Citations

Abstract Dermatomyositis is driven by overactivation of type I and II interferons and other proinflammatory cytokines that signal via the JAK-STAT pathway. We conducted a 12-week, open-label study of brepocitinib, an oral TYK2/JAK1 inhibitor, in five adults with severe cutaneous dermatomyositis. Treatment was associated with rapid, clinically meaningful improvement in cutaneous disease activity. Single-cell and spatial transcriptomic profiling of lesional skin showed marked suppression of interferon-responsive pathways and inflammatory cell states by week 4. Together with findings from a Phase 3 randomized trial in DM patients with skin and muscle involvement (VALOR, NCT05437263 ), these data support TYK2/JAK1 inhibition as a promising therapeutic strategy for DM.

Abstract Objective This study was undertaken to examine acute and chronic electroencephalographic (EEG) and seizure characteristics in new onset refractory status epilepticus (NORSE). Methods Multicenter inpatient and follow‐up clinical and EEG data were analyzed using International League Against Epilepsy definitions and American Clinical Neurophysiology Society (ACNS) EEG terminology. Results Forty‐four patients were included from the Yale NORSE/FIRES Biorepository (median age = 29 years, 33 female, 38 cryptogenic). Nine hundred twenty inpatient EEG days were reviewed (median = 13.5 days/patient). Presenting status epilepticus (SE) types included 24 convulsive SE (CSE), five focal–motor (FMSE), and 15 nonconvulsive (NCSE). Of 39 patients with post discharge follow‐up (median = 14.7 months), 61.5% ( n = 24) had seizures and required more antiseizure medications than seizure‐free patients (median = 4 vs. 1, p < .001). Inpatient EEG captured epileptiform discharges in all and periodic discharges in 38 patients. Seizures were captured in 38 patients: 33 electrographic (11 only electrographic) and 27 electroclinical. Total seizure burden ranged 6.5–29 615.0 min (median = 50.7). Seizures fulfilling ACNS EEG criteria for SE were captured in 20 patients; two had CSE and the remainder NCSE with coma, nine of whom also had FMSE. Inpatient seizure days (median = 50.0 vs. 15.5%, p = .004) and seizure burden (median = 42.9 vs. 0 min, p = .009) were higher in the first half of monitored days. Interictal findings were equally present and did not predict postdischarge seizures, whereas electroclinical seizures (90.9% vs. 45.5%, p = .037), seizure burden (median = 116.8 vs. 32.5 min, p = .045), and proportion of seizure days (36.3% vs. 20.0%, p = .037) did. Among 12 patients with follow‐up EEGs (median = 19.6 months post onset), posterior‐dominant rhythm (PDR) returned in nine; five had periodic discharges, and three had seizure captured. Significance Seizures are most commonly convulsive upon presentation and nonconvulsive or clinically subtle throughout the inpatient course in NORSE. Inpatient seizures, but not interictal abnormalities, occur earlier in the inpatient course and presence of electroclinical seizures, seizure burden, and proportion of seizure days but not interictal findings are associated with postdischarge seizures. Although return of PDR reflects neurological recovery, seizure persistence and EEG abnormalities post‐NORSE are common.

Brexucabtagene-autoleucel (brexu-cel) produces high rates of measurable residual disease-negative (MRD-) complete response (CR) in adults with Philadelphia-chromosome positive (Ph+) acute lymphoblastic leukemia (ALL); however, subsequent relapses remain frequent. It is unclear whether maintenance with tyrosine kinase inhibitors (TKIs) can enhance remission durability. We evaluated outcomes among adults with relapsed/refractory Ph+ ALL who received commercial brexu-cel and achieved MRD- CR across 19 U.S. institutions. Considering TKI maintenance as a time-varying covariate, we analyzed outcomes based on receipt of subsequent TKI maintenance versus no maintenance. Patients receiving consolidative transplantation or non-TKI maintenance were excluded. Fifty-one patients were included: 20 received TKI maintenance and 31 received no maintenance. The use of TKI maintenance was associated with a significantly lower 1-year cumulative incidence of relapse (HR 0.12; 95% CI, 0.02-0.88; p=0.037) which translated into improved progression-free survival (PFS, HR 0.19; 95% CI, 0.04-0.85; p=0.029) and a trend towards improved overall survival (OS, HR 0.34; 95% CI, 0.07-1.62; p=0.18). There was no difference in non-relapse mortality (NRM, HR 0.83; 95% CI, 0.12-5.87; p=0.85). This real-world analysis supports the administration of TKI maintenance in Ph+ ALL following achievement of MRD- CR with brexu-cel as a strategy to improve PFS following chimeric antigen receptor T cell therapy.

