IntroductionAntineutrophil cytoplasm antibody-associated vasculitis (AAV) is a form of systemic vasculitis. The current standard induction therapy with the combination of high-dose glucocorticoids and cyclophosphamide or rituximab has high remission rates of 80%–90%. However, it is also associated with various side effects, including death due to infection or cardiovascular disease. There is an unmet medical need of a new therapy to reduce side effects.Methods and analysisThis is a phase IV multicentre, open-label, randomised controlled trial that aims to evaluate the efficacy and safety of a new remission induction regimen with the combination of low-dose glucocorticoids and rituximab. Newly diagnosed patients with AAV will be assessed for eligibility at 34 tertiary rheumatology/nephrology centres in Japan. One hundred and forty patients will be randomised (1:1) to receive low-dose prednisolone (0.5 mg/kg daily) plus rituximab (375 mg/m2weekly) or high-dose prednisolone (1 mg/kg daily) plus rituximab. The trial consists of remission induction and maintenance phases. The primary endpoint of the study is the remission rate at 6 months (induction phase). Relapse and long-term safety profile will also be assessed until 24 months (maintenance phase).Ethics and disseminationThe protocol was first approved by the Institutional Review Board of Chiba University Hospital (reference number: G25051), and then approved by each participating site. The trial was registered at the University hospital Medical Information Network (UMIN) clinical registry (UMIN000014222) and ClinicalTrials.gov registry (NCT02198248). The Low-dose Glucocorticoid Vasculitis Induction Study (LoVAS) trial is currently ongoing and is due to finish in September 2019. The findings of this trial will be disseminated to participants through peer-reviewed publications and presented at national and international conferences in accordance with the Consolidated Standards of Reporting Trials (CONSORT) Statement.Trial registration numberUMIN000014222;NCT02198248.