Josephine Ackermann

Hematotoxicity represents a frequent chimeric antigen receptor (CAR) T-cell-related adverse event and remains poorly understood. In this multicenter analysis, we studied patterns of hematopoietic reconstitution and evaluated potential predictive markers in 258 patients receiving axicabtagene ciloleucel (axi-cel) or tisagenlecleucel (tisa-cel) for relapsed/refractory large B-cell lymphoma. We observed profound (absolute neutrophil count [ANC] <100 cells per µL) neutropenia in 72% of patients and prolonged (21 days or longer) neutropenia in 64% of patients. The median duration of severe neutropenia (ANC < 500 cells per µL) was 9 days. We aimed to identify predictive biomarkers of hematotoxicity using the duration of severe neutropenia until day +60 as the primary end point. In the training cohort (n = 58), we observed a significant correlation with baseline thrombocytopenia (r = -0.43; P = .001) and hyperferritinemia (r = 0.54; P < .0001) on univariate and multivariate analysis. Incidence and severity of cytokine-release syndrome, immune effector cell-associated neurotoxicity syndrome, and peak cytokine levels were not associated with the primary end point. We created the CAR-HEMATOTOX model, which included markers associated with hematopoietic reserve (eg, platelet count, hemoglobin, and ANC) and baseline inflammation (eg, C-reactive protein and ferritin). This model was validated in independent cohorts, one from Europe (n = 91) and one from the United States (n = 109) and discriminated patients with severe neutropenia ≥14 days to <14 days (pooled validation: area under the curve, 0.89; sensitivity, 89%; specificity, 68%). A high CAR-HEMATOTOX score resulted in a longer duration of neutropenia (12 vs 5.5 days; P < .001) and a higher incidence of severe thrombocytopenia (87% vs 34%; P < .001) and anemia (96% vs 40%; P < .001). The score implicates bone marrow reserve and inflammation prior to CAR T-cell therapy as key features associated with delayed cytopenia and will be useful for risk-adapted management of hematotoxicity.

Real-world evidence suggests a trend toward inferior survival of patients receiving CD19 chimeric antigen receptor (CAR) T-cell therapy in Europe (EU) and with tisagenlecleucel. The underlying logistic, patient- and disease-related reasons for these discrepancies remain poorly understood. In this multicenter retrospective observational study, we studied the patient-individual journey from CAR-T indication to infusion, baseline features, and survival outcomes in 374 patients treated with tisagenlecleucel (tisa-cel) or axicabtagene-ciloleucel (axi-cel) in EU and the United States (US). Compared with US patients, EU patients had prolonged indication-to-infusion intervals (66 versus 50 d; P &lt; 0.001) and more commonly received intermediary therapies (holding and/or bridging therapy, 94% in EU versus 74% in US; P &lt; 0.001). Baseline lactate dehydrogenase (LDH) (median 321 versus 271 U/L; P = 0.02) and ferritin levels (675 versus 425 ng/mL; P = 0.004) were significantly elevated in the EU cohort. Overall, we observed inferior survival in EU patients (median progression-free survival [PFS] 3.1 versus 9.2 months in US; P &lt; 0.001) and with tisa-cel (3.2 versus 9.2 months with axi-cel; P &lt; 0.001). On multivariate Lasso modeling, nonresponse to bridging, elevated ferritin, and increased C-reactive protein represented independent risks for treatment failure. Weighing these variables into a patient-individual risk balancer (high risk [HR] balancer), we found higher levels in EU versus US and tisa-cel versus axi-cel cohorts. Notably, superior PFS with axi-cel was exclusively evident in patients at low risk for progression (according to the HR balancer), but not in high-risk patients. These data demonstrate that inferior survival outcomes in EU patients are associated with longer time-to-infusion intervals, higher tumor burden/LDH levels, increased systemic inflammatory markers, and CAR-T product use.

