Real-world utilisation and switching between Janus kinase inhibitors in Australian patients with rheumatoid arthritis in the OPAL Dataset

Objective To describe use and treatment persistence for Janus kinase inhibitors (JAKi) in rheumatoid arthritis (RA) by line of therapy, and the mechanism of action for the drug switched to after JAKi discontinuation. Methods This was a retrospective, observational analysis using the OPAL dataset, a large collection of deidentified electronic medical records from 112 rheumatologists around Australia. Adult patients with RA were included if they initiated tofacitinib (TOF), baricitinib (BARI) or upadacitinib (UPA) between 1 October 2015 and 30 September 2021. Data were summarised using descriptive statistics. Kaplan-Meier survival was used to analyse treatment persistence. Results 5,900 patients initiated JAKi within the study window (TOF n=3,662, BARI n=1,875, UPA n=1,814). Median persistence was similar across JAKi within each line of therapy where there was sufficient follow-up, and almost 3 years for first-line: 34.9 months (95% CI 30.8, 40.7; n=1,408) for TOF, 33.6 months (95% CI 25.7, not reached; n=545) for BARI. While JAKi to JAKi switching occurred across all lines of therapy, switches to a tumour necrosis factor inhibitor (TNFi) were more frequent after first- or second-line JAKi. JAKi monotherapy use at baseline increased with line of therapy, and was highest at follow-up after switching to another JAKi. ‘Lack of efficacy’ was the most common reason for discontinuing JAKi. Conclusion In this large analysis of Australian real-world practice separated by line of therapy, treatment persistence for JAKi was high overall subject to differential follow-up, but declined in later lines. JAKi to JAKi switching was observed across all lines of therapy.