Citations

Background: Diffuse axonal brain injury (DABI) is a major component of traumatic brain injury, but the optimal timing of magnetic resonance imaging and histologic assessment after isolated DABI remains unclear. Because each method captures a different phase of injury, defining time-dependent diagnostic windows may improve experimental design and reduce animal use. Methods: Sixty-four Sprague-Dawley rats were randomized to moderate DABI or sham operation. Neurological Severity Score (NSS), 3 T diffusion tensor imaging (DTI), and histologic assessment were performed at early and late time points. Hippocampal fractional anisotropy (FA) was measured at 48 h and 1 month. β-amyloid precursor protein (β-APP) immunohistochemistry assessed acute axonal injury at 48 h, and hematoxylin and eosin (H&E) staining quantified hippocampal neuronal density at 1 month. Results: At 48 h, DABI rats had higher NSS, lower hippocampal FA, and greater β-APP-positive axonal accumulation than sham-operated rats. By 1 month, NSS and hippocampal FA no longer differed between groups, whereas hippocampal neuronal density remained significantly reduced in DABI rats, indicating persistent structural injury. Conclusions: In this rat model of isolated DABI, hippocampal FA and β-APP immunohistochemistry identified acute axonal pathology at 48 h, whereas conventional histology detected a persistent reduction in neuronal density at 1 month. These findings support a time-optimized diagnostic strategy using early DTI for noninvasive injury detection and late histology for long-term structural assessment.

Abstract Deep mutational scanning (DMS) has proven effective for mapping protein–protein interactions (PPIs), but it cannot provide complete coverage of the mutation landscape, particularly for multi‐mutant variants. To address this limitation, we trained machine‐learning (ML) models on previously generated DMS data for a stabilized amyloid precursor protein inhibitor (APPI) binding to either of two serine proteases, mesotrypsin and kallikrein‐6 (KLK6), which are implicated in various human disorders. We combined the models to accurately predict the binding selectivity of APPI variants, including double‐mutant variants, for the two serine proteases. We achieved a Pearson correlation of 0.937 between predicted log 2 selectivity enrichment ratios and DMS‐derived values. We further validated the predictions of our combined model by yeast‐surface‐display measurements and inhibition assays of purified APPI variants and revealed epistatic interactions that shape protease selectivity. Guided by binding selectivity predictions, we identified highly selective APPI variants, including the most selective mesotrypsin inhibitor reported to date. Together, these findings support the use of DMS and ML as a framework for predicting PPI selectivity and prioritizing selective therapeutic protein variants.

Importance Currently, there are no standardized outcome domains or measures in clinical trials for facial aging. Heterogeneity in outcome domains and measurement instruments across clinical trials creates difficulty in directly comparing interventions, determining superior therapies, and developing high-quality meta-analyses. Objective To develop a core outcome set (COS) of essential domains to be reported in clinical trials evaluating the efficacy of interventions for facial aging. Evidence Review PubMed/Medline, Embase, Cochrane Central Register of Controlled Trials, and CINAHL were searched from September 2005 to September 2015. An updated search of the same databases was performed from September 2015 to February 2026. Studies were included if (1) they were randomized clinical trial or controlled clinical trial in design, (2) they assessed the efficacy or safety of an intervention for facial aging, (3) they were published in English, and (4) they involved human participants. Complementary sources, including patient interviews, were used to capture further relevant outcomes. Two rounds of Delphi surveys, followed by consensus meetings, were used to identify outcome domains considered most important by both patient and physician stakeholders. Findings The final COS consists of 6 outcome domains: (1) overall convenience of treatment; (2) time to return to normal work and social activity; (3) overall assessment of focused area of treatment (at the point in time when treatment is expected to provide peak benefit); (4) duration of treatment effect; (5) severity of persistent local or systemic adverse events, including pigmentary change, skin texture change, delayed healing, scarring, and serious adverse events; and (6) patient satisfaction with treatment. Conclusions and Relevance The 6 outcome domains identified through a Delphi consensus are recommended for reporting in future facial aging trials to ensure that outcomes that matter most to patients and clinicians are measured and that results are comparable across interventions.