Sex differences in the incidence and mortality are evident in a wide range of cancers. This is not only due to sex-related variations in behavioral cancer risk factors, but also due to biological and molecular effects of sexual differentiation. Focusing on immunotherapeutic approaches like immune checkpoint inhibition or allogeneic stem cell transplantation, several reports have associated male sex with inferior outcomes. However, the exact impact remains controversial, and underlying mechanisms are incompletely understood. Here, we sought to explore the effects of the patient's biological sex on the outcomes of CD19 CAR-T cell therapy. To this end, we retrospectively analyzed disease and laboratory features together with survival in a cohort of 214 patients treated with axicabtagene ciloleucel (Axi-cel) for relapsed/refractory large B-cell lymphoma (LBCL) in the third- or later-line setting at four CAR-T centers. Predictors of progression-free survival (PFS) were analyzed by uni- and multivariate comparisons. The analyzed patient cohort comprised 119 male and 95 female patients, with a median age of 64 years (range 19-79). Most baseline patient characteristics were not significantly different for male and female patients (see attached table). Ferritin levels prior to lymphodepletion, however, were significantly higher in males (median 505 ng/ml vs. 325 ng/ml in females, p=0.025). The incidences of ASTCT grade ≥ 3 cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS) were not significantly different between females and males. However, objective response rates were significantly higher in female patients (88% vs. 75% in males, p=0.03). Additionally, females had a significantly superior PFS compared to males (median PFS not reached [95% CI 12.2 - NA months] in females vs. 4.2 months [95% CI 3.2 - 9.2 months] in males, Hazard ratio 1.8 [1.2 - 2.6], p=0.005, 1-year PFS estimate 61% in females vs. 39% in males). Overall survival (OS) was also significantly longer in females (median OS not reached in females vs. 22.6 months [95% CI 13.3 months - not reached] in males, Hazard ratio 1.7 [1.1 - 2.9], p=0.028). We confirmed the relevance of the patient's sex in multivariate analysis. We used Lasso modelling of variables with significant (p&amp;lt;0.05) association with PFS from univariate Cox regression analyses (ECOG, LDH, CRP and ferritin levels, Ann Arbor stage, bulky or extranodal disease [END], No. of therapy lines prior to CAR-T cell therapy and response to bridging therapy). Male sex, non-response to bridging, stage III/IV disease, END and No. of therapy lines remained independent risk factors for inferior PFS (Lasso coefficients &amp;gt;0.1), with male sex and non-response to bridging having the most significant effect (Lasso coefficient 0.54 for both variables). Finally, employing logistic regression of the independent variables from multivariate analysis, propensity score matching was used to better delineate the effect of sex on PFS. Sufficient balance was achieved between male and female patients, with all standardized mean differences below 0.12 after matching. In the matched analysis, PFS remained significantly superior for female patients (1-year PFS estimate 61% in females vs. 40% in males, log-rank p=0.008). For OS, the observed difference was of borderline significance in the matched dataset (1-year OS estimate 77% in females vs. 61% in males, log-rank p=0.051). Taken together, we demonstrate that female patients have significantly superior outcomes following Axi-cel therapy for r/r LBCL, even after careful adjustment for variables known to impact treatment results. A deeper understanding of the underlying mechanisms of these outcome disparities might enable the optimization of T cell-based treatment platforms in the future, both in female and male patients. Male patients may potentially benefit from intensified CAR-T (combination) treatment strategies.

