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Key Points Health care utilization rates in elderly kidney transplant were no different between the high kidney donor profile index and low kidney donor profile index group. Number of readmissions and surgical interventions in elderly kidney transplant was no different between the high kidney donor profile index and low kidney donor profile index group. Death censored graft loss was higher in the high kidney donor profile index group, whereas the patient survival was no different between the high kidney donor profile index and low kidney donor profile index groups. Background High kidney donor profile index (KDPI) kidneys (KDPI >85%) are often associated with increased risks of post-kidney transplant (KT) complications and greater health care utilization (HCU), particularly in elderly recipients with multiple comorbidities. These concerns frequently lead to underutilization of high KDPI kidneys in older transplant candidates, thereby limiting their access to transplantation despite potential clinical benefits. The aim of this study was to compare post-KT HCU between elderly recipients of high versus low KDPI deceased donor kidneys. The primary outcome included differences in hospital readmissions, surgical interventions, and outpatient service use at multiple post-transplant time points. Secondary outcome included graft function, graft survival, and patient survival. Methods A retrospective analysis of elderly solitary KT recipients (age ≥65 years) between January 1, 2011, and December 31, 2020. Patients were stratified into high KDPI (>85%, n =160) and low KDPI (≤85%, n =453) groups. We assessed inpatient and outpatient HCU, including readmissions at 30, 90, and 365 days post-transplant, surgical interventions, and outpatient visits (emergency department, transplant clinic, endocrine clinic, and ambulatory infusion units). Results There were no statistically significant differences between high and low KDPI groups in rates of hospital readmissions, surgical interventions, or outpatient visits (all P > 0.05). Delayed graft function rates were also similar ( P = 0.61). The low KDPI group had significantly higher eGFR at 4 months, 1, 2, and 3 years post-transplant (all P < 0.001). However, days alive and out of the hospital within 90 and 365 days post-transplant were comparable between the groups (all P > 0.05). Overall patient survival was similar ( P = 0.08), although death-censored graft loss was significantly higher in the high KDPI group ( P = 0.001). Conclusions Among elderly KT recipients, high KDPI kidney recipients had comparable post-transplant HCU and overall survival with those receiving low KDPI kidneys, despite lower long-term graft function. These findings suggest that high KDPI kidneys remain a viable option for older patients, offering timely access to transplantation.

Abstract Pyroptosis is a form of programmed cell death characterized by the cleavage of the gasdermin (GSDM) family proteins that form pores in the plasma membrane, cell rupture, and the release of proinflammatory cytokines. In this study, we performed immunohistochemistry for cleaved gasdermin D (GSDMD), gasdermin E (GSDME) N-terminus, and gasdermin C (GSDMC) in 2 different cohorts of diffuse large B-cell lymphoma (DLBCL) and analyzed the impact of GSDM expression on prognosis and immunity. The results showed frequent cleaved GSDMD (N-terminal) expression. Only cytoplasmic GSDMD N-terminal expression correlated with significantly better patient survival in the 2 cohorts. In contrast, GSDME was mainly expressed in the vascular endothelium, and correlated with significantly adverse prognostic effect. Correlating with the multiplex fluorescent immunohistochemistry results, we found that cytoplasmic GSDMD N-terminal expression was associated with increased CD38+ (activated) M1 macrophages in both cohorts, cognate interactions between live DLBCL cells and activated M1 macrophages (and T cells), and lower PD-1/PD-L1 expression in the analyzed cases. In contrast, T-cell pyroptosis, lymphoma cell-resistance to cell death, and phagocytosis by M2 macrophages were observed in tissues with predominantly nuclear GSDMD N-terminal expression. Bulk gene expression profiling and deconvolution analysis revealed associations of cytoplasmic GSDMD N-terminal expression with downregulation of “Don’t eat me”–signaling genes, upregulation of many RNA genes, decreased frequency of “inflammatory” lymphoma microenvironment subtype, increased frequencies of prognostically favorable cell states and ecotypes, and decreased frequency of T-cell exhaustion state. In summary, this study showed distinct cellular and subcellular patterns of 3 GSDM proteins and their associated immune response phenotypes and prognostic effects, with implications for novel therapeutic strategies for B-cell lymphoma.

