Truty, Mark J.

Abstract Introduction: Src Family Kinases (SFKs) have a crucial role in tumor proliferation, survival, and metastasis. NXP900 is a highly selective SFK inhibitor a novel mechanism of action that locks SFKs in a closed, inhibited conformation, preventing interaction with substrate proteins, unlike other SFK inhibitors like dasatinib. A phase 1 study of NXP900 in patients with advanced solid tumors was recently initiated. Our preclinical studies showed therapeutic efficacy of NXP900 in cholangiocarcinoma (CCA) through decreased YAP, RAF-MAP and PI3K-AKT signaling. Here, we examined mechanisms of sensitivity and resistance to SFK inhibition. Methods: Secondary resistance was explored by generating a NXP900-resistant human cell line (HuCCT1-R) via prolonged exposure to NXP900, followed by multiomic profiling. Primary resistance was studied in vivo using nine heterogeneous patient-derived xenograft (PDX) tumors implanted in the flanks of NOD/SCID mice. Tumor-bearing mice were treated with vehicle or 40 mg/kg NXP900 daily for up to 4 weeks. To identify factors associated with response, a multiomic approach was used, integrating RNA-Seq, global proteomics, and phosphoproteomics. A hierarchical-all-against-all algorithm (HallA) assessed associations between multiomic features and drug response in tumor growth. Kinase enrichment analysis (KEA3) identified features linked to sensitivity or resistance. Results: HuCCT1-R cells showed increased pTyr abundancy of TNK2, a protein known to increase PIP3 levels leading to AKT activation, and of DYRK3 and LAMTOR1, both of which can sustain AKT phosphorylation via mTORC, indicating acquired resistance through bypassing inhibited PI3K-AKT signaling to rescue AKT. NXP900 reduced tumor growth rates in 5 of 9 PDX models. Kinases associated with sensitivity in the PDX models included SFKs (SRC, LYN, and FYN), and AKT, PTK2, PRKCZ, EGFR, SYK, and GSK3B, suggesting involvement of the PI3K-AKT pathway in responsiveness to NXP900. Based on tumor inhibition responses in the tested models, we estimated NXP900 response for our additional PDX models, predicting 39% (11/28) of patient tumors may respond. Conclusion: This study identified molecular markers linked to response to SFK inhibition, which could be utilized for patient selection for NXP900 treatment. Further studies are validating these findings and exploring combination therapies to address resistance mechanisms. Citation Format: Hendrien Kuipers, Danielle M. Carlson, Jack W. Sample, 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. Multiomic profiling identified biomarkers of response to selective Src family kinase inhibition in preclinical models of cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5595.

Abstract Given the heterogeneous clinical behavior of pancreatic neuroendocrine tumors (pNETs), improved prognostic markers are needed to guide management and post‐resection surveillance. Patients who underwent resection of large (≥3 cm) sporadic well‐differentiated pNETs from 2000 to 2019 were identified. The Ki‐67 proliferation index was determined using immunohistochemistry, and alternative lengthening of telomeres (ALT) status was assessed using fluorescence in situ hybridization. Recurrence‐free and overall survival were estimated using Kaplan–Meier analysis. Multivariable Cox regression analysis evaluated factors associated with recurrence‐free survival. A total of 106 patients were identified. ALT was positive in 57 (54%) and negative in 49 (46%). Ki‐67 was ≥3% in 74 (70%) and <3% in 32 (30%). Tumors with Ki‐67 ≥3% were more likely to be ALT positive (61% vs. 38%, p = .046). Stratifying by ALT status and Ki‐67 proliferation index, median recurrence‐free survival was 4.6 years for patients with ALT‐positive/Ki‐67 ≥3% tumors, 3.1 years for patients with ALT‐positive/Ki‐67 <3% tumors, 12.4 years for patients with ALT‐negative/Ki‐67 ≥3% tumors, and 20.2 years for patients with ALT‐negative/Ki‐67 <3% tumors ( p < .001). Initial recurrence was distant in 82% and locoregional in 18%. Across all groups, overall survival was similar ( p = .19). In multivariable analysis, advanced age, ALT positivity, perineural invasion, and lymph node metastases were associated with increased recurrence risk (all p < .05). ALT and Ki‐67 provide complementary information on post‐resection recurrence risk, which can guide subsequent surveillance and management strategies. These data support the incorporation of ALT testing into routine clinical practice.

