Background: TERT promoter mutation (TPM) is an established biomarker in meningiomas associated with aberrant TERT expression and reduced progression-free survival (PFS). TERT expression, however, has also been observed even in tumours with wildtype TERT promoters (TP-WT). This study aimed to examine TERT expression and clinical outcomes in meningiomas. Methods: TERT expression, TPM status, and TERT promoter methylation of a multi-institutional cohort of meningiomas (n=1241) was assessed through nulk RNA sequencing (n=604), Sanger sequencing of the promoter (n=1095), and methylation profiling (n=1218). 380 Toronto meningiomas were used for discovery, and 861 external institution samples were compiled as a validation cohort. Results: Both TPMs and TERTpromoter methylation were associated with increased TERT expression and may represent independent mechanisms of TERT reactivation. TERT expression was detected in 30.4% of meningiomas that lacked TPMs, was associated with higher WHO grades, and corresponded to shorter PFS, independent of grade and even among TP-WT tumours. TERT expression was associated with a shorter PFS equivalent to those of TERT-negative meningiomas of one higher grade. Conclusions: Our findings highlight the prognostic significance of TERT expression in meningiomas, even in the absence of TPMs. Its presence may identify patients who may progress earlier and should be considered in risk stratification models.

Background: The complement C5 inhibitor (C5IT), ravulizumab, is approved in Canada for the treatment of anti-acetylcholine receptor antibody-positive (AChR-Ab+) generalized myasthenia gravis (gMG). Updated effectiveness and safety results from the ongoing MG SPOTLIGHT Registry (NCT04202341) are reported. Methods: MGFA classification and MG-ADL total scores were assessed in patients who received ravulizumab only (ravu-only) or transitioned from eculizumab to ravulizumab (ecu-to-ravu), with data available prior to C5IT initiation (“pre-C5IT”) and ≥1 assessment post-initiation (“post-ravu”). Results: Of 52 patients with 2 post-ravu assessments, average treatment duration was 10.4 months at last assessment (LA). Mean±SD MG-ADL scores improved (pre-C5IT: 7.6±3.6; LA: 3.4±3.3), as did the proportions of patients with minimal symptom expression (MSE, MG-ADL≤1) (pre-C5IT: 1/52 [2%]; LA: 17/52 [33%]) and MGFA classification 0-II (pre-C5IT: 18/45 [40%]; LA: 40/45 [89%]). In the ravu-only subgroup, outcomes improved (pre-C5IT vs LA): MG-ADL, 6.3±3.0 vs 4.0±3.4; MGFA 0-II, 9/14 [64%] vs 12/14 [86%]. The ecu-to-ravu subgroup sustained continued gradual improvement from last eculizumab assessment to LA: MG-ADL, 4.4±4.2 vs 3.0±2.8; MGFA 0-II, 19/21 [90%] vs 20/21 [95%]. Ravulizumab was well tolerated; no meningococcal infections were reported. Conclusions: These results demonstrate the long-term effectiveness and safety of ravulizumab in routine clinical practice in patients with gMG.

Background: Meningiomas are the most common intracranial tumors. Radiotherapy (RT) serves as an adjunct following surgical resection; however, response varies. RTOG-0539 is a prospective, phase 2, trial that stratified patients risk groups based on clinical and pathological criteria, providing key benchmarks for RT outcomes. This is the first study that aims to characterize the molecular landscape of an RT clinical trial in meningiomas. Methods: Tissue from 100 patients was analyzed using DNA methylation, RNA sequencing, and whole-exome sequencing. Copy number variations and mutational profiles were assessed to determine associations with meningioma aggressiveness. Tumors were molecularly classified and pathway analyses were conducted to identify biological processes associated with RT response. Results: High-risk meningiomas exhibited cell cycle dysregulation and hypermetabolic pathway upregulation. 1p loss and 1q gain were more frequent in aggressive meningiomas, and NF2 and non-NF2 mutations co-occurred in some high-risk tumors. Molecular findings led to the reclassification of several cases, highlighting the limitations of histopathologic grading alone. Conclusions: This is the first study to comprehensively characterize the molecular landscape of any RT trial in meningioma, integrating multi-omic data to refine treatment stratification. Findings align with ongoing genomically driven meningioma clinical trials and underscore the need for prospective tissue banking to enhance biomarker-driven treatment strategies.

