Carlson, Danielle Marie

ABSTRACT Cholangiocarcinoma (CCA) is a lethal biliary cancer in which chemoresistance is nearly universal, and its tumor immune microenvironment is dominated by immunosuppressive tumor-associated macrophages (TAMs) that exclude cytotoxic CD8 + T cells. How tumor cells sustain this immunosuppressive state during chemotherapy is undefined. Here we demonstrate that therapy-induced senescent-like (Sen-L) cancer cells accumulate after gemcitabine/cisplatin in human and murine CCA, are predominantly cancer cells, and predict shorter survival. Genetic elimination of Sen-L cancer cells reduces tumor burden, lowers TAM abundance, and restores intratumoral CD8 + T cells, establishing them as causal drivers. Growth differentiation factor 15 (GDF-15) is the dominant Sen-L-secreted factor and reprograms macrophages to suppress CD8 + T cells through the non-canonical receptor TGFBR2 and STAT6, and p16-restricted Gdf15 silencing phenocopies Sen-L elimination. Combined with chemotherapy, Sen-L elimination improves survival beyond chemotherapy alone. These findings establish Sen-L cancer cells and their GDF-15 output as causal, targetable drivers of macrophage-mediated immune evasion in CCA. SIGNIFICANCE STATEMENT Therapy-induced senescent-like cancer cells, not stromal cells, are the dominant senescent-like and immunosuppressive population in cholangiocarcinoma, and their elimination restores antitumor immunity. GDF-15 is their dominant secreted effector and engages a non-canonical macrophage receptor, TGFBR2, identifying a cancer-cell-to-macrophage axis and a Sen-L-elimination strategy to restore chemosensitivity. Abstract Figure Graphical abstract. Senescent-like CCA cells promote tumor immunosuppression through TAMs polarization by GDF-15

Abstract Background and Objectives Cholangiocarcinoma (CCA) is an aggressive, highly lethal cancer of the biliary tract epithelium for which tumor resection is the only curative treatment. However, approximately half of patients present with nonresectable disease and median survival of these patients is just 8-12 months. A significant need exists for tumor-targeted therapeutics for patients with advanced disease who currently have limited treatment options. We aimed to address this need by developing an aptamer-targeted therapy for delivery of siRNAs inhibiting undruggable components of the Hippo pathway, a key driver of cholangiocarcinoma. Method We applied cell-SELEX against human CCA model cell line HuCCTl with negative selection against normal hepatocytes and cholangiocytes to identify an aptamer that selectively bound tumor cells. This aptamer, termed MC7122, was chemically modified to include fluorescent labels that enabled whole-animal biodistribution studies to assess in vivo selectivity. MC7122 was then deployed onto the surface of siRNA-loaded nanovesicles to drive tumor-targeted nucleic acid delivery. Tumor-bearing mice were treated with siRNAs three times per week for two weeks alone or in combination with standard of care chemotherapy. Results Combined treatment with siRNAs and standard of care chemotherapy reduced tumor burden in mice versus vehicle controls and slowed the spread of metastasis. Importantly, we found tumor-specific target gene knockdown without corresponding off-target knockdown in healthy surrounding liver tissue. Further, we demonstrated that sites in the lung, the primary location of metastasis in this model, were reduced not because of global target knockdown in lung but due to tumor-specific knockdown at the site of liver implantation. Conclusions Aptamer-guided vesicles represent a promising platform for targeted therapy delivery for previously undruggable targets. With this platform, tumor-selective therapies can be designed to exhibit exceptionally potent cytotoxicity, as healthy tissues remain unaffected by off-target effects. Future work will focus on refinement of therapeutic siRNA target selection and modification of nanovesicle components for enhanced levels of tumor specificity.

