Smoot, Rory L.

463 Background: Molecularly targeted therapy is gaining traction in cholangiocarcinoma with the first FDA approval of a targeted agent in 2020, the FGFR inhibitor pemigatinib. Yet response rates and efficacy are modest, and most cholangiocarcinoma patients still lack targeted therapy options. The hippo pathway effector, YAP, is an oncogene that is activated in the majority of cholangiocarcinoma, yet attempts to develop YAP inhibitors have not yet been clinically successful. Recently, we described a novel mechanism of YAP regulation, via tyrosine phosphorylation by the Src-family kinase LCK. Therefore we hypothesized that LCK inhibition by may be therapeutic in cholangiocarcinoma through suppression of YAP activity. Methods: NTRC 0652-0 is a novel tyrosine kinase inhibitor with specificity for LCK. In vitro pharmacodynamics were defined. In cholangiocarcinoma cells, specificity for LCK inhibition was determined by mass spectrometry-based unbiased analysis of the tyrosine phosphoproteome following treatment with NTRC 0652-0 or genetic deletion of LCK. YAP phosphorylation and cotranscriptional activity, cell viability, and apoptosis were assessed. A panel of eight cholangiocarcinoma patient derived organoids (PDO) were characterized and tested for sensitivity to NTRC 0652-0. Two patient-derived xenograft (PDX) models bearing FGFR2-rearrangements were utilized for in vivo assessment of pharmacokinetics, toxicity, and efficacy. Results: NTRC 0652-0 demonstrated selectivity for LCK inhibition in vitro and in cholangiocarcinoma cells. NTRC 0652-0 treatment led to YAP inhibition and apoptotic cell death in cholangiocarcinoma cell lines, associated with inhibition of MCL1 expression. PDOs demonstrated variable sensitivity to NTRC 0652-0, correlated with basal YAP tyrosine phosphorylation and drug-induced suppression of YAP co-transcriptional activity. FGFR2-altered cholangiocarcinoma was also identified as a subset with enrichment of YAP target genes. Cells from an FGFR2-altered PDX were sensitive to NTRC 0652-0 despite being primarily resistant to pemigatinib. In two PDX models of FGFR2-altered cholangiocarcinoma, daily oral treatment with NTRC 0652-0 inhibited YAP tyrosine phosphorylation, and resulted in stable plasma and tumor drug levels, acceptable toxicity, and significantly decreased tumor growth. Conclusions: A novel LCK inhibitor, NTRC 0652-0, reduced YAP signaling and demonstrated preclinical efficacy in multiple patient-derived models of cholangiocarcinoma. LCK is a novel therapeutic target in cholangiocarcinoma, and YAP activation or FGFR2-alteration are potential biomarkers for response.

AXL and its corresponding ligand growth arrest–specific 6 (GAS‐6) are critically involved in hepatic immunomodulation and regenerative processes. Pleiotropic inhibitory effects on innate inflammatory responses might essentially involve the shift of macrophage phenotype from a pro‐inflammatory M1 to an anti‐inflammatory M2. We aimed to assess the relevance of the AXL/GAS‐6‐pathway in human liver regeneration and, consequently, its association with clinical outcome after hepatic resection. Soluble AXL (sAXL) and GAS‐6 levels were analyzed at preoperative and postoperative stages in 154 patients undergoing partial hepatectomy and correlated with clinical outcome. Perioperative dynamics of interleukin (IL)‐6, soluble tyrosine‐protein kinase MER (sMerTK), soluble CD163 (sCD163), and cytokeratin (CK) 18 were assessed to reflect pathophysiological processes. Preoperatively elevated sAXL and GAS‐6 levels predicted postoperative liver dysfunction (area under the curve = 0.721 and 0.722; P < 0.005) and worse clinical outcome. These patients failed to respond with an immediate increase of sAXL and GAS‐6 upon induction of liver regeneration. Abolished AXL pathway response resulted in a restricted increase of sCD163, suggesting a disrupted phenotypical switch to regeneratory M2 macrophages. No association with sMerTK was observed. Concomitantly, a distinct association of IL‐6 levels with an absent increase of AXL/GAS‐6 signaling indicated pronounced postoperative inflammation. This was further supported by increased intrahepatic secondary necrosis as reflected by CK18M65. sAXL and GAS‐6 represent not only potent and easily accessible preoperative biomarkers for the postoperative outcome but also AXL/GAS‐6 signaling might be of critical relevance in human liver regeneration. Refractory AXL/GAS‐6 signaling, due to chronic overactivation/stimulation in the context of underlying liver disease, appears to abolish their immediate release following induction of liver regeneration, causing overwhelming immune activation, presumably via intrahepatic immune regulation.

