Citations

Abstract The use of chimeric antigen receptor (CAR) T-cell therapy is increasing for adult B-cell acute lymphoblastic leukemia (B-ALL), with 3 CD19 CAR T-cell products commercially available. Several key clinical questions related to best practices for CAR T-cell administration in this population exist, and limited prospective randomized trials have been conducted to fill these knowledge gaps. Thus, to help guide clinical practice, we conducted a modified Delphi study to develop and validate consensus recommendations on the administration of commercially available CAR T-cell therapy for adults with B-ALL. Consensus panelists (n = 9) included principal investigators (PIs) from Real World Outcomes Collaborative of CAR T-Cell Therapy in Adult ALL (ROCCA) consortium sites and were selected based on expertise and CAR T-cell center volume. Final panel consensus recommendations were distributed for rating by the remaining PIs from ROCCA consortium sites, which served as the validation group (n = 27). Consensus topics included patient selection, bridging and pre–CAR T-cell leukemia staging, lymphodepletion, and CAR T-cell treatment setting, specific toxicity prevention and management, post–CAR T-cell response assessment and disease monitoring, and the role of consolidation and/or maintenance therapies after CAR T-cell therapy. Initially, 58 recommendation statements were evaluated for consensus. After 2 panel meetings, a total of 34 statements achieved consensus rating among the expert panel. After rating by the validation group, all but 1 recommendation statement continued to meet consensus, for a total of 33 consensus recommendation statements on the administration of CAR T-cell therapy in adult B-ALL.

The creation of an arteriovenous fistula in a uremic pig induces cardiac remodeling, which resembles contemporary clinical findings in patients with end-stage kidney disease (ESKD) and includes increased end-diastolic volumes and cardiomyocyte hypertrophy, potentially driven by fibrosis and senescence. This novel large animal model may now enable mechanistic and therapeutic studies aiming to ease the unacceptably high burden of cardiovascular disease on patients with ESKD.

Abstract Introduction The inhalation of aerosolized therapeutics is a promising strategy for the targeted delivery of drugs and biologics to the lungs. We have previously demonstrated the efficacy and feasibility of nebulized exosomes using a platelet-derived exosome product (PEP: Rion, Inc.), which significantly attenuated emphysema in a murine model (PMID: 38325750). However, the PEP aerosol’s physical properties—such as size, tissue deposition, anatomic location, and stability remain incompletely characterized. To address this, we utilized a cascade impactor to define aerosol particle size and deposition patterns and employed immunofluorescence staining to assess the regional and anatomic localization of nebulized PEP within the murine lung. Methods PEP particle size and tissue deposition were determined by passing the aerosol through a Marple cascade impactor (CI, DSI), which was connected to an inhalation tower (DSI). PEP aerosols were generated by a vibrating mesh nebulizer (Aerogen, Cat No AG-AL1100) at a controlled velocity and humidity and delivered to the CI at a flow rate of 2L/min. Aerosols were separated by size and allowed to deposit at the corresponding stages as they passed through the pinholes of the stage, by design. The stages were weighed after nebulization, and the percentage of aerosol deposition was calculated to simulate the human respiratory tree, according to the manufacturer’s specifications. In parallel, fluorescence DiR-labeled PEP was nebulized to spontaneously breathing mice, and confocal microscopy was used to determine intrapulmonary distribution. Results A total of 2.25 mL of PEP reconstituted in 0.9% normal saline (11.4 mg/mL final concentration) was nebulized for 35 minutes at a flow rate of 2 L/min, yielding 3.5 mg of total aerosol deposition, which is 13.6% of the total PEP mass (25.65mg) being nebulized, across the CI stages. Of this, 74% of the aerosolized particles with a particle size ≤ 1µm and deposited in Stages 7, 8 & F, corresponding to the deep regions of the lungs, specifically regions beyond the alveolar ducts and within the alveoli. In vivo 3D confocal imaging corroborated these findings, revealing abundant DiR-labeled PEP deep into the alveolar space within the peripheral regions of all lung lobes. Conclusion The study result demonstrates the feasibility and capability of delivering aerosolized PEP deeply into the alveolar regions of the lung at the given pressure, humidity, flow rate and nebulizer settings. This study establishes a methodological framework for characterizing and optimizing aerosolized exosome therapeutics for precise, region-specific delivery within the respiratory tract. This abstract is funded by: Department of Defense, Mayo Clinic Funding

