Survival Outcomes of Patients with Diffuse Large B-Cell Lymphoma Who Received Autologous Stem Cell Transplantation in Germany - Real World Evidence from an Administrative Database

Background: Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma with increasing incidence. Autologous stem cell transplantation (ASCT) is a treatment option for patients who relapse or progress after up-front chemoimmunotherapy if they suitable for ASCT. However, patients may not qualify for this treatment because of age and/or comorbidity or because they are non-responder to second-line chemoimmunotherapy. Limited real-world data of the ASCT patient population is available for Germany. Therefore, this retrospective database analysis was conducted to describe real-world survival outcomes of patients with DLBCL who received ASCT in Germany.

Patients and Methods: Using a large claims database of the German statutory health insurance with 6.7 million enrollees between 2010 and 2019, we identified patients who were newly diagnosed with DLBCL, had no other cancer co-morbidity, and received ASCT (index date). Pre-defined treatment lines were used to identify the utilization of ASCT. Unadjusted overall survival (OS) from index was plotted by means of the Kaplan-Meier estimator for the overall population and for those patients who had/had not a subsequent treatment line after ASCT. Furthermore, we performed a Cox proportional hazard survival regression with the following co-variates: age, sex, Charlson Comorbidity Index (CCI), time from start of first line treatment to ASCT, and presence of subsequent treatment after ASCT.

Results: 112patients received ASCT. Among them, 39.3% received subsequent treatment after ASCT. Time to ASCT was on average 11.7 months for the entire cohort. Median OS estimated by Kaplan-Meier was 83.4 months for the entire cohort and 27.8 months for patients who received subsequent treatment. Median OS was not estimated for the group without subsequent treatment, for whom the Kaplan-Meier curve reached a plateau at just under 90%, assuming a potential cure. Finally, the only variable significantly reducing the OS was the presence of subsequent treatment after ASCT in a time-dependent model.

Conclusion: Given the high survival outcomes, ASCT is a valuable treatment option for relapsed/refractory DLBCL. However, only a small subset of patients is fit enough to benefit from this treatment and patients who fail ASCT have a poor prognosis. Therefore, novel therapeutic approaches are required to address these unmet medical needs.