Abstract Background and Significance Somatic gain-of-function mutations in the PIK3CA gene can result in a range of vascular malformations (VMs). These rare disorders include lymphatic anomalies and PIK3CA-related overgrowth spectrum (PROS). VMs are noncancerous lesions that may be managed with treatments such as surgery, sclerotherapy, sirolimus, and non-mutant-selective PI3Kα inhibitors; however, use of systemic therapies in patients is frequently limited by drug-related adverse effects. In particular, inhibition of wild-type PI3Kα results in significant toxicity, including hyperglycemia, diarrhea and rash. RLY-2608 is a novel, allosteric, pan-mutant and isoform-selective oral PI3Kα inhibitor designed to have higher potency and improved tolerability. In a PIK3CAH1047R HUVEC xenograft mouse model, RLY-2608 demonstrated greater lesion regression and less insulin induction across clinically relevant dose levels than alpelisib (Llambi, VAC 2025). ReInspire (RLY-2608-201; NCT06789913) is an ongoing, global, multicenter study in patients with PIK3CA-driven VMs to assess the safety, pharmacokinetics, recommended adult and pediatric dosing, and efficacy of RLY-2608 based on target lesion volume and clinical outcome assessments. The design of this study, including dose selection, was informed by clinical data from the first-in-human study of RLY-2608 in adult patients with advanced solid tumors, including breast cancer (Varkaris et al, 2024). Study Design and Methods ReInspire is a 3-part study evaluating the safety and efficacy of RLY-2608 in approximately 277 patients two years of age and older with PIK3CA-driven VMs and PROS. RLY-2608 is administered orally in continuous cycles. The primary endpoints are safety, tolerability, recommended Phase 2 dose (RP2D), and efficacy of RLY-2608 per volumetric reduction on MRI (≥20% reduction from baseline to Week 24 in the sum of target lesion volumes) by blinded independent central review. Other endpoints include duration of response and change in age-appropriate clinical outcome assessments. Patients are enrolled in a staggered fashion by age, beginning with adult and adolescent participants 12 years and older (Group 1), and may be extended to pediatric participants 6 to &lt;12 years (Group 2) and 2 to &lt;6 years, based on review of cumulative clinical data. Part 1 is the open-label dose-finding portion, which initiates with randomization of Group 1 patients (n=45) to one of three dose levels with stratification according to prior alpelisib use, and will be followed by weight-based dose escalation using a Bayesian optimal interval (BOIN) design in Groups 2 and 3, if opened. Part 2 is a basket-style, open-label dose expansion that will evaluate the clinical activity of RLY-2608 at one or more RP2Ds in various populations in cohorts of 20 patients each based on Part 1 findings. Depending on the results of Parts 1 and 2, Part 3, a double-blinded, placebo-controlled, 2:1 randomized study (n=90), may be opened to patients 6 years of age and older. To enroll, patients are required to have a clinical diagnosis of PROS or a malformation within the ISSVA classifications, and the majority must have a documented activating PIK3CA mutation per local assessment of lesional tissue and/or cell-free DNA from the lesion or blood. Patients with other known pathogenic somatic or germline driver mutations (such as TIE2 (TEK) and AKT1) are not eligible. Patients must be a candidate for investigational systemic therapy; have severe, symptomatic, and/or progressive disease; and at least one target lesion amenable for volumetric assessment. Additionally, patients who have received disease-directed therapy must undergo a washout period for systemic treatment and local therapies including radiation, surgery and other procedures. Patients with Type 1 or 2 diabetes requiring antihyperglycemic medication or fasting plasma glucose ≥140 mg/dL, or glycosylated hemoglobin (HbA1c) ≥7.0% (≥53 mmol/mol) are not eligible. Statistical analyses will be primarily descriptive in nature in Parts 1 and 2, with statistical comparisons between RLY-2608 and placebo at Week 24. ReInspire is open to enrollment. Patients ≥12 years are now enrolling in Part 1. For more information, contact clinicaltrials@relaytx.com

ABSTRACT Purpose Magnetic resonance elastography (MRE) of the heart has predominantly utilized breath‐held acquisitions with limited anatomic coverage. This work investigates the feasibility of 3D, free‐breathing cardiac MRE. Methods A 3D hybrid radial and EPI acquisition is utilized and combined with retrospective binning of k ‐space via physiologic monitoring, iterative reconstruction, MRE processing and inversions, and post‐processing specialized for cardiac imaging. Results Feasibility of free‐breathing stiffness mapping of the left ventricular myocardium was demonstrated in 11 participants. Myocardial stiffness estimates were obtained throughout the left ventricle for seven temporal states of the cardiac cycle. Stiffness estimates were presented in participant‐specific images, 17‐segment bullseye plots, and stiffness plots throughout the cardiac cycle. Results indicate increased stiffness in systolic states, with localized stiffness heterogeneity observed between participants, illustrating a key benefit of 3D cardiac MRE acquisition. Mean stiffness estimates obtained through 11 subjects were 4.44 ± 0.68 kPa (begin‐systole), 5.74 ± 0.94, 5.42 ± 0.87 (end‐systole), 3.84 ± 0.71 (begin‐diastole), 3.51 ± 0.74, 3.54 ± 0.52, and 3.55 ± 0.59 kPa (end‐diastole). Statistical testing indicated significant differences in stiffness across cardiac states with one‐way, repeated‐measures ANOVA ( p < 0.001) and Friedman's test ( p < 0.001). Experiments in scanning three participants with and without applied motion indicated that stiffness changes were more robustly detected in systole than in diastole, although patterns were subject‐specific. Comparison of free‐breathing stiffness measurements against reference breath‐held measurements yielded similar systolic stiffness estimates. Conclusions This study establishes the feasibility of free‐breathing, 3D cardiac MRE in healthy volunteers. With the current framework, stiffness estimation appears more robust in systole, and the reliability of diastolic estimates is limited and subject‐specific.