Abstract Rationale Community-acquired pneumonia (CAP) remains a leading cause of morbidity and mortality worldwide; current guidelines recommend either the use of β-lactam therapy with a macrolide (azithromycin; AZM) or monotherapy with a fluoroquinolone for treatment. Limited evidence exists on their comparative effectiveness. To address this gap, we examined the differences in outcomes among CAP patients treated with β-lactam therapy plus AZM or fluoroquinolone monotherapymethods: We emulated a randomized clinical trial that hypothetically assigned patients to β-lactam therapy plus AZM or fluoroquinolone. Eligible patients were all adults hospitalized for nonsevere community-acquired pneumonia (CAP) based on ATS/IDSA criteria; at Mayo Clinic hospitals (3 academic and 16 community) between May 2018 and September 2022 and received one of the two treatments within 12 hours of admission. Ensemble machine learning with augmented inverse probability weighting (AIPW) was used to evaluate “intention to treat” effects on hospital-free days (HFDs), 180-day mortality, use of advanced respiratory support, in-hospital mortality, and the composite of advanced respiratory support and/or in-hospital mortality. We used the E-value and post-discharge systolic blood pressure (SBP) (negative outcome) to evaluate effects of potential unmeasured confounding and alternative “doubly robust” inverse probably weighting with regression adjustment (IPWRA) to evaluate robustness of the findings. Results 2,451 patients (2,142 β-lactam therapy plus AZM and 309 fluoroquinolone) were eligible and included in the analyses: 53.9% were female, 86.8% were White, and mean age was 58.4 years (SD: 17.02). Compared with β-lactam therapy plus AZM, the fluoroquinolone group experienced significantly higher HFD (1.50 days; 95% CI: 1.08, 1.91), lower use of advanced respiratory support (RR: 0.32; 95% CI: 0.09, 0.54), lower in-hospital mortality (RR: 0.14; 95% CI: 0.00, 0.40), and composite of advanced respiratory support and/or in-hospital mortality (RR: 0.29; 95% CI: 0.08, 0.49). Moderate to large e-values (ranging from 3.50 to 4.74) and use of negative outcomes (post-discharge SBP) suggested that unmeasured confounding is unlikely to change the findings. Sensitivity analysis using IPWRA showed very similar results. Conclusion Among hospitalized patients with non-severe CAP, treatment with fluoroquinolone monotherapy was associated with more hospital-free days, lower in-hospital mortality, and reduced need for advanced respiratory support compared with AZM and β-lactam combination. The findings highlight the role of fluoroquinolone as a beneficial alternative CAP patients. However, further studies are needed to explore the underlying mechanisms driving these differences and assess whether specific patient subgroups may benefit most from quinolone-based therapy. This abstract is funded by: none

Abstract Rationale Alpha1-antitrypsin (AAT; gene name SERPINA1) is a critical antiprotease that protects the lung from neutrophil elastase-mediated injury. AAT deficiency predisposes to emphysema, which is further exacerbated by cigarette smoke (CS) exposure. We previously reported (PMID: 38325750) that a nebulized human platelet-derived exosome product (PEP) attenuated CS-induced emphysema in C57BL/6 mice. Given the presence of AAT protein in these platelet-derived exosomes (identified by proteomics), we hypothesized that PEP nebulization would significantly attenuate both spontaneous and CS-induced emphysema in SERPINA1 knockout (KO) mice. Methods Transgenic SERPINA1 KO C57BL/6 mice (both sexes) exposed to CS (10 cigarettes/day and 5 days/week) for 2 months were then randomized to receive nebulized PEP or 0.9% saline (placebo) twice weekly for 4 additional weeks, with continued CS exposure. PEP was reconstituted in 0.9% saline (22.7mg/mL; ∼3 × 10¹0 vesicles/mL) and administered via pressure- and humidity-controlled nose-only inhalation tower (2.25 mL of PEP or saline over 35 minutes). Lung static compliance (Cst), cutaneous O2 saturation, mean linear intercepts (Lm), and plethysmographic parameters were measured during and after the study. Results Histological analysis of the lung tissue sections revealed that PEP significantly attenuated the CS-induced increase in alveolar size, as determined by measurement of the mean linear intercepts (Lm, p < 0.001). Lung static compliance (Cst), which was increased in CS-exposed mice, was also significantly decreased in the PEP-treated group (p < 0.001) compared to placebo in the male and female combined group. Functional respiratory parameters further supported the protective effect of PEP in this AAT-deficient model. In female mice, PEP nebulization significantly improved several CS-impaired pulmonary function parameters, including minute volume (MV, p = 0.024), the flow at the point 50% of tidal volume is expired (EF50, p = 0.021), Peak Inspiratory Flow (PIF, p = 0.009), Peak Expiratory Flow (PEF, p = 0.018), and O2 saturation (p = 0.035). However, these improvements were not observed in male mice. Conclusions These findings extend prior observations and underscore the therapeutic potential of nebulized AAT-enriched PEP directly to the alveolar region, effectively attenuating injury and improving pulmonary function in AAT deficiency-related emphysema. This abstract is funded by: Department of Defense, Mayo Clinic Funding, The Young and Middle-aged Medical High-end Talents in Chongqing Program

