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Background To compare the effectiveness of glucagon‐like peptide‐1 receptor agonists (GLP‐1 RAs) versus bariatric surgery on cardiovascular outcomes in patients with heart failure (HF) with preserved ejection fraction and obesity. Methods Using the TriNetX research network, we conducted a retrospective cohort study of adults (aged ≥18 years) with HF with preserved ejection fraction and obesity (body mass index >30 kg/m 2 ) from 2017 to 2022. Patients were categorized into 2 cohorts: those receiving GLP‐1 RAs (semaglutide or tirzepatide) and those who underwent bariatric surgery. Propensity score matching (1:1) was used to balance baseline characteristics. Primary outcomes included acute HF events and all‐cause hospitalizations. Secondary outcomes included all‐cause death, myocardial infarction, stroke, and follow‐up body mass index. Cox proportional hazard models were used to estimate hazard ratios (HRs). Results A total of 2747 patients were included per cohort (mean age, 68 years). GLP‐1 RA therapy was associated with lower incidence of acute HF events (38.9% versus 44.6%; HR, 0.78 [95% CI, 0.72–0.85]), all‐cause death (11.1% versus 14.8%; HR, 0.71 [95% CI, 0.61–0.82]), and all‐cause hospitalizations (66.4% versus 77.3%; HR, 0.62 [95% CI, 0.58–0.66]). Rates of myocardial infarction (13.8% versus 13.4%; HR 0.99 [0.86–1.14]) and stroke (9.7% versus 10.7%; HR, 0.87 [0.74–1.02]) were similar between groups. Mean body mass index at follow‐up was 38.0 in the GLP‐1 RA cohort versus 37.7 after bariatric surgery ( P =0.34). Hemoglobin A 1c at follow‐up was higher in the GLP‐1 RA group (7.4 versus 6.8; P <0.001). Conclusions In patients with HF with preserved ejection fraction and obesity, GLP‐1 RA therapy was associated with improved outcomes compared with bariatric surgery, supporting the need for prospective trials to evaluate GLP‐1 RAs as a therapeutic alternative.

Abstract BACKGROUND Children exposed to poverty during frontline therapy for B-lymphoblastic leukemia (B-ALL) experience inferior overall survival (OS), higher relapse rates, and earlier relapse than their peers. Real-world data describing treatment patterns and survival after relapse of B-ALL are lacking and, as a result, the impact of poverty following relapse remains poorly understood. This study evaluated the association of poverty exposure, proxied by insurance status, with post-relapse survival and explored potential explanatory mechanisms, including disease biology and therapy utilization. METHODS Data from Retrospective Study of Contemporary Approaches to First Relapse in B-ALL (ReCALL-1), a multicenter retrospective cohort study of patients &lt; 30 years old with first relapse of B-ALL from 2018-2022, were used. The primary exposure was poverty, proxied by insurance status at relapse, categorized as any private insurance (poverty unexposed), public-only insurance (poverty exposed), no insurance, or unknown; the latter two were not included in comparative analyses due to low numbers. The primary outcome was OS. Secondary outcomes included measurable residual disease (MRD)-negative second complete remission (CR2), relapse after CR2, non-relapse mortality (NRM), with relapse treated as a competing risk, and receipt of cellular and immunotherapies. RESULTS Among 462 patients from 31 U.S. institutions, 41% had private insurance, 47% public-only insurance, 2% no insurance, and 10% unknown. Compared to privately insured patients, those with public insurance were more likely to be Hispanic (56% vs 19%, p&lt;0.001) and have non-English preferred language (30% vs 6%, p&lt;0.001). Non-Hispanic Black patients comprised 9% of those with public insurance and 5% of those with private insurance. Disease characteristics that differed by insurance status at relapse included: Ph-like cytogenetics, more common in publicly insured (23% vs 11%, p=0.002), and infant ALL, more common in privately insured patients (10% vs 5%, p=0.06). Publicly insured patients were more likely to have experienced major organ toxicity during frontline therapy (32% vs 18%, p=0.002) and very early relapse (&lt;18m from diagnosis: 43% vs 32%, p=0.07). Other demographic and disease characteristics, including relapse site and cytomolecular features, were similar by insurance status. With a median follow-up of 51 months from relapse, 4-year OS differed by insurance (log-rank p=0.02): 72% for private vs 56% for public insurance. After adjusting for race/ethnicity and language, public insurance increased the hazard of death by 65% (aHR 1.65 95% CI 1.13-2.42, p=0.004). The association remained, but was attenuated, when unbalanced disease characteristics (time to relapse, infant ALL, Ph-like cytogenetics, prior organ dysfunction) were included (aHR 1.47, 95% CI 1.00-2.16, p=0.05). Rates of MRD-negative CR2 were similar (85% public vs 87% private). However, point estimates suggested publicly insured patients had more relapse after CR2 (44% vs 37%, p=0.42) and higher 4-year NRM (16% vs 10%, Gray's test p=0.12), though neither were significant. Treatment choices for first relapse did not differ by insurance status. Utilization of intensive reinduction (91% vs 95% for public vs private, p=0.18) and clinical trial enrollment (22% for both) were similar. Receipt of cellular therapies did not significantly differ by public vs private insurance: Chimeric Antigen Receptor-T cells (CAR-T: 38% vs 34%, p=0.41), hematopoietic cell transplant (HCT: 42% vs 47%, p=0.32). Use of blinatumomab trended higher in those with private insurance (36% vs 45%, p=0.07), and inotuzumab was similar (11% for both, p=0.87). Median time from relapse to CAR-T or HCT was comparable (to CAR-T 102 vs 100 days, to HCT 117 vs 114 days). CONCLUSION This is the first study to demonstrate differential survival by insurance type, a proxy for poverty exposure, after first relapse of B-ALL. In this large multicenter, real-world cohort, patients with public insurance had worse OS after relapse than those with private insurance. The survival disparity existed independent of other SDOH factors. Adjustment for known high-risk disease features only partially accounted for the observed differences in OS. In contrast, rates of MRD-negative CR2 and receipt of CAR-T and HCT were comparable across insurance types. These findings highlight the urgent need to identify effective interventions that will ensure equitable outcomes after relapse.