Abstract Background: Recombinant activated factor VIIa (rFVIIa, NovoSeven®) is an FDA-approved medication for managing bleeding in patients with hemophilia A or B with inhibitors and for those with congenital factor VII deficiency. Its use has expanded off-label in the perioperative context to manage unexpected bleeding complications. However, there is still a gap in real-world data regarding institutional practices, dosing, and outcomes associated with rFVIIa. Methods: With IRB approval, we identified patients who received rFVIIa in the perioperative period between 2020 to 2024 at Mayo Clinic. A detailed chart review was conducted to gather demographic data, comorbid conditions, bleeding disorders, timing, and dosing of perioperative rFVIIa (pre-, intra-, and postoperative), along with postoperative outcomes. We focused on thrombotic and bleeding events, hospital readmissions, and return to the operating room (OR). Descriptive statistics were used for patient characteristics, rFVIIa dosing patterns, and postoperative complications. Type of surgical interventions were stratified based on UCLA perioperative risk stratifications, with a risk score of 5 equating to very high risk surgery and a score of 1 equating to very low risk surgery. Results: Of the 55 patients included, the median age at surgery was 42.3 years (SD 27.4), and 69% were male. The majority were non-Hispanic white (91%). The most common bleeding diatheses were Factor VII deficiency (54.6%), Factor VIII inhibitor (12.7%), and Glanzmann thrombasthenia (7.3%). Less frequent conditions included Hemophilia A (3.6%) and Hemophilia A with inhibitors (3.6%). Among patients with Factor VII deficiency, mild deficiency accounted for 65.9% of cases, followed by severe (19.5%) and moderate (14.6%) forms. Adjunctive medications to control bleeding included emicizumab, FEIBA, and rituximab. Mean estimated blood loss was 136 mL (SD 211 mL), and mean length of stay was 5.7 days (SD 6.4). Surgical risk strongly correlated with perioperative outcomes: blood loss increased from 19 mL in very low-risk surgeries to 352 mL in very high-risk surgeries, while mean length of stay increased from 4.5 days (risk 1) to 19 days (risk 4) and 11 days (risk 5). Actual rFVIIa dosing ranged from 7.2 to 7211.5 mcg/kg per dose, with a median of 67.4 mcg/kg and a mean of 852.8 mcg/kg, reflecting variability in clinical practice. When stratified by surgical risk, the highest median doses were observed in very low- and low-risk surgeries (84.4 and 86.8 mcg/kg, respectively), while very high-risk surgeries had the lowest median dose (30.0 mcg/kg). In the postoperative period, thrombotic events did not occur in the first 90 days but were documented in 1.8% of patients between 90 and 365 days and in 1.8% after 365 days. Bleeding complications were frequent and demonstrated predominance in the immediate post-op period. Within the first 30 days after surgery, 18.2% of patients experienced bleeding complications, with 3.6% classified as major and 14.5% classified as minor, based on ISTH criteria. Between 30 and 90 days, bleeding complications occurred in 9.1% of patients (3.6% major and 5.5% minor), between 90 and 365 days, bleeding was observed in 10.9% of patients, all of which were minor, and beyond one year, bleeding complications were documented in 23.6% of patients, with 3.6% major and 21.8% minor. Readmissions were also common and followed a similar time distribution. In the first 30 days, 7.3% of patients had readmissions related to the prior surgery, and 3.6% had unrelated readmissions. Between 30 and 90 days, 3.6% of readmissions were related and 3.6% were unrelated. Between 90 and 365 days, 3.6% were related and 14.5% were unrelated to the initial procedure. Returns to the OR occurred in 1.8% of patients between 30 and 90 days and in 1.8% between 90 and 365 days. Conclusions: In conclusion, perioperative rFVIIa was most frequently used for Factor VII deficiency but was also administered to patients with Factor VIII inhibitor and Glanzmann's thrombasthenia, as well as several rare congenital and acquired bleeding disorders. Postoperative thrombotic events were rare, while ISTH-defined bleeding complications and readmissions were common. Most bleeding complications were minor, but their frequency was highest in the early postoperative period and again beyond one year. High-risk surgeries were associated with greater blood loss, prolonged hospitalization, and a higher burden of postoperative complications.

