Drug survival and the associated predictors in South Korean patients with rheumatoid arthritis receiving tacrolimus

BACKGROUND/AIMS To investigate the drug survival rate of tacrolimus (TAC) and analyze the potential predictors of this rate in patients with rheumatoid arthritis (RA) in routine care. METHODS2018-01-16 In this retrospective longitudinal study, we enrolled 102 RA patients treated with TAC from April 2009 to January 2014 at a tertiary center in South Korea. The causes of TAC discontinuation were classified as lack of efficacy (LOE), adverse events (AEs), and others. The drug survival rate was estimated using the Kaplan-Meier method and the predictors of this rate were identified by Cox-regression analyses. RESULTS TAC was discontinued in 27 of 102 RA patients (26.5%). The overall 1-, 2-, 3-, and 4-year TAC continuation rates were 81.8%, 78.4%, 74.2%, and 69.1%, respectively and the median follow-up period from the start of TAC was 32.5 months. The number of TAC discontinuations due to LOE, AEs, and others were 15 (55.6%), 11 (40.7 %), and 1 (3.7%), respectively. The baseline high disease activity was a significant risk factor for TAC discontinuation after adjusting for confounding factors (hazard ratio [HR], 2.49; 95% confidence interval [CI], 1.16 to 5.35; p = 0.019). In addition, underlying interstitial lung disease was significantly associated with TAC withdrawal due to AEs (HR, 3.49; 95% CI, 1.06 to 11.46; p = 0.039). CONCLUSIONS In our study, TAC showed a good overall survival rate in patients with RA in real clinical practice. This suggests that the long-term TAC therapy has a favorable efficacy and safety profile for treating RA.