Citations

PURPOSE In immunoglobulin light chain (AL) amyloidosis, amyloid fibrils cause organ dysfunction. Anselamimab, a monoclonal antibody, selectively binds to amyloid fibrils, accelerating their clearance. METHODS Newly diagnosed patients with European modification of Mayo 2004 stage IIIa or IIIb AL amyloidosis were randomly assigned to receive anselamimab or placebo with cyclophosphamide, bortezomib, and dexamethasone (with or without daratumumab). The primary end point was a hierarchical composite of time to all-cause mortality (ACM) and frequency of cardiovascular hospitalizations (CVHs), analyzed using the Finkelstein-Schoenfeld test and win ratio estimation. RESULTS Among 406 randomly assigned patients, the primary end point win ratio for anselamimab versus placebo was 1.11 (95% CI, 0.83, 1.50; P = .332) and the hazard ratio (HR) for ACM was 0.80 (95% CI, 0.57, 1.13; P = .290). CVH rates in the anselamimab and placebo groups were 0.59 (95% CI, 0.42, 0.83) and 0.89 (95% CI, 0.55, 1.43), respectively ( P = .145). Among patients with kappa isotype (n = 72), the win ratio was 2.06 (95% CI, 0.98, 4.31; P = .100) and anselamimab reduced ACM by 62% versus placebo (HR, 0.38; 95% CI, 0.17 to 0.86; nominal P = .012), and CVH by 71% (IRR, 0.29; 95% CI, 0.10 to 0.87; nominal P = .028) with improvements in Kansas City Cardiomyopathy Questionnaire-Overall Score. There was no clinical benefit observed in the lambda population. Anselamimab was generally well-tolerated; safety data were comparable between treatment arms overall. CONCLUSION Treatment with anselamimab, an antifibril antibody used alongside antiplasma cell dyscrasia therapy, while not meeting the primary end point in the overall population, significantly improved ACM and CVH in patients with kappa AL, potentially offering a new therapeutic option for this isotype.

Abstract Repetitive head impacts sustained during American football have been associated with neuropathological changes such as white matter shear injuries. However, the impact of specific factors, such as age of first exposure and cumulative head impact burden, on white matter integrity remains unclear. This study investigated in vivo white matter microstructural changes using diffusion tensor imaging and tract-based spatial statistics in 165 male former American football players (mean age 57.3 years, range 45–74) and 52 unexposed asymptomatic male controls (mean age 59.4 years, range 45–74) in the DIAGNOSE CTE Research Project. Compared to controls, former football players exhibited significantly higher fractional anisotropy (FA) in 1.97% of the white matter skeleton (1552 voxels; Cohen’s d = 0.587) and higher tissue-corrected FA (FAt) in 1.48% of the white matter skeleton (1004 voxels; Cohen’s d = 0.616). No significant differences were observed for mean diffusivity, axial diffusivity, radial diffusivity, or free water between football players and controls. Among football players, there were no significant differences in the white matter microstructure between players diagnosed with traumatic encephalopathy syndrome and those without the diagnosis. Lower FA was significantly associated with older age (P < 0.00001) and an earlier age of first exposure to tackle football (P < 0.01), while lower FAt was associated with greater cumulative head impact burden, specifically higher linear acceleration (P < 0.04) and rotational force (P < 0.02). This study highlights the influential role of exposure factors on white matter microstructure in former American football players, as well as the utility of diffusion tensor imaging to aid in characterizing the long-term effects of repetitive head impacts in contact sport athletes.