Abstract Introduction We previously demonstrated that nebulized platelet-derived exosome product (PEP) alleviates cigarette smoke (CS)-induced murine emphysema. To elucidate the underlying molecular mechanisms, we conducted single-nucleus RNA sequencing of lung tissue, which initially revealed a shift in the cell source for TNF signaling (a critical regulator of inflammation in COPD lungs) from innate lymphoid cells (ILC) to alveolar macrophages (aMac) after chronic CS exposure. In this study, we conducted a more in-depth analysis of cellular communication to determine the mechanism by which PEP modulates CS-induced TNF signaling in the lung microenvironment. Methods Single-cell transcriptomics and cell-cell communication analyses were performed between CS-exposed placebo control lungs vs. sham control lungs and CS-exposed PEP-treated vs. placebo control lungs using R packages, including Seurat, CellChat, Patchwork, Future, and NMF. A comparative analysis of ligand-receptor interactions across these datasets was conducted using CellChat to infer intercellular signaling networks. Results Single-nuclear RNA-seq analysis revealed that the Thy1-ITGAX_ITGB2 signaling pathway was significantly upregulated by CS, acting as the adhesive and activating bridge that facilitates the switch in TNF production from ILC to aMac. Thy1 is a GPI-anchored ligand expressed on ILCs, and ITGAX_ITGB2 is its cognate receptor on aMacs. Concurrently, Ptprc-Mrc1 signaling, an inhibitory pathway in ILC-aMac crosstalk, was downregulated, contributing to sustained aMac activation by CS. Furthermore, analysis of aMac-aMac interactions revealed upregulated GRN/Sort1 signaling, which promotes the internalization of progranulin, an anti-inflammatory glycoprotein that competes for TNF/TNFR signaling. Ptprc-Mrc1 signaling was also downregulated within the aMac autocrine/paracrine network, further perpetuating a pro-inflammatory state. In contrast, treatment with PEP downregulated Thy1-ITGAX_ITGB2 signaling and upregulated Lamc1-Cd44 signaling, a hallmark of aMac deactivation, thereby inducing a phenotypic switch in inflammatory macrophages toward a reparative M2 state, promoting the resolution of CS-induced chronic inflammation. Conclusions These data suggest that the transition of TNF production from ILCs to aMacs under chronic CS stress is driven by increased Thy1-ITGAX_ITGB2 interactions and decreased Ptprc-Mrc1 signaling between ILCs and aMacs crosstalk within the local tissue. Enhancing the crosstalk between Lamc1-Cd44 and Ptprc-Mrc1 may suppress TNF production and attenuate CS induced aMac activation. Targeting these pathways, as demonstrated by nebulized PEP treatment, holds therapeutic potential to deactivate inflamed aMacs and promote homeostasis in the inflamed lung. This abstract is funded by: Department of Defense, Mayo Clinic Funding

