Citations

Abstract Introduction: Src Family Kinases (SFKs) have a crucial role in tumor proliferation, survival, and metastasis. NXP900 is a highly selective SFK inhibitor with a novel mechanism of action that locks SFKs in a closed, inhibited conformation, providing sustained suppression of catalytic and non-catalytic functions, which is distinct from other SFK inhibitors like dasatinib. A phase I clinical trial of NXP900 in patients with advanced solid tumors is ongoing. Our preclinical studies showed therapeutic efficacy of NXP900 in cholangiocarcinoma (CCA) through decreased YAP, RAF-MAP and PI3K-AKT signaling. Multiomic profiling (RNA-seq, proteomics, phosphoproteomics) of CCA patient-derived xenografts implicated AKT pathway activation in primary NXP900 resistance. NXP900-resistant CCA cell lines generated via prolonged sublethal dose escalation showed a strong IL13RA2-AKT signature on multiomic analysis. Thus, we hypothesized that IL13RA2-AKT signaling was a mechanism of NXP900 resistance. We aimed to define this mechanism and demonstrate that the combinatorial targeting of IL13RA2 or AKT resensitizes to NXP900 treatment. Methods: HuCCT1 or HuCCT1-Resisant (HuCCT1-R) cells were injected bilaterally into the flanks of NOD/SCID mice and were allowed to grow for 3 months prior to tumor collection and analysis. Tumor engraftment and growth between HuCCT1 and HuCCT1-R groups were compared. To delineate the mechanisms for acquired NXP900 resistance, in-vitro treatment studies were performed using siRNAs targeting IL13RA2 as well as combination treatment with capivasertib, a pan-AKT inhibitor. Results: The HuCCT1-R cell line exhibited a higher rate of tumor engraftment and formed significantly larger tumors compared to the parental HuCCT1 cell line, indicating enhanced tumorigenic potential associated with acquired resistance. Silencing of IL13RA2 in HuCCT1-R cells resulted in pronounced reduction of cell proliferation and partially restored sensitivity to NXP900 treatment. Immunoblot analysis demonstrated a corresponding reduction in phosphorylated AKT (Thr308), consistent with suppression of downstream PI3K-AKT signaling. Furthermore, combination treatment of HuCCT1-R cells with the AKT inhibitor capivasertib, and NXP900 led to a significant increase in cell death and a greater inhibition in cell proliferation compared to either agent alone, indicating enhanced responsiveness and improved therapeutic efficacy. Conclusion: These findings confirm the central role of IL13RA2 signaling and the PI3K-AKT pathway in mediating acquired resistance to NXP900, consistent with our previous multiomics analysis. Importantly, this study identifies combination strategies that may be able to overcome NXP900 resistance, supporting the development of combinatorial approaches to restore therapeutic efficacy in resistant tumors. Citation Format: Shelby K. Yee, Hendrien Kuipers, Danielle M. Carlson, Jack W. Sample, Enis Ozmert, Hidemi Nishi, Erik Jessen, Dong-Gi Mun, Aushinie M. Abeynayake, Jennifer L. Tomlinson, Amro M. Abdelrahman, Nathan W. Werneburg, Binbin Li, Mitesh J. Borad, Mark J. Truty, Sumera I. Ilyas, Gregory J. Gores, Rory L. Smoot. Resistance to the SFK inhibitor NXP900 in cholangiocarcinoma is characterized by IL13RA2-AKT signaling and can be overcome by combination therapy [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 7124.