Abstract Severe neuropathies with predominant involvement of motor fibres can resemble lower motor neuron disease (LMND) phenotypes. Given the fatal prognosis of LMND, identifying underlying autoimmune syndromes is crucial to provide treatment options to patients. We investigated a novel autoantibody binding pattern observed on murine teased sciatic nerve fibres. Target antigens were identified using immunoprecipitation combined with mass spectrometry. Target specificity of these autoantibodies was validated in cell-based assays, neutralization assays and knock-out models. A retrospective study cohort consisting of different neuropathies (chronic inflammatory demyelinating polyradiculopathy n = 86, Guillain–Barré syndrome n = 37, multifocal motor neuropathy n = 18, diabetic neuropathy n = 30, other inflammatory neuropathies n = 10), amyotrophic lateral sclerosis (n = 50), multiple sclerosis (n = 50) and healthy controls (n = 50) was negative for septin multimer autoantibodies. Histopathological analysis of skin and the sural nerve including electron microscopy was performed in one seropositive patient, and autoantibody binding was characterized in vitro. Extensive immunotherapy was initiated in one patient, with clinical and serological follow-up over 4 years. Among 3543 total samples tested, three patients (two male, one female)—diagnosed with the LMND variant of amyotrophic lateral sclerosis (aged 65, 72 and 79 years, respectively)—showed a novel and distinct autoantibody binding pattern of indirect immunofluorescence staining on peripheral nerves, targeting Schmidt–Lanterman incisures (SLIs), paranodes and the abaxonal myelin. Target identification and validation revealed septin multimers as autoantibody epitopes. Despite the primarily intracellular location of septins, autoantibody binding was evident in living myelinated dorsal root ganglia, primarily at SLIs (‘incisuropathy’). Septin multimer autoantibodies further initiated complement deposition on fixed and permeabilized cell-based assays. Sural nerve and skin biopsies showed inflammation, myelin and axonal pathology. Extensive immunotherapy in one patient was followed by disease stabilization over 3 years. The other two patients died of rapid disease progression: one of them received no immunotherapy while the other had ineffective treatments with single administrations of intravenous immunoglobulin and rituximab. Our data suggest that septin multimer autoimmunity occurs in severe motor-predominant neuropathies which can clinically resemble a neurodegenerative LMND. Screening for septin multimer autoantibodies should be considered in patients presenting with this phenotype. Follow-up studies need to determine the direct pathogenicity of septin multimer autoantibodies, their potential as a biomarker of an autoimmune syndrome and responses to immunotherapy in larger cohorts.

Donation after circulatory death (DCD) livers increasingly use machine perfusion (MP). This study evaluates MP’s impact on older DCD livers based on data from the United Network for Data Sharing, covering all first adult DCD liver transplants (2016–2025). The cohort, divided into pre-MP and MP eras (separated by the FDA approval of the first normothermic MP platform in 2021), showed accelerated growth in DCD liver transplants during the MP era. Donors ≥60 rose 7.8-fold, including donors ≥70 (a USA first). By 2025, DCD livers accounted for 43.2%, with 61.35% from donors ≥50. Normothermic regional perfusion (NRP) (3.0%–21.7%), NMP (2.3%–35.6%), and sequential NRP-NMP (0.1%–19.2%) increased significantly (p < 0.001). The MP era was associated with a decrease in median waitlist time from 112 to 62 days (p < 0.001). Early graft survival was similar across ages. For ages 50–59, 1- and 3-year survivals were 87.9%/78.4% pre-MP and 90.1%/78.8% in the MP era. For 60–69, survival was 85.0%/80.6% pre-MP and 90.0%/71.3% in the MP era. DCD LTs for ≥70 were limited to the MP era with 87.8% 1-year survival. Multivariable Cox regression showed that static cold storage (HR = 1.19), donor age 50–69 versus 18–49, and recipient age (HR = 1.04) increased the risk of graft loss after adjustment. MP is associated with an increased number of older DCD liver transplants and acceptable early graft survival.

ABSTRACT The FDA Modernization Act 3.0 represents a pivotal shift in biomedical research by formally removing the requirement for animal testing and enabling regulatory acceptance of New Approach Methodologies (NAMs). This transition creates an urgent need for robust, human‐relevant biomarkers that can anchor NAM‐generated data within regulatory decision‐making, particularly for first‐in‐human studies. Extracellular vesicles (EVs), owing to their biological stability, accessibility and rich molecular cargo, may be well positioned to fulfil this role. EVs reflect dynamic cellular states and intercellular communication, making them mechanistically informative readouts of pharmacology, toxicity, immune modulation and disease biology across human‐derived model systems. This Perspective outlines how EV‐based biomarkers can support the qualification, standardization, and regulatory acceptance of NAMs, with particular emphasis on ex vivo platforms such as organoids, microtissue systems, organ‐on‐chip devices and perfused tissue slices. We highlight the advantages of EVs for longitudinal, non‐destructive sampling, representation of human variability, and integration with quantitative systems pharmacology and physiologically based pharmacokinetic models. Finally, we discuss the scientific, operational and regulatory challenges that must be addressed and argue that coordinated leadership from the International Society for Extracellular Vesicles (ISEV) is essential. The convergence of regulatory reform and EV science presents a timely call to action to establish EVs as foundational biomarkers in next‐generation, human‐centric drug development.

