Experimental therapy in Hodgkin's disease.

Hodgkin/Reed-Sternberg (H-RS) cells express lymphoid activation markers like CD25 and CD30 which are present only on a small minority of normal cells. Currently, most experimental approaches in Hodgkin's lymphoma are aimed at targeting H-RS cells via monoclonal antibodies against CD25 and CD30: immunotoxins constructed by linking the antibody moiety chemically to deglycosylated ricin A-chain destroy up to 60% of small H-RS tumors in mice. The most potent immunotoxin is currently being scaled up for clinical trials. Other experimental strategies use bispecific constructs that, after binding to the cell surface of H-RS cells, convert prodrugs into their toxic counterparts, or employ monoclonal antibodies for active immunotherapy.