Abstract Approximately 288,000 men are diagnosed with prostate cancer (PCa) in the United States each year, with cases expected to double by 2040. While metastatic PCa can be treated with androgen deprivation therapy (ADT) and AR pathway inhibitors (ARPI), it inevitably develops into treatment resistant, lethal disease. The most common ARPI resistance mechanism in PCa is the expression of AR splice variant AR-V7 that lacks the ligand binding domain and is constitutively active. Patients with PCa expressing AR-V7 experience inferior overall survival. Speckle-type POZ protein (SPOP) is an adaptor protein of the Cullin3-based E3 ubiquitin ligase that facilitates both degradative and non-degradative polyubiquitination of targets such as AR. Loss-of-function SPOP mutations occur in approximately 10-15% of prostate cancers, and SPOP-mutant PCa is a unique subtype that has been shown to be exquisitely sensitive to ADT and ARPI treatment. This sensitivity is mediated in part by increased androgen availability via upregulation of hydroxysteroid 17-beta dehydrogenase 4 (HSD17B4) and related steroid synthesis pathways, reduced AR degradation, and enhanced AR cofactor activity. The remarkable efficacy of ARPI in ADT-resistant SPOP-mutant prostate cancer is not well understood. We hypothesized a novel mechanism by which wild-type SPOP promotes AR-V7-mediated resistance to ARPI in PCa. This mechanism may explain the exceptional ARPI sensitivity of SPOP-mutant PCa, distinct from its susceptibility to ADT. We further proposed that clinical SPOP inhibition may broaden this enhanced ARPI susceptibility to the 85-90% of PCa expressing wild-type SPOP. Our results show that SPOP drives ARPI resistance in prostate cancer that can be reversed by SPOP inhibitor. Bulk RNA sequencing showed that SPOP inhibitor targets spliceosome machinery and more importantly, abrogated AR-V7 expression both at transcriptional and protein level. Further investigation revealed that wild-type SPOP ubiquitinates spliceosome regulator SFPQ, promoting AR-V7 alternative splicing and ARPI resistance. While SPOP loss is pathogenic in PCa, leveraging the weakness conferred by SPOP mutation in the 85% of patients with SPOP-wild type provides an innovative strategy to sensitize ARPI resistant disease to standard of care treatment and save lives. Citation Format: Joanina K. Gicobi, Susanna M. Gregory, Nicole A. Becker, Elizabeth A. Bering, Jacob J. Orme.. SPOP drives AR-V7-mediated ARPI resistance in prostate 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 3904.

Abstract Prostate-specific membrane antigen (PSMA) is highly expressed in tumor-associated neovasculature in hepatocellular carcinoma (HCC), highlighting its promise as a theranostic target. This prospective study aimed to evaluate the utility of novel biomarkers derived from PSMA positron emission tomography computed tomography (PET/CT) to assess treatment response in advanced HCC patients (pts) receiving first line immune checkpoint inhibitors (ICI). Methods: This study (NCT05176223) enrolled unresectable, advanced HCC pts eligible for first-line ICI (atezolizumab/bevacizumab [A/B] or durvalumab/tremelimumab [D/T]) with measurable disease according to RECIST criteria. Primary endpoints: progression-free survival (PFS) per RECIST 1.1 and mRECIST; overall survival (OS); and best overall response. The survival distribution was estimated using the Kaplan-Meier method. Observed agreement is defined as the proportion of pts whose responses, as classified by PET/CT or CT, were concordant. Weighted kappa and Cohen’s kappa were used to quantify the strength of agreement between PET/CT and CT. Pts completed up to five 68Ga-PSMA PET/CT scans and blood collections. Results: Twenty-six pts were enrolled (25 evaluable) between Oct 2022 and Nov 2024. Median follow up was 22.1 months (m) (Q1, Q3: 14.5-23.7). Median age 68 yrs, 72% male, 88% White, 68% Child-Pugh [CP] A, 32% CP B, 32% Barcelona Clinic Liver Cancer [BCLC] stage B, 68% BCLC