Lenalidomide and secondary acute lymphoblastic leukemia: a case series.

Lenalidomide is often used in the maintenance setting for multiple myeloma and has been linked to the development of secondary primary malignancies. The mechanism of lenalidomide causing secondary malignancies has not been fully elucidated, but case reports and phase 3 trials have captured this uncommon occurrence. A case series describing development of secondary acute lymphoblastic leukemia in patients receiving lenalidomide maintenance therapy is presented. Based on data published in the literature thus far and commonalities among patients in this case series, secondary acute lymphoblastic leukemia is likely duration related rather than dose related. Increased cognizance of this secondary malignancy will allow for a more accurate characterization of its true incidence. Regimens for acute lymphoblastic leukemia can be used for management of secondary acute lymphoblastic leukemia with plan for stem cell transplantation. Further studies are needed to identify risk factors for development of secondary malignancy and the best management approach for these patients.