Abstract Introduction Hodgkin's lymphoma is known to have favorable survival outcomes; however, limited data exist regarding survival disparities between rural and urban populations. In this study, we aimed to investigate the differences in survival outcomes between the two populations. Methods Data for patients diagnosed with Hodgkin lymphoma (HL) between 2000 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Rurality was identified using the Rural-Urban Continuum Codes (RUCC). Patients aged ≥ 20 years with HL as the only primary malignancy were included. Individuals with unknown race or those diagnosed at autopsy were excluded. The Ann Arbor Staging system was utilized for HL staging at diagnosis. HL-specific survival was defined as the time from diagnosis to death attributable to HL and was censored at the time of death from other causes or at last follow-up. Meanwhile, overall survival (OS) was defined as the time from diagnosis to death from any cause and was censored if the patient was still alive. A Cox proportional hazards model was performed to analyze the predictors for 10-year overall and HL-specific mortality. All statistical analyses were conducted using RStudio (version 2024.12.0). Results Between 2000 and 2015, a total of 22,505 patients diagnosed with Hodgkin lymphoma (HL) were included in the analysis. Among them, 13,657 (61%) were aged between 20 and 44 years. Overall, 10,137 patients (47%) were female, 14,885 (66%) were White, 2,672 (12%) were Black, and 3,724 (17%) were Hispanic. The majority of patients resided in urban counties, while only 2,266 (10.1%) lived in rural areas. Among rural patients, 845 (37%) were diagnosed with stage II disease, followed by 475 (21%) with stage III at the time of diagnosis. Notably, both the 10-year overall survival (69.5%) and Hodgkin lymphoma–specific survival (79.7%) were significantly lower among rural patients compared with urban patients (75.3% and 83.5%, respectively; p &lt; 0.001). In the multivariable model for 10-year HL-specific survival, older age (&gt; 65 years) was associated with the highest risk of mortality (HR 10.32; 95% CI 9.42–11.32). Although survival improved over the study period, male patients remained at increased risk of mortality (HR 1.26; 95% CI 1.18–1.35). Urban residence, diagnosis in more recent years, early stage, female sex, White race, and married status were independently associated with improved overall survival (p &lt; 0.01). Conclusion In this population-based study, both the 10-year overall and HL-specific survival were consistently lower among rural vs. urban patients. Male sex, older age, and unmarried status were particularly associated with worse survival outcomes. Further research is warranted to identify possible strategies for improving healthcare access and reducing survival disparities among rural patients.

