Effectiveness of Baricitinib and Tofacitinib Compared with BDMARDs in RA: Results from a Cohort Study Using Nationwide Swedish Register Data

Objectives: To describe the use of baricitinib and tofacitinib by Swedish RA patients and to compare their effectiveness with that of biologic DMARDs (bDMARDs).

Methods: RA patients who initiated baricitinib (n = 1420), tofacitinib (n = 316), abatacept (n = 1050), IL-6 inhibitors (IL-6is; n = 849), rituximab (n = 1101) or TNF inhibitors (TNFis; n = 6036) between January 2017 and November 2019 were followed for a minimum of 1 year using data from several linked Swedish national registers. Proportions reaching a good EULAR 28-joint DAS (DAS28) response, HAQ Disability Index (HAQ-DI) improvement >0.2 units and Clinical Disease Activity Index (CDAI) remission were compared at 1 year, imputing discontinued treatments as 'non-response'. Additionally, we compared drug retention and changes in DAS28, HAQ-DI and CDAI from baseline to 3 months after treatment initiation.

Results: On average, baricitinib, and particularly tofacitinib, were initiated as later lines of therapy and more frequently as monotherapy compared with rituximab and TNFi. Adjusted 1 year response proportions were consistently lower on TNFi compared with baricitinib, with differences of -4.3 percentage points (95% CI -8.7, 0.1) for good EULAR response, -9.9 (-14.4 to -5.4) for HAQ-DI improvement and -6.0 (-9.8 to -2.2) for CDAI remission. Comparisons with non-TNFi bDMARDs also favoured baricitinib, but not consistently. Treatment responses for tofacitinib were only marginally lower than those for baricitinib and generally similar to those of bDMARDs, with precision limited by low power. Comparisons of drug retention and changes in disease activity from baseline to 3 months supported the 1 year findings.

Conclusions: Baricitinib and tofacitinib showed at least equivalent effectiveness compared with bDMARDs after exploring several different effectiveness measures.