Clinical outcomes in transplant‐eligible patients with relapsed or refractory diffuse large B‐cell lymphoma after second‐line salvage chemotherapy: A retrospective study

OBJECTIVE: The prognosis of patients with relapsed or refractory (R/R) diffuse large B‐cell lymphoma (DLBCL) is poor. Although patients who fail first‐line salvage chemotherapy are candidates for second‐line salvage chemotherapy, the optimal treatment strategy for these patients has not yet been established. METHODS: The present, single‐center, retrospective study included transplant‐eligible patients with R/R DLBCL who received second‐line salvage chemotherapy with curative intent. RESULTS: Seventy‐six patients with R/R DLBCL received second‐line salvage chemotherapy. Eighteen (23.7%) patients were responders to the first‐line salvage chemotherapy. The overall response rate was 39.5%, and overall survival (OS) was significantly longer in patients who responded to second‐line salvage chemotherapy than those who did not. Forty‐one patients who proceeded to potentially curative treatment (autologous hematopoietic stem cell transplantation [ASCT], chimeric antigen receptor [CAR] T‐cell therapy, or allogeneic hematopoietic stem cell transplantation) had a better prognosis than those who did not. Among the 46 patients who failed to respond to the second‐line salvage regimen, only 18 (39.1%) could proceed to the curative treatments. However, among the 30 patients who responded to the second‐line salvage regimen, 23 (76.7%) received one of the potentially curative treatments. Among 34 patients who received CAR T‐cell therapy, OS was significantly longer in those who responded to salvage chemotherapy immediately prior to CAR T‐cell therapy than in those who did not respond. In contrast, the number of prior lines of chemotherapy was not identified as a statistically significant prognostic factor of survival. No significant difference was detected in OS between patients receiving ASCT and those receiving CAR T‐cell therapy after the response to second‐line salvage chemotherapy. DISCUSSION: In this study, we demonstrated that chemosensitivity remained a crucial factor in predicting survival outcomes following CAR T‐cell therapy irrespective of the administration timing, and that both ASCT and CAR T‐cell therapy were acceptable after the response to second‐line salvage chemotherapy.