stage C, 36% with microvascular invasion; 56% received A/B and 40% received D/T treatment. PSMA was positive in 96% of pts at baseline with median SUVmax 14.3 (range 5.1-40.5) and median background liver SUVmax 3.9 (range 2.1-6.8). Median (95%CI) PFS was 5.6 m (4.6-12.5) by both RECIST and mRECIST. Median (95%CI) OS was 18.6 m (7.2-not estimable), with 56% deceased. The observed agreement between PET/CT adapted PERCIST criteria compared to RECIST and mRECIST in determining the best response was 46% and 50% and weighted kappa of 0.63 (95% CI: 0.37-0.90) and 0.66 (0.41-0.92), respectively. Observed agreement between PERCIST compared to RECIST and mRECIST for responders’ assessment was 67% and 71% with Cohen’s kappa of 0.36 (0.03-0.68) and 0.43 (0.11-0.76), respectively. Conclusion: In this cohort, PSMA PET/CT avidity was observed in all but one pt with advanced HCC, each demonstrating moderate to high SUVmax values. Median OS and PFS were consistent with outcomes reported in clinical trials. Response assessment using 68Ga-PSMA PET/CT according to PERCIST criteria showed good concordance with both RECIST and mRECIST standards. Analysis of immune biomarkers is ongoing. Citation Format: Nguyen H. Tran, Jacob Hirdler, Ajith Antony, Jacob Teske, Sudhakar K. Venkatesh, Amit Mahipal, Michael S. Torbenson, Scott M. Thompson, Thor R. Halfdanarson, Zhaohui Jin, Lionel Aurelien Kankeu Fonkoua, Leslie A. Washburn, Alexander Revzin, Haidong Dong, Robert R. Mcwilliams, Aminah Jatoi, Hani M. Babiker, Mitesh J. Borad, Tanios Bekaii-Saab, Gregory J. Gores, Lewis R. Roberts, Geoffrey B. Johnson, Ajit H. Goenka. Prospective evaluation of 68Ga-PSMA PET imaging in advanced hepatocellular carcinoma patients undergoing first line immunotherapy [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 2611.

Abstract Background: Personalizing chemoradiotherapy (chemoRT) for locally advanced non-small cell lung cancer (LA-NSCLC) is limited by the lack of early biomarkers that inform response during treatment. Current circulating tumor DNA (ctDNA) molecular residual disease assays predict post-treatment outcomes but lack mid-treatment utility. ctDNA burden estimation has traditionally relied on variant-centric metrics such as maximum variant allele fraction (Max VAF), which rely on mutation-specific signals and may be confounded by histology-dependent shedding variability, allelic imbalance, and clonal hematopoiesis. Here we present circulating tumor fraction estimate (ctFE), a machine-learning composite score that integrates VAF distributions, copy-number alterations, and germline B-allele frequency deviations to approximate global tumor burden using a widely available, tumor-naïve clinical platform. Methods: A burden-based ctFE threshold was derived using pre-treatment plasma from a prospective phase II clinical trial of MR-guided hypofractionated chemoRT (LA-WU, n=26), locked, and applied unchanged to early mid-treatment samples (day 10-14). To test scalability and generalizability, its prognostic performance was validated in two real-world cohorts: 94 LA-NSCLC patients receiving definitive chemoRT (LA-RW) and 309 oligometastatic NSCLC patients receiving consolidative RT (OM-RW). ctFE and Max VAF were compared as continuous predictors across cohorts. Results: ctFE consistently outperformed Max VAF. In LA-WU, pre-treatment ctFE was associated with overall survival (OS HR=1.15, p=0.04) and progression-free survival (PFS HR=1.84, p=0.009), whereas Max VAF was not. Mid-treatment ctFE remained prognostic for PFS (HR=1.14, p=0.026). Early ctFE dynamics defined three molecular response groups with marked OS separation: consistently low, responder, and nonresponder groups (median OS 60.8 vs 13.0 vs 2.9 months, respectively; p<0.001). In multivariable models including both biomarkers, higher ctFE remained independently associated with worse survival in LA-RW (OS HR=1.88, p=0.010) and OM-RW (OS HR=1.37, p=0.040; PFS HR=1.45, p=0.008), whereas Max VAF did not. The locked