Abstract PAX5 is genetically altered in over 30% of B-ALL cases, with point mutations representing the second most common type of alteration. These point mutations are highly enriched in the DNA binding (paired) domain and have been recognized as founder events in PAX5 P80R and PAX5alt B-ALL subtypes, which account for over 12% of B-ALL. However, the molecular features and underlying mechanisms of these mutations in B-ALL remain largely undefined, limiting the development of targeted therapies and resulting in poor outcomes, especially in adult patients. We systematically investigated the functional roles and oncogenic mechanisms of PAX5 paired domain mutations. Integrated CRISPR screening and genomic profiling revealed that the paired domain is critical for PAX5 function. Disruptions in this region significantly reduced cell viability in B-ALL cell lines, and analysis of 2,955 B-ALL samples showed that recurrent PAX5 missense mutations are highly enriched in this domain, further underscoring its functional importance. Functional analysis of knock-in mice with PAX5 mutations revealed that R38H and R140L severely impair DNA binding and block B-cell differentiation, while P34L and P80R retain binding ability but alter binding specificity and gene regulation. Mice carrying homozygous (P34L, R38H, P80R, R140L) or heterozygous (R38H, P80R) mutations developed spontaneous B-ALL within one year. To model co-occurring mutations observed in patients, Pax5 R38H/P34L and R38H/R140L mice were generated. These compound mutations exhibited greater leukemogenic potential than single mutants. Transcriptomic analysis of leukemia samples showed consistent up-regulation of metabolic pathways and Myc target genes. Notably, biallelic PAX5 alterations and additional genetic lesions in signaling pathways were detected in all PAX5R38H/+ and PAX5P80R/+ leukemias, faithfully recapitulating the genetic alteration features of patient B-ALL driven by PAX5 mutations. Among Pax5-mutant mouse strains, Pax5P80R/+ mice develop B-ALL with short latency and complete penetrance, making them an ideal model to study the mutational evolution and leukemogenesis of B-ALL. To characterize the stepwise leukemogenesis process, we performed serial bone marrow aspirations in the same Pax5P80R/+ mice. In all 17 mice analyzed, we identified early preleukemic clones with only Pax5 WT deletions, followed by the emergence of leukemic clones harboring Jak1/3 mutations. Single-cell RNA/BCR-seq revealed that Pax5 WT allele deletions relieve metabolic constraints, thereby promoting clonal expansion of preleukemic B cells blocked at the pre-B stage. These changes coincide with downregulation of metabolic checkpoint genes and upregulation of glycolytic enzymes, promoting genetic instability and facilitating malignant transformation. Clinically, PAX5 P80R patients have better outcomes than PAX5alt cases. Using our mouse models, we observed that leukemic cells driven by the PAX5 P80R mutation exhibit greater sensitivity to dexamethasone compared to the ones carrying other PAX5 mutations in PAX5alt subtype, potentially due to their heightened dependence on glucose uptake and glycolysis, suggesting that metabolic rewiring driven by PAX5 mutants may influence therapeutic response. Interestingly, we found that an aberrant isoform of MEGF10 (aMEGF10) is highly and specifically expressed in PAX5 P80R B-ALL. This N-terminal truncated isoform encodes a protein that retains the intracellular immunoreceptor tyrosine-based activation motifs (ITAMs). Using CUT&Tag, we showed that PAX5 P80R directly binds to the aMEGF10 promoter. By engineering human CD34⁺ cells, we established a humanized PAX5 P80R leukemia model that recapitulates the gene expression profile of patient samples, including robust activation of aMEGF10. Functionally, aMEGF10 binds to and activates SYK, thereby promoting leukemic cell proliferation. Importantly, this oncogenic effect depends on intact ITAM motifs and SYK signaling, revealing a novel targetable vulnerability in PAX5 P80R leukemias. Overall, the study establishes that PAX5 DNA binding domain mutations contribute to leukemogenesis through stepwise loss of PAX5 WT alleles and acquisition of signaling pathway mutations, involving impaired differentiation, metabolic deregulation, and novel oncogene activation. These findings not only deepen the understanding of PAX5-driven leukemias but also highlight aMEGF10–SYK signaling as a promising therapeutic target.

Abstract Introduction Obecabtagene autoleucel (obe-cel) and brexucabtagene autoleucel (brexu-cel) are CD19 targeted chimeric antigen receptor T cell (CAR-T) therapies, approved for the treatment of adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (ALL). Mechanistic differences between obe-cel and brexu-cel including differing costimulatory domains (4-1BB vs. CD28), CD19 binding domains (intermediate vs. high affinity) and split dose (Days 1 and 10) vs. single infusion may impact in-vivo cellular kinetics that translate into variant clinical outcomes. In pivotal trials, obe-cel resulted in lower rates of severe cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS) compared to brexu-cel with comparable efficacy (Roddie et al., NEJM 2025; Shah et al., Lancet 2021). Real-world utilization and outcomes with obe-cel are unknown given the relatively recent approval. Methods The ROCCA database, comprising real world data from patients (pts) with r/r ALL treated at 40 North American institutions was utilized in this analysis. Pts with r/r ALL were eligible if