Study of Cytokine Release Syndrome Prophylaxis and Treatment With Siltuximab Prior to Epcoritamab

The goal of this clinical trial is to is to determine the safety, feasibility and efficacy of siltuximab prophylaxis of cytokine release syndrome and neurotoxicity occurring after epcoritamab subcutaneous administration for participants with large b-cell lymphoma (DLBCL) or follicular lymphoma (FL). Participants will receive siltuximab, prior to the injection of epcoritamab. Epcoritamab is administered in 28 day cycles for one year. After this injection, the physician will continue to watch participants for side effects and follow the condition for a minimum of 60 days.

Siltuximab is a monoclonal antibody that blocks interleukin-6 (IL-6) from binding to its receptor, preventing it from acting. IL-6 is a cytokine, a type of protein that is a cause of inflammatory reactions. Decreasing levels of IL-6 has been shown to reduce symptoms of cytokine release syndrome (CRS), a potential side effect of epcoritamab. Addition of siltuximab to the medications given before epcoritamab, may prevent, or reduce the severity, of CRS. Siltuximab is experimental because it is not approved by the Food and Drug Administration for treatment or prevention of CRS. Epcoritamab is a so-called bispecific antibody, which is a molecule that can bind simultaneously to two different receptors. Epcoritamab binds to a receptor called CD3 with one part of the antibody and to a receptor called CD20 with another part of the antibody. CD20 is expressed on the normal, healthy B cells but also on the cancerous lymphoma cells of B cell origin. CD3 is expressed on T cells, which are important cells of the immune system and help the body fight cancers, infections, etc. By simultaneous binding to CD3 and CD20, Epcoritamab brings T cells and B cells close together and activates the T cells to kill the B cells, including the cancerous ones.