Safety of biological and targeted synthetic disease-modifying antirheumatic drugs for rheumatoid arthritis as used in clinical practice: results from the ARTIS programme

Abstract

Objective: Longitudinal clinical registry-infrastructures such as Anti-Rheumatic Therapies in Sweden (ARTIS) allow simultaneous comparison of the safety of individual immunomodulatory drugs used in clinical practice, with consistent definitions of treatment cohorts, follow-up and outcomes. Our objective was to assess and compare incidence rates of key safety outcomes for individual targeted synthetic or biological disease-modifying antirheumatic drugs (b/ts DMARDs) in rheumatoid arthritis (RA), updating previous reports and including newer treatments including Janus Kinase inhibitors (JAKi).

Methods: Nationwide register-based cohort study including all patients with RA in Sweden registered as starting any b/tsDMARD 1 January 2010 through 31 December 2020, followed until 30 June 2021 (N=20 117). The incidence rates of selected outcomes, identified through national healthcare registers, were compared between individual b/tsDMARDs, adjusted for confounding by demographics, RA disease characteristics and comorbidity.

Results: There were marked differences in treatment discontinuations due to adverse events (rates per 1000 person-years ranged from 18 on rituximab to 57 on tofacitinib), but few significant differences were observed for the serious adverse events under study. Neither cardiovascular events nor general serious infections were more frequent on baricitinib or tofacitinib versus bDMARDs, but JAKi were associated with higher rates of hospital-treated herpes zoster (HR vs etanercept, 3.82 (95% CI 2.05 to 7.09) and 4.00 (1.59 to 10.06)). Low number of events limited some comparisons, in particular for sarilumab and tofacitinib.

Conclusion: Data from ARTIS supports that the b/tsDMARDs currently used to treat RA have acceptable and largely similar safety profiles, but differences exist in particular concerning tolerability and specific infection risks.

Keywords: Antirheumatic Agents; Arthritis, Rheumatoid; Biological Therapy; Cardiovascular Diseases; Epidemiology.

Figure 1

Crude and weighted incidence rate per 1000 person-years of selected safety outcomes by b/tsDMARD, and adjusted HRs versus etanercept, among all Swedish patients with RA who started treatment 2010–2020, followed until 30 June 2021. b/tsDMARDs, targeted synthetic or biological disease-modifying antirheumatic drugs; wHR, weighted HR from Cox regression; wIR, inverse probability of treatment weighted incidence rate per 1000 person-years, adjusted for demographics, RA clinical characteristics and comorbidity; RA, rheumatoid arthritis.

Figure 2

Crude and weighted incidence rate per 1000 person-years of selected safety outcomes by b/tsDMARD, and adjusted HRs vs etanercept, among all Swedish patients with RA who started treatment 2010–2020, followed until 30 June 2021. b/tsDMARDs, targeted synthetic or biological disease-modifying antirheumatic drugs; wHR, weighted HR from Cox regression; wIR, inverse probability of treatment weighted incidence rate per 1000 person-years, adjusted for demographics, RA clinical characteristics and comorbidity; RA, rheumatoid arthritis.

Figure 3

Incidence rate per 1000 person-years of selected safety outcomes, among all Swedish patients with RA who started b/tsDMARD 2010–2020, and a 5:1 age-sex matched general population sample, followed until 30 June 2021. HR, hazard ratio from Cox regression; RA, rheumatoid arthritis.