Abstract Background Cholangiocarcinoma (CCA) is an aggressive hepatobiliary malignancy with marked molecular heterogeneity, limited systemic treatment options, and poor prognosis. Chemoresistance and KRAS mutations remain major therapeutic challenges. Dysregulation of the Hippo pathway, particularly YAP/TAZ hyperactivation, drives CCA progression and resistance. TEAD, the essential transcriptional partner of YAP/TAZ, represents a promising target. IAG933 is a novel oral pan-TEAD inhibitor designed to disrupt YAP/TAZ–TEAD interactions. RMC-6236, a pan-KRAS inhibitor, has also gained attention. Combining TEAD and KRAS inhibition may overcome resistance and improve efficacy in CCA. Methods We evaluated IAG933 in human (HuCCT1, RBE) and murine (SB1, FAC) CCA cell lines. Cells were treated with IAG933 alone or in combination with GemCis or RMC-6236. Cell viability assays were used to determine IC50 values and calculate combination index (CI). TEAD activity was assessed by luciferase reporter and qRT-PCR of YAP/TAZ target genes (CTGF, CYR61, NUAK2). In vivo efficacy was evaluated in syngeneic orthotopic and patient-derived xenograft (PDX) models. Results IAG933 suppressed TEAD-dependent transcription (IC50≈500 nM) and downregulated YAP/TAZ target genes. Combination with GemCis or RMC-6236 produced synergistic effects (CI < 1) in all CCA lines. In vivo, IAG933 monotherapy suppressed tumor growth similarly to GemCis. Dual TEAD and KRAS inhibition achieved marked tumor regression and significantly delayed tumor regrowth after treatment cessation in KRAS-mutant PDX models. Conclusion IAG933 effectively suppresses YAP/TAZ–TEAD signaling and inhibits CCA growth. While the combination with GemCis showed limited additional benefit due to strong single-agent efficacy, synergy with RMC-6236 produced durable antitumor effects, particularly in run-out studies, delaying regrowth in KRAS-mutant models. These findings highlight IAG933 as a promising therapeutic candidate targeting the Hippo–TEAD pathway, with potential benefit in KRAS-mutant CCA.

Abstract Background Cholangiocarcinoma (CCA) is a deadly cancer of the hepatic bile duct epithelial cells. Loss-of-function mutations of epigenetic regulator ubiquitin C-terminal hydrolase deubiquitinase BRCA1associated protein 1 (BAP1) occur in 26-32% of human CCA and are associated with worse prognosis and resistance to cytotoxic therapy. The goal of this study is to identify how BAP1 loss promotes cell death evasion through metabolic rewiring. Materials and methods Isogenic wild-type and BAP1-deficient human and murine CCA cell lines were generated with shRNA/siRNA or CRISPR/Cas9 and were used to assess ferroptosis sensitivity by treatment with ferroptosis inducers. In vitro, ferroptosis was assessed by phospholipid peroxidation (C-11BODIPY), mitochondrial phospholipid peroxidation (MitoPeDPP, MitoCLox), iron overload (MitoFerro green) and cell death (CellTiter-Glo). Phospholipidomics and proteomics were performed in isogenic cells by LC-MS/MS. Syngeneic liver orthotopic CCA murine models and patient-derived xenografts (PDX) were used for in vivo pre-clinical studies. Results Our findings indicate that BAP1 loss confers CCA ferroptosis resistance. BAP1 loss protects CCA against mitochondrial iron overload, ROS accumulation, and phospholipid peroxidation. BAP1 loss protects from mitochondrial phospholipid peroxidation and cardiolipin oxidation. Unbiased phospholipidomic profiling revealed that BAP1 loss remodels membrane phospholipid composition, enriching for ferroptosis blocking monounsaturated phospholipids (MUFA-PLs) at the expense of ferroptosis-inducing polyunsaturated (PUFA-PLs). We found that BAP1 loss upregulates TLCD1, a phosphatidylethanolamine acyltransferase that incorporates MUFAs into membrane phospholipids, thereby stabilizing membranes against peroxidation. TLCD1 knockdown in ferroptosis-resistant BAP1-deficient CCA cells, restored ferroptosis sensitivity. Notably, TLCD1 is significantly upregulated in human BAP1-mutant CCA as compared to BAP1-expressing tumors. While not a mitochondrial protein, TLCD1 localizes in the ER and by the mitochondrial outer membrane, as demonstrated by our immunofluorescence analysis in human CCA cells. From a therapeutic perspective, we developed EpCAM (adhesion molecule highly expressed in CCA cells)-aptamer coated lactosomes packaged with siRNA against glutathione peroxidase 4 (GPX4), as a proof-of-concept strategy to safely induce ferroptosis selectively in CCA in vitro and in vivo. Administration of siGPX4-lactosomes in pre-clinical syngeneic liver orthotopic CCA murine models demonstrated a favorable safety profile, achieved robust intratumoral GPX4 knockdown (>50%), exhibited optimal biodistribution, induced significant tumor lipid peroxidation, and resulted in reduced tumor burden. Lastly, ferroptosis inducer JKE-1674, combined with gemcitabine/cisplatin (Gem/Cis) significantly blocked tumor growth of Gem/Cis-resistant patient-derived xenografts. Conclusions Our findings reveal that BAP1 loss reprograms mitochondrial phospholipid metabolism thus conferring CCA resistance to ferroptosis, identifying TLCD1 as a targetable metabolic vulnerability in BAP1-mutant CCA. Additionally, our findings support ferroptosis inducing compounds as promising therapeutic approaches for CCA.