Abstract Introduction: The Duffy null variant (genotype or phenotype) is associated with lower circulating absolute neutrophil counts (ANC) without increased risk for infection. It is found in ~66% of people identifying as Black or African American vs &lt;1% of people of Asian or European ancestry. Many ANC reference intervals (RI) are not representative of the Duffy null population. There are no adult Duffy null WBC RI and no pediatric Duffy null ANC or WBC RI. Thus, we aimed to assess Duffy null ANC and WBC distributions as well as develop WBC and ANC RI for adults and pediatrics. Methods: Twenty-three sites across the United States collected samples with all sites excluding participants with conditions or medications that could impact ANC or WBC. Only Duffy null participants were included. Sex, race, ethnicity, age, sample collection type, practice setting, Duffy testing method, ANC, and WBC were recorded. The non-parametric method for determining lower limit of normal (LLN), upper limit of normal (ULN), and 90% confidence intervals (CI) around the limits was performed according to the Clinical and Laboratory Standards Institute guidelines. Specific ULN and LLN are not reported as these are preliminary data. The Mann-Whitney U test was used to compare sex and prior data; differences by age groups were assessed with Kruskal-Wallis test. Results: 316 participants 18+ years-old (y/o) were assessed of whom 62.3% (n=197) are female, 97.5% (n=308) identified as Black or African American, and 94.9% (n=300) identified as non-Hispanic. Median age was 47 y/o (IQR: 32-60.5). Median ANC was 2600/uL (IQR: 1860-3530; range: 400-7400); 28.6% (n=90) of participants had ANC &lt;2000/uL, 13.6% (n=43) had ANC &lt;1500/uL, and 2.5% (n=8) had &lt;1000/uL. The 90% CI around the LLN was 810-1070/uL and 5570-7130/uL around the ULN. Consistent with prior data, there was a difference in median ANC by sex (male: 2400/uL; female: 2710/uL; p=0.02). There was no significant difference between this ANC data and previously published Duffy null ANC data (p=0.28). Median WBC was 5.4x109/L (IQR: 4.4-6.5; range: 2.10-11.64) with 4.1% (n=13) of participants with WBC &lt;3.0x109/L. The 90% CI around the LLN is 3.68-4.30x109/L and 11.02-12.97x109/L around the ULN. 515 participants between 0-17 y/o were assessed with 51.8% (n=267) females, 94.8% (n=488) identified as Black or African American, and 94.0% (n=484) identified as non-Hispanic. Among pediatric participants, 56.8% (n=291) had ANC &lt;2000/uL, 38.7% (n=198) had ANC &lt;1500/uL, and 14.4% (n=74) had ANC &lt;1000/uL. For those &lt;1 y/o (n=29), median ANC was 950/uL (IQR: 840-1360; range: 111-3910). There are currently too few samples to predict ULN and LLN. Median WBC was 8.85x109/L (IQR: 7.03-10.16; range: 4.17-13.53). For those 1-5 y/o (n=143), median ANC was 1735/uL (IQR: 1100-2550; range: 207-5810) with a 90% CI around the LLN of 207-820/uL and 4020-5810/uL around the ULN. Median WBC was 6.72x109/L (IQR: 5.64-8.25; range: 3.68-12.97). For those 6-11 y/o (n=128), median ANC was 1590/uL (IQR: 1090-2470; range: 420-5490) with a 90% CI around the LLN of 420-910/uL and 4340-5490/uL around the ULN. Median WBC was 5.42x109/L (IQR: 4.45-6.70; range: 2.80-10.50). For those 12-17 y/o (n=215), median ANC was 2190/uL (IQR: 1460-2930; range: 204-5850) with a 90% CI around the LLN of 540-930/uL and 4350-5510/uL around the ULN. Median WBC was 5.06x109/L (IQR: 4.26-6.20; range of 2.04-9.91). There is a significant difference in ANC by age category (p&lt;0.0001). Conclusion: This is the first report of healthy pediatric Duffy null ANC and WBC data and the first large-scale verification of adult Duffy null ANC and WBC data. Final RI are expected in September 2025. Among adults with the Duffy null phenotype, ANC LLN are likely between 810-1070/uL. Pediatric ANC LLN are likely as low as 207-820/uL (1-5 y/o), 420-910/uL (6-11 y/o), and 540-930/uL (12-17 y/o). These findings redefine “normal” as a significant proportion of healthy participants have ANC or WBC below current RI or below thresholds typically defined as disease. Limitations include heterogeneous sample populations and collection methods. Future analyses will assess differences between collection sites or methods. Ultimately, this work lays the foundation for a more scientifically sound and equitable approach to medical care by ensuring that RI accurately reflects health for the entire community. Healthcare systems are strongly encouraged to adopt Duffy null-specific ANC and WBC RI.