Background Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer with a 5-year survival rate of 12%. It has two major molecular subtypes: classical and basal, regulated by the master transcription factors (MTFs) GATA6 and ΔNp63, respectively. Objective This study sought to uncover the transcriptional regulatory mechanisms controlling PDAC subtype identity. Design We integrated primary tumour single-cell RNA-seq, patient-derived xenograft RNA-seq and multispectral imaging to identify MTF-dependent, subtype-specific markers. We created subtype-specific fluorescent reporter systems and conducted drug screenings to find actionable targets. We analysed chromatin accessibility (ATAC-seq), genome-wide occupancy (ChIP-seq) for epigenetic status (H3K27ac), MTFs (GATA6, ΔNp63), RNA polymerase II (Pol II), H3K4me3-anchored chromatin topology (HiChIP) and nascent RNA capture sequencing (PRO-seq). Additionally, we used nuclease-dead Cas9 (dCas9) to manipulate transcriptional regulatory mechanisms. Results Our approach identified glucocorticoid receptor (GR) agonists as agents that suppress the classical transcriptional programme by interacting with GATA6. GATA6 regulates classical-specific transcription through promoter-proximal pause release. Depletion of GATA6 increased Pol II occupancy at GATA6-bound enhancers and transcriptional start sites, stabilising enhancer–promoter interactions. Artificially inducing pausing at GATA6-bound enhancers with dCas9 abrogated target gene expression and induced pausing at both the enhancer and target gene promoter. Conversely, in basal PDAC ΔNp63 promotes Pol II recruitment and stabilises enhancer–promoter interactions. Conclusion This study provides new insights into the transcriptional control and role of GR agonists in controlling PDAC molecular subtype identity.

Abstract Background Atezolizumab plus bevacizumab (A/B) received FDA approval as the first-line therapy for patients with advanced hepatocellular carcinoma (HCC) in 2020. However, optimal subsequent treatment options are unclear. Here, we describe clinical outcomes of advanced HCC patients following first-line treatment with A/B. Patients and Methods We conducted a multi-site analysis of patients with HCC treated with first-line A/B between January 2018 and December 2022 at Mayo Clinic. This study cohort included all patients receiving second-line systemic therapy after A/B. Median overall survival (OS) and time-to-treatment discontinuation (TTD) were estimated using the Kaplan-Meier method. Child Pugh (CP) scores are also described at diagnosis, prior to first line, and prior to second-line therapy. Results Of the 342 patients who received A/B, 107 (31.3%) received second-line treatments including anti-VEGF therapy or immune checkpoint inhibitor (ICI) and were included in the final analysis. Median OS for all patients was 11.1 months from initiation of second-line therapy. Median OS was 10.7 months (95% CI: 7.2-12.8) and 15.7 months (95%CI: 6.8-NE) for those receiving anti-VEGF inhibitors and ICI ( P = .50). Median TTD for second-line therapies was 2.4 months (95% CI: 1.7-3.3) and 2.6 months (95% CI: 1.5-5.1) for anti-VEGF inhibitors and ICI, respectively (P = .87). In multivariate analyses, CP was significantly associated with survival. Conclusion Following first-line A/B treatment, there is no statistically significant difference in survival between ICI and anti-VEGF therapy, nor in time to treatment discontinuation. CP score remains an important prognostic tool.

ABSTRACT Background Surgical resection for pancreas ductal adenocarcinoma (PDAC) remains the mainstay of treatment. Regardless of enhanced survival rates, disparities in patient outcomes and experiences driven by the social determinants of health (SDH) persist. The area deprivation index (ADI) comprises 17 indicators related to education, employment, housing‐quality, and poverty. We sought to examine the impact of ADI on surgical outcomes of PDAC patients. Methods Patients who underwent pancreatoduodenectomy or distal pancreatectomy for PDAC between January 2011 and December 2022 were identified. ADI was calculated using patient zip codes and categorized into quartiles, with the highest indicating the most marginalized. The primary outcome was loss to follow‐up after surgical resection. To account for confounders, a competing risk multivariable regression analysis was used. Results A total of 1001 patients had a mean age of 66.6 (±9.64), with 46.3% ( n = 463) of patients being female. A majority, 94.6% ( n = 947), identified as white, and 64.1% ( n = 641) had at least a college degree. The median length of follow‐up after surgery was 1.8 years (interquartile range: 0.9–3.5). Multivariable analysis adjusting for competing risk of death, showed that patients who are least marginalized are 1.57 times more likely to have their follow‐up than those most marginalized (hazard ratio: 1.57, 95% confidence interval: 1.08–2.29, p = 0.017). Conclusion SDH impact many aspects of patient's care including a higher risk of loss to follow‐up for marginalized patients after surgery for PDAC. Future efforts should seek to identify and lower barriers faced by marginalized patients with system‐level changes to ensure equitable access.

