Citations

AbstractBackgroundNormative models (NM) of brain metrics based on large, diverse populations offer novel strategies to detect individual brain abnormalities. To create an age‐dependent statistical model of brain microstructure over the human lifespan, we built the largest multi‐site NM of white matter (WM) diffusion tensor imaging (DTI) metrics based on 54,591 subjects. We used state‐of‐the‐art tools to adjust for site‐dependent effects.MethodWe used Hierarchical Bayesian Regression (HBR) to determine the age trajectory and lifespan centile curves (ages 3‐100 years) by merging data from different sections of the lifespan. We analyzed 19 international public datasets with the ENIGMA‐DTI protocol. Mean fractional anisotropy (FA), mean, axial, and radial diffusivity (MD, AxD, RD) were extracted for 21 bilateral ROIs from the JHU‐WM atlas and the whole WM skeleton. Regressions were run with each metric per ROI as a function of age and sex, and the DTI protocol as the batch effect (37 protocols). Z‐scores were derived for 81 patients with Alzheimer’s disease (AD; mean age: 77y±8.4, 46M/35F) and 225 MCI participants (mean age: 75.1y±8.1, 127M/98F) and extreme deviations (Z>|2|) were quantified for each condition. ROI‐wise areas under the ROC curve were calculated to determine the classification accuracy of the Z‐scores.ResultThe average FA for the overall WM skeleton reached its peak value at 27 years, with minima for MD, RD and AxD at 47, 42 and 54 years, respectively. We found extreme FA deviations (Z>2) for MCI (AUC=0.67) and AD (AUC=0.66) in the genu of the corpus callosum, extreme RD deviations (Z<2) in the tapetum (AUC=0.73) and Extreme AxD deviations (Z>2) for MCI in the superior longitudinal fasciculus (AUC=0.65). See Figures 1 & 2.ConclusionNM of brain microstructure with HBR yielded lifespan trajectories for widely‐used DTI metrics. By pooling large scale multi‐site dMRI to create a statistical reference, single subject deviations are detectable across the lifespan for AD and MCI. These NM will be publicly available to the research community.

AbstractBackgroundAutosomal dominant progranulin (GRN) mutations are a common genetic cause of frontotemporal lobar degeneration. Though clinical trials for GRN‐related therapies are underway, there is an unmet need for biomarkers that can predict symptom onset and track disease progression. We previously showed that presymptomatic GRN carriers exhibit thalamocortical hyperconnectivity that increases with age when they are presumably closer to symptom onset. However, whether hyperconnectivity arises concomitantly with markers of neurodegeneration remains unclear.MethodUtilizing T1 and task‐free functional magnetic resonance imaging (tf‐fMRI) from 49 presymptomatic and 26 symptomatic GRN mutation carriers, we determined the relationships between functional connectivity as measured by voxel‐wise whole brain degree and GRN‐relevant markers of disease progression, which included plasma neurofilament light chain (NfL) concentrations, CSF complement C1q and C3b protein levels, grey matter atrophy, and OCD symptom severity.ResultNfL concentrations were associated with frontotemporoparietal and thalamic hyperconnectivity in presymptomatic GRN carriers and extensive regions of atrophy in symptomatic carriers. Complement levels were associated with regions of hyperconnectivity, but not gray matter, in symptomatic carriers. Presymptomatic carriers with thalamic hyperconnectivity tended to have lower grey matter volume in bilateral insula and left lateral parietal cortex, which are among regions that deteriorate in GRN‐FTD. OCD symptom severity was associated with hypoconnectivity across all GRN carriers.ConclusionIn presymptomatic carriers, the co‐occurrence of hyperconnectivity, high NfL, and low gray matter suggests that tf‐fMRI hyperconnectivity may portend the onset of the neurodegenerative phase. These findings point toward hyperconnectivity as an indicator of approaching symptomatic onset.