Abstract Introduction: The real-world outcomes in patients (pts) with PCALCL in the era of targeted therapies like Brentuximab Vedotin (BV) is not well defined due to lack of large multicenter studies. We conducted a multicenter retrospective analysis (RWA) to assess patient and disease characteristics, treatment patterns, survival outcomes and impact of novel therapies in this rare type of cutaneous T cell lymphoma (CTCL). Methods: The analysis included 167 adult (≥18 years) patients (pts) with PCALCL across 9 academic institutions in the United States diagnosed between 01/2012 to 06/2022. The study was approved by the Institutional Review Boards at the respective sites. Demographic and disease factors were summarized using descriptive statistics. Overall survival (OS) and relapse-free survival (RFS) were estimated using Kaplan-Meier method and compared via log rank tests. Prognostic models included factors such as age, sex, race, performance status (PS), disease stage, type of initial lesion, presence of B symptoms, previous history of lymphomatoid papulosis and prior transplant. Prognostic factors for survival were assessed using both univariable and multivariable Cox proportional hazard models. Results: The median age at diagnosis was 61 (range 18-93) years. The majority of pts were male (55%) and white (82%), with good PS as indicated by an ECOG 0-1 (71%). The initial skin presentation consisted of tumors in 62% of the pts, while 34% presented with plaques or patches. Notably, no pts presented with erythroderma. Most pts underwent PET scan for staging at initial diagnosis (83%) with the majority having early-stage (IA-IIA) disease (86%). Furthermore, palpable lymph nodes (11%) and the presence of B symptoms (4%) were rare at diagnosis, and no pts had blood involvement. The most common sites of involvement were extremities (33%) followed by the head and neck (H&N) and trunk (31% each). Immunophenotyping revealed CD4 positivity in 59% of pts and CD8 positivity in 25%. The T cell receptor (TCR) rearrangement was positive in 28% of pts, though it was not completed in the majority of cases (72%). Most common initial treatments included localized radiation (61%) and surgical excision (19%). A small subset of pts received frontline systemic chemotherapy regimens such as cytotoxic chemotherapy (11%), BV (8%) and oral methotrexate (MTX) (8%). Approximately 7% of the pts had a stem cell transplant. Overall response rate (ORR) for radiation, oral MTX, BV and cytotoxic chemotherapy were 78% (CR:78% 74/100), 42% (CR:63% 6/12) and 39% (CR:67% 6/12), 89% (CR: 88% 15/18) respectively. At a median follow-up of 3.8 years (range 0.04-10.23), the median RFS and OS were 2.7 years (95% CI:1.86, 3.43) and 12 years (95% CI:10.6- NA) respectively. The estimated 3- and 5-year RFS are 46% (95% CI:0.38, 0.55) and 37% (95% CI:0.28, 0.46) respectively. The estimated 3- and 5-year OS were 89% (95% CI:0.82, 0.93) and 82% (95% CI:0.73, 0.88) respectively. At the time of the last follow-up, 79% were alive, while 21% were deceased. The cause of death (COD) was unknown in 50% of the cases and only 10% (3/of deaths were attributed to lymphoma. Other known CODs included infection (20%) and second malignancies 7%. On univariate analysis (UVA), age (p=.007), female sex (p=.04), ECOG PS 1-2 compared to 0 (p=.007) and prior transplant (p=.009) predicted for worse RFS. On multivariate analysis (MVA), only ECOG PS 1-2 (HR 2.31, 95 CI:1.06, 1.18, p=.009) and prior transplant (HR 5.38, 95 CI:2.30, 12.57, p=.0001) had a significant impact on RFS. Age and presence of B symptoms were strong predictors of OS on both UVA (age p=&lt;.0001; B symptoms p=&lt;.0001) and MVA (age: HR 1.12, 95 CI:1.06, 1.18, p=&lt;.0001; B symptoms: HR 16.48, 