The rationale and primary objective is to evaluate the feasibility of adding induction and maintenance Avelumab into the standard Rituximab, Cyclophosphamide, Doxyrubicin, Vincristine and Prednisolone (RCHOP) regimen in order to examine the effect of programmed death-ligand 1(PDL1) inhibition in patients with stage II, III and IV DLBCL.