A descriptive observational cohort study to assess effectiveness of risk minimization activities in baricitinib incident users treated for rheumatoid arthritis in Nordic countries

Background: Baricitinib is approved in Europe to treat moderate to severe rheumatoid arthritis (RA) in adults. Additional risk minimisation measures (aRMM) were implemented to inform prescribers and patients to avoid using baricitinib during pregnancy, monitor blood lipids during treatment and of the signs and symptoms of infections and VTE. As required by GVP Module XVI, aRMM are to be assessed for effectiveness.

Objectives: This study assesses the aRMM in Europe by describing the pattern of baricitinib use and the occurrence of pregnancy, tuberculosis or viral hepatitis infections, or changes in lipid levels in relation to use in routine clinical care in the first years baricitinib is used in RA patients.

Methods: This cohort study was based on routinely collected healthcare data from Danish, Swedish, Norwegian, and Finnish national registers. The study included patients diagnosed with RA treated with baricitinib between 2017-2021. Eligible patients at the time of baricitinib initiation were ≥ 18 years, and did not migrate 5 year prior treatment. Patients were followed from treatment start until initiation of a b/tsDMARD, discontinuation of baricitinib, end of study, death, or emigration.
Diagnoses for infections (active tuberculosis or viral hepatitis) and hyperlipidemia were gathered from patient registers. Information on pregnancies was obtained from medical birth and patient registers. Statin use was identified from prescription and drug reimbursement registers as a proxy for adherence to lipid monitoring recommendations.

Results: Altogether 3,913 patients had incident baricitinib treatment: 433 (Denmark), 1,993 (Sweden), 913 (Norway), and 574 (Finland). Of the patients treated with baricitinib, 0.2% had infections and 0.6% hyperlipidemia, and 9.3% a change in statin prescription, as a marker for lipid level assessment. Eight pregnancies (1% of women aged 18-50 years) had a potential overlap with baricitinib treatment.

Conclusions: This study based on population-based Nordic data identified low occurrence of selected infections and pregnancies, suggesting that prescribers adhered to recommendations within the aRMM. There are some limitations to be considered: (1) only registered events could be evaluated, (2) the use of statin prescriptions as a proxy for lipid level assessment will not distinguish patients who had their lipid level assessed, but required no change in statin prescriptions from patient who did not have their lipid level assessed. This study was able to monitor the relevant events within the baricitinib aRMM. This study indicates sufficient communication of select risks with baricitinib.