研究目的:
To evaluate the efficacy and safety of lenalidomide, rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R2-CHOP) chemotherapy versus placebo, rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (placebo-R-CHOP) chemotherapy in patients who have previously untreated ABC type DLBCL