Inebilizumab is a humanized anti-CD19 monoclonal antibody with enhanced antibody-dependent cell-mediated cytotoxicity against B cells. Inebilizumab can be used to treat a range of autoimmune diseases associated with CD19 B cells, such as multiple sclerosis and optic neuromyelitis.

Derived from the mouse anti-human mAb HB12b, Inebilizumab had already shown impressive activity in depleting B cells in transgenic mice carrying the human CD19 gene (hCD19 Tg)[1].
Inebilizumab potently depletes CD19-expressing B cells, including primary human B cells, B cell lines derived from multiple tumor types, and neoplastic B cells[1].
Inebilizumab demonstrates equal or better activity than Rituximab in depleting human primary B cells in autologous ADCC assays and shows potent ADCC activity against human in vitro-differentiated and primary plasma cells[1].

In vivo, Inebilizumab (MEDI-551) (i.v.; once; 0-10 mg/kg) depletes B cells from blood and spleen by mouse macrophages, and it induces phagocytosis of murine B cells ex vivo[2].