Conceptual aspects of combining rituximab and Campath-1H in the treatment of chronic lymphocytic leukemia.

Monoclonal antibody-based therapy has emerged as a novel approach in the treatment of hematologic malignancies. The safety and tolerability of monoclonal antibodies make these compounds attractive and easy to administer, even in elderly, heavily pretreated patients. Chronic lymphocytic leukemia is an incurable disease with few therapeutic options once patients fail purine analogue-based therapy. Two monoclonal antibodies have shown activity in this disease. The first is rituximab (Rituxan; Genentech, Inc, South San Francisco, CA, and IDEC Pharmaceuticals, San Diego, CA), a chimeric human-mouse anti-CD20 antibody. The second is Campath-1H, a humanized form of a rat antibody active against CD52. We hypothesize that combining both antibodies in patients who have failed conventional therapies and express both CD20 and CD52 might have enhanced efficacy and therapeutic benefit. This concept is being explored at our institution in the context of a phase I/II clinical trial. The outcome and feasibility of this combination opens the way for future combination therapies using novel biologic agents. Copyright 2002 by W.B. Saunders Company.