Successful treatment of adult-onset Still's disease with tocilizumab monotherapy: two case reports and literature review

Adult-onset Still's disease (AOSD) is a systemic inflammatory disease of unknown etiology. Recently, it has been reported that quite a few cases of refractory AOSD were successfully treated with tocilizumab (TCZ) and corticosteroids were withdrawn in some of these patients. We report two AOSD patients who were treated successfully with TCZ monotherapy; thus, avoiding corticosteroid treatment. Because both of the patients refused to take corticosteroids, we planned to treat them with 8 mg/kg of TCZ monotherapy at weeks 0, 2, 6 and subsequently every 4 weeks. The efficacy of TCZ was assessed by patients' clinical symptoms such as fever, arthralgia, skin eruptions, and laboratory markers such as serum levels of CRP, ferritin, and IL-6. We also reviewed 14 previous case reports including 30 cases who had been treated with TCZ for AOSD. Our patients responded rapidly and have been maintained in clinical remission without corticosteroid treatment. In the literature review, concomitant corticosteroid treatment described in 13 cases was successfully tapered in 7 and discontinued in 6 cases. TCZ monotherapy can be a candidate for the first-line therapy for some AOSD patients.