Background: Janus kinase inhibitors (JAKi), like baricitinib, are used as monotherapy (MONO) and in combination with methotrexate (MTX) in rheumatoid arthritis (RA) patients. This study aimed to evaluate the long-term efficacy, drug survival and safety of baricitinib MONO versus combination therapy (COMBO) in a prospective cohort of patients with RA.
Methods: We analysed data from 219 RA patients initiating baricitinib in a single-centre, prospective observational cohort between 2017 and 2023. Clinical data, patient-reported outcomes and safety events were collected every 3 months. Drug survival was analysed using the Kaplan-Meier method, and longitudinal outcomes were assessed using linear mixed-effects models.
Results: The cohort included 219 patients (165 MONO, 54 COMBO) with high baseline disease activity (mean DAS28-ESR 4.0). Both groups showed rapid and sustained clinical improvement, with disease activity stabilising in the low range by 6 months of treatment. One third of the patients (n=72, 33%) achieved Boolean remission, with no significant difference between groups (p=0.35). Median drug survival was 36 months and was similar for both regimens (log-rank p=0.82). Discontinuation due to adverse events occurred in 10.9% of patients. Four thrombotic events were noted, all in patients with pre-existing cardiovascular risk factors, with no new safety signals emerging.
Conclusions: In this real-world cohort, baricitinib demonstrated sustained long-term effectiveness, drug survival and an acceptable safety profile. The similar outcomes observed for MONO and COMBO indicate that baricitinib may be used effectively as MONO in patients with RA for whom MTX is not suitable or tolerated.
Keywords: Arthritis, Rheumatoid; DMARD; Epidemiology.
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