ABSTRACT Objective Little is known about shifting from pediatric to adult‐focused multiple sclerosis (MS) care. This study aims to explore transition of care and follow‐up in the US pediatric‐onset MS (POMS) population. Methods Surveys were distributed to 10 sites in the US Network of Pediatric MS Centers (US NPMSC) about transition‐of‐care practices. A cohort of POMS/clinically isolated syndrome (CIS) at 12 US NPMSC sites was analyzed. The primary comparison was between < 18 and ≥ 18‐years of age. The primary outcome was 1‐ and 2‐year lapse in last follow‐up visit, measured from last recorded database visit to data lock date or, if ≥ 18 years of age, up to 1 year after a patient reached their site's typical transition age, if earlier. Secondary outcomes were baseline factors associated with follow‐up lapse. The model was adjusted for preidentified confounders. Results Compared with < 18 years, age ≥ 18 was associated with greater hazard of 1‐ and 2‐year follow‐up lapse. In POMS/CIS, the estimated hazard was 1.61 for 1‐year lapse (95% confidence interval [CI] 1.32–1.97, p < 0.001) and 1.40 for 2‐year lapse (95% CI 1.11–1.76, p = 0.004). In POMS‐only, the estimated hazard was 1.70 for 1‐year lapse (95% CI 1.33–2.18, p < 0.001) and 1.49 for 2‐year lapse (95% CI 1.11–1.99, p = 0.007). Platform injectable disease‐modifying therapy was associated with greater and intravenous with lesser hazard of lapse in follow‐up, while MS was associated with lower hazard than CIS. Conclusion Variable transition‐of‐care practices and barriers were reported by major US POMS centers. Before typical transition age, age ≥ 18 was associated with greater hazard of 1‐ and 2‐year follow‐up lapse than < 18. Developing standardized, targeted transition‐of‐care practices in POMS may be important.

Summary: Microsurgery is a specialized field within plastic surgery constrained by the high cost and limited availability of surgical microscopes, particularly in resource-limited settings. This lack of access hinders trainees from developing essential microsurgical skills. Previous efforts have explored smartphone-based alternatives, but there remains a need for high-fidelity, accessible training microscopes. This study presents a novel, low-cost, travel-friendly surgical microscope designed for microsurgery training. Modified binocular objective lenses enable near-field stereoscopic viewing using a dual-mirror array. A 3D-printed chassis provides the correct top-down orientation, and an integrated light source operates on standard or battery power, ensuring usability in low-resource environments. Initial testing demonstrated a fixed 6.5× magnification, allowing trainees to perform end-to-end anastomoses on 2-mm vessels. Prototypes were deployed for microsurgery training in the United States, Rwanda, Ethiopia, and Vietnam through the SHARE (Surgeons in Humanitarian Alliance for Reconstruction, Research and Education) plastic surgery organization, Nuoy Reconstructive International, and the senior author’s home institution. The authors’ investigation continues to assess the effectiveness of the microscope compared with state-of-the-art surgical microscopes. By offering a low-cost, portable solution without compromising image quality, this innovation has begun to transform microsurgical education and operating room–based microscopy worldwide, increasing accessibility for trainees and patients in diverse settings.

Abstract Background: Canine nodal marginal zone lymphoma (MZL) is the second most common histologic diagnosis of diffuse B-cell lymphomas in dogs, but a molecular profile that can distinguish this condition from the more common canine diffuse large B-cell lymphoma (DLBCL) has been elusive. Here, we use single-cell sequencing to define the transcriptomic signatures of canine MZL before and after oncolytic virotherapy followed by traditional chemotherapy. Objective: The aims of this study were to define the canine MZL transcriptome at single cell resolution and to evaluate its changes in the face of selective pressures introduced by therapy. Methods: Longitudinal biopsies and fine needle aspirates were collected from a dog with MZL enrolled in an immunotherapy trial. Peripheral blood B-cells from healthy dogs served as reference controls. Single-cell sequencing was done using the 10x Genomics Chromium GEM X platform (v3.1), and data was aligned to the canFam4_Y genome. Quality control, clustering, and cell annotation were performed using Seurat in R (v4.4.0). Differential gene expression analysis (DGEA) was performed on 500 randomized MZL B-cells and 500 healthy canine B-cells. InferCNV was deployed on the longitudinal MZL samples for prediction of tumor B-cell CNV profiles. Results: When compared to normal peripheral blood B-cells, the tumor cells were characterized by downregulation of quiescence-associated genes, including KLF2. Copy number analysis uncovered loss on canine chromosome 20 (CFA20) encoding KLF2, gain on CFA13, and gains on CFA32 and CFA36. While an anti-viral T-cell response was identified after VSV treatment, the B-cell subpopulations retained stable transcriptomes, with a disappearance of proliferating B-cells after chemotherapy. Conclusion: This is the first report describing the molecular properties of canine MZL at single cell resolution. Clonal diversity was apparent in the tumor, with copy number loss on CFA20, presumably leading to loss of KLF2. The transcriptional features of the tumor cells remained stable even in the face of a T-cell response to an oncolytic virus. Taken together, the results document silencing of KLF2 as a key phenotypic homology between canine and human MZL, supporting the potential for comparative approaches to enhance our understanding of the significance of KLF2 silencing in this disease. Citation Format: Elise Weir, Grace Walker, Jaime F. Modiano, Aaron L. Sarver, Shruthi Naik, Amy Treeful. Reduced KLF2 expression in canine marginal zone lymphoma mirrors human disease [abstract]. In: Proceedings of the Fifth AACR International Meeting on Advances in Malignant Lymphoma: From Discovery to Clinical Impact; 2026 Jun 24-27; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2026;7(3_Suppl):Abstract nr A043.

