New Frontiers in Monoclonal Antibodies for Relapsed/Refractory Diffuse Large B-Cell Lymphoma

Simple Summary Forty percent of patients with diffuse large B-cell lymphoma (DLBCL) have a refractory or relapsed (R/R) disease. In this setting, prognosis is poor, particularly for patients not eligible for autologous stem-cell transplantation or CAR-T-cell therapy, thus representing an unmet need in the field of hematological malignancies. Currently, the optimal treatment approach for these patients remains controversial. Over the last few decades, monoclonal antibodies (mAbs) have dramatically changed the therapeutic landscape for cancer patients. The aim of our review is focused on novel and emerging therapeutic strategies based on different types of mAbs, including monospecific and bispecific mAbs as well as antibody-drug conjugates and immune checkpoint inhibitors, in the challenging setting of R/R DLBCL.Abstract Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive lymphoma. Approximately 60% of patients are cured with R-CHOP as a frontline treatment, while the remaining patients experience primary refractory or relapsed disease (R/R). The prognosis for R/R DLBCL patients who are neither eligible for autologous stem-cell transplantations nor CAR-T-cell treatment is poor, representing an important unmet need. Monoclonal antibodies (mAbs) have dramatically improved therapeutic options in anti-cancer strategies, offering new opportunities to overcome chemo-refractoriness in this challenging disease, even in cases of primary non-responder DLBCL. Several novel mAbs, characterized by different mechanisms of action and targets, are now available for R/R DLBCL. Unbound mAbs induce an immune response against cancer cells, triggering different mechanisms, including antibody-dependent cellular cytotoxicity (ADCC), activation of antibody-dependent cell-mediated phagocytosis (ADCP) and complement-dependent cytotoxicity (CDC). Antibody-drug conjugates (ADCs) and radioimmunotherapy (RIT), respectively, deliver a cytotoxic payload or a beta-emitter radionuclide to the targeted cells and nearby bystanders. Bispecific T-cell engagers (BiTes) and immune checkpoint inhibitors (ICIs) redirect and enhance the immune response against tumor cells. Here, we review therapeutic strategies based on monoclonal antibodies for R/R DLBCL.