Prostate‐specific membrane antigen (PSMA) is a validated target for molecular diagnostics and targeted radionuclide therapy. Our purpose was to evaluate PSMA expression in hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), and hepatic adenoma (HCA); investigate the genetic pathways in HCC associated with PSMA expression; and evaluate HCC detection rate with 68Ga‐PSMA‐11 positron emission tomography (PET). In phase 1, PSMA immunohistochemistry (IHC) on HCC (n = 148), CCA (n = 111), and HCA (n = 78) was scored. In a subset (n = 30), messenger RNA (mRNA) data from the Cancer Genome Atlas HCC RNA sequencing were correlated with PSMA expression. In phase 2, 68Ga‐PSMA‐11 PET was prospectively performed in patients with treatment‐naïve HCC on a digital PET scanner using cyclotron‐produced 68Ga. Uptake was graded qualitatively and semi‐quantitatively using standard metrics. On IHC, PSMA expression was significantly higher in HCC compared with CCA and HCA (P < 0.0001); 91% of HCCs (n = 134) expressed PSMA, which principally localized to tumor‐associated neovasculature. Higher tumor grade was associated with PSMA expression (P = 0.012) but there was no association with tumor size (P = 0.14), fibrosis (P = 0.35), cirrhosis (P = 0.74), hepatitis B virus (P = 0.31), or hepatitis C virus (P = 0.15). Overall survival tended to be longer in patients without versus with PSMA expression (median overall survival: 4.2 vs. 1.9 years; P = 0.273). FGF14 (fibroblast growth factor 14) mRNA expression correlated positively (rho = 0.70; P = 1.70 × 10‐5) and MAD1L1 (Mitotic spindle assembly checkpoint protein MAD1) correlated negatively with PSMA expression (rho = −0.753; P = 1.58 × 10‐6). Of the 190 patients who met the eligibility criteria, 31 patients with 39 HCC lesions completed PET; 64% (n = 25) lesions had pronounced 68Ga‐PSMA‐11 standardized uptake value: SUVmax (median [range] 9.2 [4.9‐28.4]), SUVmean 4.7 (2.4‐12.7), and tumor‐to‐liver background ratio 2 (1.1‐11). Conclusion: Ex vivo expression of PSMA in neovasculature of HCC translates to marked tumor avidity on 68Ga‐PSMA‐11 PET, which suggests that PSMA has the potential as a theranostic target in patients with HCC.

