Efficacy and safety of sirukumab in Japanese patients with active rheumatoid arthritis who were refractory or intolerant to anti-tumor necrosis factor therapy: Subgroup analysis of a randomized, double-blind, multicenter, phase 3 study (SIRROUND-T)

<b>Objective:</b> To evaluate the efficacy and safety of sirukumab, a human anti-interleukin six monoclonal antibody, in Japanese patients with rheumatoid arthritis who were refractory to anti-tumor necrosis factor therapy. <b>Methods:</b> This subgroup analysis, based on a double-blind, placebo-controlled, 52-week phase 3, global study (SIRROUND-T) assessed the American College of Rheumatology (ACR) 20 response at week 16 (primary endpoint). Secondary endpoints: ACR 50, Disease Activity Score in 28 joints-C reactive protein, Health Assessment Questionnaire-Disability Index and safety were assessed. <b>Results</b> 116/878 patients received sirukumab 50 mg/4 weeks (q4w, <i>n</i> = 35), 100 mg/2 weeks (q2w, <i>n</i> = 44) or placebo (<i>n</i> = 37) subcutaneously. Significantly more patients achieved ACR 20 response at week 16 with sirukumab (50 mg q4w:20 [57.1%]; <i>p</i> p = .001) versus placebo (7 [18.9%]); consistent significant improvement in secondary endpoints at week 24 and 52 was observed. At week 24, incidence of treatment-emergent adverse events (TEAEs) was numerically higher with sirukumab groups (50 mg q4w:29 [82.9%]; 100 mg q2w:38 [86.4%] versus placebo (28 [75.7%]); however, at week 52, sirukumab combined groups had comparable incidence of TEAEs. <b>Conclusion:</b> Efficacy findings through 52 weeks were comparable between sirukumab doses in Japanese patients and consistent with primary SIRROUND-T study results. No new safety signals were observed.