Characteristics of patients initiating treatment with baricitinib and outcomes at follow-up: analysis of BSRBR-RA Registry data

OBJECTIVES: To describe selected baseline characteristics, continuation with baricitinib and disease activity over time in patients initiating treatment with baricitinib in a UK real-world rheumatology setting. METHODS: Baseline and follow-up data were analysed from baricitinib-treated patients newly recruited to the British Society for Rheumatology Biologics Registry–RA (BSRBR-RA) baricitinib cohort between 1 January 2018 and 31 March 2020. The primary objective was to evaluate continuation of baricitinib treatment in patients with at least one follow-up. Analyses were performed using the full baricitinib cohort, overall and by patient subgroup: biologic DMARD (bDMARD)/targeted synthetic (ts)DMARD-naive vs -experienced, baricitinib 4 vs 2 mg, age ≥65 vs <65 years, monotherapy vs combination therapy and male vs female. RESULTS: At baseline, the study cohort (n = 561) was 76.5% female, mean age 60.0 years, had longstanding (mean 13.1 years) and severe RA, and 54.0% had previously received a bDMARD/tsDMARD. Of 265 and 110 patients completing the 6- and 12-month follow-ups with available data, 77.7 and 69.1% remained on baricitinib at each time, respectively. In all Kaplan–Meier analyses, >60% of patients remained on baricitinib at 540 days. Continuation of baricitinib therapy differed between some subgroup pairs (bDMARD/tsDMARD naive/experienced, baricitinib 2 mg/4 mg). Disease activity was lower at both follow-ups than at baseline, overall and in all subgroups. CONCLUSION: In the early years of real-world baricitinib use in the UK, a high proportion of patients continued with treatment at both 6 and 12 months, at which times disease activity was lower than at baseline.