Evaluation of the Safety and Effectiveness of Add-On Tacrolimus in Patients with Rheumatoid Arthritis Who Failed to Show an Adequate Response to Biological DMARDs: The Interim Results of a Specific Drug Use-Results Survey of Tacrolimus.

Background: Tacrolimus (TAC) is an immunosuppressive macrolide that blocks T-cell activation by specifically inhibiting calcineurin. TAC was approved in Japan for the treatment of rheumatoid arthritis (RA) in 2005. However, the safety and effectiveness of TAC adding on to biological disease-modifying anti-rheumatic drugs (DMARDs) in the real clinical setting may not be clear enough.

Objectives: We report here the interim results of post marketing surveillance (PMS) of TAC adding on to biological DMARDs in RA patients who failed to show an adequate response to biological DMARDs.

Methods: Patients who had an inadequate response to biological DMARDs were enrolled. An inadequate response to biological DMARDs was defined as that all of the following conditions were met: a Simplified Disease Activity Index (SDAI) score of >3.3 when TAC was started; both the tender joint count and swollen joint count were the same or increased compared with those at 4-8 weeks prior to TAC; and biological DMARDs were used for at least 8 weeks prior to TAC. This study was conducted in compliance with the ministerial ordinance on "Good Post-Marketing Study Practice" (GPSP).

Results: The safety data collection and evaluation for 172 patients and effectiveness data collection and evaluation for 165 patients were reported. The mean age was 61.9 years. Adverse drug reactions occurred in 18 patients. The mean SDAI decreased from 20.1 at baseline to 11.7 at week 24.

Conclusions: TAC is well tolerated and effective when added on to biological DMARDs in RA patients who failed to achieve an adequate response to biological DMARDs.