5624 Background: Endometrial cancer (EC) is the most common gynecologic cancer and abnormal uterine bleeding (AUB) is the predominant presenting symptom. While <10% of AUB represents underlying EC, endometrial sampling is currently required to rule out EC. To develop an alternative, non-invasive rule-out strategy, we aimed to refine a previously reported EC-associated methylated DNA marker (MDM) panel in vaginal swabs. Methods: Patients ≥18 years old with AUB who met ACOG recommendations for endometrial sampling and those undergoing a hysterectomy for biopsy-proven EC or atypical hyperplasia (AH) were prospectively enrolled in a multicenter cohort study. A vaginal fluid specimen was collected via swab by a provider during a speculum exam. DNA was extracted from samples and bisulfite treated, followed by a target and signal amplification method to detect 8 previously identified MDMs. The cross-validated EC classification model used the mean of standardized MDMs. Clinical classification of benign endometrium (BE), EC, and AH was based on central pathology review. EC diagnoses were based on hysterectomy specimens. Endometrioid and mucinous constituted type 1 EC; serous, carcinosarcoma, clear cell, and mixed histology ECs were collectively analyzed as type 2. Results: Of 693 participants enrolled, 670 were evaluable with valid results: 524 in the AUB cohort and 146 in the suspected EC cohort. Within the AUB cohort, 16 had EC or AH. The final analysis cohort included 508 BE, 156 EC, and 6 AH. Of the evaluable participants 20% identified as Black, 3% Asian or Pacific Islander, 75% White, and 3% Other; 7% reported Hispanic ethnicity. Median age was 66 and 50 years for EC and BE AUB, respectively; 80% of those with EC and 43% with benign AUB reported being postmenopausal. Among participants with EC, 102 (65%), 17 (11%), 30 (19%), 6 (4%) were stage I, II, III, and IV, respectively; one EC was unstaged. Type 2 EC accounted for 42 (27%) of all EC cases. A 4-MDM panel yielded an AUC of 0.97 (0.96-0.99, 95% CI) for EC; models with 5-8 MDMs gave identical performance. All-stage EC sensitivity was 97, 97, 96, 95, and 92% at specificities ranging from 75, 80, 85, 90, and 95%, respectively. At the 85% (82-88%) specificity threshold, sensitivities across EC stage, type, and age were consistently high (Table). Sensitivity for AH was 33% (10-70%). Conclusions: An MDM panel demonstrated high sensitivity for EC across stage and EC type, supporting the potential for a non-invasive vaginal swab-based test to rule out EC. Future studies are necessary to finalize the panel and algorithm, prior to validating the test. Clinical trial information: NCT06294886 . EC Sensitivity (%, 95% CI) at 85% Specificity All Stages (n=156)* 96 (92-98) Stage I (n=102) 94 (88 - 97) II (n=17) 100 (82 - 100) III (n=30) 100 (89 - 100) IV (n=6) 100 (61 - 100) Type 1 (n=114) 95 (89 - 98) 2 (n=42) 100 (92 -100) Age ≤ 66 yrs (n=86) 95 (89 - 98) > 66 (n=70) 97 (90 - 99) *n=1 EC was un-staged.

