Background The 2008 American College of Rheumatology Recommendations has been updated last year, abatacept (ABT) has become available as the first biologic agent for patients with established RA¹. The efficacy and safety of ABT in biologic naïve patients has been reported in clinical trials, but still uncertain in clinical practice.

Objectives We studied the clinical outcome of ABT treatment for 52 weeks in patients without previous biologic history (Naïve group) and with previous biologic treatment (Switch group). We assessed whether the history of previous biologic treatment had any impact on the ABT clinical efficacy in RA.

Methods All RA patients who underwent ABT treatment for longer than 52 weeks (n=156) at Nagoya University Hospital and 12 other institutes (Tsurumai Biologics Communications registry : TBCR study group) were enrolled in this study. We compared disease activities using DAS28 CRP between Naïve group (n=71) and Switch group (n=85). Furthermore, EULAR response criteria and drug retention rate at 52 weeks were evaluated. The last observation carried forward (LOCF) method was used in each analysis.

Results In the baseline characteristics data, there was no significant difference between Naïve and Switch group, except for age (65.1 and 61.9 years old), disease duration (10.4 and 12.6 years) and prednisolone user (38.5 and 61.5%). Disease activities were significantly decreased at 4 weeks in both groups, and further decreasing were observed continuously (Fig. 1). At 52 weeks, the percentage of the patients who achieved low disease activity (DAS28 < 2.7) in Naïve group (47.8%) was apparently higher than that in Switch group (23.8%) (Fig.2). EULAR response rate was 75.3% in Naïve group (good 36.2%, moderate 39.1%), while 47.5% in Switch group (good 17.5%, moderate 30.0%). Drug retention rate at 52 weeks was 81.7% in Naïve group and 71.8% in Switch group (Fig 3).

Conclusions Although the clinical efficacy of ABT was demonstrated in patients with the history of biologics treatment, the responsiveness to ABT was superior in the biologic naïve patients. Our data suggest that ABT is useful in biologic naïve patients in clinical practice.

References

1. Singh JA, Furst DE, Bharat A, Curtis JR, Kavanaugh AF, Kremer JM, et al. 2012 update of the 2008 American College of Rheumatology recommendations for the use of disease-modifying antirheumatic drugs and biologic agents in the treatment of rheumatoid arthritis. Arthritis care & research. 2012;64:625-39.

Disclosure of Interest M. Hanabayashi: None Declared, T. Kojima Speakers bureau: Mitsubishi Tanabe Pharma Corporation, Takeda Pharma Corporation, Eisai Pharma Corporation, Chugai Pharma Corporation, Abbott, Bristol-Myers Squibb and Pfizer., N. Takahashi: None Declared, K. Funahashi: None Declared, D. Kato: None Declared, Y. Hattori: None Declared, N. Ishiguro Speakers bureau: Mitsubishi Tanabe Pharma Corporation, Takeda Pharma Corporation, Eisai Pharma Corporation, Chugai Pharma Corporation, Abbott, Bristol-Myers Squibb and Pfizer.