Feasibility Study of Induction and Maintenance Avelumab Plus R-CHOP in Patients With Diffuse DLBCL: The AvR-CHOP Study

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. Primary endpoint: • Immune related toxicity which requires discontinuation of Avelumab. Secondary endpoints: * Response rates (according to the Lugano classification for Response Criteria for NonHodgkin Lymphoma); * Failure free survival; * Overall survival; * Overall toxicity of treatment (according to CTCAE v 4.0). Methodology: All patients (n=28) will receive Avelumab and rituximab 2 weekly for 2 cycles, then RCHOP chemotherapy 3 weekly for 6 cycles then Avelumab 2 weekly for 6 cycles. The sequential treatment schedule has been designed for several reasons: concurrent Avelumab and RCHOP might result in reduced efficacy of Avelumab owing to the high dose prednisolone component of RCHOP; immune related toxicities of Avelumab given concurrently with RCHOP might result in chemotherapy dose delays and reduced chemotherapy efficacy; the Avelumab plus rituximab prephase will allow for the preliminary assessment of nonchemotherapy agents Avelumab plus rituximab in treatment naïve patients. Assessments: * Patients will be reviewed at baseline and prior to each cycle of treatment for toxicity * Positron emission tomography-computed tomography (PET/CT) will be performed at baseline, after induction phase, after cycle 2 RCHOP, at end of Avelumab (Av) RCHOP and at end of maintenance phase Avelumab. * Following completion of treatment, patients will be followed up for a total of 5 years (at 3,6,9,12,18,24,36,48 and 60 months posttreatment). No formal routine imaging will be performed during follow up. In patients with relapse, follow up only for survival will be every 3 months.