Background: Segmental arterial mediolysis (SAM) is a non-inflammatory vasculopathy that primarily affects the abdominal visceral arteries leading to hemorrhage, ischemia, or pseudoaneurysms. Its presentation can be mimicked by other vasculopathies including vasculitis involving the medium-sized blood vessels making it difficult to diagnose. Case Presentation: A 55-year-old woman presented with a two-hour history of sudden-onset, severe epigastric pain radiating to the chest. She was noted to be hypotensive with low hemoglobin 8.8 g/dL suspicious for a hemorrhagic cause. Her case was complicated by elevated international normalized ratio 3.7 in the setting of warfarin therapy for the mechanical mitral valve. The remainder of her complete blood count, complete metabolic panel, inflammatory markers, autoantibody serologies, and infectious testing were negative. Abdominal computed tomography angiogram revealed hemoperitoneum, bilateral renal infarctions, a large mesenteric hematoma, aneurysmal disease of the common hepatic and inferior mesenteric arteries, thrombosis and proximal dissection of the superior mesenteric artery, acute thrombosis of the left external iliac vein, and multiple sites of arterial extravasation from the pancreaticoduodenal artery and its branches. Mesenteric artery angiogram showed multivessel visceral artery aneurysms and stenoses characteristic of SAM for which she underwent transcatheter arterial embolization of the bleeding vascular bed. We provide a narrative literature review with a focus on common presentations and differentiating characteristics of vasculopathies that can involve medium-sized blood vessels. It is important to accurately diagnose SAM and its potential mimics as management strategies differ. Conclusions: SAM presents with medium vessel vasculopathy without vasculitis. Differentiation from mimics can be difficult but aided by familiarity of their characteristic findings and differentiating clinical characteristics.

PURPOSE We tested the hypothesis that adding metastasis-directed therapy (MDT) to standard-of-care (SOC) systemic therapy improves progression-free survival (PFS) among patients with oligometastatic disease. METHODS EXTEND was a multicenter randomized phase II trial. Patients with 1-5 metastases were randomly assigned to MDT + SOC versus SOC in one of the six baskets (breast, pancreas, kidney, two prostate baskets, and an other basket) with basket-specific stratification and powering. PFS, the primary end point, was prespecified in the per-protocol set within each basket, across all baskets, and across all baskets excluding the prostate baskets. Exploratory end points included circulating tumor DNA (ctDNA) and immune profiling. RESULTS From 2018 through 2023, 521 patients were screened, 350 were randomly assigned, and 334 were analyzed per protocol (MDT + SOC, n = 166; SOC, n = 168). Radiotherapy was used as MDT for 98% of metastases (370/379). Overall, after a median follow-up of 53 months, PFS was improved with MDT + SOC (hazard ratio [HR], 0.54 [95% CI, 0.41 to 0.72], P < .001). Similarly, PFS was improved when excluding the prostate baskets (HR, 0.60 [95% CI, 0.40 to 0.89]). Within each basket, PFS superiority was identified for the pancreas, prostate, and other baskets, whereas the breast and kidney baskets were inconclusive. At enrollment, detectable ctDNA correlated with shorter PFS and survival; by contrast, ctDNA clearance 3 months postenrollment correlated with improved survival. MDT + SOC-induced systemic immune activation was most pronounced among baskets demonstrating PFS superiority. CONCLUSION The phase II EXTEND trial supports the addition of MDT to SOC for oligometastatic disease. Histology-specific efficacy signals were identified for phase III testing. Translational insights suggest the potential for optimizing the definition of oligometastasis using ctDNA and point to systemic immune responses as a possible mechanism of benefit from MDT.

Purpose To investigate the clinical features, treatments, and outcomes of patients with secondary orbital lymphoma. Major Findings In this cohort of 31 patients, 15 (48.4%) were female and 27 (87.1%) were white. Follicular lymphoma was the most common subtype (n = 13, 41.9%) and was more associated with unilateral disease compared to other subtypes (p = 0.01). Common presenting symptoms included a palpable mass (n = 17, 54.8%), eyelid swelling (n = 16, 51.6%), and ptosis (n = 12, 38.7%). Patients were most often diagnosed with Ann Arbor Stage IV lymphoma (n = 17, 54.8%) via incisional biopsy (n = 13, 41.9%). Radiation therapy (n = 9, 29.0%) was the most common initial treatment, and most patients received radiation (n = 19, 61.3%) and/or chemotherapy (n = 21, 67.7%). A majority of patients had final best corrected visual acuity (BCVA) within 1 line of initial BCVA (n = 19, 82.6%) and had no local recurrences (n = 21, 67.7%). However, complete remission was rare (n = 3, 9.7%), and systemic recurrence occurred in over half of patients (n = 18, 58.1%). Conclusions Follicular lymphoma was the predominant subtype of secondary orbital lymphoma in this cohort. Most patients with secondary orbital lymphoma presented with advanced disease where few achieved complete remission and more than half of the patients developed systemic recurrence despite majority retaining visual acuity.