Background Short-term outcomes after pancreatoduodenectomy (PD) are well-studied, but long-term reoperation rates and their indications remain poorly characterized. Methods A single-center retrospective chart review was performed on patients who underwent PD for pancreatic adenocarcinoma between 1/2011 and 12/2021. Reoperations occurring >90 days after PD were dichotomized to being related or unrelated to the index PD or pancreatic adenocarcinoma. The Kaplan-Meier analysis estimated the incidence of long-term reoperation at 1 and 5 years postoperatively. Results Six-hundred twenty-eight patients were included. The 5-year incidence of any additional operation >90 days after PD was 30.0% (95% CI 23.2-36.2%), and the 5-year incidence of any long-term related reoperation was 21.2% (95% CI 15.0-26.8%). The most common indications for reoperations by 5-year incidence were cancer recurrence (12.8%, 95% CI 7.6-17.7%), incisional hernia (6.2%, 95% CI 2.6-9.7%), small bowel obstruction (1.3%, 95% CI 0.2-2.4%), and leak, fistula, or infection (1.0%, 95% CI 0.1-2.0%). Of the examined risk factors, only 90-day reoperation was found to be predictive of long-term related reoperations ( P = 0.02). Additionally, the 5-year incidence of endoscopic or interventional radiology procedures was 20.2% (95% CI 14.5-25.4%). However, 40.9% (95% CI 33.6-47.3%) of patients required additional surgery or procedures of any kind between 90 days and 5 years after PD. Discussion Within 5 years of PD, one in three patients required additional surgery, and one in five had operations for related indications. Related reoperative indications included recurrence, hernia, PD-specific complications, and small bowel obstruction. However, the rates of each of these reoperations were relatively low.

Cholangiocarcinoma (CCA) is a highly aggressive form of liver cancer and is an increasing cause of cancer‐related death worldwide. Despite its increasing incidence globally and alarming mortality, treatment options for CCA have largely remained unchanged, stressing the importance of developing new effective therapies. YAP activation is common in CCA, and its major transcriptional signaling partners are the TEAD proteins. CA3 is a small‐molecule YAP‐TEAD disrupter discovered utilizing a TEAD reporter assay. Utilizing CCA, gastric cancer cell lines, and patient‐derived xenograft models (PDX), we demonstrate that CA3 is effective in inducing cell death and delaying tumor growth in both FGFR2 fusion and wild‐type models. CA3 was associated with on‐target decreases in YAP‐TEAD target gene expression, TEAD reporter activity, and overall TEAD levels. Hippo pathway signaling was not altered as there was no change in YAP phosphorylation status in the cells exposed to CA3. RNA sequencing of gastric cancer and CCA models demonstrated upregulation of an androgen receptor–mediated transcriptional program following exposure to CA3 in five unique models tested. Consistent with this upstream regulator analysis, CA3 exposure in CCA cells was associated with increased AR protein levels, and combinatorial therapy with CA3 and androgen receptor blockade was associated with increased cancer cell death. CA3 behaves functionally as a YAP‐TEAD disrupter in the models tested and demonstrated therapeutic efficacy. Exposure to CA3 was associated with compensatory androgen receptor signaling and dual inhibition improved the therapeutic effect.