95 CI: 3.69, 73.60, p=.0002). However, the impact of B symptoms should be interpreted with caution as only 4% of pts presented with this at baseline. On UVA, each one-year increase in age was associated with an 8.5% rise in the risk of death. ECOG PS 1-2 was associated with worse OS on univariate analysis (HR 2.62, 95% CI 0.99, 6.93, p=.05), but was not significant on MVA (HR 1.05, 95% CI 0.368, 2.974, p=.93). Conclusions: In this large RWA of PCALCL, excellent long-term survival was observed with predominantly skin directed frontline therapies. The use of systemic treatments, including BV, was infrequent as first line therapy. Older age and poor PS were significant predictors for reduced survival.

Abstract Introduction:A comprehensive integration of significantly mutated genes and pathways with molecular subgroups is lacking in adult B-ALL. Furthermore, the genomic drivers underlying each subgroup remain to be identified.We aimed to perform genomic analysis on a large cohort of patients with adult B-ALL, and to correlate genomic markers with achievement of MRD negativity enabling blinatumomab randomization, and with subsequent response to blinatumomab. Methods:For genomic analysis, we studied 569 adults with newly diagnosed B-ALL registered for initial screening on the ECOG-ACRIN-led E1910 trial (NCT02003222), which evaluated the addition of blinatumomab to standard consolidation chemotherapy. The median age was 52 yrs (range 30 to 71 yrs), with 52% males. Analysis was performed on tumor and matched-normal samples using whole transcriptome sequencing (RNA-seq; tumor only; n=569), whole exome sequencing (n=490), whole genome sequencing (n=131), and single nucleotide polymorphism array (n=445). B-ALL cases were classified into 22 molecular groups. Outcome analysis was limited to patients enrolled and treated on E1910 (n=319). Results: Driver genes (n=268) were identified by the mutation-significance detection tool dNdScv or by the presence of pathogenic variants in known cancer genes, with NUP188 identified as a novel driver gene. Recurrently mutated pathways included: B-cell development (46%), cell cycle (44%), epigenetic regulation (30%), other transcriptional regulation (27%), Ras signaling (25%), RNA machinery (17%) and JAK-STAT signaling (8%). A high frequency of high-risk subtypes was observed including BCR::ABL1 (20%), BCR::ABL1-like (18%), low hypodiploid (14%) and KMT2A (12%). Using tSNE analysis, we identified a new cluster of cases (n=20, 3.5%) lacking a known subgroup driver, with overexpression of CEBPA (n=13) or CEBPB (n=7), distinct from CEBPE/ZEB2, termed “CEBP-altered” ALL (CEBPalt). Five of 13 cases with high CEBPA expression harbored an IGH::CEBPA rearrangement and one harbored a RXRA::CEBPA enhancer hijacking alteration. Of the 7 cases with high CEBPB expression, 5 harbored IGH::CEBPB, and two of these had concomitant clonal BCR::ABL1 fusions. To identify additional mechanisms of CEBP deregulation, in situ Hi-C coupled to H3K27 acetylation immunoprecipitation (HiChIP) was performed on 5 cases. Four cases showed evidence of de novo CEBPA enhancer activity. In two cases, we identified novel insertions (12 and 34nt) ~2kb downstream of CEBPA. A novel translocation and enhancer hijacking event between LINC00426 and the 5' UTR of CEBPB was identified in the remaining case. Overall, we confirmed genomic alterations of CEBPA or CEBPB in 16 of 20 cases with available material. Thus, we have identified a new molecular subgroup of adult B-ALL characterized by genomic alterations that drive enhancer hijacking and oncogenic deregulation of CEBPA/CEBPB. Several subgroups were enriched in patients that failed induction chemotherapy (n=62) or were MRD-positive (n=63) compared to those that achieved MRD-negative status (n=194): BCR::ABL1-like (30 vs 14%, p&lt;0.001), KMT2A (18 vs 9%, p=0.03) and BCL2/MYC (5 vs 1%, p=0.06). Conversely, the following subgroups were enriched in patients that achieved MRD-negativity: PAX5alt (6 vs 18%, p=0.002), TCF3::PBX1 (0 vs 5%, p=0.01) and ZNF384 (2 vs 6%, p=0.08) Within each molecular subgroup we compared the survival of patients who