The CD19 CAR T-cell products Axi-cel and Tisa-cel induce complete responses (CR) in 40-58% of patients (pts) with relapsed/refractory (r/r) Diffuse Large B-Cell Lymphoma (DLBCL). However, treatment can be associated with significant toxicity, with Cytokine release syndrome (CRS) and Immune effector cell-associated neurotoxicity syndrome (ICANS) as the most prominent and specific adverse events of CAR T-cell therapy. Toxicity profiles differ between both commercially available products, mainly due to their divergent co-stimulatory domain (4-1BB in Tisa-cel vs. CD28 in Axi-cel). Here, we report our single-center experience of DLBCL patients treated with Axi-cel or Tisa-cel at the LMU Munich University Hospital between January 2019 and June 2020. Toxicities, response rates and survival of DLBCL patients were retrospectively assessed. As of June 2020, 48 patients were enrolled for CD19-CAR T-cell therapies at our centre, and 37 DLBCL patients (pts) were apheresed. Median time interval between apheresis and CAR T-cell treatment was 39 days. So far, 31 DLBCL pts were transfused (Axi-cel: 18, Tisa-cel: 13). Median age of transfused pts was 60 years (range 19-74, Axi-cel: 60 years, Tisa-cel: 60 years). ECOG was 0-1 in 19 and 2-3 in 12 pts at time of CAR T-cell transfusion (Axi-cel: 0-1 in 13 and 2-3 in 5 pts, Tisa-cel: 0-1 in 6 and 2-3 in 7 pts). 13 pts had undergone prior stem cell transplant (9 autologous, 3 allogeneic, Axi-cel: 4 auto, 2 allo; Tisa-cel: 5 auto, 1 allo). Median number of prior DLBCL therapy lines was four (range 2-9, Axi-cel: 4, Tisa-cel: 4). Only 9/31 pts (29%) met the inclusion criteria of the pivotal clinical trials (due to e.g. infection, CNS disease, thrombocytopenia) at time of enrolment into our CAR T-cell treatment program. 23 pts (74%) received bridging chemotherapy (Axi-cel: 13/18 pts [72%]; Tisa-cel: 10/13 [77%]). Further details on radiographic response and the incidence of toxicities for all treated pts are summarized in the accompanying table. Response assessment after three months using PET/CT was available for 28 pts. Objective response rate (ORR) was 46%, with CR in eight (28%) and partial remission (PR) in five pts (18%). CRS occurred in 29/31 pts (84% CRS °1-2, 10% °3). Tocilizumab was applied in all CRS pts, with a median of four total infusions (range 1-4). 16 pts (52%) developed ICANS (33% °1-2, 16% °3-4, and 3% °5), which was managed with steroids in 9/16 pts. With a median follow-up of seven months, median progression-free survival (PFS) was 2.4 months for all pts. PFS was significantly longer for pts with normal vs. elevated LDH at time of apheresis (not reached vs. 1.5 mo, p=0.031). PFS of patients with two prior lines of therapy (n=7) was comparable with pts with three (n=5) or more (n=15) lines (2 lines: 3.1 mo, ≥3 lines: 1.9 mo, p=0.520). The time interval of ≤ 12 months (n=8 pts) from initial diagnosis of DLBCL to CAR T-cell transfusion was not prognostic and did not identify patients with worse PFS (≤12 mo: 1.7 months, &amp;gt;12 mo: 2.8 mo, p=0.569). In summary, in our cohort of heavily pretreated patients with a median of four prior DLBCL therapy lines, we observed an ORR of 46% (28% CR) at 3 months after CAR T-cell therapy, with no significant differences between patients treated with Axi-cel and Tisa-cel. In line with results of the pivotal clinical trials, treatment with Axi-cel was associated with a moderately higher incidence of ICANS. Overall, CAR T-cell toxicities were well manageable. Normal LDH levels at time of apheresis identified patients with high probability of sustained remission. In contrast, the number of prior therapy lines or the time interval from initial diagnosis of DLBCL to CAR T-cell transfusion had no impact on PFS. These hypothesis-generating findings might be helpful for future clinical decision-making, but need to be confirmed in a larger cohort. Therefore, we have set up a comprehensive patient monitoring program to identify predictive clinical and immunological markers of response and survival in CAR T-cell treated DLBCL patients. We will present updated results with longer follow-up at the annual meeting. Figure Disclosures Buecklein: Celgene: Research Funding; Pfizer: Consultancy; Gilead: Consultancy, Research Funding; Novartis: Research Funding; Amgen: Consultancy. Blumenberg:Novartis: Research Funding; Celgene: Research Funding; Gilead: Consultancy, Research Funding. Subklewe:Seattle Genetics: Research Funding; Morphosys: Research Funding; Celgene: Consultancy, Honoraria; Novartis: Consultancy, Research Funding; Janssen: Consultancy; Pfizer: Consultancy, Honoraria; Gilead Sciences: Consultancy, Honoraria, Research Funding; Roche AG: Consultancy, Research Funding; AMGEN: Consultancy, Honoraria, Research Funding.

