| abstract |
An objective of the present invention is to provide a therapeutic agent for treating rheumatoid arthritis, juvenile rheumatoid arthritis, macrophage activation syndrome, septicemia, and FR-β expressing leukemia, which induces apoptosis in activated macrophages and folate receptor beta (FR-β) expressing leukemia cells to specifically destroy these cells. An FR-β monoclonal antibody of the present invention is preferably an IgG-type monoclonal antibody which specifically reacts with a human-type FR-β antigen and is produced from a clone resulting from immunization with an FR-β expressing B300-19 cell. The FR-β monoclonal antibody of the present invention specifically reacts with the FR-β antigen of activated macrophages and FR-β expressing leukemia cells and a therapeutic agent of the present invention contains an FR-β antibody immunotoxin which causes apoptosis in activated macrophages and FR-β expressing leukemia cells, as an active ingredient. Further, suitable administration form for the therapeutic agent of the present invention includes Intravenous injection as well as joint injection in the case of therapeutic agents for rheumatoid arthritis and juvenile arthritis. |