OBJECTIVE Craniopharyngiomas are benign intracranial tumors that can be difficult to manage operatively and often result in postoperative complications and prolonged recovery. Understanding the factors that influence length of stay (LOS), discharge disposition, and readmission can guide perioperative planning and patient counseling. The authors examined the clinical, radiographic, and surgical predictors of extended LOS (eLOS), nonhome discharge, 90-day readmission, and hospitalization ratio (HR) after craniopharyngioma resection using a large, multicenter cohort. METHODS A retrospective analysis was conducted using the Registry of Adenomas of the Pituitary and Related Disorders database, encompassing 469 patients who underwent craniopharyngioma resection at 14 US academic centers from 2011 to 2025. Patients were stratified by 4 outcomes: eLOS (> 75th percentile), discharge to home versus skilled nursing facility/rehabilitation, 90-day hospital readmission, and hospitalization ratio (i.e., integration of initial and readmission LOS). Multivariable logistic regression models identified independent predictors for each outcome among patient and surgical variables. RESULTS An eLOS (> 10 days) was independently associated with preoperative memory loss (OR 3.75, 95% CI 1.95–7.21), gait imbalance (OR 5.90, 95% CI 1.53–22.70), and postoperative complications (OR 4.07, 95% CI 2.34–7.06). The use of a nasoseptal flap was protective against an eLOS (OR 0.52, 95% CI 0.28–0.93). Discharge to home was predicted by an endoscopic approach (OR 3.87, 95% CI 1.78–8.44) and postoperative intact thirst (OR 2.22, 95% CI 1.05–4.66) and negatively predicted by preoperative diabetes mellitus (OR 0.21, 95% CI 0.09–0.50), LOS (OR 0.87, 95% CI 0.84–0.91), and postoperative cognitive dysfunction (OR 0.30, 95% CI 0.13–0.72). Among 385 patients with follow-up data, a 90-day readmission was independently associated with postoperative complications (OR 5.62, 95% CI 3.12–10.13), preexisting coronary artery disease (OR 4.30, 95% CI 1.46–12.69), and postoperative cognitive dysfunction (OR 3.33, 95% CI 1.76–6.44). A higher HR was associated with diabetes mellitus (unstandardized B 0.059, 95% CI 0.010–0.108, p = 0.02), postoperative complications (unstandardized B 0.054, 95% CI 0.021–0.086, p = 0.001), and postoperative cognitive dysfunction (unstandardized B 0.049, 95% CI 0.006–0.092, p = 0.02). Tumor pathologic subtype and size, prior treatment, extent of resection, and surgeon experience were not directly predictive of outcomes. CONCLUSIONS Cognitive and functional status, systemic comorbidities, and postoperative complications, in addition to surgical approach, are important predictors of the early clinical course after craniopharyngioma surgery. Early identification of high-risk patients may help to guide treatment decisions, improve discharge planning, and reduce healthcare utilization.

BACKGROUND AND OBJECTIVES: Craniopharyngiomas are complex intracranial tumors that pose significant challenges in surgical management. We aimed to develop risk-stratified surgical outcome benchmarks for adult patients undergoing endoscopic craniopharyngioma resection by using the Registry of Adenomas of the Pituitary and Related Disorders database to facilitate comparisons across institutions and guide clinical decision-making. METHODS: A retrospective cohort of adult patients (18 years and older) with craniopharyngioma undergoing a first-time endoscopic transnasal surgery across 14 academic centers in the United States was analyzed using data collected from 2011 to 2024. Patients were stratified into low-risk and high-risk cohorts based on criteria including age, body mass index, selected tumor characteristics (size, infundibular relationship, intraventricular extension), and previous radiation. Surgical outcomes were analyzed, and benchmarking ranges were defined using the established methodology. RESULTS: The overall cohort included 318 patients with a mean age of 50 years. Upon benchmarking analysis (50th-75th percentile performance), low-risk patients (n = 136) had a median length of stay of 4.0 to 6.0 days, 90-day readmission rates of 15.5% to 22.2%, skilled nursing facility discharge rates of <1.0%, postoperative cerebrospinal fluid leak incidence of <1.0% to 14.3%, gross total resection rates of 50.0% to 60.8%, new postoperative arginine vasopressin deficiency rates of 33.3% to 50.0%, and tumor progression/recurrence rates of <1.0% to 18.3% over a median follow-up period of 27.0 (IQR 10.5-56.5) months. Benchmarking ranges were proposed for each outcome to facilitate cross-institutional comparisons. CONCLUSION: Establishing surgical outcome benchmarks for adult patients undergoing craniopharyngioma resection using data from the Registry of Adenomas of the Pituitary and Related Disorders provides a framework for assessing surgical performance and guiding clinical decision-making. Benchmark ranges can inform institutional quality improvement efforts, perioperative risk stratification, and patient counseling regarding expected postoperative outcomes.