Abstract Background: Cholangiocarcinoma (CCA) is an aggressive hepatobiliary malignancy with limited treatment options. CCA exhibits a distinct desmoplastic and tolerogenic tumor immune microenvironment (TIME) characterized by elevated bile acid concentrations resulting from obstructive cholestasis and dysregulated bile acid metabolism. TGR5 is an essential component of bile acid signaling. We hypothesize that bile acids promote CCA progression by establishing an immunosuppressive TIME through TGR5 signaling, which can be therapeutically targeted using SBI-364, a novel potent small molecule TGR5 inhibitor. Methods: Single-cell RNA sequencing (scRNA-seq) of immune cells from human intrahepatic (iCCA) and perihilar (pCCA) CCA tumors were conducted. Therapeutic studies were performed using syngeneic murine models of iCCA (PMID: 38458319), a novel syngeneic model of pCCA, and patient-derived xenograft (PDX) models. In collaboration with Sanford Burnham Prebys, SBI-364, a first in-class competitive TGR5 antagonist, was assessed in vivo. Additionally, we performed co-culture experiments with bile acid +/- SBI-364-treated murine bone marrow-derived monocytic myeloid-derived suppressor cells (M-MDSCs) and CD8+ T cells to assess functional immunosuppressive effects. Results: Human scRNA-seq revealed significantly increased TGR5 (GPBAR1) expression predominantly in myeloid cell populations within the CCA TIME. SBI-364 treatment significantly reduced tumor burden in both syngeneic orthotopic iCCA models and a novel pCCA model that recapitulates the anatomic characteristics of perihilar CCA. In contrast, NOD/SCID mice bearing PDX535 (predicted sensitive) and PDX136 (predicted resistant), SBI-364 treatment did not achieve tumor reduction, suggesting that TGR5 inhibition predominantly attenuates tumor progression through modulation of bile acid-immune cell interactions. SBI-364 treated murine tumors had a significant reduction in immunosuppressive macrophages expressing interleukin-10 and M-MDSCs compared to vehicle treated tumors. Furthermore, bile acid-treated M-MDSCs exhibited enhanced suppression of CD8+ T cell proliferation and function, an effect that was abrogated by SBI-364 co-treatment. Conclusion: We demonstrate that TGR5 inhibition represents a promising therapeutic strategy across multiple immunocompetent preclinical CCA models. We demonstrate that the bile-acid TGR5 axis promotes CCA progression via immunosuppressive myeloid cells. Specifically, TGR5 signaling potentiates the immunosuppressive capacity of M-MDSCs, contributing to an immunosuppressive niche that facilitates tumor progression. These results establish TGR5 as a rational therapeutic target for overcoming immune evasion in cholangiocarcinoma. Citation Format: Enis Hikmet Ozmert, Binbin Li, Jingchun Yang, Hannah Elizabeth Stumpf, Jessica R. Willhite, Danielle Carlson, Jennifer L. Tomlinson, Jon Covel, Raghuveer Ramachandra, Steven Olson, Rory L. Smoot, Sumera Ilyas. Therapeutic targeting of TGR5 abrogates bile acid driven myeloid cell immunosuppression in cholangiocarcinoma [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 2896.

