On February 22, 2017, the U.S. Food and Drug Administration (FDA) granted approval for the use of lenalidomide as maintenance therapy after autologous hematopoietic stem cell transplantation (auto-HSCT) for patients with multiple myeloma. The approval was based on evidence from two randomized, blinded trials of maintenance lenalidomide versus placebo in patients with myeloma who had undergone auto-HSCT along with a
third trial of lenalidomide versus no therapy. Each of the trials demonstrated superior progression-free survival for the patients treated with lenalidomide. The effect on overall survival was mixed, with one trial showing longer overall survival and another showing no effect. Subgroup analysis suggested better results for patients with International Staging System stage I or II disease compared with stage III disease. Safety evaluation did not reveal any new safety concerns. More second primary malignancies were observed in the lenalidomide arm compared with the placebo arm. The FDA concluded that lenalidomide maintenance showed a favorable benefit-to-risk ratio when used as maintenance therapy after auto-HSCT. IMPLICATIONS FOR PRACTICE Prior to this approval, there were no U.S. Food and Drug Administration-approved maintenance therapies for patients with multiple myeloma (MM) who have undergone autologous hematopoietic stem cell transplantation (auto-HSCT). Maintenance therapy with lenalidomide after auto-HSCT in patients with MM demonstrated an approximately 15- to 18-month advantage in progression-free survival compared with placebo at the time of the primary analysis. Patients treated with lenalidomide also appeared to have a survival advantage compared with patients treated with placebo. Because of the high rate of relapse of MM in patients following auto-HSCT and because MM is a serious and often fatal disease, these results appear to be clinically meaningful.