Abstract Background: Pyrimidine synthesis is a therapeutic vulnerability in cancer but inhibition results in toxicity to normal cells. Differential targeting of CTP synthase 1 (CTPS1), sparing the CTPS2 isoenzyme, is a therapeutic strategy in lymphoid cancers, supported by human genetic studies, that can potentially avoid toxicity; however, CTPS2 activity may compensate in epithelial tumours. Loss of CTPS2 protein expression characterises 25% of solid tumours and is predicted to expose a synthetic lethal vulnerability to CTPS1 inhibition. Dencatistat (STP938) is a first in class oral CTPS1 inhibitor showing &gt;1,300-fold selectivity over CTPS2. In preclinical studies, CTPS2 expression was confirmed as a key modulator of response to CTPS1 inhibition, and dencatistat induced tumour regression in an in vivo model of CTPS2 negative ovarian cancer. Study design: The study comprises a standard 3+3 phase 1a dose escalation design, in which intra-patient dose escalation is encouraged, followed by a phase 1b safety expansion. The dose escalation study is recruiting participants with high grade advanced tumours who have exhausted standard of care therapy (excluding haematological cancers, salivary gland tumours and low grade tumours of any tissue). In addition, participants with high grade serous ovarian cancer whose tumours lack expression of CTPS2 (per central laboratory testing by immunohistochemistry) are eligible for backfill into cleared cohorts during dose escalation. The recommended phase 2 dose (RP2D) will be nominated based on safety, tolerability, target engagement and early signs of clinical efficacy. The phase 1b safety expansion study will recruit participants with CTPS2 negative ovarian, lung or endometrial cancer who will receive treatment at the RP2D. Standard inclusion criteria apply; patients with ECOG performance score &gt;2 (&gt;1 for phase 1a in France) or active/symptomatic CNS metastases are not eligible. The primary objectives of the study are to evaluate the safety and tolerability of single agent dencatistat and to determine the RP2D for further development. Secondary objectives comprise evaluation of pharmacokinetic properties and preliminary clinical activity. Exploratory endpoints include evaluation of target engagement, molecular features associated with response, and determination of drug metabolites. The study opened to enrolment in the UK, France and USA in September 2024 and is currently in dose escalation (NCT06297525). The phase 1b study is expected to commence mid-2026 and will include additional centres in Spain. Citation Format: Donna M. Graham, David Sommerhalder, Douglas Orr, Rowan Miller, Neeharika Makani, David O'Malley, Ira Winer, Philip A. Beer, Karen Smith, Maureen Higgins, John R. Hawse, Xiyin Wang, Saravut J. Weroha, Christophe Massard, Patricia Roxburgh. Lack of CTPS2 expression exposes synthetic lethal vulnerability to selective CTPS1 inhibition: A phase 1 dose escalation study of dencatistat (STP938) with safety expansion in biomarker selected cohorts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr CT075.

Abstract Purpose: This multicenter, multi-surgeon retrospective study aimed to identify risk factors for postoperative cerebrospinal fluid (CSF) leak following endonasal resection of craniopharyngioma, while evaluating the "perception gap" through a surgeon survey. Methods: A retrospective review was conducted on 416 patients who underwent endoscopic transsphenoidal surgery (ETS) for craniopharyngioma from 20 institutions. Factors were compared between patients with and without postoperative CSF leak, and between Early (2007-2015) and Late (2016-2025) Epochs. Complementing the clinical data, a survey of 19 neurosurgeons captured expert perspectives on risk stratification and management strategies. Results: Overall postoperative CSF leak rate was 13.5% (56/416 patients). Univariate analysis identified predominantly cystic tumors (34% vs. 21%, p = 0.034)and intraoperative lumbar drain (LD) use ( p < 0.028) as associated with postoperative CSF leak. BMI ( p = 0.587), prior surgery ( p = 0.576), and tumor size ( p = 0.363) were not significant. In the multivariable analysis, LD use was associated with a higher postoperative CSF leak rate (OR 1.91, 95% CI 1.06–3.46; p = 0.030). Between Epochs, nasoseptal flap (NSF) utilization increased from 70.7% to 87.6% ( p <0.001). NSF was protective (OR 0.28, 95% CI 0.07–0.92; p = 0.037) in the Early Epoch; no factors were significant in the Late Epoch. The surgeons’ survey identified prior surgery and intraoperative high flow leaks as primary risks; however, their LD protocols diverged from clinical data. Conclusion: Despite increased use of NSF, CSF leak persists. The study highlights a significant divergence between expert perception and clinical data regarding lumbar drains.

