CD19-directed chimeric antigen receptor (CAR) T cells have evolved as new standard-of-care (SOC) treatment in patients with relapsed/refractory large B-cell lymphoma (LBCL). Here, we report the first German real-world data on SOC CAR-T cell therapies with the aim to explore risk factors associated with outcome. Patients who received SOC axicabtagene ciloleucel (axi-cel) or tisagenlecleucel (tisa-cel) for LBCL and were registered with the German Registry for Stem Cell Transplantation (DRST) were eligible. Main outcomes analyzed were toxicities, response, overall survival (OS), and progression-free survival (PFS). We report 356 patients who received axi-cel (n=173) or tisa-cel (n=183) between November 2018 and April 2021 at 21 German centers. Whereas the axi-cel and tisa-cel cohorts were comparable for age, sex, LDH, IPI, and pretreatment, the tisa-cel group comprised significantly more patients with poor performance status, ineligibility for ZUMA-1, and need for bridging, respectively. With a median follow-up alive of 11 months, Kaplan-Meier estimates of OS, PFS, and non-relapse mortality (NRM) 12 months after dosing were 52%, 30%, and 6%, respectively. While NRM was largely driven by infections subsequent to prolonged neutropenia and/or severe neurotoxicity and significantly higher with axi-cel, significant risk factors for PFS on multivariate analysis included bridging failure, elevated LDH, age, and tisa-cel use. In conclusion, this study suggests that important outcome determinants of CD19-directed CAR-T cell treatment of LBCL in the real-world setting are bridging success, CAR-T product selection, LDH, and the absence of prolonged neutropenia and/or severe neurotoxicity. These findings may have implications for designing risk-adapted CAR-T cell therapy strategies.

PURPOSE: Although chimeric antigen receptor T therapy (CAR-T) cells are an established therapy for relapsed/refractory multiple myeloma (RRMM), there are no established models predicting outcome to identify patients who may benefit the most from CAR-T. PATIENTS AND METHODS: This is an international retrospective observational study including patients with RRMM infused with currently available commercial or academically produced anti–B-cell maturation antigen (BCMA) CAR-T. We describe characteristics and outcomes in Europe (n = 136) and the United States (n = 133). Independent predictors of relapse/progression built a simple prediction model (Myeloma CAR-T Relapse [MyCARe] model) in the training cohort (Europe), which was externally validated (US cohort) and tested within patient- and treatment-specific subgroups. RESULTS: The overall response rate was 87% and comparable between both cohorts, and complete responses were seen in 48% (Europe) and 49% (the United States). The median time to relapse was 5 months, and early relapse <5 months from infusion showed poor survival across cohorts, with the 12-month overall survival of 30% (Europe) and 14% (the United States). The presence of extramedullary disease or plasma cell leukemia, lenalidomide-refractoriness, high-risk cytogenetics, and increased ferritin at the time of lymphodepletion were independent predictors of early relapse or progression. Each factor received one point, forming the three-tiered MyCARe model: scores 0-1 (low risk), scores 2-3 (intermediate risk), and a score of 4 (high risk). The MyCARe model was significantly associated with distinct 5-month incidence of relapse/progression ( P < .001): 7% for low-risk, 27% for intermediate-risk, and 53% for high-risk groups. The model was validated in the US cohort and maintained prognostic utility for response, survival, and outcomes across subgroups. CONCLUSION: Outcomes of patients with RRMM after CAR-T are comparable between Europe and the United States. The MyCARe model may facilitate optimal timing of CAR-T cells in patient-specific subgroups.

B-cell maturation antigen (BCMA)-targeting chimeric antigen receptor (CAR) T cells revolutionized the treatment of relapsed/refractory multiple myeloma (RRMM). However, data on cellular (CAR) T cell dynamics and the association with response, resistance or the occurrence of cytokine release syndrome (CRS) are limited. Therefore, we performed a comprehensive flow cytometry analysis of 27 RRMM patients treated with Idecabtagene vicleucel (Ide-cel) to assess the expansion capacity, persistence and effects on bystander cells of BCMA-targeting CAR T cells. Additionally, we addressed side effects, like cytokine release syndrome (CRS) and cytopenia. Our results show that in vivo expansion of CD8⁺ CAR T cells is correlated to response, however persistence is not essential for durable remission in RRMM patients. In addition, our data provide evidence, that an increased fraction of CD8⁺ T cells at day of leukapheresis in combination with successful lymphodepletion positively influence the outcome. We show that patients at risk for higher-grade CRS can be identified already prior to lymphodepletion. Our extensive characterization contributes to a better understanding of the dynamics and effects of BCMA-targeting CAR T cells, in order to predict the response of individual patients as well as side effects, which can be counteracted at an early stage or even prevented.

