Preclinical Models Of Hepatocellular Carcinoma Research Articles

Phase II HEPANOVA trial of tumor treating fields concomitant with sorafenib for advanced hepatocellular carcinoma.

TPS603 Background: Tumor Treating Fields (TTFields) are a non-invasive, regional antimitotic treatment modality, which has been approved for the treatment of glioblastoma and malignant pleural mesothelioma by the FDA. TTFields predominantly act by disrupting the formation of the mitotic spindle during metaphase. TTFields were effective in multiple preclinical models of hepatocellular carcinoma (HCC), leading to a significant increase in cell death. The Phase 2 HEPANOVA [NCT03606590] study is the first trial testing TTFields in HCC patients, and is designed to test the safety and efficacy of adding TTFields to sorafenib in advanced HCC. Methods: (N = 25) with unresectable HCC who are not amenable to any local treatment will be enrolled in this prospective, single-arm study. The study enrolls patients with ECOG score of 0-2 and Barcelona clinic liver cancer (BCLC) stage 0-C. Patients must have a measurable disease per RECIST Criteria. Having implanted electronic devices in the torso is exclusionary. Sorafenib will be administered at standard dose (400 mg twice daily). TTFields (150 kHz) will be delivered for 18 hours/day until local disease progression per RECIST Criteria. Clinical follow up will be performed q4w, and a CT/MRI scan q12w. Following disease progression in the liver, patients will discontinue TTFields and be followed monthly for survival. Overall response rate will be the primary endpoint and in-field control rate, progression-free survival rate at 12 month (PFS12), OS rate at 1 year and toxicity will all be secondary endpoints. Sample size was calculated using an Exact test for proportions considering the weighted average of ORR of patients who had either complete or partial response per RECIST criteria in historical studies with sorafenib is 4.5%. A sample size of 25 patients was required to achieve a power of approximately 80% at a one-sided alpha level of 0.05 using a single sample Exact test for proportions. Clinical trial information: NCT03606590.

The cGAS-STING pathway is a therapeutic target in a preclinical model of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, and the incidence of HCC is increasing. Recently, cancer immunotherapy has emerged as an efficient treatment against some cancers. Here we have used a mouse model of mutagen-induced HCC to explore the therapeutic usefulness of targeting the DNA-activated STING pathway in HCC. STING-deficient mice exhibited unaltered initial development of HCC, but had higher number of large tumors at late stages of disease. In the liver of STING-deficient HCC mice, we observed reduced levels of phospho-STAT1, autophagy, and cleaved caspase3. These responses were activated in the liver by treatment with a cyclic dinucleotide (CDN) STING agonist. Importantly, CDN treatment of mice after HCC development efficiently reduced tumor size. Initiation of CDN treatment at an even later stage of disease to allow HCC detection by MR scanning revealed that the majority of tumors regressed in response to CDN, but new tumors were also detected, which were unresponsive to CDN treatment. Overall, the modulation of the STING pathway affects the development of HCC, and holds promise for a use as a treatment of this disease, most likely in combination with other immunomodulatory treatments such as PD1 inhibitors or with standard of care.

Abstract 2344: The cGAS-STING pathway is a therapeutic target in a preclinical model of hepatocellular carcinoma

Abstract Activation of the STING pathway is currently being explored in cancer immune therapy. The first STING agonist tested was DMXAA, but failed in clinical trial, since it does not bind human STING. The second generation of STING agonists are cyclic di-nucleotides (CDNs), either the naturally produced 2’3’ cyclic GMP-AMP or derivatives, and many of these has proven to have high affinity for all common human variations of STING. In our work, we have focused on 3’3’-cyclic 3’3’-cAIMP (Invivogen) for analysis of anticancer activity in mice. Hepatocellular carcinoma (HCC) is the most common primary liver cancer, and the incidence of HCC is increasing. We have used a mouse model of mutagen-induced HCC to explore the therapeutic usefulness of targeting the DNA-activated STING pathway in HCC. STING-deficient mice exhibited unaltered initial development of HCC, but had higher number of large tumors at late stages of disease. In the liver of STING-deficient HCC mice, we observed reduced levels of phospho-STAT1, autophagy, and cleaved caspase 3. These responses were activated in the liver by treatment with a cyclic dinucleotide (CDN) STING agonist. Importantly, CDN treatment of mice after HCC development efficiently reduced tumor size. Initiation of CDN treatment at an even later stage of disease to allow HCC detection by MR scanning, revealed that the majority of tumors regressed in response to CDN, but new tumors were detected, which were unresponsive to CDN treatment. Conclusion: modulation of the STING pathway impacts on development of HCC, and holds promise for use in treatment of this disease, most likely in combination with other immunomodulatory treatments such as PD1 inhibitors or with standard of care. Citation Format: Martin K. Thomsen. The cGAS-STING pathway is a therapeutic target in a preclinical model of hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2344.