they were apheresed for obe-cel since its approval (11/8/2024) or brexu-cel over a comparable period (since 8/1/24) and had at least 30 days of follow up. Data cut off was 7/15/2025. CRS/ICANS were graded per ASTCT criteria. Measurable residual disease (MRD) was assessed by flow cytometry and/or next generation sequencing per institutional standards. Results 38 pts have undergone apheresis for obe-cel (36 infused, all received both infusions) and 54 (53 infused) for brexu-cel over the study period. Pts in the obe-cel and brexu-cel cohorts had the following baseline characteristics: median age, 47 vs. 39 years; ECOG 2+, 15% vs. 26%; Ph+ disease, 24% vs 13%; KMT2Ar, 0 vs. 4%; TP53m, 11% vs 11%, and hypodiploid karyotype, 5% vs 6%. The following prior treatment patterns were observed: median lines of therapy before CAR-T 3 vs. 3; prior SCT 24% vs. 30%, prior blinatumomab 68% vs. 46%, prior inotuzumab 45% vs. 30%. At apheresis, active disease (&gt;5% bone marrow blasts) was present in 47% vs. 55% of obe-cel and brexu-cel pts, respectively; the remainder were in CR (with 18% vs. 22% in MRD- CR, respectively). Among obe-cel (n= 35 [92% of cohort]) and brexu-cel (21 [38% of cohort] pts with disease re-assessment prior to lymphodepletion (LD), 31% vs. 43% had active BM disease, respectively; few pts (24% vs. 17%) had &gt;20% marrow disease burden prior to LD. CAR-mediated toxicity differed significantly between the cohorts. CRS occurred in 56% of obe-cel pts compared to 94% of brexu-cel pts (p &lt; 0.0001). There were no Gr3+ CRS events among the obe-cel pts; 3 (6%) brexu-cel pts had Gr3+ CRS (p = 0.27). ICANS occurred in 17% of obe-cel pts vs. 51% of brexu-cel pts (p = 0.001). Gr3+ ICANS occurred in 6% of obe-cel vs. 32% of brexu-cel pts (p = 0.0027). Among the obe-cel pts, CRS occurred in 31% after the first infusion and 46% after the second; ICANS occurred in 3% after the first infusion and 15% after the second. Prolonged Gr4 neutropenia (ANC &lt; 500 cells/uL beyond day 30 from infusion) occurred in 24% of obe-cel vs. 28% of brexu-cel pts (p = 0.73). Deaths within the first 28 days of infusion occurred in 0 obe-cel pts and 4 brexu-cel pts (2 of infection, 1 of infection/brain bleed, and 1 of liver failure in the setting of Gr4 CRS and HLH). Response rates were high and did not significantly differ between cohorts (p = 0.85). Among the 31 obe-cel pts with available response data, 25 (81%) achieved an MRD- CR/CRi, 3 (10%) had an MRD+ CR/CRi, 2 (6%) had a CR/CRi with unknown MRD, and 1 (3%) did not respond. Among 41 brexu-cel pts with available response data, 33 (80%) had an MRD- CR/CRi, 4 (10%) an MRD+ CR/CRi, and 4 (10%) CR/CRi with unknown MRD. Conclusion Pts selected for obe-cel apheresis were similar to those for brexu-cel over the study period (noting that not all centers had access to obe-cel during this time). Similar to clinical trial results, obe-cel was associated with lower rates of CRS/ICANS. Rates of MRD-negative CR were high and did not differ between cohorts. A larger sample and longer follow up are required for further analyses; we anticipate a cohort of ~75 obe-cel treated pts by the annual meeting and will provide updated data.

Abstract Introduction: Brexucabtagene autoleucel (Brexu-cel) is a CD19-targeted chimeric antigen receptor (CAR-)T cell therapy approved for treatment of relapsed/refractory (r/r) B-ALL. Brexu-cel's approval was founded on data from the ZUMA-3 trial, in which 78 patients (pts) were treated at the pivotal dose of 1x10e6 CAR-T cells/kg, resulting in a complete remission (CR) rate of 73%. Three-year follow-up from ZUMA-3 demonstrated median relapse-free and overall survival (RFS/OS) of 11.6 and 25.6 months (mos) for all treated pts. Amongst responders, the median OS was 60.4 mos for those who did not receive a subsequent allogeneic hematopoietic cell transplant (HCT) (n=43), but only 36.3 months for those who did (n=14). This has led some to conclude that HCT may not be beneficial following brexu-cel therapy for r/r B-ALL; however, it must be noted that 29 (37%) of the pts treated on ZUMA-3 received brexu-cel for post-HCT relapse. T cells collected from individuals who relapse in the post-HCT setting are largely of donor origin, making the CAR-T product comparable to a genetically modified donor lymphocyte infusion (DLI). The immunology at play in this scenario may be different from that in which CAR-T cells are of truly autologous origin. Methods: The Real-World Outcomes Collaborative for CAR-T in ALL (ROCCA) consortium database includes pt characteristics and outcomes of brexu-cel therapy given as standard-of-care across 41 US institutions. We identified pts who achieved an MRD negative (neg) CR by either flow cytometry (minimum sensitivity 10e-4) or NGS following brexu-cel for r/r Ph neg B-ALL and categorized them into three groups with regard to use of HCT: Never HCT, Pre-CAR HCT, or Post-CAR HCT. Pts who received second HCT following brexu-cel for post-HCT relapse (n=9) were excluded. Pt/disease characteristics, RFS, and OS were assessed for each group, landmarked at 73 days after brexu-cel infusion (the median time to consolidative allogeneic HCT). Results: In the ROCCA database we identified 165 pts who achieved MRD neg CR following brexu-cel, amongst whom 69 never underwent HCT, 49 were transplanted pre-CAR (ie, brexu-cel served as a genetically modified DLI), and 47 underwent post-CAR consolidative HCT while in CR. The median follow-up is 373 days. The median age was higher in the Never HCT group (49, range 19-83) in comparison