Abstract Background: Cholangiocarcinoma (CCA) is an aggressive hepatobiliary malignancy with marked molecular heterogeneity, limited systemic treatment options, and poor prognosis. Chemoresistance and KRAS mutations remain major therapeutic challenges. Dysregulation of the Hippo pathway, particularly YAP/TAZ hyperactivation, drives CCA progression and resistance. TEAD, the essential transcriptional partner of YAP/TAZ, represents a promising target. IAG933 is a novel oral pan-TEAD inhibitor designed to disrupt YAP/TAZ-TEAD interactions. RMC-6236, a pan-KRAS inhibitor, has also gained attention. Combined TEAD and KRAS inhibition may overcome resistance and improve efficacy in CCA. Methods: We evaluated IAG933 in human (HuCCT1, RBE) and murine (SB1, FAC) CCA cell lines. Cells were treated with IAG933 alone or in combination with GemCis or RMC-6236. Cell viability assays were used to determine IC50 values and calculate combination indexes (CI). TEAD activity was assessed by luciferase reporter and qRT-PCR of YAP/TAZ target genes (CTGF, CYR61, NUAK2). Transcriptomic alterations were analyzed by RNA sequencing. In vivo efficacy was evaluated in syngeneic orthotopic and patient-derived xenograft (PDX) models. Results: IAG933 suppressed TEAD-dependent transcription (IC50 ≈ 500 nM) and downregulated YAP/TAZ target genes. Combination with GemCis or RMC-6236 produced synergistic effects (CI < 1) in all CCA lines. Transcriptomic analysis revealed activation of oxidative stress response pathways, particularly SOD2 upregulation. MitoSOX staining confirmed increased mitochondrial ROS after treatment. In vivo, IAG933 monotherapy suppressed tumor growth similarly to GemCis. Dual TEAD and KRAS inhibition achieved marked tumor regression and significantly delayed tumor regrowth after treatment cessation in KRAS-mutant PDX models. Conclusion: IAG933 effectively suppresses YAP/TAZ-TEAD signaling and inhibits CCA growth. While the combination with GemCis showed limited additional benefit due to strong single-agent efficacy, synergy with RMC-6236 produced durable antitumor effects, particularly in run-out studies, delaying regrowth in KRAS-mutant models. These findings highlight IAG933 as a promising therapeutic candidate targeting the Hippo-TEAD pathway, with potential benefit in KRAS-mutant CCA. Citation Format: Hidemi Nishi,Erik Jessen,Danielle M. Carlson,Amro M. Abdelrahman,Enis H. Ozmert,J. Pedro Fincatto Safi,Brandon A. Wilbanks,Shelby K. Yee,Jack W. Sample,Nathan W. Werneburg,Rory L. Smoot. TEAD inhibition by IAG933 as a novel therapeutic strategy for cholangiocarcinoma [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 3081.