Abstract CT175: HEPANOVA Phase II study design for advanced hepatocellular carcinoma: Tumor treating fields concomitant with sorafenib

Abstract Background Tumor Treating Fields (TTFields) are a non-invasive, regional antimitotic treatment modality, which has been approved for the treatment of glioblastoma by the FDA. TTFields predominantly act by disrupting the formation of the mitotic spindle during metaphase. TTFields were effective in multiple preclinical models of hepatocellular carcinoma (HCC), leading to a significant increase in cell death. The Phase II HEPANOVA study is the first trial testing TTFields in HCC patients, and is designed to test the safety and efficacy of adding TTFields to sorafenib in advanced HCC. Methods Trial Design: Patients (N=25) with unresectable HCC who are not amenable to any local treatment will be enrolled in this prospective, single-arm study. The study enrolls patients with ECOG score of 0-2 and Barcelona clinic liver cancer (BCLC) stage 0-C. Patients must have a measurable disease per RECIST Criteria. Having implanted electronic devices in the torso is exclusionary. Sorafenib will be administered at standard dose (400 mg daily). TTFields (150 kHz) will be delivered for 18 hours/day until local disease progression per RECIST Criteria. Clinical follow up will be performed q4w, and a CT/MRI scan q12w. Following disease progression in the liver, patients will discontinue TTFields and be followed monthly for survival. Overall response rate will be the primary endpoint and in-field control rate, progression-free survival rate at 12 month (PFS12), OS rate at 1 year and toxicity will all be secondary endpoints. Sample size was calculated using an Exact test for proportions considering the weighted average of ORR of patients who had either complete or partial response per RECIST criteria in historical studies with sorafenib is 4.5%. A sample size of 25 patients was required to achieve a power of approximately 80% at a one-sided alpha level of 0.05 using a single sample Exact test for proportions. Citation Format: Anca-Ligia Grosu, Eleni Gkika, Thomas Brunner, Robert Thimme, Uri Weinberg. HEPANOVA Phase II study design for advanced hepatocellular carcinoma: Tumor treating fields concomitant with sorafenib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT175.

Targeting myeloid-derived suppressor cells in the treatment of hepatocellular carcinoma: current state and future perspectives.

Systemic therapy for advanced hepatocellular carcinoma (HCC) has been focusing on overcoming tumor angiogenesis and immunosuppression. Myeloid-derived suppressor cells (MDSCs) promote both angiogenesis and immunosuppression in the tumor microenvironment (TME). Multiple clinical studies have demonstrated the prognostic implications of and suggested the translational significance of MDSCs in patients with HCC. In preclinical HCC models, targeting MDSCs has been shown to enhance antitumor efficacy of sorafenib or immune checkpoint inhibitors. Reversing the protumor effects of MDSCs could be achieved by depleting MDSCs, blocking MDSC trafficking and migration into TME, and inhibiting the immunosuppressive functions of MDSCs. To date, these strategies have not yet been validated to be clinically useful in patients with malignancy including HCC. Future studies should focus on identifying specific markers for human MDSCs and developing combination approaches incorporating MDSC-targeting therapy in the treatment of HCC.

Abstract No. 611 Immunologic ramifications of tumor-specific hyperthermia in a preclinical model of hepatocellular carcinoma

Recent clinical trials have demonstrated that immune checkpoint inhibitors are effective for only ∼20% of hepatocellular carcinoma (HCC) patients. Adjuvant hyperthermia treatment can potentially overcome barriers to immunotherapy by inducing immunogenic cell death; however, existing hyperthermia modalities are poorly optimized for immune stimulation. The purpose of this study was to evaluate the immunologic ramifications of a novel hyperthermia modality that promotes tumor-specific heat generation. An orthotopic HCC model was generated by subcapsular implantation of syngeneic McA-RH7777 hepatoma cells in female Buffalo rats (n=20). 96h following the i.v. administration of 0.5mg/kg indocyanine green (ICG), tumor-specific hyperthermia at sublethal (42–47C) or ablative (> 50C) temperatures was generated by illuminating the tumor (or adjacent liver tissue as control) with a 785nm near infrared laser coupled to a clinical fiberoptic catheter. 72h after treatment, normal and tumor tissue were harvested for immunohistochemistry, multi-color flow cytometry, and transcriptomic analysis. Principal component analysis of RNAseq data revealed distinct expression profiles as a function of thermal dose. In particular, sublethal hyperthermia was found to upregulate pathways associated with immunogenic cell death such as the unfolded protein response. It also suppressed non-immunogenic cell death pathways such as apoptosis and upregulated genes associated with the type I interferon response. Both sublethal and ablative hyperthermia doses were associated with an increase in CD8+ cytotoxic T-cell infiltration within the tumors. Paradoxically, ablative hyperthermia was also associated with an increase in the expression of multiple components of the hepatocyte growth factor/cMet pathway. Tumor-specific hyperthermia is associated with transcriptional and microenvironmental modifications that can improve anti-tumor immunity.

