Treating chronic lymphocytic leukemia with thalidomide and lenalidomide.

INTRODUCTION: Chronic lymphocytic leukemia (CLL) is biologically, as well as clinically, highly heterogeneous. In CLL patients, immunosuppression is a consequence of the disease, which plays a key role in effecting the quality of life and overall survival. Treatment modalities should ideally not only reduce tumor burden, but also augment immune function in CLL patients. AREAS COVERED: The current review summarizes biological and clinical data on thalidomide and lenalidomide in CLL. EXPERT OPINION: Immunomodulatory drugs such as thalidomide and lenalidomide show both antitumor activity and immunostimulation. Three main mechanisms of action seem to play a role in cancer, including i) anti-angiogenic, ii) immunomodulatory and iii) tumoricidal effects. The exact contributions of these effects seem to be unique for different diseases. The two representatives of this family of drugs studied in CLL include thalidomide and its analog lenalidomide. These drugs proved to be effective as single agents and in the combination setting in CLL. Toxicities have been identified but largely controlled by a low starting dose, with gradual dose escalation.