Comparison of Outcomes of Donor Lymphocyte Infusions With or Without Lenalidomide in Patients with Hematological Malignancies Post Allogeneic HSCT.

Outcomes with DLI alone for post-transplant relapsed hematological malignancies are poor especially in acute leukemias. Addition of immunomodulatory drugs to DLI may augment GVL effect. Use of lenalidomide with DLI to augment GVL has not been previously reported. This retrospective analysis was to compare the outcomes of DLI with or without lenalidomide. All consecutive patients who received DLI from 01/2010 through 01/2020 were included. DLIs were given without any immunosuppression. Lenalidomide, when used, was given continuously, starting with 1st or subsequent DLI. Patients who received lenalidomide were compared with those who did not. Event (hematological relapse or death) free survival (EFS) and overall survival (OS) were calculated from 1st DLI. Primary objective was to compare OS. Secondary objectives were EFS, CR rates, acute GVHD, lenalidomide toxicities and DLI related mortality (TRM). Total 61 patients received DLI-43 without and 18 with lenalidomide; all outcomes in the 2 groups were similar. There were 26 patients with HLA-A*24 and/or HLA-B*40. Among these, trend towards improvement in OS (median OS not reached vs. 8 months, 4 year OS was 62% vs. 32%, p  = 0.1) and EFS (median 9 vs. 1 month, 4 year EFS 50% vs. 22%, p  = 0.1) was seen with lenalidomide. Overall, there was no improvement in outcomes by adding lenalidomide to DLI. However, among patients with HLA*24 or B*40, there was a trend to improved survival with lenalidomide. Use of lenalidomide to augment the GVL effect of DLI warrants further exploration.