achieved MRD-negative status after induction and were randomized to receive blinatumomab plus chemotherapy (n=93) or chemotherapy only (n=91). Although numbers were low, blinatumomab improved relapse-free survival for patients with hyperdiploid, PAX5alt, BCR::ABL1-like and KMT2A ALL compared to chemotherapy alone. Clonal hematopoiesis of indeterminate potential (CHIP)-related gene mutations were identified in 121 of 417 cases analyzed (29% total: somatic 74%, remission 31%, both 5%). TP53 mutations were most frequent (n=65 patients), with the majority identified in patients with low hypodiploid (n=52). Interestingly, patients with CRLF2 rearrangements collectively harbored the highest number of other CHIP gene mutations (n=13), including DNMT3A (n=4), TET2 (n=3) and ASXL1 (n=3). Conclusions:We provide a comprehensive landscape of genomic alterations in adult B-ALL and identify a new group characterized by deregulation of CEBPA/CEBPB (CEBPalt). We also provide insights into the efficacy of blinatumomab in different molecular subgroups of adult B-ALL.

Abstract Introduction: Autologous CD19 CART therapies have been utilized across a wide range of B cell driven autoimmune diseases (AD), including systemic lupus erythematous (SLE), idiopathic inflammatory myopathies (IIM), systemic sclerosis (SSc), & myasthenia gravis (MG). To date, a number of autologous CD19-CART therapies have delivered durable drug free responses in AD patients. However, the safety profile of autologous CD19-CART therapies across different AD has yet to be fully explored. This is especially true for CRS & ICANS. Here, we provide novel insight into the mechanism underlying the safety profile of resecabtagene autoleucel (rese-cel) an autologous CD19 41BBz CART therapy across four separate Phase I/II clinical trials in SLE, IIM, SSc, & MG. Objectives: The primary objective of each trial is safety & tolerability of rese-cel at Day 29. Key secondary objectives include changes in clinical scores & use of immunomodulatory agents. Key translational assessments include CART cell pharmacokinetics (PK), impact on peripheral B cell populations (pharmacodynamics), & serum cytokine levels. Methods: 19 Patients (data cutoff: 6/2/2025 SLE; 5/6/2025 IIM, SSc, and MG), with active disease refractory to standard of care have been treated across 4 Phase I/II clinical trials in SLE (8 patients; NCT06121297), IIM (8 patients; NCT06154252), SSc (2 patients; NCT06328777), & MG (1 patient; NCT06359041). All patients were treated with a single weight-based infusion of rese-cel at a dose of 1 x 106 cells/kg following lymphodepletion (flu 25 mg/m2/d on Days -5, -4, & -3, & cy 1,000 mg/m2/d on Day -3). All non-glucocorticoid immunomodulatory agents were stopped prior to lymphodepletion. Glucocorticoids were tapered post-infusion. Patients were not given prophylactic tocilizumab pre-infusion. Translational assessments were determined as follows: CART PK was evaluated by flow cytometry & dPCR; B-cell enumeration & phenotyping were evaluated by flow cytometry; & serum cytokines were evaluated via immunoassay. Results: Across all indications (19 patients), 7 episodes of CRS were observed (7/19). 6 of 7 patients experienced a Grade 1 CRS, & 1 patient had a Grade 2 CRS. 2 patients developed ICANS; 1 patient had a Grade 4 (previously presented at ACR Convergence 2024), & the other patient had a Grade 3. Both ICANS events were rapidly resolved without sequelae using standard therapy. These CRS and ICANS events differed across indications. In IIM, 4 of 8 patients experienced Grade 1 CRS and no patients experienced ICANs. In SLE, 2 patients experienced Grade 1 CRS and one developed Grade 4 ICANs. In SSC, 1 of 2 patients experienced Grade 2 CRS & the other experienced Grade 3 ICANS. In MG, no CRS or ICANS was observed. Rese-cel infusion products were ~ 66% transduced, with a mean CD4:CD8 ratio of 6. Post-infusion, peak CART expansion was observed on day 12 & the mean peak expansion was 89 cells/µL (SD +/- 214). B cells were rapidly depleted from peripheral blood post-infusion, with nadir occurring at 13 days & repopulation beginning at 62 days