P1462: POPULATION-BASED REAL WORLD RESULTS OF CD19-DIRECTED CAR T-CELL THERAPY FOR PATIENTS WITH RELAPSED OR REFRACTORY LARGE B-CELL LYMPHOMA: A DUTCH CAR T-CELL TUMORBOARD EXPERIENCE

Abstract

Background: CD19-directed CAR T-cell therapy has become standard of care for patients with relapsed/refractory (R/R) large B-cell lymphoma (LBCL) and durable responses are seen in up to 40% of treated patients. Optimal selection of patients who will benefit from CAR T-cell therapy is important. In the real world reasons for ineligibility of patients who meet the registration label are often not reported. Additionally, data on health-related quality of life (HR-QoL) after infusion are scarce. Real world (in)eligibility and HR-QoL can play an important role in guiding treatment choices with novel therapeutic options becoming available. In the Netherlands, population-based referral and eligibility assessment for CAR T-cell therapy are centralized in a national tumorboard. A multicenter expert team discusses cases and data are collected in a national registry from time of referral. The aims of the tumorboard and registry are to capture population-based data on patients potentially eligible for CAR T-cell therapy and to optimize (cost-) effective, high quality care. Aims: To evaluate real world results of axicabtagene ciloleucel (axi-cel) for R/R LBCL on a population level, including reasons for ineligibility, efficacy, toxicity and (in a subset of patients) HR-QoL. Methods: For this prospective multicenter cohort study, all adult patients referred to the tumorboard for treatment of R/R LBCL with axi-cel were included from May 1st 2020 – October 19th 2021. Descriptive statistics were used for baseline characteristics, Kaplan Meier methods for survival analysis, regression models for univariate/multivariate analysis and linear mixed models for HR-QoL over time. Results: In total, 186 patients were referred to the tumorboard, 57 were not approved for axi-cel during the online tumorboard meeting, mostly (n=23) due to rapid progression (RP). The 129 approved patients were screened at a CAR T center, 32 were rejected (n=21 RP). Ninety-seven patients underwent apheresis of whom 7 did not receive axi-cel, mostly due to RP (n=6). Ninety patients were infused with CAR T-cells. Data of 74 of these patients are currently available for toxicity/efficacy analysis and updated results, including HR-QoL, will be presented during the EHA meeting. Median age was 59-years (min-max 27-79), 81% received bridging therapy. Best overall response rate was 82.4 %, including 66.2% complete remissions (CR). Median time to response was 1 month and all patients achieved their best response within 3 months. Four patients with PR at 1 month achieved a CR at month 3. The PFS and OS curves are shown in Figure 1. All grades CRS occurred in 89%, including ≥grade 3 in 2.7%, median time to onset was 3 days (min-max 0-14) and median duration 6 days (min-max 1-17). All grades ICANS occurred in 58%, including ≥ grade 3 in 27%, with a median time to onset of 7 days (min-max 1-28) and a median duration of 7 days (min-max 1-28). Non-relapse mortality was 1.4% due to one grade 5 ICANS event. Image:Summary/Conclusion: The merit of a national tumorboard is to enable prospective, in-dept evaluation of rejected as well as CART-infused patients. Twenty-eight percent of the referred patients in the Dutch population that fulfilled the indication criteria for R/R LBCL treatment with axi-cel could not receive the therapy due to rapidly progressive disease. A relatively low percentage of patients, 7%, underwent leukapheresis but eventually did not receive axi-cel. Efficacy and toxicity in our cohort are comparable with ZUMA-1 study results and other large real world cohorts.