Abstract INTRODUCTION Diffusion‐weighted magnetic resonance imaging (dMRI) is sensitive to the microstructural properties of brain tissues and shows great promise in detecting the effects of degenerative diseases. However, many approaches analyze single measures averaged over regions of interest without considering the underlying fiber geometry. METHODS We propose a novel macrostructure‐informed normative tractometry (MINT) framework to investigate how white matter (WM) microstructure and macrostructure are jointly altered in mild cognitive impairment (MCI) and dementia. We compared MINT‐derived metrics with univariate diffusion tensor imaging (DTI) metrics to examine how fiber geometry may impact the interpretation of microstructure. RESULTS In two multisite cohorts from North America and India, we find consistent patterns of microstructural and macrostructural anomalies implicated in MCI and dementia; we also rank diffusion metrics' sensitivity to dementia. DISCUSSION We show that MINT, by jointly modeling tract shape and microstructure, has the potential to disentangle and better interpret the effects of degenerative disease on the brain's neural pathways. Highlights Changes in diffusion tensor imaging metrics may be due to macroscopic changes. Normative models encode normal variability of diffusion metrics in healthy controls. Variational autoencoder applied on tractography can learn patterns of fiber geometry. WM microstructure and macrostructure are modeled with multivariate methods. Transfer learning uses pretraining and fine‐tuning for increased efficiency.

Introduction: Complex karyotype (CK, ≥3 chromosome (chr) abnormalities (abn)) is an important adverse prognostic indicator in chronic lymphocytic leukemia (CLL). CK at diagnosis (dx) of CLL, particularly with major structural chr abn (i.e. unbalanced translocation, add, marker, ring chr), called type-2 CK (CK2), has been associated with an increased risk of Richter transformation (RT) (Visentin Haematologica 2022). RT is defined as development of aggressive lymphoma, most often large B-cell lymphoma, in the setting of CLL. In patients (pts) with relapsed/refractory CLL treated with ibrutinib, CK as a continuous variable and the presence of polyploidy were independent predictors for RT. CK is a common finding at the time of RT, and high-CK (≥5) has been associated with short survival in RT, although previous studies predominantly included pts with prior chemoimmunotherapy (CIT) administration for their CLL. The prognostic significance of CK in pts with RT whose prior CLL-directed therapies include only non-CIT, as is the current standard of care for CLL, has not been evaluated. Methods: We conducted a multicenter, retrospective analysis of pts from 14 academic centers. Pts with RT diagnosed between 6/2011 to 6/2023, who had CLL-directed treatment that did not include prior CIT, with stimulated karyotype data available, were included. Pts who did not receive treatment for their CLL prior to developing RT were not included. Baseline pt, disease, and cytogenetics data were collected via chart review at time of CLL diagnosis and at the development of RT. Karyotype abn up to 20 were counted on both CLL tissue (peripheral blood or bone marrow) and RT tissue using IWGMC guidelines (Chun Leuk Res 2010). CK was categorized as CK1 (balanced abn, deletion, aneusomies) or CK2. Polyploidy was defined as ≥58 chrs. Karyotype was considered evolved if one or more chr abn were seen in a follow-up sample of CLL tissue that were not seen at CLL dx.TP53 disruption was defined as presence of del(17p) or TP53 mutation. Overall survival (OS) was measured from RT dx and estimated using the Kaplan-Meier method. Cox regression model was used to identify prognostic factors associated with OS. Results: A