Objective: The aim of this study was to define robust benchmark values for the surgical treatment of perihilar cholangiocarcinomas (PHC) to enable unbiased comparisons. Background: Despite ongoing efforts, postoperative mortality and morbidity remains high after complex liver surgery for PHC. Benchmark data of best achievable results in surgical PHC treatment are however still lacking. Methods: This study analyzed consecutive patients undergoing major liver surgery for PHC in 24 high-volume centers in 3 continents over the recent 5-year period (2014–2018) with a minimum follow-up of 1 year in each patient. Benchmark patients were those operated at high-volume centers (≥50 cases during the study period) without the need for vascular reconstruction due to tumor invasion, or the presence of significant co-morbidities such as severe obesity (body mass index ≥35), diabetes, or cardiovascular diseases. Benchmark cutoff values were derived from the 75th or 25th percentile of the median values of all benchmark centers. Results: Seven hundred eight (39%) of a total of 1829 consecutive patients qualified as benchmark cases. Benchmark cut-offs included: R0 resection ≥57%, postoperative liver failure (International Study Group of Liver Surgery): ≤35%; in-hospital and 3-month mortality rates ≤8% and ≤13%, respectively; 3-month grade 3 complications and the CCI: ≤70% and ≤30.5, respectively; bile leak-rate: ≤47% and 5-year overall survival of ≥39.7%. Centers operating mostly on complex cases disclosed better outcome including lower post-operative liver failure rates (4% vs 13%; P = 0.002). Centers from Asia disclosed better outcomes. Conclusion: Surgery for PHC remains associated with high morbidity and mortality with now the availability of benchmark values covering 21 outcome parameters, which may serve as key references for comparison in any future analyses of individuals, group of patients or centers.

Abstract Background:Biliary tract cancers (BTC) are rare, chemo resistant and are associated with a poor prognosis. Preclinical and early clinical work had demonstrated interesting anti-tumor activity from targeting fibroblast growth factor receptor (FGFR) pathway. We hypothesized that ponatinib, a multi-targeted tyrosine kinase inhibitor with activity against FGFR, would be active in BTC patients with FGFR alterations.Methods:This was a multi-center, single institution pilot study of ponatinib in patients with advanced, refractory BTC with FGFR alterations. The primary end point was overall response rate, with secondary points of overall survival (OS), progression-free survival (PFS) and Health Related Quality of Life (HRQoL) assessment. Results:Twelve patients were enrolled prior to early termination of the trial. Clinical benefit (defined as complete/partial response + stable disease) of 45.5% was observed. All observed toxicities were manageable and reversible. Toxicities were mild, with lymphopenia (75%), rash (63%) and fatigue (50%) being the most frequent. No significant detriment in global QoL was observed.Conclusions:Ponatinib as a single agent in FGFR altered BTC is tolerable with very modest clinical activity. This is the first report of prospective assessment of FGFR inhibition in BTC using ponatinib, and the first study to report its effect on HRQoL. Further development of ponatinib will involve correlative studies to better refine patient selection, focus on combinations with other molecular targeted agents, conventional cytotoxic chemotherapy, and studies to better understand mechanisms of treatment resistance.

PURPOSECholangiocarcinomas (CCA) are a group of heterogeneous tumors arising from the biliary epithelia. Significant sequencing efforts have provided further insights into the molecular mechanisms of this disease including fibroblast growth factor receptor ( FGFR) alterations, which occurs in approximately 15%-20% of intrahepatic CCAs. Herein, we describe the FGFR inhibitor (FGFRi)-associated treatment toxicity and cancer-specific outcomes from a multicenter single-institution cohort.METHODSThis is a retrospective study of patients with CCA and known FGFR alterations treated with FGFRi. We describe the toxicity and efficacy in patients treated at Mayo Clinic between January 2010 and December 2020.RESULTSOur group identified 61 patients with advanced or metastatic CCA, 19 males (31%) and 42 females (69%), harboring FGFR alterations who received FGFRi. The most common grade 1 or higher adverse events for all patients included fatigue (92%), AST elevations (78%), anemia (80%), decreased platelet count (63%), and hyperphosphatemia (74%). Median progression-free survival on FGFRi was 5.8 months for all patients (95% CI, 4.9 to 9.0). Females had significantly longer progression-free survival at 6.9 months (95% CI, 5.2 to 11.8) on FGFRi compared with males at 4.9 months (95% CI, 2.8 to not estimable; P = .038).CONCLUSIONFGFRi are well tolerated with clinical efficacy. With the recent approval of FGFRi by the US Food and Drug Administration and ongoing clinical trials for new FGFRi, understanding outcomes and toxicity associated with these medications is important for precision oncology.