Abstract Introduction Pancreatic adenocarcinoma (PDA) will be the second leading cause of cancer related death by 2030 and patient response to chemotherapy is poor with a strong likelihood of cancer recurrence. While past studies have investigated pre- and post-chemotherapy patient samples, there is a paucity of studies looking at fresh, patient matched samples which allow us to observe interpatient heterogeneity in chemotherapy response. Methods Here, we study the effects of chemotherapy on five different patients using sc-RNA sequencing of matched treatment naïve and post treatment tissue biopsies to compare the effects of chemotherapy, not only on the tumor cells, but also on the tumor microenvironment – a key contributor to tumor survival and proliferation. We utilized the Seurat v4 pipeline and CellChat v2 to observe transcriptomic differences in epithelial cells, myeloid cells, t-Cells, and fibroblasts and their corresponding putative interactions in pre- and post- treatment states. Results Unsurprisingly, we found insufficient tumor epithelial cells post-treatment to perform further analysis on due to the intended cytotoxic effects of chemotherapy. Therefore, we turned our focus to the tumor microenvironment, where we had sufficient numbers of stromal and immune cells, to investigate the effects of chemotherapy. We identified that fibroblasts changed the most consistently across all patients in response to chemotherapy. The fibroblasts clustered into three distinct groups: an immunomodulatory group, a myofibroblastic and neurotropic group, as well as a mixed group expressing genes from all three categories. Interestingly, the neurotropic fibroblast signature was universally enriched after chemotherapy in all five patients, despite having a small and clinically heterogeneous cohort. Conclusions Through an analysis of each fibroblast group in the treatment naïve and post treatment categories, we observed that a specific set of fibroblasts become less myofibroblastic and increasingly neurotropic following treatment, leading us to posit that fibroblasts altered by exposure to chemotherapy may potentially contribute to a ‘pro-tumor’ environment that supports recurrence. To test this in vitro, we treated patient derived fibroblasts with Gemcitabine and used RTPCR to analyze their relative changes in gene expression. We specifically probed for genes that were definitive of myofibroblasts and neurotropic fibroblasts and saw that post-chemotherapy exposure, neurotropic genes such as NEGR1 and NFIA were upregulated. This validated our scRNA conclusions that fibroblasts become increasingly neurotropic following treatment and then differentially interact with their surrounding environment. In future studies, we will further analyze the role these neurotropic fibroblasts play in chemoresponse and tumor recurrence. Matched samples are critical to studies of chemotherapy effects on PDA due to the fact that they allow us to deconvolute one aspect of PDA heterogenity - interpatient heterogeneity - which is a large limitation in studies of this disease. Citation Format: Aylin Z Henstridge, Padma Kadiyala, Ahmed M Elhossiny, Jianhua Liu, Vaibhav Sahai, Nicole Peterson, Jorge Machicado, Richard Kwon, Allison Schulman, Erik Wamsteker, George Philips, Martin Fernandez-Zapico, Mark Truty, Costas Lyssiotis, Timothy Frankel, Filip Bednar, Marina Pasca di Magliano, Eileen S Carpenter. Neurotropic fibroblast population increases following exposure to chemotherapy in pancreatic adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A062.

AbstractBackgroundProton pump inhibitors (PPIs) negatively impact fluoropyrimidine‐based chemotherapy efficacy in colorectal cancer. This study assessed PPI impact on major pathologic response (mPR) rates of pancreatic adenocarcinoma (PDAC) patients receiving fluoropyrimidine‐based chemotherapy.MethodsAn institutional retrospective review of resected PDAC patients receiving neoadjuvant fluoropyrimidine‐based chemotherapy (98% FOLFIRINOX) from 2011 to 2021 was conducted. Outcomes were stratified by use or nonuse of PPIs within 6 months of neoadjuvant chemotherapy initiation. Primary outcome was mPR defined as complete or near complete response.ResultsAmong 540 patients included, the median age was 64 (IQR: 60–70) years, 297 (55%) were male, and 202 (37%) were PPI users. 170 (31%) patients had mPR with similar rates among PPI users and nonusers (29% vs. 33%, p = 0.38). No difference in mPR was seen between PPI users and nonusers receiving chemoradiation (35% vs. 36%, p = 0.89) or ≥8 cycles of NAC (33% vs. 36%, p = 0.55). Median OS for PPI users was 30.9 versus 31.7 months for nonusers (p = 0.62). On multivariable analysis, PPI therapy was not associated with decreased survival.ConclusionPPI usage did not significantly influence mPR or OS following neoadjuvant fluoropyrimidine‐based chemotherapy in resected PDAC patients. Further analysis of all patients, not just those who underwent resection, is required.