Objectives: This observational study compares the effectiveness of baricitinib (BARI), a targeted synthetic disease-modifying antirheumatic drug (tsDMARD), with alternative biological DMARDs (bDMARDs) in patients with rheumatoid arthritis (RA), from a prospective, longitudinal cohort.

Methods: We compared patients initiating a treatment course (TC) of BARI, tumour necrosis factor inhibitors (TNFi) or bDMARDs with other modes of action (OMA), during a period when all these DMARDs were available in Switzerland. The primary outcome was drug maintenance; secondary outcomes included discontinuation rates related specifically to ineffectiveness and adverse events. We further analysed rates of low disease activity (LDA) and remission (REM) at 12 months and drug maintenance in bDMARD-naïve and tsDMARD-naïve population.

Results: A total of 1053 TCs were included: 273 on BARI, 473 on TNFi and 307 on OMA. BARI was prescribed to older patients with longer disease duration and more previous treatment failures than TNFi. Compared with BARI, the adjusted drug maintenance was significantly shorter for TNFi (HR for discontinuation: 1.76; 95% CI, 1.32 to 2.35) but not compared with OMA (HR 1.27; 95% CI, 0.93 to 1.72). These results were similar in the b/tsDMARD-naïve population. The higher discontinuation of TNFi was mostly due to increased discontinuation for ineffectiveness (HR 1.49; 95% CI, 1.03 to 2.15), with no significant differences in drug discontinuation for adverse events (HR 1.46; 95% CI, 0.83 to 2.57). The LDA and REM rates at 12 months did not differ significantly between the three groups.

Conclusions: BARI demonstrated a significantly higher drug maintenance compared with TNFi, mainly due to lower drug discontinuations for ineffectiveness. We found no difference in drug maintenance between BARI and OMA. Clinical outcomes did not differ between the three groups. Our results suggest that BARI is an appropriate therapeutic alternative to bDMARDs in the management of RA.