Continuous treatment in multiple myeloma - ready for prime time?

Recently, non-genotoxic drugs have succeeded in several hematologic malignancies such as chronic myeloid leukemia (CML) or indolent non-Hodgkin's lymphomas. Unlike this, alkylating chemotherapy is still a backbone of anti-myeloma drug treatment in the vast majority of 'medically fit' subjects. With the introduction of the immunomodulatory drugs thalidomide and lenalidomide, a novel class of compounds was integrated into therapy of multiple myeloma. Either drug may be delivered for a prolonged time; however fatigue, constipation and neuropathy prevent thalidomide from serving as a 'continuous' treatment. Lenalidomide has been approved for treatment of relapsed multiple myeloma, to be delivered as a continuous therapy. Since the drug lacks thalidomide's severe side effects, it is being explored on a continuous maintenance basis both after conventional therapy and after autologous stem cell transplantation. Preliminary data of respective clinical trials that have become available show highly significant differences in event-free survival times, favoring continuous lenalidomide over placebo. Currently, it is still unclear whether this will translate also into an overall survival benefit after prolonged follow-up.