Background: The WHO grade of meningioma was updated in 2021 to include homozygous deletions of CDKN2A/B and TERT promotor mutations. Previous work including the recent cIMPACT-NOW statement have discussed the potential value of including chromosomal copy number alterations to help refine the current grading system. Methods: Chromosomal copy number profiles were inferred from from 1964 meningiomas using DNA methylation. Regularized Cox regresssion was used to identify CNAs independenly associated with post-surgical and post-RT PFS. Outcomes were stratified by WHO grade and novel CNAs to assess their potential value in WHO critiera. Results: Patients with WHO grade 1 tumours and chromosome 1p loss had similar outcomes to those with WHO grade 2 tumours (median PFS 5.83 [95% CI 4.36-Inf] vs 4.48 [4.09-5.18] years). Those with chromosome 1p loss and 1q gain had similar outcomes to those with WHO grade 3 cases regardless of initial grade (median PFS 2.23 [1.28-Inf] years WHO grade 1, 1.90 [1.23-2.25] years WHO grade 2, compared to 2.27 [1.68-3.05] years in WHO grade 3 cases overall). Conclusions: We advocate for chromosome 1p loss being added as a criterion for a CNS WHO grade of 2 meningioma and addition of 1q gain as a criterion for a CNS WHO grade of 3.

Background: Meningiomas exhibit considerable heterogeneity. We previously identified four distinct molecular groups (immunogenic, NF2-wildtype, hypermetabolic, proliferative) which address much of this heterogeneity. Despite their utility, the stochasticity of clustering methods and the requirement of multi-omics data limits the potential for classifying cases in the clinical setting. Methods: Using an international cohort of 1698 meningiomas, we constructed and validated a machine learning-based molecular classifier using DNA methylation alone. Original and newly-predicted molecular groups were compared using DNA methylation, RNA sequencing, whole exome sequencing, and clinical outcomes. Results: Group-specific outcomes in the validation cohort were nearly identical to those originally described, with median PFS of 7.4 (4.9-Inf) years in hypermetabolic tumors and 2.5 (2.3-5.3) years in proliferative tumors (not reached in the other groups). Predicted NF2-wildtype cases had no NF2 mutations, and 51.4% had others mutations previously described in this group. RNA pathway analysis revealed upregulation of immune-related pathways in the immunogenic group, metabolic pathways in the hypermetabolic group and cell-cycle programs in the proliferative group. Bulk deconvolution similarly revealed enrichment of macrophages in immunogenic tumours and neoplastic cells in hypermetabolic/proliferative tumours. Conclusions: Our DNA methylation-based classifier faithfully recapitulates the biology and outcomes of the original molecular groups allowing for their widespread clinical implementation.

Background: The combination of PARP inhibitor and immune checkpoint inhibitors have been proposed as a potentially synergistic combinatorial treatment in IDH mutant glioma, targeting dysregulated homologous recombination repair pathways. This study analyzed the cell-free DNA methylome of patients in a phase 2 trial using the PARP inhibitor Olaparib and the PD-1 inhibitor Durvalumab. Methods: Patients with recurrent high-grade IDH-mutant gliomas were enrolled in a phase II open-label study (NCT03991832). Serum was collected at baseline and monthly and cell-free methylated DNA immunoprecipitation and high-throughput sequencing (cfMeDIP-seq) was performed. Binomial GLMnet models were developed and model performance was assessed using validation set data. Results: 29 patients were enrolled between 2020–2023. Patients received olaparib 300mg twice daily and durvalumab 1500mg IV every 4 weeks. The overall response rate was 10% via RANO criteria. 144 plasma samples were profiled with cfMeDIP-seq along with 30 healthy controls. The enriched circulating tumour DNA methylome during response periods exhibited a highly specific signature, accurately discriminating response versus failure (AUC 0.98 ± 0.03). Additionally, samples that were taken while on treatment were able to be discriminated from samples off therapy (AUC 0.74 ± 0.11). Conclusions: The cell-free plasma DNA methylome exhibits highly specific signatures that enable accurate prediction of response to therapy.