total of 64 eligible pts were identified. Median age at RT dx was 65 years (range 40-89) and 71.9% of pts were male. Of those evaluated (n=49), 79.6% had unmutated IGVH. Median number of therapies for CLL prior to RT was 1 (range 1-5) and included BTK inhibitor (n=37), BCL2 inhibitor (n=3), both (n=18), or other non-CIT treatment (n=6). At CLL diagnosis, 54.7% of pts had a CK, and the median number of chr abn was 3 (range 0-20). Of those with CK, 96.9% had a CK2, and 6.3% had a polyploid subclone. TP53 disruption was found in 46% of pts. At time of RT, chr analysis of CLL tissue was available for 38 pts and showed 78.9% had a CK, and the median number of chr abn was 8 (range 0-20). Polyploidy was found in 29.6%. TP53 disruption (46 pts evaluated) was found in 52.2%. Karyotype evolution from dx (35 pts evaluated) occurred in 74.3% of pts. In RT tissue, of those evaluated (n=29), 96.6% were clonally related to the preceding CLL. MYC translocation (45 pts evaluated) occurred in 17.8%. CK (20 pts evaluated) was found in 70%, with a median number of chr abn of 8 (range 0-20). Of those with CK, 33.3% had a polyploid subclone. With a median follow-up of 17.8 months (range 2.1-83.0) there were 42 deaths, with a median OS of 14.3 months (range 6.9-29.1). For this subset of patients with karyotype data available who would go on to develop RT, an exploratory univariable analysis for OS from RT found that increasing number of chr abn as a continuous variable at CLL dx was associated with worse OS (HR 1.10, 95% CI 1.02-1.19, p=0.01). Similarly, at RT, increasing number of chr abn in CLL tissue (HR 1.09, 95% CI 1.02-1.16, p=0.01) and in RT tissue (HR 1.09, 95% CI 1.01-1.18, p=0.03) was also prognostic of survival. Karyotype evolution in CLL tissue at RT (HR 3.02, 95% CI 1.02-8.94, p=0.05) was borderline significant for worse OS. Conclusions: Our multi-center study identified increasing number of chr abn at CLL diagnosis and at time of RT, and clonal evolution in the CLL tissue, are associated with worse OS in pts with RT whose CLL was treated without CIT. Limitations include incomplete cytogenetics data across the cohort and potential variability across institutions in cytogenetics laboratory practices. This provides further evidence for the clinical utility of chr analysis in the modern era of CLL therapy.

Introduction: GOLCA is a potential first-in-class CELMoDTM agent for the treatment of lymphoma, purposefully designed to target the proteins Ikaros/Aiolos to produce dual immunomodulatory and anti-tumor activity, with preferential distribution to lymphoid organs. Pharmacodynamic data in pts with R/R FL show that, combined with RTX, the immunomodulatory effects of GOLCA are significantly increased (Chavez et al, EHA 2024, #1132). GOLCA as monotherapy (mono) and + RTX has been shown to be well-tolerated and effective in pts with R/R DLBCL (Chavez et al, ASH 2023, #4496) and R/R FL (Chavez et al, EHA 2024, #1132). Here, we report 30 mo follow up of pts with R/R FL who received GOLCA mono, and updated safety/efficacy of GOLCA + RTX from the ongoing Phase 1/2 CC-99282-NHL-001 study (NCT03930953). Methods: Pts with R/R FL with ≥ 2 prior lines of therapy (L) received GOLCA mono at different dosing schedules during part A (dose exploration) and GOLCA ± RTX at 0.2 mg or 0.4 mg days (d) 1-14 every 28 d (q28d) in part B (dose expansion). Total treatment duration with GOLCA was up to 2 years or until progressive disease or unacceptable toxicity, whichever occurred first. The efficacy-evaluable population consisted of pts completing ≥ 1 cycle of GOLCA and having baseline tumor assessment and ≥ 1 post-baseline tumor assessment or clinical progression or disease-related death. Results: As of May 31, 2024, 63 pts with R/R FL have enrolled: GOLCA mono (n = 19) at