Lenalidomide: a review of its continuous use in patients with newly diagnosed multiple myeloma not eligible for stem-cell transplantation.

Lenalidomide (Revlimid(®)) is a second-generation immunomodulatory drug structurally related to thalidomide, with improved efficacy and tolerability, for which the label in the EU was recently expanded to include continuous therapy in patients with previously untreated multiple myeloma not eligible for stem-cell transplantation. In randomized, controlled clinical trials, continuous lenalidomide therapy, either in combination with dexamethasone (FIRST trial) or as maintenance monotherapy following induction with melphalan/prednisone/lenalidomide (MM-015 trial), significantly improved progression-free survival (PFS) compared with induction therapy alone (with non-lenalidomide- or lenalidomide-containing regimens) in patients with newly diagnosed multiple myeloma not eligible for stem-cell transplantation. The improvements in PFS with continuous lenalidomide were reflected in improved health-related quality-of-life measures. An overall survival benefit was observed in the FIRST trial, but not in the MM-015 trial. Continuous lenalidomide and continuous thalidomide regimens displayed similar efficacy, but lenalidomide was associated with significantly less toxicity than thalidomide. Continuous use of lenalidomide did not appear to negatively impact on the drug's tolerability and did not increase the incidence of neutropenia or second primary malignancy compared with shorter-term use. The incidence of most adverse events began to reduce after about 18 months of therapy. In conclusion, continuous lenalidomide regimens provide an effective longer-term treatment option in patients with newly diagnosed multiple myeloma ineligible for stem-cell transplantation.