Clinical effects of alemtuzumab (Campath-1H) in B-cell chronic lymphocytic leukemia.

Alemtuzumab (Campath-1H) is a monoclonal antibody (MAb) that shows its most powerful effects in clearing malignant CD52-bearing cells from the blood and bone marrow. Attention had therefore focused on the use of alemtuzumab in the treatment of B-cell chronic lymphocytic leukemia (B-CLL), in which symptoms are the result of an expansion of a CD1a+/CD5+/CD23+/CD52+ malignant clone, causing lymphocytosis in the circulation and pervasive infiltration of the bone marrow. In clinical trials, in heavily pretreated patients, alemtuzumab was effective, producing responses in about one-third of patients who had failed to respond previously to chemotherapy, including fludarabine. In addition, there was an even higher clinical effect in the bone marrow. Alemtuzumab treatment has also allowed patients with advanced disease to proceed to stem cell transplantation, and preliminary data indicate that alemtuzumab is highly effective in previously untreated patients with B-CLL.