Inhibition of the dipeptidyl peptidase DPP4 (CD26) reveals IL-33-dependent eosinophil-mediated control of tumor growth.

Post-translational modification of chemokines mediated by the dipeptidyl peptidase DPP4 (CD26) has been shown to negatively regulate lymphocyte trafficking, and its inhibition enhances T cell migration and tumor immunity by preserving functional chemokine CXCL10. By extending those initial findings to pre-clinical models of hepatocellular carcinoma and breast cancer, we discovered a distinct mechanism by which inhibition of DPP4 improves anti-tumor responses. Administration of the DPP4 inhibitor sitagliptin resulted in higher concentrations of the chemokine CCL11 and increased migration of eosinophils into solid tumors. Enhanced tumor control was preserved in mice lacking lymphocytes and was ablated after depletion of eosinophils or treatment with degranulation inhibitors. We further demonstrated that tumor-cell expression of the alarmin IL-33 was necessary and sufficient for eosinophil-mediated anti-tumor responses and that this mechanism contributed to the efficacy of checkpoint-inhibitor therapy. These findings provide insight into IL-33- and eosinophil-mediated tumor control, revealed when endogenous mechanisms of DPP4 immunoregulation are inhibited.

Phase II HEPANOVA trial of tumor treating fields concomitant with sorafenib for advanced hepatocellular carcinoma.

TPS470 Background: Tumor Treating Fields (TTFields) are a non-invasive, regional antimitotic treatment modality, which has been approved for the treatment of glioblastoma by the FDA. TTFields predominantly act by disrupting the formation of the mitotic spindle during metaphase. TTFields were effective in multiple preclinical models of hepatocellular carcinoma (HCC), leading to a significant increase in cell death. The Phase 2 HEPANOVA study is the first trial testing TTFields in HCC patients, and is designed to test the safety and efficacy of adding TTFields to sorafenib in advanced HCC. Methods: Patients (N = 25) with unresectable HCC who are not amenable to any local treatment will be enrolled in this prospective, single-arm study. The study enrolls patients with ECOG score of 0-2 and Barcelona clinic liver cancer (BCLC) stage 0-C. Patients must have a measurable disease per RECIST Criteria. Having implanted electronic devices in the torso is exclusionary. Sorafenib will be administered at standard dose (400 mg twice daily). TTFields (150 kHz) will be delivered for 18 hours/day until local disease progression per RECIST Criteria. Clinical follow up will be performed q4w, and a CT/MRI scan q12w. Following disease progression in the liver, patients will discontinue TTFields and be followed monthly for survival. Overall response rate will be the primary endpoint and in-field control rate, progression-free survival rate at 12 month (PFS12), OS rate at 1 year and toxicity will all be secondary endpoints. Sample size was calculated using an Exact test for proportions considering the weighted average of ORR of patients who had either complete or partial response per RECIST criteria in historical studies with sorafenib is 4.5%. A sample size of 25 patients was required to achieve a power of approximately 80% at a one-sided alpha level of 0.05 using a single sample Exact test for proportions. Clinical trial information: NCT03606590.