with the Pre-CAR HCT (40, 24-72) and Post-CAR HCT (34, 18-70) groups. Thirty-five percent were &gt;60yo in the Never HCT group vs 20% in the Pre-CAR HCT and 9% in the Post-CAR HCT groups. Ph-like disease was present in 38%, 29%, and 43% of the Never HCT, Pre-CAR HCT, and Post-CAR HCT groups, respectively (p=0.35). No significant differences were observed in pre-apheresis bone marrow blasts, presence of CNS disease at apheresis, prior blinatumomab or inotuzumab treatment, or use of bridging therapy across the groups, though there was a higher prevalence of non-CNS extramedullary disease in the Pre- and Post-CAR HCT groups (32, 39%) vs the Never HCT group (13%) (p=0.004). A minority of pts in all groups were deemed to be in MRD neg CR prior to apheresis (6-20%). Median RFS was 260 days in the Never HCT group and not reached in the Pre- and Post-CAR HCT groups (p=0.002), with respective 1-yr RFS of 38%, 64%, and 67%. Median OS was not reached in any group and was similar for all at 1-yr at 68-79% (p=0.13). Characteristics of those in the Never HCT group who were least likely to relapse included age &gt;60 (OR 0.22, CI 0.07-0.73 vs age 18-39, p=0.024) and those with non-Ph-like B-ALL (OR 0.33, CI 0.12-0.94, vs Ph-like, p=0.037) in univariate analyses. Conclusions: Real-world data regarding outcomes following brexu-cel therapy allow evaluation of the role for consolidative allogeneic HCT, which remains one of the most important unresolved questions in the use of CAR-T therapy for r/r B-ALL. This analysis demonstrates that a first consolidative HCT after achieving MRD neg CR with brexu-cel is associated with a significant decrease in relapse. Additionally, use of brexu-cel for post-HCT relapse is also associated with a significantly lower risk of relapse compared with those who never received an allogeneic HCT. With the current duration of followup, OS is not significantly different across the three groups. These data suggest there is a benefit for relapse-free survival in pts receiving an allogeneic HCT at some point in the course of treatment for r/r Ph neg B-ALL.

Abstract Background: Sickle cell disease (SCD) is marked by wide variability in clinical phenotypes and severity due to environmental, clinical, and genetic factors. Variants in iron-regulatory genes are well described modifiers of clinical presentation in different diseases, but their role in modulating SCD phenotype has been sparsely studied in African populations. In this cross-sectional study, we investigated the role of single nucleotide polymorphisms (SNPs) in iron-regulatory genes in SCD severity and lifetime transfusion(Tx) requirement. Methods: The study was approved by the institutional review board of Lagos University Teaching Hospital, Lagos, Nigeria. Clinical data were abstracted from medical records and patient interviews using a structured questionnaire. Participants were recruited in steady state and were stratified according to the severity score previously described by Shah et al. (Clinicoecon Outcomes Res. 2020;12:625). Biochemical analyses included serum transferrin and serum iron; transferrin saturation (TS) was calculated. Genotyping was performed using the Axiom Precision Medicine Research Array (PMRA; Thermo Fisher Scientific). Seventy-one single nucleotide polymorphisms (SNPs) in genes implicated in iron metabolism were analyzed, including SLC40A1 (ferroportin), HFE (homeostatic iron regulator), HJV (hemojuvelin), HAMP (hepcidin), and TFR2 (transferrin receptor 2). SNPs whose variants were not represented in this cohort, including HFE C282Y and H63D, were excluded. Ensembl and NCBI databases were used to describe the wild-type (WT)/variant alleles and gene consequences. Univariate and multivariate logistic regression were used to analyze binary outcomes, and age-adjusted linear regression for Tx burden. Odds ratios (OR) and regression coefficients (β) were estimated using the WT as the reference. Multiple-testing correction was performed as necessary. Statistical analyses were conducted in R version 4.4.1, with p&lt;0.05 considered significant. Results: We included 60 genotyped, confirmed HbSS patients; median age was 22 years (range: 18–43), 22 (37.3%) were female, 42 (70.0%) were classified as mild severity (Class I), 5 (8.0%) as Class II, and 13 (22.0%) as severe (Class III). Twenty-seven (45.0%) had never received a blood Tx, while 33 (55.0%) had received Tx, median of 2units (range: 1-10). On univariate analysis (UVA), five SNPs (rs10218795, rs10188230, rs114250626, rs4287798, and rs634349) were significantly associated with severe phenotype; three of these remained significant on multivariable analysis (MVA). Two were associated with higher odds of severe phenotype: rs10177654 (OR = 28.9, 95% CI: 3.0–100.0, p = 0.03) and rs10218795 (OR = 15.0, 95% CI: 2.4–327.0, p&lt;0.01), while rs10188230 was associated with lower odds (OR = 0.03, 95% CI: 0.008–0.28, p&lt;0.01). Results remained consistent after adjusting for age. For lifetime transfusion burden, both UVA and MVA identified two significant SNPs: rs4667289, associated with higher transfusion burden (β = 2.6, 95% CI: 0.04–5.2, p = 0.047) and rs11568344, associated with lower transfusion burden (β = –1.8, 95% CI: –3.5 to –0.36, p = 0.02). Genotype distributions for the five significant SNPs were as follows: rs10177654 (SLC40A1, transcription factor binding site), TT(WT) 12 (20.3%), TC 30 (50.8%), CC 17 (28.8%); rs10188230 (SLC40A1, intron variant), TT (WT) 32 (54.2%), TC 22 (37.3%), CC 5 (8.5%); rs10218795 (HJV, intron variant), CC (WT) 22 (37.3%), TC 29 (49.2%), TT 8 (13.6%); rs4667289 (SLC40A1 proximal intergenic), GG (WT) 46 (78.0%), AG 10 (16.9%), AA 3 (5.1%); rs11568344 (SLC40A1 splice region variant), GG (WT) 47 (79.7%), AG 9 (15.3%), AA 3 (5.1%). Compared with the homozygous WT, patients with rs10188230 had a lower median TS (21.65% vs. 43.3%, p = 0.04), while those with rs4667289 had a higher median TS (83% vs. 31%, p&lt;0.01). When adjusted for age and lifetime Tx, rs4667289 remained significant (β = 47.8, 95% CI 3.6-82.8, p = 0.03). No other SNPs showed association with TS. Conclusion: We present novel genetic data on iron-regulatory variants in African patients with sickle cell disease, identifying SNPs in SLC40A1 and HJV associated with disease severity. Most of these are yet to be fully described in the literature, and their intronic locations suggest possible regulatory roles. We hope to further validate these findings in larger cohorts and through functional studies to clarify their impact on iron metabolism and clinical significance.

Abstract Introduction Pronounced disparities in pediatric B-lymphoblastic leukemia (B-ALL) outcomes by race and ethnicity persist in the contemporary era. Gaps in overall survival (OS) from initial diagnosis are wider than event-free survival, suggesting that post-relapse mechanisms may contribute. However, data on treatment and outcomes after relapse are lacking. In a large, multicenter, real-world cohort of children and young adults with high-risk 1st relapse of B-ALL, we sought to (1) define survival outcomes by race/ethnicity and (2) explore if differences in therapy utilization drive outcomes. Methods We conducted an analysis within the Retrospective Study of Contemporary Approaches to 1st Relapse in B-ALL (ReCALL-1) cohort, which includes patients &lt;30 years who initiated 1st relapse therapy between 2018-2022. This analysis was restricted to patients treated at US centers for “high-risk” 1st relapse, defined as relapse for which hematopoietic cell transplant (HCT) is generally standard-of-care: Early relapse (medullary &lt;36m; isolated extramedullary &lt;18m), late relapse with persistent end of reinduction disease, Ph+ B-ALL or age ≥18 years. Patients with Trisomy 21, those who received cell therapy before relapse and those who died during reinduction were excluded. The primary exposure was race/ethnicity categorized as Hispanic, non-Hispanic Black (NHB), non-Hispanic White (NHW), and other/unknown. The primary outcome was OS from relapse. Multivariable Cox regression models were constructed to include other social drivers of health (SDOH; health insurance, preferred language) and disease characteristics. Results Of 479 patients in ReCALL-1, 311 from 31 centers met inclusion for this analysis (41% Hispanic, 7% NHB, 46% NHW, 5% NH-other/unknown). With a median follow-up of 47m, OS differed by race/ethnicity (log-rank p=0.017): Hispanic, 4y OS 59%; NHB, 37%; NHW, 68%. Compared to NHW patients, NHB patients had an increased hazard of death (HR 2.3, 95% CI 1.3-4.3, p=0.006), while Hispanic patients were more similar to NHW patients (HR 1.3, 95% CI 0.9-2.0, p=0.16). Adjustment for SDOH only marginally attenuated the risk for NHB patients (aHR 2.0, 95% CI, 1.1-3.7, p=0.031) and led to equivalent outcomes for Hispanic patients (aHR 0.9, 95% CI, 0.5-1.5, p=0.66). Adjusting for disease characteristics that differed by race/ethnicity at p&lt;0.2 (time to relapse, Ph+, Ph-like, KMT2Ar, age ≥18, or relapsed infant ALL) did not diminish the risk for NHB patients (aHR 2.0, 95% CI, 1.1-3.7, p=0.032) while outcomes remained equivalent for Hispanic patients (aHR 1.2, 95% CI, 0.8-1.8, p=0.40). Point estimates of cumulative incidence of non-relapse mortality (NRM) were highest in NHB patients (Hispanic, 4y NRM 13%, NHB 22%, NHW 11%), but this trend was not statistically significant (Gray’s p=0.52). Only 17% of patients initiated therapy for relapse on a clinical trial with no differences observed by race/ethnicity. Most patients received definitive treatment for relapse with either CAR T cell therapy (CART) or HCT: 79% overall, 74% Hispanic, 91% NHB, and 83% NHW. CART and HCT were utilized equally (39% and 40%, respectively) and the proportion that received each therapy did not vary by race/ethnicity. Time to CART/HCT, external referral for treatment, receipt of investigational v commercial CART, and use of post-CART consolidative HCT revealed no differences by race/ethnicity. Of the 66 patients (21%) who did not receive cell therapy, 26 had planned for CART or HCT, but did not receive due to disease progression or NRM (n=24; 12 Hispanic, 10 NHW), or insurance barriers (n=2, both Hispanic). After HCT, OS was worse for NHB patients (log-rank p=0.03) with 4y OS of 42% v 85% for NHW and 75% for Hispanic. Post-CART, 4y OS was 40% for NHB v 59% for NHW and 51% for Hispanic, but this difference was not statistically significant. Conclusion In a large real-world cohort of children with high-risk 1st relapse of B-ALL, we found a two-fold increased hazard of death for NHB patients compared to NHW patients, even after adjustment for other SDOH factors and high-risk disease features. In contrast to previous studies of adult patients, children appeared to have equal access to cell therapies across races/ethnicities. We found that Hispanic patients, who comprised &gt;40% of the cohort, had similar survival to NHW children, suggesting that availability of cellular and immunotherapies may be mitigating historically observed disparities for children with relapsed B-ALL.