Abstract INTRODUCTION: Cholangiocarcinoma (CCA) is a deadly cancer of the hepatic bile duct epithelial cells. Loss-of-function mutations of epigenetic regulator ubiquitin C-terminal hydrolase deubiquitinase BRCA1-associated protein 1 (BAP1) occur in 26-32% of human CCA and are associated with worse prognosis and resistance to cytotoxic therapy. The goal of this study is to identify how BAP1 loss promotes cell death evasion through metabolic rewiring. MATERIALS & METHODS: Isogenic wild-type and BAP1-deficient human and murine CCA cell lines were generated with shRNA/siRNA or CRISPR/Cas9 and were used to assess ferroptosis sensitivity by treatment with ferroptosis inducers. In vitro, ferroptosis was assessed by phospholipid peroxidation (C-11BODIPY), mitochondrial phospholipid peroxidation (MitoPeDPP, MitoCLox), iron oeverload (MitoFerro green) and cell death (CellTiter-Glo). Phospholipidomics and proteomics were performed in isogenic cells by LC-MS/MS. Isogenic liver orthotopic CCA murine models were used for in vivo pre-clinical studies. RESULTS: Our findings indicate that BAP1 loss confers CCA ferroptosis resistance. BAP1 loss protects CCA against mitochondrial iron overload, ROS accumulation, and phospholipid peroxidation. Strikingly, BAP1 loss protects from mitochondrial phospholipid peroxidation and cardiolipin oxidation. Unbiased phospholipidomic profiling revealed that BAP1 loss remodels membrane phospholipid composition, enriching for ferroptosis-blocking monounsaturated phospholipids (MUFA-PLs) at the expense of ferroptosis-inducing polyunsaturated (PUFA-PLs). We found that BAP1 loss upregulates TLCD1, a phosphatidylethanolamine acyltransferase that incorporates MUFAs into membrane phospholipids, thereby stabilizing membranes against peroxidation. TLCD1 knockdown in BAP1-deficient CCA cells, restored ferroptosis sensitivity Notably, TLCD1 is significantly upregulated in human BAP1-mutant CCA as compared to WT tumors. We identified TLCD1 in the endoplasmic reticulum, Golgi and by mitochondrial outer membrane. In syngeneic liver orthotopic CCA murine models, engineered EpCAM-aptamer-coated lactosomes carrying GPX4 siRNA selectively targeted CCA cells, inducing ferroptosis and robustly suppressing tumor growth without systemic toxicity. Lastly, BAP1-mutant patient-derived xenografts (PDXs) and organoids were resistant to ferroptosis inducers, as compared to WT controls. CONCLUSIONS: Our findings reveal that BAP1 loss rewires mitochondrial phospholipid metabolism thus conferring CCA resistance to ferroptosis, identifying TLCD1 as a targetable metabolic vulnerability in BAP1-mutant CCA. Citation Format: Yu Zhao, Peyton Classon, Danielle Marie Carlson, Jayla Millender, Irene K. Yan, Sumera Ilyas, Rory L. Smoot, Gregory J. Gores, TUSHAR PATEL, Davide Povero. BAP1 loss confers ferroptosis resistance to cholangiocarcinoma via TLCD1-mediated membrane phospholipid remodeling [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 2433.

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 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.

ABSTRACT The limited efficacy of current therapies against cholangiocarcinoma (CCA) necessitates the development of novel treatment strategies. Src family kinases (SFKs) contribute significantly to tumor progression and resistance in CCA. Therefore, we investigated the novel, first-in-class SFK ‘OFF’ inhibitor NXP900 in diverse preclinical CCA models, including those with acquired resistance. This study evaluated the therapeutic effects of NXP900 and detailed adaptive molecular responses to SFK inhibitor therapy. We also aimed to identify biomarkers predictive of drug sensitivity using integrated multiomic profiling and develop strategies to overcome resistance. NXP900 inhibited YAP activity through direct inhibition of tyrosine phosphorylation and indirect activation of the Hippo pathway via LATS. These effects were associated with decreased tumor cell viability in CCA cell lines and several in vivo models. Notably, IDH -mutant patient-derived xenograft CCA models were particularly sensitive to NXP900. NXP900 also synergized with gemcitabine/cisplatin chemotherapy, enhancing antitumor efficacy in both in vitro and in vivo models. Multiomic analyses combining transcriptomics, global proteomics, and phosphoproteomics identified molecular features associated with primary response and acquired resistance. IL13RA-AKT signaling was upregulated in resistant models; NXP900 sensitivity could be restored with AKT or IL13RA2 inhibition. Together, these findings demonstrate the therapeutic potential of NXP900 as a novel YAP inhibitor in CCA and support further investigation in a clinical trial. Graphical Abstract