various dosing schedules and GOLCA + RTX at 0.2 mg (n = 22) or 0.4 mg (n = 22) on d1-14 q28d schedule. The median time from diagnosis to first dose of GOLCA was 68 mo (range, 23-136) and 59 mo (range, 15-309) in GOLCA mono and + RTX cohorts, respectively. The median number of prior therapies received was 4 (range, 2-11), and 3 (range, 1-12) in GOLCA mono and + RTX cohorts, respectively. In the GOLCA mono and + RTX cohorts, 9/19 (47%) and 13/43 (30%) pts had received prior lenalidomide (len)-based therapy, with 5/9 and 7/13 having len-refractory disease, respectively. In the GOLCA + RTX cohort, 10/43 (23%) had prior CAR T cell therapy and 6/43 (14%) had prior anti-CD20xCD3 bispecific antibody with or without CAR T cell therapy. In the GOLCA + RTX-treated safety population (n = 43), the incidence of treatment emergent adverse events (TEAEs) was similar across 0.2 and 0.4 mg dose levels (DL). The most frequent grade (G) 3+ TEAEs were neutropenia (44%) and anemia (12%). The incidence of febrile neutropenia was 7%. Serious adverse events occurred in 30% of pts, with febrile neutropenia and pneumonia being the most common, in 2 pts (5%) each, as well as pulmonary embolism in 1 pt. Neutropenia led to GOLCA dose interruption in 4 pts (9%) and dose reduction in 1 pt (2%). No pts discontinued treatment because of GOLCA-related TEAEs. Non-hematological TEAEs (e.g., GI toxicity, rash, fatigue) were all low-grade (except 1 pt with G3 fatigue). There were no new safety signals identified for GOLCA mono (part A) at the 30-mo follow up period. In the efficacy-evaluable population, at a median follow up of 6 mo (range 3-18), the ORR and CRR in the GOLCA + RTX cohort (n = 29) were 57% and 29% at 0.2 mg dose (n = 14) and 93% and 67% at 0.4 mg dose (n = 15), respectively. The median time to response was 2 mo (first response assessment). At the 0.4 mg DL of GOLCA + RTX, consistent responses were seen in pts at 2L/3L and 4L+, including in those with prior exposure to len-based therapies and/or T-cell-redirecting therapy. At the 0.4 mg DL, 12/14 (86%) pts remained in response at the time of data cut-off. In pts receiving GOLCA mono across different dose schedules in part A (n = 12), ORR and CRR were 67% and 42%, respectively. Responses were durable, with median DOR of 22 mo (range, 2-51) at a median follow up of 30 mo. 33% of pts (4/12) have completed 2 yrs of protocol defined GOLCA treatment and remain in response at the 1 yr post-treatment follow-up period, without requiring any intervening treatment. Conclusions: GOLCA 0.4 mg + RTX was well tolerated and highly active in heavily pre-treated pts with R/R FL, including those with prior exposure to len-based therapies and/or T-cell-redirecting therapies. Treatment with fixed-duration GOLCA mono led to durable responses including a subset of pts remaining treatment free, without progression at extended follow up. These data further support development of GOLCA + RTX as a fixed-duration, chemotherapy-free, outpatient treatment option in pts with R/R FL, and also pts with newly diagnosed advanced stage FL (NCT06425302).

Introduction: Richter transformation is the development of an aggressive lymphoma, most commonly diffuse large B-cell lymphoma, in patients (pts) with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Transformation into Hodgkin lymphoma (HT) is a rare event and outcomes in pts with this complication in the current CLL/SLL therapeutic era of small molecule inhibitors (SMI; e.g., Bruton tyrosine kinase inhibitors [BTKi] and BCL2 inhibitors [BCL2i]) are unknown. Methods: We conducted a retrospective study of pts from 12 academic centers. Pts with HT who had not previously received chemotherapy for CLL/SLL-directed treatment (tx) were included. Pt, disease, and tx characteristics were collected. HT was