Current clinical evidence of tocilizumab for the treatment of ANCA-associated vasculitis: a prospective case series for microscopic polyangiitis in a combination with corticosteroids and literature review.

The purpose of this study is to report the efficacy and safety of a combination of tocilizumab (TCZ) and high-dose corticosteroid (CS) in two patients with microscopic polyangiitis (MPA) and review the published current clinical evidence on TCZ in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), except for large vessel vasculitis (LVV) and polymyalgia rheumatica (PMR). Two MPA patients were treated with TCZ at 8 mg/kg every month for 1 year and CS (prednisolone 1 mg/kg/day for 2 weeks, followed by tapering) in a prospective single-arm, single-center, cohort, open-label pilot study (UMIN clinical trials: 000012072). We performed a systematic literature search (PubMed and ICHUSHI [Japan Medical Abstracts Society] until June 30, 2017) to identify published reports on patients with all vasculitis other than LVV/PMR, who were treated with TCZ. We successfully treated the first patient. However, the other patient had serious infection probably associated with the combination of TCZ and high-dose CS. The literature review identified 22 reports with a total of 34 patients who received TCZ for AAV, rheumatoid vasculitis, and other types of vasculitis, in addition to our patients. In 15 of 17 patients (88.2%) with primary and secondary AAV, especially MPA, TCZ induced clinical remission, although TCZ use for rheumatoid vasculitis and vasculitis with mucocutaneous lesions is controversial. This study suggested that TCZ therapy is a potential treatment strategy for patients with AAV. However, TCZ combined with high-dose of CS might not be an appropriate treatment. Future studies are needed to confirm our findings.