Abstract Introduction: Lymphomas are among the most common malignancies in dogs, and their morphologic and biological similarities to human counterparts have established them as widely accepted models of human disease. However, emerging molecular data suggest that conservation varies by subtype, and that many common lymphoma subtypes are principally convergent rather than homologous conditions, requiring a critical reassessment of when and how canine lymphomas provide relevant models of human disease. Methods: We employed conventional pathology, immunohistochemistry, and next generation sequencing platforms, including single-cell sequencing and spatial genomics, to characterize the transcriptional landscape and cellular organization of canine lymphomas, complemented by population metadata. Results: Our analysis revealed that canine DLBCL lacks the traditional GCB/ABC bifurcation seen in humans. While activation of NFκB pathways is seen commonly in these tumors, a germinal center-like DLBCL subtype is not apparent in dogs, and the transcriptional signatures are distinct from those of activated B-cell like DLBCL. Instead, we identified a novel canine-specific DLBCL subset driven by an AP-1-associated transcriptional signature, mirroring advanced human follicular lymphoma rather than human DLBCL. In contrast, emerging data suggest that downregulation of quiescence programs might be a shared feature of both human and canine MZLs, making this subtype a candidate for conserved disease mechanisms. While canine T-cell lymphomas exhibited extensive transcriptional heterogeneity, the samples in our dataset did not align with established human T-cell subgroups, suggesting that high incidence in dogs might not equate to molecular similarity. Conclusions: Our results suggest canine and human lymphomas are principally convergent rather than homologous diseases whose evolution and topological organization are constrained by developmental programs. The distinct transcriptional programs of canine and human DLBCLs reveal informative biological divergence, while potential shared features of MZL suggest contexts where comparative oncology may illuminate conserved disease mechanisms. Canine T-cell lymphomas exhibit extensive transcriptional heterogeneity that, at present, defies simple classification, mirroring challenges in their human counterparts and underscoring the need for larger studies to establish molecular patterns that inform causation, prognosis, and treatment. These findings highlight contexts where distinct and conserved molecular features between canine and human lymphoma can reveal shared and divergent disease mechanisms, ultimately underscoring the need for subtype-specific validation as canine lymphomas are adopted as models of human disease. Use of AI: Generative AI was used to improve clarity and readability of the abstract. AI was not used to conduct the study or to produce new text or material. Citation Format: Jaime F. Modiano, Amy E . Treeful, Grace E. Walker, Davis M. Seelig, Caitlyn M. Callaghan, Timothy D. O'Brien, Shruthi Naik, Aaron L. Sarver. Different paths to the same destination: Molecular divergence and functional convergence in human and canine lymphomas [abstract]. In: Proceedings of the Fifth AACR International Meeting on Advances in Malignant Lymphoma: From Discovery to Clinical Impact; 2026 Jun 24-27; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2026;7(3_Suppl):Abstract nr A023.

Abstract The impact of microglia antigen presentation on CNS infiltrating CD8 T cells responses during neurotropic virus infection remains undefined. Using Theiler’s murine encephalomyelitis virus (TMEV) infection of neurons as a model system, we generated H-2K b and H-2D b Tmem119 conditional knockout mice. During TMEV infection, we determined using Tmem119 K b cKO mice that microglia H-2K b contributes to antiviral CD8 T cell proliferation in the brain. Meanwhile, using Tmem119 D b cKO mice we determined that microglia H-2D b increased antiviral CD8 T cell perforin levels and the capacity to induce blood-brain barrier (BBB) disruption. Furthermore, microglial H-2D b was essential for antigen-specific reactivation of CD8 tissue resident memory (TRM) cell recall responses and BBB disruption long after virus had been cleared. These findings demonstrate discrete roles of individual MHC class I genes on microglia in CD8 T cell proliferation, effector functions, memory recall and neuropathology.