categorized into 3 groups: “Concurrent HT,” defined as HT and CLL/SLL diagnosed simultaneously (within 3 months); “HT without prior CLL/SLL tx,” defined as HT and CLL/SLL diagnosed &gt;3 months apart with the CLL/SLL never treated; and “HT with prior non-chemotherapy tx for CLL/SLL” defined as having received non-chemotherapy CLL/SLL-directed tx prior to the diagnosis (dx) of HT. Overall survival (OS) was measured from HT dx and estimated using the Kaplan-Meier method. Cox regression model was used to identify prognostic factors associated with OS. Results: Within a total cohort of 402 pts with Richter transformation (all histologies) without prior chemotherapy, 41 pts with HT (10%) were identified: 12 with concurrent HT, 10 with HT without prior CLL/SLL tx, and 19 with HT with prior non-chemotherapy tx for CLL/SLL. The median age at CLL/SLL dx was 62 years (range 31-96 years) and 73% were male. At CLL/SLL dx, 67% (14/21 evaluated) had unmutated IGHV, and 24% (8/34 evaluated) had TP53 disruption (del(17p) and/or TP53 mutation). The median age at HT dx was 65 years (range 31-96 years) among all pts. At HT dx, there was no significant difference in highest SUV on PET (median 12.3, range 3-31.1), lactate dehydrogenase (LDH) level (median 242 U/L, range 112-859 U/L), or lymph node longest diameter (median 4.6 cm, range 1.6-25 cm) among the 3 subgroups. The median time from CLL/SLL dx to HT dx was 5.4 years (range 0.3-16.5 years) in pts with HT without prior CLL/SLL tx and 4.2 years (range 0.5-17.3 years) in pts with HT with prior non-chemotherapy tx for CLL/SLL. The median number of prior non-chemotherapy CLL/SLL-directed tx was 1 (range 1-6) and included BTKi only (n=17) and BTKi and BCL2i sequentially (n=2); no patient had received only prior BCL2i. Among the 19 pts with HT with prior non-chemotherapy tx for CLL/SLL, 18 pts were on active tx at time of dx (17 BTKi, 1 BCL2i). Initial HT management included: doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD; n=16), brentuximab vedotin (BV)-AVD (n=10), radiation only (n=2), other systemic tx (n=11), and supportive cares / hospice (n=2). All but 1 of the 11 other systemic tx were various HL tx regimens. Across all pts with available data (n=32), the overall response rate to 1st line HT tx was 78% (69% complete response rate); 13% had progressive disease and 9% (n=3; all with concurrent HT) died within 6 months without formal response assessment. A total of 11 pts received at least 1 additional line of therapy for HT, which included BV (n=4), an immune checkpoint inhibitor (n=1), or both (n=6) at any point beyond 1st line HT tx. Median follow-up from HT dx was 32.8 months (range 2.4-253.8 months). The 36-month OS for the entire cohort was 75% (95% CI: 55-87%). The 36-month OS estimates by subgroups were: 62% (95% CI: 26-84%) in pts with concurrent HT, 100% in pts with HT without prior CLL/SLL tx (no events by 36 months), and 67% (95% CI: 33-87%) in pts with HT with prior non-chemotherapy tx for CLL/SLL. Exploratory univariable analysis identified TP53 disruption at CLL dx (HR 12.36; 95% CI: 2.55-59.84) and lymph node longest diameter (HR 1.32 per 1 cm increase; 95% CI: 1.12-1.55) and LDH 2-fold increase (HR 3.97; 95% CI 1.24-12.68) at HT dx as prognostic for worse OS. HT subgroup was not prognostic. Conclusions: This is the largest report of outcomes in pts with CLL/SLL who develop HT following SMI tx without any prior chemotherapy, representing a contemporary cohort. Prior CLL/SLL tx status was not associated with OS; however, cautious interpretation is required given the sample size. Our findings support the use of appropriate HL-directed treatment in the setting of HT; however, OS estimates remain worse than would be expected in an older adult de novo HL cohort (Cheng Blood Adv 2022).