ctFE threshold stratified OS across all cohorts (LA-WU HR=5.93; LA-RW HR=9.08; OM-RW HR=2.26; all p<0.001). Conclusion: ctFE provides clinically meaningful pre- and mid-treatment risk stratification and consistently outperforms Max VAF across locally advanced and oligometastatic NSCLC cohorts. We show that ctFE is a biologically informative, clinically generalizable and scalable ctDNA burden metric measurable using a tumor-naïve, off-the-shelf assay, supporting its practical utility in biomarker-adapted radiotherapy strategies. Citation Format: Ayesha Hashmi, Jessica Linford, Pradeep S. Chauhan, Kaushal Parikh, Rotem Ben-Shachar, John Guittar, Malvika Pillai, Jyoti Patel, Matteo Bergsagel, Nicholas P. Semenkovich, Kenneth R. Olivier, Sean S. Park, Dawn Owen, David M. Routman, Katie N. Lee, Alex D. Sherry, Aaron S. Mansfield, Daniel Morgensztern, Ramaswamy Govindan, Clifford G. Robinson, Carmen Bergom, Saiama N. Waqar, Bruna Pellini Ferreira, Gregory R. Vlacich, Aadel A. Chaudhuri. Early ctDNA quantification by ctFE outperforms Max VAF for survival stratification across locally advanced and oligometastatic NSCLC treated with radiotherapy [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 1183.

Abstract Background: Cholangiocarcinoma (CCA) is a highly lethal epithelial cell malignancy of the hepatic biliary tract. Efficacy of current standard-of-care therapy is limited. Ferroptosis, an iron-catalyzed, caspase-independent cell death driven by phospholipid peroxidation, has emerged as a novel therapeutic target. Our goal is to develop a tumor-selective therapeutic approach targeting ferroptosis in CCA using siRNA-based nanotherapeutics. Materials & Methods: Milk-derived nanovesicles (lactosomes) coated with EpCAM aptamer and packaged with siRNA against Glutathione Peroxidase 4 (siGPX4-lactosomes) and Ferroptosis Suppressor Protein 1 (siFSP1-lactosomes), were used to induce ferroptosis in murine CCA cells (FAC) and in syngeneic liver orthotopic CCA-bearing mice. In vitro, lactosome uptake and efficacy were assessed by fluorescence-based, cell-viability and molecular biology assays. In vivo, target engagement, tissue distribution, safety and efficacy were assessed. Results: EpCAM (epithelial cell adhesion molecule expressed on CCA cells)-coated lactosomes showed robust uptake by FAC cells in a EpCAM-dependent manner. EpCAM knockdown via siRNA reduced lactosome uptake, confirming aptamer selectivity. Dose-dependent siGPX4/siFSP1-lactosome treatment led to GPX4/FSP1 knockdown and induced ferroptotic cell death in up to 60% of FAC cells after 72 hours (p<0.001 vs. siNC). In CCA-bearing mice, intravenous administration of siRNA lactosomes was well-tolerated with no liver or systemic toxicity observed and demonstrated robust tumor distribution compared to non-tumorous tissues. Efficacy studies demonstrated that siGPX4/siFSP1-lactosomes significantly reduced intratumor Gpx4 and FSP1 mRNA expression by 40-60% and induced significant upregulation of ferroptosis markers Ptgs2 and Acsl4 (p<0.01 vs. siNC). Ferroptosis in siRNA-lactosome treated tumors was confirmed by immunohistochemistry for phospholipid peroxidation markers oxPAPC and 4-HNE. Additionally, proliferation marker Ki67 was significantly downregulated in siGPX4/siFSP1-lactosome treated tumors (p<0.05 vs. siNC), indicating ferroptosis-mediated tumor suppression. Importantly, siGPX4/siFSP1-lactosomes reduced tumor burden and expression of CCA markers CK19/7 in treated mice, as compared to control mice. Conclusions: siRNA-based nanotherapeutics targeting CCA can effectively and safely induce ferroptosis in vitro and in vivo, representing a potential therapeutic strategy for CCA treatment. Citation Format: Peyton Classon, Danielle Marie Carlson, Jayla Millender, Irene Yan, Sumera Ilyas, Rory L. Smoot, TUSHAR PATEL, Gregory J. Gores, Davide Povero. Targeting cholangiocarcinoma with ferroptosis-inducing siRNA-based nanotherapeutics [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 5664.

