Real-world use of tafasitamab preceding CD19-directed chimeric antigen receptor T-cell therapy for relapsed or refractory diffuse large B-cell lymphoma

Potential CD19 antigen loss following CD19-directed therapy has raised concerns over sequential use of these therapies. Tafasitamab, a CD19-targeting immunotherapy, combined with lenalidomide, is approved for relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL) treatment in adults ineligible for autologous stem cell transplantation. This retrospective analysis examined characteristics and outcomes of adults with R/R DLBCL who received tafasitamab preceding CD19-directed chimeric antigen receptor T-cell (CAR-T) therapy in a real-world setting. Nine patients received tafasitamab and lenalidomide immediately preceding CAR-T. Median (first quartile [Q1]-third quartile [Q3]) follow-up time since tafasitamab initiation was 26.1 (18.0-28.0) and after CAR-T was 9.3 (1.9-16.7) months. Of the 9 patients, 4 had complete response, 4 had partial response, and 1 had stable disease following tafasitamab; all discontinued tafasitamab due to disease progression. Median (Q1-Q3) tafasitamab therapy duration was 11.0 (8.1-14.1) months. Three patients had CD19 testing following tafasitamab discontinuation, and all tests were positive. Median (Q1-Q3) time from tafasitamab discontinuation to CD19 testing was 7 (6-9) days. Among the 9 patients, median (Q1-Q3) time from tafasitamab discontinuation to CAR-T administration was 3.2 (2.3-3.6) months. Four patients had complete response, 3 had partial response, and 1 had progressive disease as best response to CAR-T; 1 patient had data unavailable. This small real-world analysis demonstrated disease response to CAR-T therapy and detectable CD19 expression following tafasitamab treatment, adding to literature investigating treatment outcomes associated with sequential use of anti-CD19 therapies in patients with R/R DLBCL.