Neuroblastoma RAS Viral Oncogene Homolog (NRAS) Is a Novel Prognostic Marker and Contributes to Sorafenib Resistance in Hepatocellular Carcinoma

Inhibition of the RAS-RAF-ERK-pathway using sorafenib as a first-line and regorafenib as a second-line treatment approach is the only effective therapeutic strategy for advanced hepatocellular carcinoma (HCC). Recent studies suggest that wild-type KRAS and HRAS isoforms could majorly contribute to HCC progression and sorafenib resistance. In contrast, the role of neuroblastoma RAS viral oncogene homolog (NRAS) in HCC remained elusive. In this study, wild-type NRAS was found to be overexpressed in HCC cell lines, preclinical HCC models, and human HCC tissues. Moreover, NRAS overexpression correlated with poor survival and proliferation in vivo. However, si-RNA-pool–mediated NRAS knockdown showed only slight effects on HCC proliferation, clonogenicity, and AKT activity. We determined that KRAS upregulation served as a functional compensatory mechanism in the absence of NRAS, which was overcome by combined inhibition of NRAS and KRAS in HCC cells. Furthermore, NRAS expression was elevated in sorafenib-resistant compared to nonresistant HCC cells, and NRAS knockdown enhanced sorafenib efficacy in resistant cells. In summary, NRAS appears to be a prognostic marker in HCC and contributes to sorafenib resistance. Regarding potential therapeutic strategies, NRAS inhibition in HCC should be combined with KRAS inhibition to prevent KRAS-mediated rescue effects.

Pharmacokinetic interaction study of novel combination of palbociclib and sorafenib for hepatocellular carcinoma in SD rats

Hepatocellular carcinoma (HCC) is a fatal oncogenic disorder with few therapeutic options. Novel therapeutic strategy with combination of a selective CDK4/6 inhibitor palbociclib (PAL) with a tyrosine kinase inhibitor (TKI) sorafenib (SOR) is reported to impair tumour growth and significantly increased survival in various preclinical models of HCC. In the current work a sensitive and rapid UHPLC–QTOF-MS method was established for the concurrent quantification of PAL and SOR in rat plasma using ibrutinib as internal standard (IS). Chromatographic separation was carried out on an Agilent Poroshell EC C18 (50 mm × 3 mm, 2.7 μm) using gradient mobile phase consisting of 0.1% formic acid and acetonitrile. Flow rate of 0. 45 mL/min with a run time of 5 min was used for separation. A simple sample preparation approach of protein precipitation was used in the current study. The mass spectrometric analysis of selective ions at [M + H]+m/z 448.2455 for PAL, m/z 465.0936 for SOR and m/z 441.2034 for IS was monitored with extracted ion chromatography. The LC-MS method meets the regulatory bio-analytical guidelines, exhibited good sensitivity and linearity over the range of 1.0–2000.0 ng/mL for PAL and SOR. The pharmacokinetic parameters of PAL remained unchanged when SOR was co-administered with PAL. The study pointed out that the co-intake of PAL with SOR resulted in a slight increment of Cmax (11.21%) and AUC (7.95%) levels of SOR when co-administered with PAL when compared to individual oral intake in SD rats. The current method provides a modern rapid and sensitive tool for pharmacokinetic studies of PAL and SOR in a pre-clinical set up.

SUMOylation regulates LKB1 localization and its oncogenic activity in liver cancer.