Abstract Background and Objectives Pancreatic neuroendocrine tumors (pNETs) in patients with hereditary cancer syndromes are typically multifocal. In contrast, sporadic pNETs are usually unifocal and the incidence of multifocal sporadic pNETs is unknown. The primary aim of this study was to investigate the incidence of multifocality in sporadic pNETs and any associated effect on recurrence risk and survival. Methods Patients who underwent resection of pNETs at Mayo Clinic from 2000 to 2019 were identified and clinical data were obtained from medical records. Syndromic disease was defined as pNETs arising in the setting of a hereditary cancer syndrome. Statistical comparisons were made using χ 2 , Fisher's exact, and Kruskal–Wallis tests and survival was assessed using the Kaplan–Meier method. Results Six hundred and sixty‐one patients with sporadic pNETs and fifty‐nine with syndromic pNETs were identified. Multifocal disease was present in 4.8% of sporadic patients and 84.7% of syndromic patients ( p < .001). Within patients with sporadic pNETs, clinicopathologic features and recurrence‐free and overall survival were similar between patients with unifocal and multifocal disease. Conclusions Multifocal sporadic pNETs are rare and multifocality is not associated with worse survival or increased recurrence risk. Patients with multifocal sporadic pNETs can likely be safely managed with a combination of resection and observation as indicated for each tumor.

AbstractIntroductionAlthough surgical resection is necessary, it is not sufficient for long‐term survival in pancreatic ductal adenocarcinoma (PDAC). We sought to evaluate survival after up‐front surgery (UFS) in anatomically resectable PDAC in the context of three critical factors: (A) margin status; (B) CA19‐9; and (C) receipt of adjuvant chemotherapy.MethodsThe National Cancer Data Base (2010–2015) was reviewed for clinically resectable (stage 0/I/II) PDAC patients. Surgical margins, pre‐operative CA19‐9, and receipt of adjuvant chemotherapy were evaluated. Patient overall survival was stratified based on these factors and their respective combinations. Outcomes after UFS were compared to equivalently staged patients after neoadjuvant chemotherapy on an intention‐to‐treat (ITT) basis.ResultsTwelve thousand and eighty‐nine patients were included (n = 9197 UFS, n = 2892 ITT neoadjuvant). In the UFS cohort, only 20.4% had all three factors (median OS = 31.2 months). Nearly 1/3rd (32.7%) of UFS patients had none or only one factor with concomitant worst survival (median OS = 14.7 months). Survival after UFS decreased with each failing factor (two factors: 23 months, one factor: 15.5 months, no factors: 7.9 months) and this persisted after adjustment. Overall survival was superior in the ITT‐neoadjuvant cohort (27.9 vs. 22 months) to UFS.ConclusionDespite the perceived benefit of UFS, only 1‐in‐5 UFS patients actually realize maximal survival when known factors highly associated with outcomes are assessed. Patients are proportionally more likely to do worst, rather than best after UFS treatment. Similarly staged patients undergoing ITT‐neoadjuvant therapy achieve survival superior to the majority of UFS patients. Patients and providers should be aware of the false perception of ‘optimal’ survival benefit with UFS in anatomically resectable PDAC.

