A drug used to treat a rare condition called Castleman disease in patients who do not have HIV or human herpesvirus 8. It is also being studied in the treatment of multiple myeloma. CCLB8 binds to a protein called interleukin-6 (IL-6), which is made by some white blood cells and other cells in the body. CCLB8 may help reduce inflammation and stop the growth of cancer cells or abnormal blood cells. It is a type of monoclonal antibody.