Alemtuzumab in the treatment of chronic lymphocytic lymphoma.

Alemtuzumab was the first monoclonal antibody to be humanized, a process which embeds rodent sequence fragments in a human IgG framework. The antibody target is CD52, an antigen expressed on normal lymphocytes as well as many T- and B-cell neoplasms. It therefore has a potential broad application across a spectrum of B- and T-cell malignancies as well as use as an immunosuppressant drug in, for example, bone marrow transplantation. The original licensing in the USA and Europe was for the treatment of fludarabine-refractory chronic lymphocytic leukemia (CLL). However, recent trials using alemtuzumab as a first-line agent for CLL have shown superior response rates compared with traditional alkylator therapy and this has led to US FDA approval for first-line treatment for CLL. It seems to be particularly useful in patients with CLL who have deletion of the TP53 tumor suppressor gene, a subset of disease that responds poorly to other currently available chemotherapeutics.