Abstract Introduction: CD19-directed CAR T-cell (CAR-T) therapy has substantially improved clinical outcomes for adults with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). However, notable toxicities are associated with CAR-T, including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Variable practice patterns have emerged regarding the use of CRS/ICANS prophylaxis (ppx) via corticosteroids and/or other pharmacologic agents, but the utility of these approaches on reducing CRS or ICANS following CAR-T in B-ALL remains unknown. Thus, we utilized the Real-World Outcomes Collaborative for CAR T in ALL (ROCCA) database to evaluate associations between ppx and the development and severity of CRS or ICANS following brexucabtagene autoleucel (brexu-cel) for B-ALL. Methods: Adult patients (pts) who received standard-of-care brexu-cel for relapsed/refractory B-ALL across 40+ US centers were included. Primary endpoints were the incidence of CRS and ICANS within 28 days of CAR-T infusion. Secondary endpoints included timing of CRS and ICANS onset, progression-free survival (PFS) and overall survival (OS). Univariable and multivariable logistic regression evaluated associations between ppx and incidence of CRS/ICANS; KM and log-rank methods were used for survival analyses. Results: A total of 378 pts were included: 53 pts (14.0%) received CRS/ICANS ppx and 325 (86.0%) received no ppx. Ppx agents included steroids only (26.4%), steroid and anakinra (52.8%), anakinra only (15.1%), and steroid and tocilizumab (5.7%). Pts in the ppx group had a higher proportion of Hispanic pts (64% vs 34%), Ph-like (36% vs 19%) and a lower proportion had 0-5% bone marrow blasts at apheresis (38% vs 53%). The ppx and no ppx groups were similar in age, prior therapies, CAR-T indication, and marrow blasts &gt;50%. Cumulative incidence of any grade (gr) CRS was 94% with ppx and 86% with no ppx (p=0.025), of any gr ICANS was 53% with ppx and 51% with no ppx (0= 0.85). Cumulative incidence of gr 3-4 CRS was 9% in the ppx group and 10% in the no ppx group (p=1.00), of gr 3-4 ICANS was 26% in the ppx group and 29% in the no ppx group (p=0.71). Median time to onset for any gr CRS or any gr ICANS was identical in the ppx and no ppx cohorts (CRS: 5 days, range ppx 1-9 days, no ppx 0-14 days; ICANS: 7 days, ppx 1-20 days, no ppx 0-16 days). Univariate logistic regression analyses showed no significant association between ppx and the incidence of gr 2-4 CRS (OR 1.34, 95% CI: 0.75-2.40, p=0.326) or gr 3-4 ICANS (OR 0.88, 95% CI: 0.46-1.70, p=0.708). Multivariate analysis adjusting for ethnicity, leukemia genetic sub-type, and pre-apheresis disease burden similarly found no significant associations between ppx and gr 2-4 CRS (adjusted OR 1.06, 95% CI: 0.55-2.01, p=0.870) or gr 3-4 ICANS (OR 1.23, 95% CI: 0.59-2.55, p=0.584). When comparing steroid-only ppx (N=14) to steroid combinations or other drug ppx (N=39), there was no significant differences in gr 2-4 CRS (57% vs 44%, p=0.345) or gr 3-4 ICANS (43% vs 21%, p=0.115). Comparing cumulative incidence of dexamethasone (dex) exposure, pts in the ppx group had numerically greater dex exposure than pts in the no ppx group, with median (range) dosing of 182 mg (10-1386mg) and 100mg (1-4000mg), respectively. Finally, we found no significant differences in PFS or OS based on ppx. Median PFS was 9.6 months in the ppx group vs 13.3 months in the no ppx group (p=0.646) and median OS was 17.2 months in the ppx group vs 34.4 months in the no ppx group (p=0.170). Conclusions: In this large cohort of adult patients with R/R ALL receiving brexu-cel CAR-T therapy, prophylaxis intended to prevent CRS/ICANS was ineffective at reducing CRS/ICANS incidence, time to onset, or overall steroid exposure. Furthermore, PFS and OS were comparable between patients who received prophylaxis and those who did not. In the absence of prospective trials in B-ALL, these data suggest that current strategies of CRS/ICANS prophylaxis has limited benefit.