BACKGROUND AND OBJECTIVES: Stroke has the largest proportion of the global burden of neurological disorders with projected mortality rates to increase more rapidly in low- and middle-income countries than in high-income countries, and people of African descent are at greater risk. To better understand the burden, risk factors, and care pathways, this study aimed to review the risk factors, clinical presentation, and outcomes of patients presenting with stroke or stroke-like symptoms in a tertiary hospital in Sierra Leone. METHODS: A retrospective chart review was conducted of all patients presenting with neurological or neurosurgical conditions from January 2019 through December 2023 and those with stroke or stroke-like symptoms were included in this study. RESULTS: One thousand two hundred ninety-seven patients were diagnosed with stroke. Of these, a small majority were male (712, 54.9%), and the mean age was 57.8 years. About a third (38.1%) of the stroke patients were aged 60 years and above, and 562 (43.3%) were between 41 and 60 years. A majority of stroke patients (68.6%) had a prior diagnosis of hypertension, while significantly fewer had a documented diagnosis of diabetes (8.8%) and 4.6% of patients had a known prior stroke. Only half (50.8%) with ordered computed tomography scan were able to complete the ordered imaging. From these imaging findings, 123 patients (9.6%) were diagnosed with hemorrhagic stroke, while the remainder were diagnosed with ischemic stroke or transient ischemic attack vs hypertensive urgency. 32.9% experienced in-hospital mortality, while only 6.5% followed up. CONCLUSION: This study documents the significant stroke burden in Sierra Leone, much of which is unaddressed due to lack of specialty resources including inadequate community engagement to raise awareness of risk factors and preventative measures. Poor health-seeking behavior and access to medical services also contribute to this burden. These data are imperative to identify systems gaps and help support ongoing capacity building efforts.

TPS3184 Background: Replication stress (RS) creates cancer cell vulnerability to which the critical DNA damage response kinase, ATR (Ataxia-Telangiectasia and Rad3-related) responds. ATR senses the stress, halts the cell cycle, and promotes DNA repair to allow proliferation. Alnodesertib is an ATR inhibitor developed to prevent cancer cells from successfully repairing RS and proliferating further. In earlier stages of alnodesertib development, preclinical and translational research demonstrated that tumor cells experience three combined biological insults: irinotecan-induced RS, endogenous RS via ataxia-telangiectasia mutated (ATM) loss, and RS rescue prevention by ATR inhibition. Data from the dose escalation and initial dose expansion cohorts of this trial in a tumor agnostic population showed encouraging results in ATM-negative cancers (confirmed Overall Response Rate of 50% in 20 patients with ATM negative cancers and responses across 8 cancer types including complete responses, Ulahannan et al, AACR 2025). Tumor-specific dose expansion cohorts are now enrolling, including colorectal cancer (CRC) and pancreas ductal adenocarcinoma (PDAC). Methods: Two tumor-specific cohorts are now open, each enrolling approximately 50 patients (pts): ATM-negative CRC and ATM-negative PDAC. Pts will receive the recommended dose of alnodesertib 200mg orally on days 1-3 and 8-10 combined with low-dose irinotecan 60mg/m 2 IV on days 1 and 8, of each 21-day cycle. Tumor tissue is prescreened by immunohistochemistry for ATM protein loss (H score 0) for enrollment eligibility. Pts with CRC must have received a maximum of 2 prior chemotherapies excluding prior trifluridine/tipiracil, fruquintinib, or regorafenib, and pts with PDAC must have received a maximum of 1 prior chemotherapy for advanced disease. Prior targeted agents are allowed and do not count as prior lines of therapy. Key objectives include safety, tolerability, and preliminary efficacy. Clinical trial information: NCT04657068 .

