Alemtuzumab is a drug used in the treatment of chronic lymphocytic leukemia (CLL), cutaneous T-cell lymphoma (CTCL) and T-cell lymphoma under the trade names Campath, MabCampath and Campath-1H, and in the treatment of multiple sclerosis as Lemtrada. It is also used in some conditioning regimens for bone marrow transplantation, kidney transplantation and islet cell transplantation.
It is a monoclonal antibody that binds to CD52, a protein present on the surface of mature lymphocytes, but not on the stem cells from which these lymphocytes are derived. After treatment with alemtuzumab, these CD52-bearing lymphocytes are targeted for destruction.
Alemtuzumab is used as second-line therapy for CLL. It was approved by the US Food and Drug Administration for CLL patients who have been treated with alkylating agents and who have failed fludarabine therapy. It has been approved by Health Canada for the same indication, and additionally for CLL patients who have not had any previous therapies.
(Mab)Campath was withdrawn from the markets in the US and Europe in 2012 to prepare for a higher-priced relaunch of Lemtrada aimed at multiple sclerosis.