post-infusion on average. Re-emergent B cells were largely of the CD24+CD38+ transitional naïve phenotype. Commensurate with B cell depletion, serum BAFF induction was observed, with a mean fold induction of 16 & mean peak level of 56,404 pg/µL (SD: +/- 45,547). Serum cytokines associated with CRS & ICANS; IFNg, IL6, & IL8 reached peak elevation on days 10, 9, & 10 respectively post-infusion. The mean peak elevation for IFNg, IL6, & IL8 were 232 pg/ µL (SD: +/- 320), 44 pg/ µL (SD: +/- 60), & 80 pg/ µL (SD +/- 73), respectively. Conclusion: Rese-cel appears to be well tolerated in autoimmune patients with rates of CRS & ICANS of 37% & 11% across all autoimmune indications, respectively (SLE patients had a 25% CRS rate & 12.5% ICANS rate, IIM patients had a 50% CRS rate & 0% ICANS rate, SSC patients had a 50% CRS & 50% ICANS rate, & MG patients had a 0% CRS & ICANS rate). Notably, the frequency & severity of CRS appears to be low, with no CRS in 63% of patients (12/19) & most CRS events (6/7) being Grade 1. The lower frequency & severity of both CRS & ICANS events are likely correlated with the relatively modest induction of serum IFNg, IL6, & IL8 found in autoimmune patients post rese-cel weight-adjusted dose infusion. High BAFF levels reflect deep systemic B cell depletion. Together, these data support further support late-stage clinical development of rese-cel in autoimmune disease.

Abstract Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL), accounting for approximately 30% of all NHL cases. DLBCL diagnosis relies on histologic examination, immunophenotyping, molecular and fluorescence in situ hybridization (FISH) analysis to differentiate it from similar NHL subtypes with overlapping morphological features, including more high-grade lymphomas like double-hit lymphoma. Because FISH is performed in a panel of single- or dual-target test format and analyzed through microscopy and manual image analysis, assessment of multiple target biomarkers can be cumbersome and expensive. As additional biomarkers for diagnosis, subtyping, prognosis, and therapeutic decision-making become available, target panels will become larger, posing additional challenges to clinical laboratories. Patients and Methods In this study, Hi-C sequencing of FFPE samples was performed to identify all genomic rearrangements by a single sequencing analysis for an unselected DLBCL case series of 159 patients, and the results were compared to FISH for the detection of clinically important variants. Results Hi-C sequencing showed superior performance compared to FISH: standard FISH for DLBCL includes testing for MYC, BCL2, and BCL6. Between FISH and Hi-C, these biomarkers were detected 105 times, of which, FISH detected 80/105 (76%) and Hi-C detected 102/105 (97%). The cohort included 4 double-hit lymphomas by FISH but Hi-C sequencing detected five. Besides DLBCL diagnostic biomarkers (MYC, BCL2, BCL6), many additional biomarkers were detected by Hi-C sequencing including variants not tested by FISH because the clinical suspicion was ambiguous and the relevant FISH probes were not used, and those not tested because the biomarkers were not thought to be common and, hence, left out of the FISH panel. In total, Hi-C sequencing detected additional biomarkers in 42 (26%) cases, including (1) variants targeted by FISH (i.e. MYC, BCL2, BCL6) but negative, (2) classification biomarkers for other lymphomas (CCND1, MALT, IRF4), and (3) those not tested because the biomarkers are not common and not included in the FISH panel. These additional biomarkers were supportive of suspected diagnosis of DLBCL versus double-hit lymphoma (24 cases), prompted reconsideration of a different diagnosis that may have led to different treatments (6 cases, e.g. mantle cell lymphoma), or biomarkers such as PDL1, ALK, and ATM which have implications for targeted therapies and/or inclusion in clinical trials (5 cases). Conclusion The Hi-C FFPE sequencing technology has the potential to improve the workflow of pathology labs for detection of a wide range of structural variants informing precision diagnosis and treatment for lymphomas.