Lenalidomide alone or lenalidomide plus dexamethasone significantly inhibit IgG and IgM in vitro…A possible explanation for their mechanism of action in treating multiple myeloma

► Lenalidomide dramatically inhibits de novo synthesis of human IgM and IgG. ► Putative pokeweed stimulated B cell blasts are targeted by lenalidomide. ► Inhibition of IgM and IgG could explain how lenalidomide effectively treats multiple myeloma.