Observational study evaluating wait time and clinical outcomes in patients (pts) with diffuse large B-cell lymphoma (DLBCL) who received chimeric antigen receptor (CAR) T-cell therapy (T-CT).

Abstract

e19577 Background: 5-year survival rates for DLBCL pts in the first-line setting range from 60% to 70%. Up to 50% of pts become refractory to or relapse (r/r) after treatment. Autologous CAR T-CT has shown efficacy in r/r DLBCL in ≥2 lines of treatment but faces significant challenges with cell collection and manufacturing that may delay pt treatment. This study assessed the impact of wait time for CAR T-CT (time between apheresis and CAR T-CT administration) on progression-free survival (PFS) in DLBCL pts. Methods: Data from pts in the electronic health record-derived de-identified US-based Flatiron Health database, who had a DLBCL diagnosis after Jan 1, 2011, and a documented CAR T-CT administration date, were included. Pts missing a documented apheresis date were excluded. Demographic and clinical characteristics were assessed within 6 months (mos) prior to index date (CAR T-CT administration). Pts were followed from index date to the first of pt death or end of data availability. Given no established clinically relevant cut points, short wait time was defined as < median time between apheresis and index date. Long wait time was defined as ≥ median time. 3-, 6-, and 12-mo PFS probabilities (95% confidence intervals [CIs]) by wait time were reported. Results: 91 DLBCL pts received CAR T-CT; 78 had a documented apheresis date. Median time from apheresis to index date was 37 days (interquartile range: 25, 116). 55% of pts experienced longer wait times (≥37 days). 45% experienced shorter times (<37 days). Pts were mostly white (80%–84%), male (57%–65%), and older (median: 60–67 years), with similar median follow-up time from index (4.0–4.7 mos). More pts with short wait times had stage 4 disease than those with long wait times (51% vs 28%). 71% of pts with shorter wait times received axicabtagene ciloleucel. Among those with long wait times, 72% received tisaggenlecleucel. More pts with long wait times received bridging therapy (66% vs 74%). Pts with short wait times had a higher 3-mo PFS probability than pts with long wait times. The 6- and 12-mo PFS probabilities were lower in those with shorter wait times (Table). No statistical comparisons were made due to small sample size. Conclusions: This real-world study showed no meaningful differences in PFS between wait times in DLBCL pts in the United States. Results from this study show evidence of channeling bias which is an important consideration for evaluating real-world data to construct external control arms. Future studies are needed to further evaluate the impact of delayed treatment in pts with r/r DLBCL. Funding: Takeda Development Center Americas, Inc.[Table: see text]