THU0577 Tocilizumab monotherapy for adult onset still's disease – results of 52-week treatment of a prospective, single-center, single-arm, open trial

Background Adult-onset Still9s disease (AOSD) is a systemic inflammatory disease of unknown etiology. Corticosteroids still provide mainstay AOSD therapy despite various adverse effects. Recently, AOSD patients have been successfully treated with anti-cytokine therapies such as with TNF-α blocking agents, an IL-1 receptor antagonist, and an anti-IL-6 receptor monoclonal antibody. Among these case reports, TCZ seems to be highly effective for treating patients refractory to TNF antagonists and IL-1 antagonist. Objectives To assess the efficacy and safety of tocilizumab (TCZ) monotherapy for the induction therapy of adult onset Still9s disease (AOSD) in a prospective single-arm, single-center, cohort, pilot study. Methods Seven AOSD patients (male 2, female 5) who had agreed with our prospective trial since April 2010 till May 2015 were enrolled. Our study protocol is that patients received 8 mg/kg of intravenous TCZ fortnightly for the first two months (five courses), then monthly for the next 5 months and after that they stop TCZ therapy and we monitor symptoms about AOSD relapses. In this report, we evaluated the efficacy and safety in 52 week. Efficacy was evaluated by serum markers (WBC, CRP and serum ferritin), clinical symptoms and ratio of patients who required additional therapy, and safety was evaluated by adverse events for 52 week. Results The mean age was 41.4. The ratio of fever, arthralgia, rash and sore throat are 100% (n=7/7), 100% (n=7/7), 85.7% (n=6/7) and 71.4% (n=5/7) respectively. LOCF analysis revealed that WBC, CRP and serum ferritin level decreased significantly from 14757±4667/μl to 6985±2903/μl, from 13.4±7.1mg/dl to 0.3±0.6mg/dl and from 6927±5376ng/ml to 2416±5589ng/ml at month 7 (TCZ final infusion) respectively (each, P Conclusions TCZ monotherapy can be an alternative treatment strategy for AOSD in some patients. References Sakai R, et al.:Clin Rheumatol. 2012 Mar;31(3):569–74. Ortiz-Sanjuan F et al.: Arthritis Rheumatol. 2014 Jun;66(6):1659–65. Disclosure of Interest T. Kondo: None declared, Y. Okada: None declared, A. Shibata: None declared, K. Chino: None declared, T. Kurasawa: None declared, A. Okuyama: None declared, H. Takei: None declared, K. Amano Grant/research support from: Chugai Pharmaceutical Co.Ltd.