Lenalidomide in multiple myeloma: current experimental and clinical data.

Lenalidomide (LEN) is a structural analogue of Thalidomide and is currently considered a promising compound among immunomodulatory drugs. Following the demonstration of its potent anti-angiogenic, anti-inflammatory, and antineoplastic effects in preclinical models, LEN has emerged as an interesting option for the management of selective hematologic malignancies and may also have a possible role in certain solid tumors as well. It is currently approved in the second-line therapy of multiple myeloma (MM) as well as in myelodysplastic syndrome characterized by 5q minus abnormalities. LEN has been found to be effective in the treatment of both of these conditions and to possess a manageable toxicity profile. In MM, a number of ongoing clinical trials are defining its role in the treatment of newly diagnosed disease as well as in maintenance therapy. Combination approaches pretransplant have shown great promise. Its role in the management of relapsed and refractory disease is now well established. Its long-term tolerability profile appears favorable although an increased risk in new malignancies in patients receiving LEN as maintenance post-stem cell transplant warrants some caution, with follow-up studies being important in determining the long-term implications of this observation.