Introduction/Objectives: House call programs provide care for homebound patients. We conducted a case-control study to compare hospitalization and/or emergency department (ED) use by patients enrolled in a primary care house call program versus ambulatory (community-dwelling) patients. Methods: Program enrollees (cases) were matched by age and self-reported gender to community-dwelling patients (controls). The primary exposure was the combination of hospitalization and/or ED visits for 1 year before the index date (October 1, 2024). We used unadjusted and adjusted conditional logistic regression to determine differences in health care use. Results: We identified 26 cases (median [range] age, 84 [66-98] years; 16 [62%] female) and 130 controls. All cases had 4 or more chronic diseases, as compared with 87 (67%) of controls ( P = .003). A higher proportion of cases than controls had previous hospitalization and/or ED visits (84.6% vs 27.7%; P < .001). After adjusting for the number of chronic illnesses, no differences in previous hospitalization and/or ED use were identified between groups. Conclusions: Cases had more chronic illnesses and more hospitalizations and/or ED visits than community-dwelling controls. The comorbid health burden of participants in the house call program drove greater health care use and justifies a higher level of care for this medically complex patient population.

ABSTRACT BACKGROUND Increasing evidence suggests that accurate prediction of Alzheimer’s disease (AD) symptom onset requires more than amyloid- and tau-centric biomarkers such as cerebrospinal fluid (CSF) Aβ42/40, total tau and p-tau181 and plasma p-tau217. Autosomal dominant AD (ADAD), caused by pathogenic PSEN1, PSEN2 and APP mutations with predictable age at symptom onset, presents a unique opportunity to characterize the chronological changes in proteins beyond amyloid and tau and clarify them as early biomarkers of disease onset or as biomarkers related to disease staging and progression monitoring. METHODS We measured 972 CSF samples corresponding to 484 participants of the Dominantly Inherited Alzheimer Disease Network (DIAN) using the NULISASeq 120 CNS Disease Panel. We first benchmarked the technology against gold-standard measurements followed by the identification of proteins that were differentially abundant in relation to mutation status and symptomatology. Next, we determined the chronological emergence of protein changes in relation to the estimated years to onset (EYO). Finally, we assessed whether specific protein measures improved the prediction of EYO in the ADAD. FINDINGS NULISA measurements were comparable to those previously published. We demonstrated that known early alterations in CSF amyloid and tau were followed by inflammatory and neurodegenerative responses suggesting that clinical manifestation of AD happens before the inflammatory processes is fully developed. Finally, we found a multi-protein composite approach for predicting EYO that outperformed single biomarker values. INTERPRETATION Our results suggest that the main CSF proteomic landscape changes in ADAD are due to the presence of a pathogenic mutation and occur prior to symptom onset. Improved performance of multi-protein composite to predict EYO compared to single biomarker values highlights the added value of multiplex proteomic signatures for biomarker panel development. FUNDING National Institute on Aging, Alzheimer’s Association, German Center for Neurodegenerative Diseases, Raul Carrea Institute for Neurological Research, Japan Agency for Medical Research and Development, Ministry of Health & Welfare and Ministry of Science and ICT, Republic of Korea, Spanish Institute of Health Carlos III.