Establishing a strategy for sequencing of T cell–redirecting therapies for relapsed/refractory multiple myeloma (RRMM) is a pressing clinical need. We longitudinally tracked the clinical and immunologic impact of bispecific T cell–engaging antibodies (BsAb) as bridging therapy (BT) to subsequent B-cell maturation antigen–directed chimeric antigen receptor T (CAR-T) cell therapies in 52 patients with RRMM. BsAbs were a potent and safe option for BT, achieving the highest overall response rate (100%) to BT compared with chemotherapy, anti-CD38, or anti-SLAMF7 antibody–based regimens (46%). We observed early CD4+CAR+ and delayed CD8+CAR+ T-cell expansion in patients receiving BsAbs as BT. In vitro cytotoxicity of CAR-T cells was comparable among BT options. Single-cell analyses revealed increased clonality in the CD4+ and CD8+ T-cell compartments in patients with previous exposure to BsAbs at leukapheresis and on day 30 after CAR-T cell infusion. This study demonstrates the feasibility and efficacy of BT with BsAbs for CAR-T cell therapy in RRMM. Significance: CAR-T cell therapy and BsAbs have revolutionized treatment of triple-class refractory multiple myeloma; however, optimal sequencing is unknown. We demonstrate that BT with BsAb before B-cell maturation antigen–directed CAR-T cell therapy is safe and effective, which might have implications for other hematologic malignancies as well. See related commentary by Bal and Costa, p. 10

For most patients with acute myeloid leukemia (AML), an allogeneic hematopoietic stem cell transplantation (HSCT) offers the highest chance of cure. Recently, the European LeukemiaNet (ELN) published updated recommendations on the diagnosis and risk classification in AML based on genetic factors at diagnosis as well as a dynamic adjustment (reclassification) according to the measurable residual disease (MRD) status for the favorable and intermediate risk groups. Validation of the ELN2022 risk classification has not been reported. We retrospectively analyzed 522 AML patients who received an HSCT at a median age of 59 (range 16–76) years. For patients with adequate material available and in remission prior to HSCT (n = 229), the MRD status was evaluated. Median follow-up after HSCT was 3.0 years. ELN2022 risk at diagnosis was in 22% favorable, in 26% intermediate, and in 52% adverse. ELN2022 risk at diagnosis is associated with the cumulative incidence of relapse/progression (CIR), event-free survival (EFS), and overall survival (OS) in the whole patient cohort, as well as the subgroup of patients transplanted in first remission. However, the risk stratification based on the ELN2022 classification did not significantly improve outcome prognostication in comparison to the ELN2017 classification. In our study, the newly added group of patients with myelodysplasia-related gene mutations did not have adverse outcomes. Re-classifying these patients into the intermediate risk group and adjusting the grouping for all AML patients by MRD at HSCT, led to a refined and improved risk stratification, which should be validated in independent studies.

Idecabtagene vicleucel (ide‐cel) and ciltacabtagene autoleucel (cilta‐cel) have revolutionized the treatment of relapsed/refractory multiple myeloma (RRMM), but direct comparisons are lacking. Leveraging an international multicenter RRMM cohort, we compared the outcome of ide‐cel (n = 162) versus cilta‐cel (n = 42). Co‐primary efficacy endpoints of the study were overall response rate (ORR) and progression‐free survival (PFS). Co‐primary safety endpoints were the incidence of cytokine release syndrome (CRS) and immune‐effector cell‐associated neurotoxicity syndrome (ICANS). Median turnaround time between apheresis and infusion was 47 days for ide‐cel versus 68 days for cilta‐cel (p < 0.001). Cilta‐cel showed significantly higher ORR (93% vs. 79%; p < 0.001), with complete response at Day 30 of 48% versus 26% (p < 0.001). The 10‐month PFS and overall survival (OS) was 82% and 90% for cilta‐cel versus 47% and 77% ide‐cel (p < 0.001 and p = 0.06), and improved outcome for cilta‐cel was confirmed after multivariable adjustment. Incidence of CRS and ICANS appeared similar (81% and 19% for cilta‐cel versus 85% and 19% for ide‐cel), while 10% and 7% in the cilta‐cel group versus 4% and 2% in the ide‐cel group showed severe CRS and ICANS grade 3–4, with CRS occurring significantly earlier for ide‐cel (median, 2 days vs. 4 days; p < 0.001). Nonrelapse mortality was 5% for cilta‐cel versus 3% for ide‐cel (p = 0.51). Cilta‐cel showed later peak of CAR‐T expansion at Day 14 versus Day 7 for ide‐cel, while cilta‐cel expansion was associated with ICANS. Our study provides real‐world evidence that cilta‐cel was associated with superior outcomes and distinct cellular dynamics versus ide‐cel in triple‐class exposed RRMM.