P188 Baricitinib effectiveness after a previous inadequate response to an alternative JAK inhibitor: results from the Swiss rheumatoid arthritis register

Abstract Background/Aims Previous research has suggested that switching between b/tsDMARDs with different mode of action may be more effective than switching agents within the same mechanism of action. Limited data exists about the impact of an inadequate response to a previous JAK-inhibitor (JAKi) on subsequent JAKi effectiveness. Methods This is a nested study within the Swiss Clinical Quality Management (SCQM) registry of RA patients. All patients initiating baricitinib treatment courses (BARI) between 01-09-2017 and 01-06-2020, with at least one follow-up visit, were included. We compared the time to treatment discontinuation, as a measure of drug effectiveness, of BARI with a previous history of an inadequate response (IR) to tofacitinib (“BARI-post-TOFA”) or without (“BARI-initial”). Tofacitinib IR was defined as previous tofacitinib treatment discontinuation for adverse events or for ineffectiveness. Baseline characteristics were compared using t-tests or χ2. We used Kaplan-Meier curve to display crude time to discontinuation and a Cox model to estimate adjusted hazard ratio (HR). Cox model was adjusted for potential confounding factors: age, BMI, concomitant csDMARD, concomitant steroid usage, baseline CDAI, disease duration, smoking status, line of therapy, gender and seropositivity to RF/ACPA. Results Of the 273 included BARI, 72 were initiated in patients with a history of a previous tofacitinib IR (Table 1). No differences were found between the “BARI-post-TOFA” and the “BARI-initial” groups in terms of time-to-discontinuation, as demonstrated by both the unadjusted Kaplan-Meier survival analysis (Log-rank p = 0.44) and the fully adjusted Cox analysis (Hazard Ratio BARI-post-TOFA vs BARI-initial = 0.76 (95% IC [0.42 - 1.34]; p = 0.34). Other covariates significantly associated with drug maintenance were active smoking (p = 0.03) and CDAI score (p < 0.01). Conclusion In this preliminary analysis, a history of prior tofacitinib IR did not appear to significantly impact subsequent drug maintenance of baricitinib. Disclosure B.T.P. Gilbert: Other; Invited speaker for Lilly Symposium SGR Congress Lausanne (2021). D.S. Courvoisier: None. D. Mongin: None. K. Lauper: None. V.A. Guimaraes: Other; Clinical Research Scientist Immunology at Eli Lilly (Suisse) S.A. R.B. Mueller: None. A. Finckh: Grants/research support; Invited speaker and consultant for Eli Lilly. Has received research grant from Eli Lilly.