Background: Nipocalimab is a human IgG1 monoclonal antibody targeting FcRn that selectively reduces IgG levels without impacting antigen presentation, T- and B-cell functions. This study describes the effect of nipocalimab on vaccine response. Methods: Open-label, parallel, interventional study randomized participants 1:1 to receive intravenous 30mg/kg nipocalimab at Week0 and 15mg/kg at Week2 and Week4 (active) or no drug (control). On Day 3, participants received Tdap and PPSV®23 vaccinations and were followed through Wk16. Results: Twenty-nine participants completed the study and are included (active, n=15; control, n=14). Participants with a positive anti-tetanus IgG response was comparable between groups at Wk2 and Wk16, but lower at Wk4 (nipocalimab 3/15 [20%] vs control 7/14 [50%]; P=0.089). All maintained anti-tetanus IgG above the protective threshold (0.16IU/mL) through Wk16. While anti-pneumococcal-capsular-polysaccharide (PCP) IgG levels were lower during nipocalimab treatment, the percent increase from baseline at Wk2 and Wk16 was comparable between groups. Post-vaccination, anti-PCP IgG remained above 50mg/L and showed a 2-fold increase from baseline throughout the study in both groups. Nipocalimab co-administration with vaccines was safe and well-tolerated. Conclusions: These findings suggest that nipocalimab does not impact the development of an adequate IgG response to T-cell–dependent/independent vaccines and that nipocalimab-treated patients can follow recommended vaccination schedules.

Background: We’ve adopted a novel approach that combines cellular barcoding with CRISPR/Cas-9 technology and single-cell RNA sequencing known as continuous lineage tracing to track the development, treatment and inevitable recurrence of glioblastoma. Methods: Patient derived glioma initiating cell lines were engineered with expressed DNA barcodes with CRISPR/Cas-9 targets and engrafted into NOD scid-mice. Clonal and relationships are surmised through identification of expressed barcodes, and cells were characterized by their transcriptional profiles. Phylogenetic lineage trees are created using lineage reconstructive algorithms to define cell fitness and expansion. Results: Our work has revealed a significant amount of intra-clonal cell state heterogeneity, suggesting that tumour cells engage in phenotype switching prior to therapeutic intervention. Phylogenetic lineage trees allowed us to define a gene signature of cell fitness. GBMs exist along a transcriptional gradient between undifferentiated but “high-fit” cells and terminally differentiated, “low-fit” cells, lending further evidence that these tumours consist of pools of cells that are capable of recapitulating the tumour microenvironment after treatment. Conclusions: We have successfully engineered a set of glioma initiating tumours with a novel lineage tracing technique, creating a powerful tool for real-time tracing of tumour growth through the analysis of highly detailed singe-cell RNA sequencing data with associated clonal and phylogenetic relationships.

Improving neonatal piglet survival is a key driver for improving pig production and enhancing animal welfare. Gestational diabetes is a risk factor for neonatal morbidities in humans, such as hypoglycaemia and respiratory distress(1). There is limited knowledge on the association of gestational diabetes with neonatal survival in commercial pigs. An early study suggested that the diabetic condition of late-gestating sows was positively correlated with the first-week newborn piglet mortality(2). Genetic selection in recent decades for heavier birth weight may have increased the prevalence or severity of gestational diabetes in pigs, considering the positive correlation between gestational diabetes and birth weight. We hypothesised that the diabetic condition of late gestating sows positively correlates with the neonatal piglet mortality rate in sows with modern genetics. Mixed-parity sows (1.5 ± 1.6 parity for mean ± standard deviation (SD); Large White × Landrace) from a commercial piggery in Australia were randomly selected and participated in an oral glucose tolerance test (OGTT) during two seasons (118 sows in winter and 118 sows in summer). On the d109 day of gestation, sows were fed 3.0 g dextrose per kg of metabolic body weight after fasting overnight. Tail blood glucose concentrations were measured using a glucometer (Accu-Chek ®, Roche Diabetes Care Australia Pty) at −10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 105, 120 minutes relative to dextrose feeding. The glucose increment (2.5 ± 1.29 mM for mean ± SD) during OGTT was calculated using the maximum concentration substrating the fasting concentration of blood glucose. The 24-hour piglet mortality rate (5% ± 8.8% for mean ± SD) was calculated as the ratio between piglets that died during the first 24 hours and the total number of born alive on a litter basis. The effect of sow glucose increment, season (winter vs summer), glucose increment × season, number of piglets born alive, and sows parity on the 24-h piglet mortality rate as analysed using a Generalised Linear Model (SPSS 27th Version, IBM SPSS Statistics, Armonk). Results showed that the 24-hour piglet mortality rate was numerically higher in winter than in summer although insignificant (5.7% vs 4.2%, p = 0.41). The glucose increment of gestating sows was positively correlated with the 24-hour piglet mortality rate during winter but not summer, as evidenced by an interaction trend between glucose increment and season (p = 0.059). The regression coefficient suggested that every extra unit (mM) of glucose increment during OGTT corresponded to a 1.4% increase in the 24-hour piglet mortality rate in winter. In conclusion, the diabetic condition of late-gestating sows is a risk factor for neonatal piglet mortality in winter. Developing nutritional strategies to mitigate the diabetic condition of late-gestating sows may benefit neonatal piglet survival.

