Drug retention rates of biological agents in adult onset Still's disease.

OBJECTIVES

To assess drug retention rates (DRRs) and reasons for discontinuation of biologic disease-modifying antirheumatic drugs (bDMARDs) in a large monocentric cohort of patients with adult onset Still's disease (AOSD).

METHODS

Clinical data of AOSD patients treated with at least one bDMARD and followed up at our Center were retrospectively evaluated. Data about disease duration, number of previous bDMARDs, concomitant treatments, and reasons for therapy discontinuation were collected. Survival curves were examined by the Kaplan-Meier method and compared using a stratified log-rank test. 24-month DRRs were calculated for each bDMARD. Hazard ratio (HR) for previous bDMARD use was evaluated.

RESULTS

Forty-two AOSD patients received a total of 79 bDMARD-courses. Anakinra (ANK; n = 41) was the most frequently used bDMARD, followed by tocilizumab (TCZ; n = 21) and Tumor Necrosis Factor inhibitors (TNFi; n = 17). Biologic agents were administered concomitantly with prednisone in all cases (mean dose, 23 ± 18 mg/day) and with csDMARD therapy in 54 (68%) of courses. Thirty-six (46%) treatment courses were discontinued by 24 months. DRRs at 24 months were 62.5% for TCZ, 53.1% for ANK, and 11.8% for TNFi. ANK and TCZ DRRs were similar (p = 0.576), but significantly higher than TNFi (p = 0.015). Previous biologic therapies did not impact DRR (HR 0.73, 95% CI = 0.40 - 1.31, p = 0.288).

CONCLUSIONS

In our AOSD study population, 24 months DRRs of TCZ and ANK were similar and significantly higher than the TNFi DRR. Previous use of biologic agents did not affect DRRs.