Retention of baricitinib-treated patients with rheumatoid arthritis in Japan: Interim results from a prospective observational cohort study.

OBJECTIVES

To assess the retention rate, changes in disease activity and patient-reported outcomes (PROs), and predictors of treatment discontinuation among baricitinib-treated patients with rheumatoid arthritis (RA) in routine clinical practice in Japan.

METHODS

This ongoing, multi-centre, prospective, observational study (starting February 2021) included ≥20-year-old baricitinib-treated patients with RA. Baricitinib's retention rate and effectiveness were evaluated until 12 months. The association between patient characteristics and retention was evaluated using Random Forest analysis.

RESULTS

This interim analysis included 353 patients (mean [standard deviation; SD] age 63.4 [13.6] years; 70.0% female). The 12-month retention rate was 70.2% (95% confidence interval [CI] 65.1, 74.6). The 12-month remission rates were 35.3%, 41.1%, and 79.6% per Clinical Disease Activity Index, Simplified Disease Activity Index, and Disease Activity Score with 28 joints-C-reactive protein. The mean (SD) changes in PROs from baseline scores were: physician global assessment of disease activity (-33.8 [27.8]), patient global assessment of disease activity (-18.3 [29.4]), Health Assessment Questionnaire-Disability Index (-0.33 [0.53]), and pain (-19.4 [27.0]). Ten variables influenced the model's prediction of treatment discontinuation.

CONCLUSIONS

Evidence from this interim analysis suggested the favourable effectiveness and drug survival of baricitinib in real-world Japanese patients with RA.