Introduction: CD20xCD3 bispecific antibodies (BsAbs) represent a major advance in the treatment of relapsed or refractory (r/r) large B-cell lymphoma (LBCL). In their pivotal trials, epcoritamab (Epcor) and glofitamab (Glofi) showed an overall response rate (ORR) and complete response rate (CRR) of 52-63% and 39%, respectively, in patients (pts) with r/r LBCL after 2 or more prior lines of therapy (LOT). Data on the efficacy and safety of BsAbs in standard of care (SOC) setting is limited. Here, we report our multicenter retrospective study on SOC BsAbs for the approved indication in r/r LBCL. Methods: All pts who received SOC BsAbs for r/r LBCL at four cancer centers in Florida were included. Pts who died before the first response evaluation were considered to have disease progression. Median follow up time was calculated using reverse Kaplan Meier (KM) method. Univariate analysis (UVA) and multivariate analysis (MVA) of response rates were done using logistic regression. UVA and MVA of PFS and OS were done using Cox proportional hazard model. Median PFS (mPFS) and median OS (mOS) were estimated using KM method. Results: As of June 1, 2024, a total of 69 pts received SOC BsAbs for r/r LBCL (43 epcor and 26 glofi). Forty pts (58.0%) were male; median age was 66 years (range 32-89); ECOG &gt;= 3 in 14 (20.3%) pts; transformed indolent lymphoma in 20 (29.0%); Richter transformation in 3 (4.4%); HGBL with MYC/BCL2 rearrangements (double-hit lymphoma [DHL]) in 12 (17.4%); bulky disease&gt;10cm in 33 (47.8%); IPI score &gt;= 4 in 15 (21.7%). Pts received a median of 3 prior LOT (range 2-12); 46 (66.7%) had primary refractory disease; 40 (58.0%) received prior CD19 CAR-T therapy; 35 pts (50.7%) would not have met the inclusion criteria of the pivotal trials due to: ECOG&gt;=3 (n=14), thrombocytopenia (n=11), neutropenia (n=2), CNS involvement (n=6), recent infection (n=6), prior CAR-T within 30 days (n=1), and CrCL&lt;45 (n=2). Among the 69 pts, 65 were evaluable for response. At a median follow up of 7 months, the ORR and CRR were 52.3% and 26.2%, respectively. Median PFS was 4.2 months (m) (95%CI: 2.8-6.9). Median OS was 6.2m (95%CI: 5.9-not reached [NR]). The ORRs in pts without prior CAR-T (CART-naive), progressed after achieving CR/PR to prior CAR-T (CART-R), and not achieving CR/PR to prior CAR-T (CART-NR) were 13/25 (52.0%), 18/24 (75%), and 3/16 (18.8%), respectively, p&lt;0.01. In the UVA of ORR, the following factors were associated with lower response: CART-NR (18.8% vs 63.3%, p&lt;0.01) and ECOG &gt;=3 (21.4% vs 60.8%, p=0.01). Bulky disease, IPI &gt;=4, DHL, &gt;=4 prior lines of therapy, DLBCL subtype or BsAb type was not associated with response. In MVA, only CART-NR was a significant predictor of lack of response to BsAb (odds ratio 5.6, 95%CI: 1.3-24). In the UVA of PFS, CART-NR and ECOG &gt;=3 were associated with shorter mPFS (1.9m [95%CI: 0.6-3] vs 5.4m [95%CI: 4.0-NR] in CAR-T non-responders vs responders; 1.1m [95%CI: 0.4-3.2] vs 5.4m [95%CI: 3.2-NR] in ECOG&gt;=3 vs &lt;3). In the MVA, CART-NR and ECOG&gt;=3 were associate with shorter PFS (HR 2.7, p&lt;0.01 and 2.5, p&lt;0.02, respectively). One of the 3 pts with Richter transformation had continuous PR at 5 months. Cytokine release syndrome (CRS) occurred in 21 pts (36.2%), including 4 (5.8%) grade (Gr) &gt;= 3. Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 12 pts (17.4%) with 6 (8.7%) Gr &gt;= 3. Gr3-4 neutropenia was observed in 18 pts (26.1%); Gr3-4 thrombocytopenia in 10 (14.5%). Infection all grades and Gr &gt;= 3 occurred in 26 pts (37.7%) and 19 pts (27.5%), respectively. Among them, bacterial infection was identified in 13, COVID in 5, fungal in 2, and CMV in 1 patient. Conclusion: BsAbs had comparable efficacy in SOC setting as in the pivotal trials. CRS and ICANS were mostly low-grade; however, a high incidence of serious infection was observed. Pts with no response to prior CAR-T also had poor BsAbs response. This could reflect a common mechanism of resistance to immunotherapy, either due to tumor characteristics or host T-cell exhaustion. Longer follow-up is needed to evaluate the durability of response.