Background: Patients with primary sclerosing cholangitis (PSC) are at risk for developing gallbladder neoplasia (GBN) and biliary neoplasia, including cholangiocarcinoma (CCA), because of chronic inflammation and an underlying field effect. However, the risk of CCA after GBN detection in those with PSC remains poorly understood. We aimed to determine if the incidence of CCA is higher in those with GBN. Methods: We conducted a retrospective review of adult patients with large-duct PSC seen at Mayo Clinic between January 1, 1995, and December 31, 2019. Incidence rates for CCA development were calculated. Cox regression analyses were performed to determine features associated with CCA development beginning at the time of PSC diagnosis. Results: Our study included 1,829 patients with PSC. CCA and GBN developed in 334 (18.26%) and 71 individuals (3.88%), respectively. Among those with GBN, 14 (19.72%) developed CCA. The annual incidence of CCA was nearly twofold higher in patients with GBN (4.34% versus 2.21%). GBN was associated with CCA in an unadjusted analysis (hazard ratio 2.14 [95% CI 1.16–3.94]). When adjusting for other predictors of CCA, an association between GBN and CCA may remain. Conclusions: While few patients with PSC develop GBN, this subgroup is more likely to develop CCA. Consequently, once GBN is detected, clinicians should consider more intensive screening for CCA.

Objectives: To assess how social risk factors and socioeconomic status (SES) affect health care costs at a large, integrated health system of 45 clinics in Iowa, Minnesota, and Wisconsin. Methods: We retrospectively reviewed administrative patient cost data from January 1 through December 31, 2022. Social risk factors (lack of financial resources, food insecurity, intimate partner violence, unmet transportation needs, and housing instability) were determined with patient questionnaires. Cost z -scores were compared across all risk-factor quartiles. We used a housing-based measure to objectively determine SES. Results: We analyzed data from 410 624 patients empaneled with 689 family medicine clinicians. Self-reported risk factor data were incomplete for 219 321 patients. Costs were higher for those with higher social risk (mean cost z -score: high risk = 0.38, low risk = 0.11; P < .001). In addition, higher costs were associated with increasing age, greater medical complexity (higher Adjusted Clinical Group scores), White race, and lack of financial resources. Although we observed geographic variations in cost, urban and rural locations did not have significant cost differences. Costs were similar across all quartiles of SES, and the absolute difference in cost z -scores between the highest and lowest SES quartiles was only 0.04. The multivariate analysis, which adjusted for age, medical complexity, race, sex, and objective SES, showed that these specific associations were substantially decreased and no longer significantly associated with mean cost z -scores. Conclusions: Patient-reported social risk factors were significantly associated with increased cost of care in a large, multispecialty health system in the midwestern US. These associations were decreased in the multivariate analysis. Results should be interpreted cautiously for readers outside the midwestern US, given potential responder bias and the racial homogeneity (92% White) of the study cohort.

Abstract INTRODUCTION Visual perceptual difficulties occur in dementia with Lewy bodies (DLB). Normative data and cut scores for DLB and mild cognitive impairment with Lewy bodies (MCI‐LB) are needed for the 20‐item Noise Pareidolia Task. METHODS Participants included 344 cognitively unimpaired (CU), 112 DLB, and 105 MCI‐LB. Cumulative percentile ranking was used for normative classification. Receiver operating characteristic analyses, convergent validity, and associations with visual hallucinations (VH) were assessed. RESULTS In CU participants, a perfect score was average, one error was low average, and two or more errors fell below average. A cut score of one or more errors optimally distinguished CU participants from DLB (Total score area under the curve [AUC]: 0.82, Noise score AUC: 0.77) and MCI‐LB (Total score AUC: 0.75, Noise score AUC: 0.74). A cut score of two or more errors lowered sensitivity but increased specificity to 94%. Performance was associated with VH in DLB, but not MCI‐LB. DISCUSSION Results establish normative data for the 20‐item Noise Pareidolia Task and support its use in DLB and MCI‐LB.