Molecular Monitoring With Circulating Tumor DNA and Nivolumab Maintenance

Patients suffering from diffuse large B-cell lymphoma (DLBCL) who relapse within 12 months of chemotherapy usually undergo salvage therapies, followed by autologous transplant with a low success rate. These treatments for relapse have significant toxicities and may not be tolerated well by the patients. These patients need an effective means of identifying relapse at an early time point to be treated effectively. Detection of circulating tumor DNA (ctDNA) has been reported to be a sensitive and more specific method to detect relapse at an early stage compared to PET/ CT scans. Purpose of this trial is to monitor patients who have undergone successful chemotherapy for the presence of ctDNA. Patients who test positive for ctDNA would be treated with Nivolumab for a period of 2 years to avoid complete relapse.

Primary Objective: To determine if nivolumab administration, as a maintenance strategy in DLBCL patients with high risk of relapse, can convert positive ctDNA to negative ctDNA and/or result in relapse free survival (RFS-ctDNA) of 9 months or longer after positive ctDNA was documented. Secondary Objectives: 1. To evaluate safety of nivolumab as maintenance drug in post-induction, post-salvage and post-autologous transplant setting 2. Relapse free survival (RFS-ctDNA) for nivolumab treated patients 3. Proportion of patients who are able to convert from ctDNA positive to ctDNA negative after nivolumab treatment 4. To validate NeoLabs assay platform by comparing the results to Clonoseq platform.