Corticosteroid-free treatment of tocilizumab monotherapy for microscopic polyangiitis: a single-arm, single-center, clinical trial

Abstract

Objectives: To assess the efficacy of tocilizumab (TCZ) monotherapy for the remission induction of microscopic polyangiitis (MPA) in a prospective single-arm, single-center, cohort, pilot study.

Methods: Eligible patients were aged between 20 and 80 years and were newly diagnosed with MPA according to Watts’ classification algorithm. Seven patients received 8 mg/kg of intravenous TCZ fortnightly for the first 2 months (5 courses), and monthly for the next 10 months (10 courses). One year after TCZ monotherapy, the patients were followed-up without any treatment. The protocol did not permit the use corticosteroids or any other immunosuppressants. Complete remission (CR) was defined as the Birmingham Vasculitis Activity Score of 0 at two consecutive visits made at least a month apart.

Results: CR was achieved in two of six patients (33.3%) at 6 months and three patients (50.0%) at 12 months. Two patients were withdrawn: one because of inefficacy at 6 weeks and the other because of flare at 6 months. One patient voluntarily withdrew after CR at 3 months. Four patients (66.7%) could be kept drug-free after 1 year of TCZ without relapse for 6–15 months at the last visit.

Conclusion: TCZ monotherapy may be an alternative treatment strategy in some patients with MPA.

Keywords:

• Antineutrophil cytoplasmic antibody
• Microscopic polyangiitis
• Tocilizumab
• Vasculitis

Acknowledgments

The authors thank all clinical research assistants in the Department of Rheumatology and Clinical Immunology, Saitama Medical Center, Saitama Medical University, including Izumi Ohshima, Masami Sato, Mayumi Suzuki, Miyuki Suzuki, Takashi Kukita, Machiko Kawamura, and Megumi Sawada. The authors also thank colleagues in the Department of Nephrology and Hypertension for taking renal biopsies, in the Department of Diagnostic Pathology for the helpful interpretation of pathological findings, in the Department of Neurology for examining nerve conduction velocity, in the Department of Dermatology for taking skin biopsies, and in the Department of Radiology for analyzing chest CT images, which were all affiliated to Saitama Medical Center, Saitama Medical University.

Conflict of interest

K.A. has received research grants from Chugai Pharmaceutical Co., Ltd.; speaking fees from AbbVie GK.; Astellas Pharma Inc.; Bristol-Myers K.K.; Chugai Pharmaceutical Co., Ltd.; Mitsubishi Tanabe Pharmaceutical Co.; and Pfizer Japan Inc. The other authors have no conflicts of interest to declare. This research was not supported by any specific grant from any funding agency in public, commercial, or nonprofit sectors.

Supplementary material available online