Abstract Objectives Carbapenem resistance is a growing public health crisis with regional variability in incidence. We characterized the susceptibility of carbapenem-resistant Gram-negative rods (CR-GNRs) from the Pacific Northwest to five reserve beta-lactam agents including cefiderocol and aztreonam-avibactam. Methods A panel of 162 CR-GNRs from unique patients were tested against cefiderocol, aztreonam-avibactam, ceftazidime-avibactam, meropenem-vaborbactam and ceftolozane-tazobactam, with a subset of isolates derived from patients with bacteraemia (n = 55). Whole-genome sequencing (WGS) was performed on representative Stenotrophomonas maltophilia isolates displaying a range of cefiderocol MICs (n = 9). Results Among all isolates, the MIC50 and MIC90 to cefiderocol was 0.25 and 4 mg/L, respectively, compared with 4 and >64 mg/L for aztreonam-avibactam. Overall, 98.3% of S. maltophilia (n = 60), 91.2% of Enterobacterales (n = 34) and 88.5% of Pseudomonas aeruginosa (n = 26) isolates were susceptible to cefiderocol, while 78.6% of other non-fermenters had MICs ≤4 mg/L. Aztreonam-avibactam and cefiderocol exhibited similar activity against Enterobacterales and S. maltophilia, but aztreonam-avibactam was less active against other organisms. WGS of S. maltophilia isolates with elevated cefiderocol MICs identified disruptive mutations in PBP-encoding genes (mrcB/PBP1b and pbpC/PBP1c) that were not observed in highly susceptible isolates. The bacteraemia cohort had many comorbidities and a 29% 30 day all-cause mortality. In this cohort, cefiderocol demonstrated the highest in vitro activity as extrapolated from MICs, followed by ceftazidime-avibactam, aztreonam-avibactam, meropenem-vaborbactam and ceftolozane-tazobactam, respectively. Conclusions Cefiderocol exhibited the greatest in vitro activity against various CR-GNRs species in a Pacific Northwest population enriched for severely ill patients. Susceptibility to other agents was more variable among tested organisms.

7532 Background: BsAbs are highly effective, off-the-shelf T-cell engagers recently approved for relapsed/refractory multiple myeloma (MM) but remain underutilized in real-world settings. In partnership with the Florida Society of Clinical Oncology (FLASCO), a statewide initiative was launched to expand BsAb access through peer-led regional discussions focused on operational barriers, care transitions, and therapy management strategies. This study assessed the real-world impact of these interventions on BsAb utilization in FL. Methods: Multidisciplinary discussion forums were held in 4 FL metropolitan areas (Jan-Apr 2024). We conducted single and controlled interrupted time series (ITS) analyses using IQVIA eLAAD claims data (Apr 2023 - Sep 2025) including adult patients with a diagnosis of MM, evidence of claim activity, and provider state information. Fifth line or later (5L+) status was estimated as 3.3% of MM prevalence (Nikolaou et al.) BsAb utilization (% of MM 5L+ patients receiving a BsAb) was evaluated using segmented regression to estimate pre- and post-intervention trends, excluding the intervention period. We reported BsAb utilization by comparing FL with all other states, between community versus academic settings, and assessing the number of sites administering BsAb. Results: Before the intervention, BsAb utilization among MM 5L+ patients in FL rose from 8.2% (Apr 2023) to 11.2% (Dec 2023) (0.3 pp/mo; p=0.23), compared with a rise from 6.7% to 16.3% (1.3 pp/mo; p<0.0001) across all other states over the same time period. Post-intervention, BsAb utilization in FL increased from 22.8% (May 2024) to 35.9% (Sep 2025), reflecting a 7.0% immediate increase and 0.8 pp/mo sustained growth, exceeding the post-intervention trend observed across all other states (23.5% to 30.3%; 0.5 pp/mo). Overall, although pre-intervention BsAb utilization in FL was lower than all other states, FL demonstrated a 1.2 pp/month higher post-intervention utilization trend (p<0.001; Table). Post-intervention, FL community sites showed a 0.13 pp/mo higher BsAb utilization trend than academic sites, and the number of community sites administrating BsAb increased from 5 to 9, with no change among academic sites. Conclusions: This study suggests that the FLASCO-led, collaborative model increased BsAb utilization in FL community oncology sites and offers a framework for broader community adoption across other states. Parameter estimates from ITS model(s). FL (%) p-value Other US States (%) p-value Difference CITS:FL - Other US States (%) p-value Intercept (Apr 2023) 8.6 <.0001 7.7 <.0001 0.9 0.52 Monthly change pre-intervention 0.3 0.23 1.3 <.0001 -0.9 0.002 (Apr - Dec 2023) Immediate change post-intervention 7 0.01 0.2 0.87 6.8 0.01 (May 2024) Monthly change post-intervention 0.8 <.0001 0.5 <.0001 1.2 0.0003 (May 2024 – Sep 2025)