Abstract Background: Mixed acinar neuroendocrine carcinoma (MANEC) of the pancreas is an extremely rare histopathologic subtype. MANEC is an amphicrine malignancy composed of at least 25% of acinar cell carcinoma (PACC) and neuroendocrine carcinoma (pNET). No standard systemic treatment is available for MANEC and current recommendations are derived from standard of care for PACC or pNET. Platinum based regimens have been approved for PACC while targeted agents (sunitinib and everolimus) are approved for pNET. This study aimed to investigate the antitumor effect and toxicities of both platinum based and targeted agents on a successfully first described patient derived xenograft (PDX) of metastatic MANEC of the pancreas. Methods: Several generations of PDX from a surgically resected metastatic MANEC of the pancreas was histologically validated. PDX-MANEC tumors were heterotopically implanted into NOD/SCID mice and randomized into 6 groups (4 mice each) as in table 1. The study continued for 3 weeks. Antitumor efficacy was determined based on change in the tumor volume. Toxicity was assessed change in mice weights. Results: Table 1 shows the changes in tumor volume and mouse weight in all study arms compared to controls end point. Only FOLFIRINOX and gemcitabine/cisplatin arms revealed overall decrease in tumor volume lower than starting volume in controls. All arms other than sunitinib, led to decrease in overall tumor volume compared to control tumor volumes over time. All treatment arms led to lower trending mouse weights (toxicities) except sunitinib, however only the everolimus arm had statistical significance. Conclusion: Both platinum-based regimens and everolimus revealed significant tumor control. No synergistic effect observed in sunitinib/everolimus. Preclinical studies are undergoing to investigate other effective and less toxic therapeutics for MANEC. Table 1.Delta in tumor volumes of PDX-MANEC-P after multiple platinum-based chemotherapy regimens and targeted therapeutics from the standard of care for other pancreatic cancer subtypes including PACC and pNET.ControlFOLFIRINOXGemcitabine and CisplatinSunitinibEverolimusSunitinib and EverolimusDelta in tumor volume in mm3 at the study end (mean ± standard deviation)3225 ± 2054-609.3 ± 351.8-654.7 ± 92.561583 ± 950.3-178.1 ± 61.58-160.8 ± 86.55P value (column group vs. control)&lt;0.0010.0030.0950.0010.001Delta in mice weight in grams at the study end (mean ± standard deviation)0.84 ± 1.68-1.26 ± 0.84-8.5 ± 1.630.86 ± 1.22-2.2 ± 1.61-1.42 ± 1.27P value (column group vs. control)0.058&lt;0.0010.9810.0070.050 Citation Format: Amro M. Abdelrahman, Jennifer A. Yonkus, Roberto Alva-Ruiz, Jennifer L. Leiting, Nellie A. Campbell, Lewis R. Roberts, Michael L. Kendrick, David M. Nagorney, Sean P. Cleary, Travis E. Grotz, Gregory J. Gores, Jun Yin, Rondell P. Graham, Thorvardur R. Halfdanarson, Rory L. Smoot, Mark J. Truty. Preclinical efficacy of platinum based chemotherapy regimens and targeted therapeutics in the first successful described patient derived xenograft model of mixed acinar neuroendocrine carcinoma of the pancreas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 413.

Abstract To repurpose therapeutics for fibrolamellar carcinoma (FLC), we developed and validated patient-derived xenografts (PDX) from surgical resections. Most agents used clinically and inhibitors of oncogenes overexpressed in FLC showed little efficacy on PDX. A high-throughput functional drug screen found primary and metastatic FLC were vulnerable to clinically available inhibitors of TOPO1 and HDAC and to napabucasin. Napabucasin's efficacy was mediated through reactive oxygen species and inhibition of translation initiation, and specific inhibition of eIF4A was effective. The sensitivity of each PDX line inversely correlated with expression of the antiapoptotic protein Bcl-xL, and inhibition of Bcl-xL synergized with other drugs. Screening directly on cells dissociated from patient resections validated these results. This demonstrates that a direct functional screen on patient tumors provides therapeutically informative data within a clinically useful time frame. Identifying these novel therapeutic targets and combination therapies is an urgent need, as effective therapeutics for FLC are currently unavailable. Significance: Therapeutics informed by genomics have not yielded effective therapies for FLC. A functional screen identified TOPO1, HDAC inhibitors, and napabucasin as efficacious and synergistic with inhibition of Bcl-xL. Validation on cells dissociated directly from patient tumors demonstrates the ability for functional precision medicine in a solid tumor. This article is highlighted in the In This Issue feature, p. 2355