Where Does Lenalidomide Fit in Non-del(5q) MDS?

Lenalidomide is nowadays an accepted standard treatment for del(5q) MDS. In non-del(5q) disease, its role is more difficult ot define. Studies have shown that about 18 % of patients treated with a standard dose of 10 mg/day on 21 out of 28 days might achieve erythroid transfusion independence rates that last 6 months or longer. The responses to lenalidomide seem to be inversely correlated to the pre-treatment EPO level. The higher the EPO level, the lower the responses. In the absence of other cytogenetic or molecular predictive factors that allow to discern which patient benefit most from treatment, its incorporation into the treatment algorithm is dependent on the available alternatives, including erythropoietic agents, immunosuppressive treatments and experimental strategies like thrombopoietin receptor agonists or the antagonists of transforming growth factor beta. Given that 90 % of responses to lenalidomide occur within four months of treatment, patients not responding within this time frame should discontinue therapy.