Alemtuzumab (Campath-1H,Campath1) for the treatment of lymphoid malignancies: chronic lymphocytic leukemia and T-cell prolymphocytic leukemia

Objective. To provide a comprehensive review of the clinical pharmacology and toxicology of the monoclonal antibody alemtuzumab, with particular reference to its use in its approved indication, B-cell chronic lymphocytic leukemia, as well as the non-approved indication, T-cell prolymphocytic leukemia.

Data Sources. A MEDLINE search was conducted using the terms ‘alemtuzumab’ and ‘Campath.’ All data available from MEDLINE were reviewed. The reference lists from retrieved articles were reviewed and other relevant papers identified. The abstract books from the annual meetings of the American Society of Hematology were also reviewed.

Data Extraction. The aim of the review was to be comprehensive and descriptive. Studies containing information deemed to be of interest were reviewed by the author.

Data Summary. CD52 is a surface antigen expressed on all B- and T-lymphocytes. Because of the presence of this surface antigen on both normal and malignant lymphocytes, the use of antibody as a treatment option is then possible. Alemtuzumab (Campath-1H, Campath¹) is a humanized anti- CD52 antibody that has been shown to be active against certain hematological malignancies, particularly lymphoproliferative diseases in the blood. The overall response rate for patients with chronic lymphocytic leukemia relapsed after fludarabine or alkylating therapy ranged from 33% to 70%, with most patients entering partial remission. The average duration of response is approximately 11 - 12 months. For patients with T-cell prolymphocytic leukemia failed first-line chemotherapy, overall response rate to alemtuzumab therapy ranged from 76% to 31%, with majority of patients entering complete remission. The average duration of response is approximately 7-9 months. Major adverse effects of alemtuzumab include infusion-related reactions, prolonged lymphopenia, and opportunistic infections (CMV, Herpes zoster, and PCP). Prophylactic use of acyclovir and trimethroprim/sulfamethoxazole are recommended while patient is receiving alemtuzumab and continued for 2 months after alemtuzumab therapy is completed.