Biologics for the treatment of adult-onset still's disease.

Introduction: Adult-onset Still's disease (AOSD) is a systemic inflammatory disorder of unknown etiology, and approximately 60-70% of patients develop a chronic form. Up to 20-30% of patients who are refractory to conventional therapy need biologic agents. Recently, anti-cytokine biologic agents according to pathophysiology have resulted in significant progress in the treatment of AOSD. Area Covered: Due to rarity and heterogeneous features of the disease, treatment of AOSD is not based on the controlled study but on case-based retrospective data. Here, we review the current status of the pathogenesis, limitations of therapeutic guidelines and outcome measures, utility of biologic agents, and future perspectives for treatment. Expert opinion: IL-1 inhibitors are more effective for systemic manifestations and IL-6 inhibitors for both joint disease and systemic features. Anti-TNF agents would be useful for patients with the pure rheumatoid subgroup. Systemic manifestations respond rapidly, but arthritis shows rather slow response. Clinical response must be obtained within 2 to 3 months, and biologics with different mechanisms of action are required for non-responders. For patients in prolonged remission, we need to try tapering of biologics. Randomized controlled studies, new therapeutic agents, and composite biomarkers are required to improve the outcome of patients with AOSD.