An experimental study is conducted to compare droplet generation in a deep-water plunging breaker in filtered tap water and in the presence of low and high bulk concentrations of the soluble surfactant Triton X-100. The breakers are generated by a programmable wave maker that is set with a single motion profile that produces a highly repeatable dispersively focused two-dimensional (2-D) wave packet with a central wavelength of $\lambda _0=1.18\,\rm m$. The droplets are measured with an in-line cinematic holographic system. It is found that the presence of surfactants significantly modifies the overall droplet number and the distributions of droplet diameter and velocity components produced by the four main droplet producing mechanisms of the breaker as identified by Erinin et al. ( J. Fluid Mech., vol. 967, 2023, p. A36). These modifications are due to both surfactant-induced changes in the flow structures that generate droplets and changes in the details of droplet production mechanisms in each flow structure.

Objectives/Goals: To evaluate equity in utilization of free initial health evaluation (IHE) services among members of a limited health care program, the World Trade Center (WTC) Health Program (Program), to inform intervention development and provide insights for similar healthcare programs. Methods/Study Population: We included Program members who newly enrolled during 2012–2022, and who had an IHE or were alive for ≥ 1 year after enrollment. Program administrative and surveillance data collected from January 2012 to February 2024 were used. We evaluated two outcomes: timely IHE utilization (proportion of members completing an IHE within 6 months of enrollment) and any IHE utilization (proportion completing an IHE by February 2024). We described IHE utilization by enrollment year and various members’ characteristics and conducted multivariable logistic regression models to estimate adjusted odds ratios for IHE utilizations to identify factors related to potential inequities for the two member types: Responders, who performed support services, vs. Survivors, who did not respond but were present in the New York disaster area. Results/Anticipated Results: A total of 27,379 Responders and 30,679 Survivors were included. Responders were 89% male, 70% 45–64 years old at enrollment and 76% White. Survivors were 46% female, 54% 45–64 years old at enrollment, and 57% White. Timely IHE utilizations remained relatively stable (~65%) among Responders across time and increased from 16% among Survivors who enrolled in 2017 to 68% among Survivors who enrolled in 2021. Timely IHE utilization was lower for younger members (enrolled Discussion/Significance of Impact: This study highlights Program achievements and gaps in providing equitable IHE services. Strategies to improve members’ equitable IHE utilization can include: adopt/expand flexible scheduling; increase non-English language capacity and cultural competency; and facilitate transportation/assistance for members with accessibility barriers.

Matching-adjusted indirect comparison (MAIC) has been increasingly applied in health technology assessments (HTA). By reweighting subjects from a trial with individual participant data (IPD) to match the summary statistics of covariates in another trial with aggregate data (AgD), MAIC enables a comparison of the interventions for the AgD trial population. However, when there are imbalances in effect modifiers with different magnitudes of modification across treatments, contradictory conclusions may arise if MAIC is performed with the IPD and AgD swapped between trials. This can lead to the “MAIC paradox,” where different entities reach opposing conclusions about which treatment is more effective, despite analyzing the same data. In this paper, we use synthetic data to illustrate this paradox and emphasize the importance of clearly defining the target population in HTA submissions. Additionally, we recommend making de-identified IPD available to HTA agencies, enabling further indirect comparisons that better reflect the overall population represented by both IPD and AgD trials, as well as other relevant target populations for policy decisions. This would help ensure more accurate and consistent assessments of comparative effectiveness.