Abstract Embryonal tumors with multilayered rosettes (ETMR) are rare, highly aggressive tumors of infancy with extremely poor outcomes and no established standard of care therapy. ETMRs were recognized as a distinct molecular entity in 2016, however, the absence of prospective, biology-driven clinical trials has limited translation of these insights into standardized, risk-adapted treatment approaches for this vulnerable population. To address this gap, the Collaborative Network for Neuro-oncology Clinical Trials (CONNECT) developed CURE(Clinical trial advancing Understanding of Rare Embryonal Brain Tumors), an international, multi-institutional, molecularly guided umbrella trial. All patients enroll through the centralized CURE-Screening protocol, which provides rapid comprehensive molecular profiling with real-time central pathology, molecular, and radiographic review to confirm diagnosis, define molecular subtype, and determine eligibility and assignment to disease-specific treatment arms. CURE-ETMR represents the first disease-specific arm to open within this platform. Following centralized screening, children with newly diagnosed ETMR are assigned to clinically defined risk strata using integrated molecular, radiographic, and clinical criteria. Patients will be treated using a risk-adapted multimodal approach in which we prioritize maximal safe surgical resection with consideration of second-look surgery based on centralized imaging review; administer induction chemotherapy followed by consolidation with high-dose chemotherapy and autologous hematopoietic cell rescue or dose-intensified chemotherapy, selectively incorporate radiation sparing approach or early focal radiotherapy for patients with unresectable residual disease or brainstem involvement; deliver intrathecal chemotherapy for leptomeningeal prophylaxis; and include biologically informed maintenance therapy. In parallel, protocol-required longitudinal collection of tumor tissue, cerebrospinal fluid, blood, and advanced neuroimaging supports integrated molecular, liquid biopsy, and imaging biomarker analyses to identify predictors of treatment response, resistance, and relapse. Primary objectives include evaluation of feasibility, safety, progression-free survival, and overall survival compared with molecularly annotated historical cohorts. This centralized screening to assignment framework establishes a scalable model for prospective, biology-driven trials in rare embryonal brain tumors.

Abstract Background Oligodendrogliomas were previously defined by histology, but since 2016, the WHO has integrated molecular signatures to create the entity of IDH-mutant 1p/19q-codeleted oligodendroglioma. These tumors harbor recurrent genetic alterations—including IDH mutations, CIC and FUBP1 loss-of-function mutations, and PI3K-activating mutations—that collectively define a genetic profile distinct from IDH-mutant astrocytoma and IDH wild-type glioblastoma. The paucity of faithful model systems has impeded progress in advancing mechanistic insights and therapeutic development for oligodendroglioma. Results To test whether recurrent mutations found in oligodendroglioma patients would drive tumor formation in mice, we utilized in utero electroporation to introduce combinations of gain- and loss-of-function mutations into the developing cortex. Initial tests that included expression of IDH-and PIK3CA-mutants with Cic and Fubp1 loss (termed Oligo) were non-tumorigenic but biased cells towards glial lineages. Introducing Cdkn2a-loss, which is normally suppressed by IDH-associated epigenetic changes in human tumors, to the Oligo combination (termed Oligo-Cdkn2a) resulted in fully penetrant tumor formation. Histopathological review showed the Oligo Cdkn2a-loss mouse model resembled grade II/III oligodendroglioma with rounded nuclei and open chromatin. If Trp53-loss is used (termed Oligo-Trp53) in place of Cdkn2a-loss, tumor histology shifts to a more astrocytic phenotype with angulated nuclei with denser chromatin, demonstrating a direct impact of Trp53-loss on histological features. Bulk RNA-sequencing verifies metabolic alterations driven by the presence of IDH-mutations in Oligo-Cdkn2a mouse models compared to an IDH wild-type GBM model. Single-cell transcriptional profiling shows that Oligo-Cdkn2a tumors contain an increased population of tumor cells that resemble more differentiated oligodendrocytes. Examination of the tumor immune microenvironment within Oligo-Cdkn2a and IDHWT GBM mouse models is being performed to determine changes in immune cell infiltration and transcriptional programs. Conclusion We have created, to our knowledge, the first murine model of IDH-mutant 1p/19q-codeleted oligodendroglioma that incorporates Cic loss. This immune-competent mouse model of IDH-mutant 1p/19q-codeleted oligodendroglioma offers a powerful new tool for interrogating tumor biology and evaluating preclinical therapeutic strategies.