Abstract Breast and ovarian cancers are major causes of cancer mortality in women with frequent relapse after curative intent treatment, underscoring the need for novel therapeutics. To this end, we identified CTPS1 as an essential gene in multiple breast and ovarian cancer models, including those resistant to chemotherapy and PARP inhibitors. CTPS1 and CTPS2 are responsible for de novo synthesis of cytidine triphosphate (CTP) which is required for DNA/RNA polymerization, phospholipid synthesis and protein glycosylation. We found CTPS1 to be the predominant isoform expressed in cancer cells, with significantly higher levels in advanced and resistant disease models compared to normal tissue, benign lesions and treatment naïve cancers. Using CTPS1 siRNAs and CTPS1-dTAG (degradation tag) cell lines, we discovered that depletion of CTPS1 induces S-phase cell cycle arrest followed by apoptosis. Leveraging a first-in-class, highly selective, and orally bioavailable CTPS1 inhibitor (STP938) developed by Step Pharma, we identified nanomolar IC50 values across a panel of cell lines, both in 2D and 3D culture systems, and potent anti-neoplastic activity ex vivo and in vivo using patient-derived xenograft (PDX) models. STP938 also synergized with standard-of-care chemotherapy agents and PARP inhibitors, including in therapy-resistant models. Given the essentiality of CTP for biosynthetic processes, we performed bulk and single cell RNA-seq, total and phospho-proteomics, metabolomics, and lipidomic strategies to examine changes induced by acute and chronic STP938 exposure. This revealed that cancer cells are able to overcome pharmacologic CTPS1 inhibition by rewiring of pyrimidine and purine synthesis pathways, upregulation of the pentose phosphate pathway, and extensive remodeling of lipid synthesis pathways including shifts in PC/PE content, increased lysophospholipid production, and altered mitochondrial lipid composition (decreased cardiolipin and increased PG). To identify genetic drivers of STP938 resistance and synthetic lethal vulnerabilities, we performed a genome-wide CRISPR knockout screen together with a PRISM drug sensitivity screen. Genes regulating dNTP biosynthesis, S-phase progression, and RNA processing were identified as primary escape mechanisms, while DHODH inhibitors, purine and nucleoside analogs, and mitosis modifiers were implicated as synthetic lethal opportunities. Notably, we discovered that 25% of ovarian tumors lack CTPS2 protein expression, suggesting near complete reliance on CTPS1 for survival. Thus, a Phase 1a/b clinical trial of STP938 (NCT06297525) has been initiated, including an expansion cohort for patients with CTPS2-null ovarian tumors. These laboratory discoveries and ongoing clinical efforts aim to enable broader uptake of this novel therapeutic approach to improve long-term outcomes in patients with CTPS1-dependent disease. Citation Format: Xiyin Wang, Michael Emch, Lauren Voll, Rebecca Epp, Esther Rodman, Noa Odell, Hannah Smith, Nicole Pearson, Xiaonan Hou, Matthew Goetz, Scott Kaufmann, S. John Weroha, Phillip Beer, John Hawse. CTPS1 as a metabolic vulnerability and novel therapeutic target in breast and ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 4560.