Abstract INTRODUCTION Outcomes for 1st relapse of pediatric B-lymphoblastic leukemia (B-ALL), especially high/intermediate-risk (HR/IR) relapse, remain unacceptably poor. Limited enrollment of this population on cooperative group clinical trials has impeded our ability to study potentially effective regimens. In the current era, patients can access innovative immunotherapies commercially. However, there is no mechanism to capture outcomes for these off-study patients and no comparative effectiveness data to guide treatment selection. METHODS We conducted a multicenter, retrospective study of patients &lt;30 years who initiated 1st relapse therapy at a participating center from 2018-2022 (ReCALL-1 Study). Objectives were to define real-world survival outcomes, compare response rates of reinduction strategies, describe the post-reinduction treatment landscape, and, for patients with HR/IR relapse, assess the comparative effectiveness (CE) of blinatumomab to hematopoietic cell transplant (blina/HCT) v CD19 CAR T cells (CART). For the CE analysis, we emulated an open-label, randomized study of blina/HCT v CART who achieved an M1/M2 marrow at the end of an intensive reinduction (EoRI). Patients were classified by their intended treatment at EoRI. Cox regression models were used to adjust for unbalanced patient and disease features by arms. The primary outcome was overall survival (OS) from EoRI. RESULTS The full cohort included 479 patients from 33 centers (31 US, 2 international). Median time to relapse was 31 months (m); 77% had bone marrow (BM) involvement and 31% central nervous sytem involvement. With a median follow-up of 49m from relapse, 4 year (y) OS, event-free survival (EFS), and non-relapse mortality (NRM) were 64%, 43%, and 13%, respectively. Among patients with very early BM (&lt;18m, n=79), early BM (18-35m, n=76), late BM (≥36m, n=162), and isolated CNS (n=85) relapses, 4y OS/EFS were 29%/20%, 57%/35%, 78%/49%, and 84%/61%, respectively. Only 19% received reinduction therapy on a clinical trial. Among patients with BM disease, R3 reinduction (n=179) and VXLD (n=61) had identical MRD-negative (&lt;0.01%) CR rates of 38% (p=1.00) and equivalent treatment failure (TF; M3 or extramedullary disease) rates: R3, 8% v VXLD 7%, p=0.79. Blina (n=33) and inotuzumab-based (n=21) reinductions achieved MRD-negative CR rates of 39% and 52%, respectively, but higher TF rates of 39% and 24%. Reinduction mortality was 2%: R3, n=5; VXLD, n=3; 3-drug reinduction, n=1. Overall, as part of 1st relapse therapy, 36% received CART (78% commercial product), 44% HCT, 40% blina, and 11% inotuzumab. The emulated trial included 159 patients, 95 on blina/HCT and 64 on CART. Study arms were well matched by demographics, cytogenetics, and relapse sites, but CART patients were more likely to have relapsed &lt;18m from diagnosis (34% v 24%) and have EoRI M2 marrows (31% v 11%), and less likely to have private insurance (36% v 51%). Unadjusted OS was comparable between arms (log rank p=0.18): CART, 60% at 4y; blina/HCT, 71%, as was NRM (10% v 13% at 4y). EFS was lower for CART (p=0.049): 4y EFS 35% v 49% for blina/HCT. After adjustment for unbalanced covariates, the hazard of death was equivalent for CART as compared to blina/HCT (aHR 1.1, 95% CI 0.6-2.1, p=0.67) and EFS became more comparable (aHR 1.3, 95% CI 0.8-2.1, p=0.22). 91% of blina/HCT and 97% of CART received their intended cell therapy; time from EoRI to cell therapy was shorter for CART (67 v 86 days, p&lt;.001). In the CART arm, 34% underwent consolidative HCT; 1/3 were preplanned and 2/3 due to loss of B cell aplasia or NGS-MRD positivity. Of those with a 2nd relapse, CART patients were more likely to be CD19 negative (47% v 10%, p=0.003). CONCLUSION In this multicenter, real-world cohort of children treated for 1st relapse in the immunotherapy era, suboptimal outcomes for early BM relapse persisted, with particularly dismal 4y OS of 29% for relapses &lt;18m after diagnosis. In contrast, survival for late BM and isolated CNS relapses compared favorably to historic data. Only 1 in 5 patients initiated relapse therapy on a clinical trial and although 1st relapse is not an approved indication for commercial CART in pediatrics, 36% received CART. In an emulated trial of post-reinduction blina/HCT v CART, adjusted EFS and OS were comparable, suggesting that CART may be a viable alternative to HCT for select patients. Post hoc analyses will identify whether specific subgroups may benefit more from one strategy.