Hairy cell leukemia future or investigational therapies

Experimental therapies
Three immunotoxin drugs are in Phase II trials at the NIH's National Cancer Institute in the U.S.: BL22, HA22 and LMB-2.

All of these protein-based drugs combine part of an anti-B cell antibody with a bacterial toxin to kill the cells on internalization. BL22 and HA22 attack a common protein called CD22, which is present on hairy cells and healthy B cells. LMB-2 attacks a protein called CD25, which is not present in HCL-variant, so LMB-2 is only useful for patients with HCL-classic or the Japanese variant.

All three of these therapies are available only at the National Cancer Institute in Bethesda, Maryland, USA. While initial results are generally favorable, it is likely to be a number of years before these drugs are available on the market.