In a deal worth up to $1.8 billion, Biogen Inc. is buying Human Immunology Biosciences Inc. (Hibio), bolstering its late-stage immune-disease treatment portfolio and diversifying its pipeline. The massive amount comprises $1.15 billion up front and as much as $650 in potential milestone payments. The deal in rare diseases brings Biogen phase III-ready felzartamab, a fully human monoclonal antibody that selectively depletes CD38-positive plasma cells and natural killer cells. Hibio also is developing izastobart, an anti-C5aR1 antibody. Both assets were in-licensed from Morphosys AG in June 2022. Hibio also has mast cell programs in the discovery stage.