Background: In 2015 the first B-cell acute lymphoblastic leukemia (B-ALL) patient receiving CAR T-cell therapy in Europe was reported to the EBMT registry. Today, the EBMT registry counts with more than 9000 patients treated with CAR T-cell therapies across all indications. Here, on behalf of the GoCART coalition, we present the outcomes of the largest European cohort of B-ALL patients treated with autologous, second generation, CD19-targeted CAR T-cells to date. Methods: Adult and paediatric patients with B-ALL received treatment with CAR T-cell therapy using either academic or commercially available products in 40 centres across 17 different countries. Safety was retrospectively assessed as per ASCTC 2019 consensus grading and CTCAE, and efficacy as per NCCN guidelines. Relapse incidence was defined as haematological relapse or progression after CART with non-relapse mortality as competing event. Leukemia free survival (LFS) was defined as being alive without occurrence of relapse. Follow-up includes patients treated from 2016 to Dec 2023 until data cutoff in June 2024. Results: A total of 345 patients (173 adults and 172 pediatrics) received therapy from 2016 to 2023 with tisagenlecleucel (65.2%), varnimcabtagene autoleucel (25.8%), brexucabtagene autoleucel (5.5%), and others (3.5%). Median age at infusion was 18 yrs. (range, 1.1-78.2) and 41.7% were females. High-risk features were identified including cytogenetic/genomic high-risk as per ELN guidelines (33.8%), relapse after allo-HCT (57.7%), early relapse (&lt;1 year) after prior allo-HCT (30.4%), ≥3 prior treatment lines (55.5%) including prior exposure (and refractoriness) to blinatumomab and inotuzumab in 27.3% (34%) and 28.8% (32.3%), respectively. Median time from diagnosis to CART infusion was 2.8 years (0.1-17.9). Median time from last relapse prior CART to infusion was 2 months (range, 0.9-38.4). Bridging therapy was administered in 86.4% (298) of patients based on high or low intensity chemotherapy (32.1% or 26.5%, respectively), inotuzumab-ozogamicin (13.4%), TKI (8.2%), involved-site therapy (intrathecal chemotherapy, radiotherapy, orchiectomy) (3.5%), and blinatumomab (2.6%), alone or in combination. Prior to infusion, 34.7% had more than 5% BM blast count, 16.3% had circulating blasts in PB, and 20.6% had extramedullary disease. Lymphodepletion was performed in all but one patient, based on fludarabine and cyclophosphamide regimens. The reverse Kaplan-Meier median follow-up was of 2.2 years. The incidence of any grade (and severe) CRS was 71.6% (14.5%), and for ICANS was 15.7% (7.6%). The cumulative incidence of MRD-negative CR at month +3 was 76.9% (71.9-81.1), followed by a 2-year overall survival of 64.6% (58.7-69.8), leukemia-free survival of 48% (42.1-53.7), and relapse incidence of 45.5% (39.6-51.2). Non-relapse mortality at 2 years was 6.5% (4-9.6), 2-year cumulative incidence of subsequent HSCT of 33.3% (28-38.7) and second CAR-T infusions of 12.4% (8.8-16.6). Allogeneic HSCT after CAR-T was performed in 113 cases including 67 (59.3%) HSCT-naïve patients, due to molecular or overt disease relapse (60.9%), and other non-relapse reasons including suboptimal CAR-T persistence/B-cell aplasia (19.1%), pre-CAR-T high-risk features (13.6%), second malignancies (1.8%), and others. Second CAR-T infusions were performed in 39 cases due to molecular or overt disease relapse (79.5%) or suboptimal CAR-T persistence/B-cell aplasia in the absence of relapse (20.5%). Conclusions: The results from this European study demonstrate that CD19-targeted CAR T-cell therapy is an effective treatment for patients with high-risk B-cell ALL, providing substantial leukemia-free survival and overall survival rates despite the high-risk nature of the patient population. The necessity for bridging therapies and subsequent consolidative approaches, such as HSCT and second CAR T infusions, underscores the complexity and tailored nature of managing R/R B-ALL. These findings support the continued use and further investigation of CAR T-cell therapy in diverse clinical settings, emphasizing the importance of post-infusion strategies to sustain long-term remission. This will provide deeper insights into the factors influencing outcomes and help refine treatment protocols to improve patient care.

