOBADASER registry from January 2007 to July 2020 were included. According to the start date of a first- or second-line biologic therapy, patients were stratified into four time periods: 2007-2009; 2010-2013; 2014-2017; 2018-2020 and analyzed cross-sectionally in each period. Demographic and clinical variables, as well as the type of biologic used, were assessed. Generalized linear models were applied to study the evolution of the variables of interest over time periods, the diagnosis, and the interactions between them. A total of 4543 patients initiated a first biologic during the entire time frame of the study. Over the four time periods, disease evolution at the time of biologic initiation (p < 0.001), disease activity (p < 0.001), retention rate (p < 0.001) and the use of tumor necrosis factor inhibitors as a first-line treatment (p < 0.001) showed a significant tendency to decrease. Conversely, comorbidities, as assessed by the Charlson index (p < 0.001), and the percentage of patients using bDMARDs in monotherapy (p < 0.001), and corticosteroids (p < 0.001) tended to increase over time. Over the entire period of the study's analysis, 3289 patients started a second biologic. The following trends were observed: decreased DAS28 at switching (p < 0.001), lower retention rates (p = 0.004), and incremental changes to the therapeutic target between the first and second biologic (p < 0.001). From 2007 until now rheumatic patients who started a biologic were older, exhibited less clinical activity, presented more comorbidities, and switched to a different biologic more frequently and earlier.