Overall Survival Benefits Provided by Lenalidomide Maintenance after Chimeric Antigen Receptor T Cell Therapy in Patients with Refractory/relapsed Diffuse Large B-cell Lymphoma.

Background:Chimeric antigen receptor T cell (CAR-T) therapy has achieved remarkable effects in refractory/relapsed (R/R) diffuse large B-cell lymphoma (DLBCL). However, many patients receiving CAR-T therapy still eventually die of disease recurrence or progression due to target antigen loss or exhaustion of CAR-T cells. Therefore, maintaining the efficacy of CAR-T has become a particular research focus. As lenalidomide can regulate T cell function, we conducted a study to evaluate the efficacy of lenalidomide maintenance after CAR-T therapy in R/R DLBCL patients.Methods:Seven R/R DLBCL patients who received lenalidomide maintenance after CAR-T therapy and nine DLBCL patients that underwent CAR-T treatment alone were included. The clinical data of all subjects were collected to evaluate the efficacy of lenalidomide maintenance. In order to understand the possible mechanisms of lenalidomide in CAR-T therapy, CAR-T copies of peripheral blood were regularly detected by quantitative real-time polymerase chain reaction, and an in vitro test was also conducted.Results:Overall survival (OS) was significantly prolonged in the lenalidomide maintenance group. Furthermore, one case responding to CAR-T therapy initially but suffering a relapse shortly achieved complete remission again after lenalidomide exposure, with an increase in the number of CAR-T copies detected. The in vitro test showed that lenalidomide could delay the exhaustion of CAR-T cells.Conclusions:Lenalidomide maintenance after CAR-T therapy is a safe and effective choice for R/R DLBCL patients. We confirmed that lenalidomide maintenance can improve patients' OS, and the delayed exhaustion of CAR-T cells may contribute to this OS benefit.