Background: The prognosis of patients (pts) with relapsed or refractory B ALL (r/r B-ALL) treated with CAR T-cells and receive a 2nd CART infusion is unknown. Few reports with limited numbers of patients suggest that 2nd CART infusion is feasible with questionable efficacy. This GoCART coalition registry study aimed at compiling data to investigate the indications, efficacy, and toxicity of CART2 infusion in pts with r/r B-ALL. Methods: This is a multicenter, retrospective registry study that included pediatric and adult patients with r/r B-ALL who received autologous CD19-targeted CAR T-cell therapy (CART1) and subsequently were treated with a second administration of CD19 and/or CD22-targeted CAR-T cell therapy (CART2) from 2017 to 2023. Baseline features, prior stem cell transplant (SCT), indications for CART2 and outcomes were collected. Relapse incidence (RI) was defined as overt recurrence, non-relapse mortality (NRM) as death without relapse occurrence, leukemia free survival (LFS) as being alive without occurrence of relapse and overall survival (OS) as being alive. RI and NRM were estimated using cumulative incidence function and OS and LFS Kaplan-Meier estimation. Results: Out of 345 pts who received CART1, 39 (2y cumulative incidence of second CART: 12.4% (95%CI: 8.8-16.6)) received CART2. Reasons for CART2 were overt relapse (n= 26; 66.7%), molecular relapse by measurable residual disease (MRD+) (n=5; 12.8%), and B-cell recovery (BCR) in the absence of relapse (n=8; 20.5%). Seventeen pts (43.6%) were female and median age at CART2 infusion was 19 yrs (range: 6.9-67.1), including 19 children and 20 adults. 74.4% of the pts had received a prior SCT, 25 pts (64%) before CART1, 2 (5.1%) only between CART1 and CART2, and 2 (5.1%) before CART1 and between CART1 and CART2. Among the 31 pts who received CART2 for relapse, this was CD19+ in 24 (92.3%), CD19- in 2 (7.7%), and unknown in 5. CART1 products were varnimcabtagene autoleucel (ARI-0001) (23), tisagenlecleucel (13), brexucabtagene autoleucel (1), and other experimental (2). All CART2 products targeted CD19 except 2 (1 CD22 and 1 dual CD19-CD22). Median time between CART1 and CART2 was 11.0 months. For patients who received CART2 for BCR, median time between CART1 and CART2 was shorter than for those who received it for relapse: 2.4 (IQR: 2.3-3.3) months vs. 12.4 (IQR:6.4-19.3) months. Regarding leukemic burden at the time of CART2 infusion, 19 pts (48.8%) were in overt relapse (14/19 with extramedullary disease, including 7 in CNS), 12 (30.1%) were in complete remission (CR) MRD+ and 8 (20.5%) CR MRD-. With a median follow-up time of 2.3 yrs [95% CI: 1.2-3.4], the 2-yr OS and LFS after CART2 were 47.1% [95% CI: 27.8-64.3] and 39.9% [95% CI: 24-55.3], respectively. 2-yr RI was 54.5% (95% CI: 36.5-69.4) and NRM was 5.6% (95% CI 1-16.8). 2-yr OS, LFS and RI for pts in CR at CART2 infusion irrespective to MRD were 76.1%, 63.3% and 25.6% while for those not in CR these outcomes were 17.7%, 15% and 85%, respectively (p= 0.007, 0.006 and 0.002). 2-yr LFS (71.4% [95% CI 25.8-92]) and RI (0%) was significantly better for pts receiving CART2 for BCR than in those who received it for relapse (31.6% [15.6-48.9] and 68.4% [46.7-82.8]; p= 0.036, p=0.002). Conclusion: This is a large registry study describing indications and outcome of CART2 in patients with r/r B-ALL. At 2-yrs after CART2, the LFS was of 39.9% and for patients receiving CART2 due to B-cell recovery was of 71.4%. These results show that CART2 is associated with low NRM and might be a bridge to SCT or other additional therapies. Updated results with data about subsequent therapies after CART2 will be presented at ASH meeting.