After a screening period of up to 28 days, subjects with IgG4-RD at high risk of flare due to multi-organ disease and recent active disease will be randomized in a 1:1 ratio to receive intravenous (IV) inebilizumab or placebo after premedication during the 52-week randomized control period (RCP). All subjects will receive an initial tapering dose of glucocorticoids (GCs) to complete treatment of their active disease. Flares occurring during study will be treated. The primary endpoint is time to a first adjudication committee-determined, investigator-treated disease flare during the RCP. The primary analysis will be conducted when the last subject completes the RCP visit or discontinues the RCP. This study includes an optional 3-year open-label treatment period. The study also includes a Safety Follow-up Period (SFUP) after IP discontinuation of up to 730 days. The expected duration of each subject's participation in this study is up to 400 days (screening and RCP), plus up to 1095 days for eligible subjects who enroll in the optional open label period (OLP), and up to 730 days for the SFUP after IP discontinuation, for a total maximum duration of up to 2273 days (screening, RCP, interval between RCP and OLP, OLP, and FSUP).
This study aims to evaluate the efficacy and safety of inebilizumab for the prevention of flare of Immunoglobulin G4-related disease (IgG4-RD).