SAT0209 Early Response to Tocilizumab (TCZ) and Benefit of Continued TCZ Treatment in Partial TCZ Responders: Results of the Mirai-Study

BackgroundMIRAI (NCT01332994) investigated the early response at week 16 to the IL-6 inhibitor tocilizumab (TCZ). Patients who only partially responded may benefit from continued TCZ treatment. Non-responders to TCZ subsequently received 1 cycle of rituximab (RTX; anti-CD20 therapy).ObjectivesWe report efficacy results of early TCZ responders (week 16) and those of partial TCZ responders who continued TCZ treatment (week 32).MethodsMIRAI was a German, multicenter, two-arm, open-label, phase-III-study. A homogeneous population of biological naïve patients (pts) with moderate/severe active RA who inadequately responded to traditional DMARDs was included. All pts received 4 TCZ infusions (8 mg/kg, q4w; 1st treatment period). At week 16, early TCZ responder (DAS281.2 or DAS28≥2.6 and ≤3.2) received further 4 TCZ infusions; non-responders (ΔDAS28≤1.2 and DAS28>3.2) received subsequent RTX treatment (1g each at weeks 16 and 18). At week 32, DAS28/ACR/ CDAI/SDAI response was evaluated.ResultsOf the 519 pts treated with TCZ, 217 early TCZ responders (DAS28