Real-World Analysis of Therapeutic Patterns in Patients Affected by Rheumatoid Arthritis in Italy: A Focus on Baricitinib.

The objective of this study was to evaluate treatment patterns in patients with rheumatoid arthritis (RA), with a focus on the utilization of baricitinib, an oral highly selective Janus kinase 1 and 2 inhibitor, in an Italian real-world setting. This observational retrospective analysis was based on data collected in selected Italian administrative databases. Patients aged ≥ 18 years with a diagnosis of RA defined by hospitalization discharge diagnosis (International Classification of Diseases, Ninth Revision, Clinical Modification code 714.0) or by disease exemption code 006 for RA in 2018 were included. The index date (ID) was defined as the date of first prescription for a drug indicated for RA during the inclusion period. Patients without a prescription for biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) before the ID were considered to be b/tsDMARD naïve. A further analysis was performed on patients only receiving baricitinib. A total of 41,290 RA patients were enrolled, of whom 55.6% were not treated with conventional synthetic DMARDs (csDMARDs) or b/tsDMARDs, 39.4% were receiving therapy with csDMARDs, and 5.0% were using b/tsDMARDs. In the latter group, 2.7% (n = 56) were receiving therapy with baricitinib. In 2018, 13.2% of csDMARD-treated patients switched to b/tsDMARDs, of whom 4.3% (n = 93) of these switched to baricitinib. In total, 149 patients (mean age ± standard deviation 57.6 ± 12.1; 12.8% male) had a baricitinib prescription, of whom 51% were b/tsDMARD naïve. At baseline, 61.7% of baricitinib users were receiving combination therapy with csDMARDs plus corticosteroids, 26.2% were receiving combination therapy with corticosteroids, and 8.1% were receiving combination therapy with csDMARDs; 4% were receiving baricitinib monotherapy. During follow-up, the proportion of patients receiving baricitinib monotherapy increased to 38.9%, while 26.9, 18.8, and 15.4% of baricitinib users received combination therapy with corticosteroids, csDMARDs plus corticosteroids, and csDMARDs, respectively. This study provides a current view of the treatment patterns in Italian patients with RA in a real-world setting of daily clinical practice, with a focus on baricitinib utilization.