Subsequent biologic and targeted synthetic disease modifying anti rheumatic drugs after fulfilling difficult-to-treat rheumatoid arthritis criteria: a survival analysis

Abstract

Objectives: To evaluate the survival of different biologic or targeted-synthetic disease-modifying antirheumatic drugs (b/tsDMARD) administered after fulfilling difficult-to-treat rheumatoid arthritis (D2TRA) criteria, and to assess factors related to treatment discontinuation.

Methods: Retrospective study including D2TRA patients. Drug retention of the b/tsDMARD administered after fulfilling D2TRA was assessed by Kaplan-Meier plots and the log-rank test. Cox hazard models were used to identify factors affecting treatment discontinuation.

Results: Of the 122 patients included, 75 maintained active treatment (61.5%) with a subsequent line after D2T compared to 47 (38.5%) who discontinued and required more successive lines of b/tsDMARDs. The median survival of the treatments was 78.3(7.6) months and the treatment after D2T with the better rate of survival was rituximab, followed by JAKi and IL6Ri, while worse survival rates were associated with abatacept and TNFi. Significant differences were noted among b/tsDMARDs (log-rank p < 0.01) and to evaluate these differences, a Cox regression was performed, taking each b/tsDMARD as a reference and comparing it with the others. DAS28 values 6-months after initiation of treatment were higher in those patients who discontinued treatment [4.4(1.2) vs 3.5(1.3), p = 0.01]. The multivariate cox regression model revealed that treatment choice after D2T [HR = 1.26(95%CI 1.06-1.05)] and lower DAS28 values at 6 months [HR = 1.49(95%CI 1.16-1.52)] were independent risk factors associated with treatment discontinuation.

Conclusions: Once patients met the D2TRA criteria, the subsequent line of b/tsDMARDs with the best survival rates were rituximab, JAKi and IL6Ri. Moreover, DAS28 at 6-months of treatment after D2T was an independent risk factor for drug discontinuation. Key Points • Rituximab, IL6Ri and JAKi have better retention rates in patients after fulfilling D2TRA criteria • Clinical disease activity in the first six months after fulfillment of D2TRA criteria is an independent risk factor of subsequent treatment survival.

Keywords: Difficult-to-treat rheumatoid arthritis; Disease modifying antirheumatic drugs; Efficacy of treatments; Retention rates.