Efficacy and safety of canakinumab in patients with adult-onset Still's disease: Results from an open-label phase III study in Japan.

OBJECTIVES

To evaluate the efficacy and safety of canakinumab 4 mg/kg every 4 weeks administered subcutaneously in Japanese adult-onset Still's disease patients.

METHODS

Fourteen participants were included in this open-label, single-arm, active-treatment study. The primary endpoint was the adapted ACR30 response, with a predefined 95% CI lower limit requirement of 40% at Week 8. Secondary endpoints included glucocorticoid tapering from Weeks 8 to 28; adapted ACR30/50/70/90/100 responses over time; and the systemic feature score over time.

RESULTS

The primary endpoint was not met [6/11 patients (54.5%); 95% CI: 20.6-88.5; one-sided P = 0.249]. From Weeks 8 to 28, 6/11 patients (54.5%) successfully tapered oral glucocorticoids. At Week 28, among the 11 patients assessed, 70% achieved adapted ACR30 and adapted ACR50, 60% achieved adapted ACR70 and adapted ACR90, and 40% achieved adapted ACR100. At Week 28, the mean (SD) change from baseline in the systemic feature score was -4.3 (2.06). All 14 patients had at least one treatment-emergent adverse event. Six participants (42.9%) had serious adverse events. Three patients had serious infections; all were considered treatment-related and all recovered.

CONCLUSION

Although the primary endpoint was not met, the Week 28 analysis showed that canakinumab treatment led to improvements in various efficacy outcome measures in Japanese patients with adult-onset Still's disease, with no unexpected safety signals.