Persistence of Janus-kinase (JAK) inhibitors in rheumatoid arthritis: Australia wide study

Abstract

Background: To compare persistence of disease-modifying antirheumatic (DMARDs), with a focus on Janus kinase (JAK) inhibitors in Australian rheumatoid arthritis (RA) patients.

Methods: A retrospective observational study was conducted among 4,521 RA patients (females n=3,181 [70.4%]), using data from the Services Australia 10% Pharmaceuticals Benefits Scheme (PBS) dataset, aged ≥18 years and initiating a DMARD between 2011 to 2021. Kaplan-Meier analysis was used to estimate persistence rates, defined as occurrence of 6 months gap after the end of a drug dispensing.

Results: Twelve-month persistence rates were 72% for upadacitinib, 61% for baricitinib, 58% for subcutaneous tumor necrosis factor-alpha inhibitors (TNFi), 55% for tocilizumab, 53% for tofacitinib, and 49% for abatacept. Median treatment persistence was not reached for upadacitinib (n=574) and baricitinib (n=553); and was 15.0 months for tofacitinib (95% CI 13.5-19.5), 20.5 months for TNFi (95% CI 19.0-22.4), 19.1 months for tocilizumab (95% CI 17.9-23.6), and 12.5 months for abatacept (95% CI 10.4-14.9). Persistence rates on first-line JAK inhibitors were 68% for upadacitinib and baricitinib and 55% for tofacitinib, and 49% for TNFi, 55% for abatacept, and 57% for tocilizumab; rates were sustained for upadacitinib, TNFi, and tocilizumab but dropped to 59% for baricitinib and 47% for abatacept in the second-line treatment. For each b/tsDMARD, persistence rates were higher when combined with methotrexate or other conventional synthetic DMARDs. The median oral glucocorticoid dose decreased from 4.3 mg/day (range:0-40) to 2.3 mg/day (range:0-22) over 2 years. Changes were significant for all RA DMARDs, tofacitinib and baricitinib combined (1-2 years post initiation only), TNFi, abatacept, and tocilizumab.

Conclusions: In a real-world setting, we showed highest persistence rates on upadacitinib, followed by baricitinib and then TNFi therapy and was improved by co-therapy. All agents appeared to be corticosteroid sparing.

Keywords: Baricitinib; DMARD; Discontinuation; Effectiveness; Glucocorticoids; Janus kinase inhibitors; Persistence; Rheumatoid arthritis; Tofacitinib; Upadacitinib.