CD19 CAR T-cell therapy (CAR-T) has significantly improved the prognosis of patients with relapsed/refractory (R/R) large B-cell lymphoma (LBCL). Real-world evidence has largely mirrored the clinical outcomes observed in registrational trials for these patients. However, a trend towards inferior survival in European (EU) patients and with tisagenlecleucel has been noted (Bethge WA et al., Blood 2022; Bachy E et al, EHA Annual Meeting 2022). The underlying logistic, patient- and disease-related reasons for these discrepancies remain poorly understood. Here, we sought to characterize potential differences between EU and US R/R LBCL patients treated with standard-of-care tisagenlecleucel (Tisa-cel) or axicabtagene ciloleucel (Axi-cel) and their influence on survival outcomes. To this end, we retrospectively evaluated CAR-T time intervals from indication (usually time of tumor board decision) to infusion, baseline demographic, disease and laboratory features together with survival in 374 patients treated at five EU and one US CAR-T centers. A significant proportion of patients received intermediary anti-lymphoma therapy not only between apheresis and CAR-T infusion ("bridging"), but also between indication to CAR-T therapy and apheresis (coined "holding therapy"). While 22% of EU patients and 27% of US patients received holding therapy (p=0.33), a significantly higher proportion of EU patients were treated with bridging therapy (90% vs. 70% in US, p<0.0001). EU patients displayed prolonged apheresis-to-infusion intervals (49 vs. 30 days, p<0.0001). Tisa-cel was significantly more frequently applied in Europe (74% of EU patients) than in the US (15%, p<0.0001). Baseline characteristics are summarized in table 1. Interestingly, LDH levels (321 vs. 271 U/l in US, p=0.02) and the inflammatory marker ferritin (675 vs. 425 ng/ml in US, p=0.004) were significantly elevated in the EU vs. the US cohort. Overall, we observed inferior survival outcomes in the patients treated in the EU cohort (median progression-free survival [PFS] 3.1 vs. 9.2 months in the US, p<0.0001; 1-year PFS estimate 26% in EU vs. 48% in US) and with Tisa-cel (median PFS 3.2 vs. 9.2 months with Axi-cel, p<0.0001, 1-year PFS estimate 23% with Tisa-cel vs. 49% with Axi-cel). In univariate Cox regression analysis, more prior therapy lines, refractoriness to the latest therapy prior to CAR-T indication, ECOG ≥ 2, Ann-Arbor stage ≥ III, presence of extranodal disease (END), longer apheresis-to-infusion intervals, higher ferritin, CRP and LDH levels, non-response to bridging, and Tisa-cel use were significantly associated (p<0.05) with impaired progression-free survival (PFS). On multivariate Lasso modelling of these variables (from n=277 patients, excluding CAR-T product to delineate product-independent risk factors), non-response to bridging, elevated ferritin, and increased CRP remained independent risk factors for inferior PFS. These factors were weighted into a patient-individual "HRscore" using factor-specific Lasso coefficients (non-response to bridging: 0.35, ferritin: 0.10, CRP: 0.01). The HRscore was significantly elevated in EU patients (p=0.03 for EU vs. US), and notably also in the Tisa-cel cohort (p=0.0009 for Tisa-cel vs. Axi-cel). Risk stratification by the HRscore was confirmed by a second Lasso model only incorporating variables that were available at CAR-T indication (ferritin: 0.13, LDH: 0.09, END: 0.04, CRP: 0.03). Notably, PFS of Axi-cel was superior to Tisa-cel in patients with lower HRscores (median PFS not reached for Axi-cel vs. 7.4 months for Tisa-cel, p=0.002). In patients with high HRscores, PFS was similar for Axi-cel and Tisa-cel (2.9 months for both products, p=0.49). Taken together, these data provide insight on potential explanations for the inferior survival outcomes in EU patients receiving CD19 CAR-T cells for r/r LBCL. Differences in tumor burden and chemo-sensitivity (evidenced by LDH, END and non-response to bridging), systemic inflammation (ferritin, CRP), and CAR-T product were associated with observed PFS disparities between EU and US. Of note, superior outcomes with Axi-cel were mainly observed in patients with lower-risk disease. Our results highlight the importance of careful patient selection and, importantly, identify a high-risk patient cohort with significant medical need for further CAR-T treatment optimization. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal