Safety and effectiveness of tacrolimus add-on therapy for rheumatoid arthritis patients without an adequate response to biological disease-modifying anti-rheumatic drugs (DMARDs): Post-marketing surveillance in Japan

<b>Objectives:</b> Post-marketing surveillance (PMS) was conducted to assess the safety and effectiveness of tacrolimus (TAC) add-on therapy for patients with rheumatoid arthritis (RA) and an inadequate response to biological disease-modifying anti-rheumatic drugs (DMARDs). <b>Methods:</b> Patients with RA from 180 medical sites across Japan were registered centrally with an electronic investigation system. The observational period was 24 weeks from the first day of TAC administration concomitantly with biological DMARDs. <b>Results:</b> Safety and effectiveness populations included 624 and 566 patients, respectively. Patients were predominantly female (81.1%), with a mean age of 61.9 years. Overall, 125 adverse drug reactions (ADRs) occurred in 94 patients (15.1%), and 15 serious ADRs occurred in 11 patients (1.8%). These incidences were lower compared with previously reported incidences after TAC treatment in PMS, and all of the observed ADRs were already known. A statistically significant improvement was observed in the primary effectiveness variable of Simplified Disease Activity Index after TAC treatment; 62.7% of patients achieved remission or low disease activity at week 24. <b>Conclusions:</b> TAC is well tolerated and effective when used as an add-on to biological DMARDs in Japanese patients with RA who do not achieve an adequate response to biological DMARDs in a real-world clinical setting.