This is a phase 3, multicenter, randomized, double-blind, placebo-controlled trial designed to compare the efficacy and safety of the humanized monoclonal anti CD19 antibody tafasitamab plus lenalidomide in addition to R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) versus R-CHOP in previously untreated, high-intermediate and high-risk patients with newly-diagnosed DLBCL