BackgroundEven though liver kinase B1 (LKB1) is usually described as a tumor suppressor in a wide variety of tissues, it has been shown that LKB1 aberrant expression is associated with bad prognosis in Hepatocellular Carcinoma (HCC).MethodsHerein we have overexpressed LKB1 in human hepatoma cells and by using histidine pull-down assay we have investigated the role of the hypoxia-related post-translational modification of Small Ubiquitin-related Modifier (SUMO)ylation in the regulation of LKB1 oncogenic role. Molecular modelling between LKB1 and its interactors, involved in regulation of LKB1 nucleocytoplasmic shuttling and LKB1 activity, was performed. Finally, high affinity SUMO binding entities-based technology were used to validate our findings in a pre-clinical mouse model and in clinical HCC.FindingsWe found that in human hepatoma cells under hypoxic stress, LKB1 overexpression increases cell viability and aggressiveness in association with changes in LKB1 cellular localization. Moreover, by using site-directed mutagenesis, we have shown that LKB1 is SUMOylated by SUMO-2 at Lys178 hampering LKB1 nucleocytoplasmic shuttling and fueling hepatoma cell growth. Molecular modelling of SUMO modified LKB1 further confirmed steric impedance between SUMOylated LKB1 and the STe20-Related ADaptor cofactor (STRADα), involved in LKB1 export from the nucleus. Finally, we provide evidence that endogenous LKB1 is modified by SUMO in pre-clinical mouse models of HCC and clinical HCC, where LKB1 SUMOylation is higher in fast growing tumors.InterpretationOverall, SUMO-2 modification of LKB1 at Lys178 mediates LKB1 cellular localization and its oncogenic role in liver cancer.FundThis work was supported by grants from NIH (US Department of Health and Human services)-R01AR001576-11A1 (J.M.M and M.L.M-C.), Gobierno Vasco-Departamento de Salud 2013111114 (to M.L.M.-C), ELKARTEK 2016, Departamento de Industria del Gobierno Vasco (to M.L.M.-C), MINECO: SAF2017–87301-R and SAF2014–52097-R integrado en el Plan Estatal de Investigación Cientifica y Técnica y Innovación 2013–2016 cofinanciado con Fondos FEDER (to M.L.M.-C and J.M.M., respectively), BFU2015–71017/BMC MINECO/FEDER, EU (to A.D.Q. and I.D.M.), BIOEF (Basque Foundation for Innovation and Health Research): EITB Maratoia BIO15/CA/014; Instituto de Salud Carlos III:PIE14/00031, integrado en el Plan Estatal de Investigación Cientifica y Técnica y Innovacion 2013–2016 cofinanciado con Fondos FEDER (to M.L.M.-C and J.M.M), Asociación Española contra el Cáncer (T.C.D, P·F-T and M.L.M-C), Daniel Alagille award from EASL (to T.C.D), Fundación Científica de la Asociación Española Contra el Cancer (AECC Scientific Foundation) Rare Tumor Calls 2017 (to M.L.M and M.A), La Caixa Foundation Program (to M.L.M), Programma di Ricerca Regione-Università 2007–2009 and 2011–2012, Regione Emilia-Romagna (to E.V.), Ramón Areces Foundation and the Andalusian Government (BIO-198) (A.D.Q. and I.D.M.), ayudas para apoyar grupos de investigación del sistema Universitario Vasco IT971–16 (P.A.), MINECO:SAF2015–64352-R (P.A.), Institut National du Cancer, FRANCE, INCa grant PLBIO16–251 (M.S.R.), MINECO - BFU2016–76872-R to (E.B.). Work produced with the support of a 2017 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation (M.V-R). Finally, Ciberehd_ISCIII_MINECO is funded by the Instituto de Salud Carlos III. We thank MINECO for the Severo Ochoa Excellence Accreditation to CIC bioGUNE (SEV-2016-0644). Funding sources had no involvement in study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication.

Comparison of dynamic contrast-enhanced magnetic resonance imaging and contrast-enhanced ultrasound for evaluation of the effects of sorafenib in a rat model of hepatocellular carcinoma

ObjectivesTo compare the accuracy of contrast-enhanced ultrasound (CEUS) and Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for the assessment of changes in tissue vascularization as result of sorafenib treatment in a rat model of hepatocellular carcinoma (HCC). MethodsMale Buffalo rats with orthotopic liver tumors treated daily with 7.5 mg/kg sorafenib via oral gavage for 2 weeks (n = 9) were subject to DCE-MRI and CEUS 2 weeks after tumor implantation - right before treatment initiation - and also after treatment completion - right before tumor harvest. Untreated animals (n = 10) were used as control. Tumor tissue sections were stained for hematoxylin-eosin, pimonidazole, and CD34 for quantitative assessment of necrosis, hypoxia, and microvessel density (MVD), respectively. ResultsOf all the DCE-MRI parameters that were evaluated, only volume transfer constant (Ktrans) measurements were significantly lower in sorafenib-treated tumors (0.18 vs 0.33 min−1, p < 0.01), indicating a substantial decrease in vascular permeability caused by the therapy. This reduction was associated with decreased MVD (3.9 vs 10.8% CD34+ cells, p < 0.01), higher tumor necrosis (31.9 vs 21.8%, p < 0.001) and hypoxia (19.7 vs 10.5% pimonidazole binding, p < 0.01). Moreover, statistical analysis demonstrate significant correlation of DCE-MRI Ktrans with histopathologic tissue necrosis (r = −0.537, p < 0.05) and MVD (r = 0.599, p < 0.05). Interestingly, none of the CEUS measurements were significantly different between the control and treatment groups, and did not show statistical correlation with any of the histopathological parameters assessed (p > 0.05). ConclusionsSorafenib-induced reduction in vascular permeability in this preclinical model of HCC is detected more accurately through DCE-MRI than CEUS, and DCE-MRI parameters strongly correlate with histopathological changes in tissue vascularization and tissue necrosis.

Abstract 4792: Preclinical evaluation of GST-HG161, a potent and highly selective c-MET inhibitor

Abstract Objective: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Studies indicate that aberrant activation of mesenchymal-epithelial transition factor (c-MET) is associated with HCC development. Blocking c-MET signaling shows antitumor efficacy in patients with HCC. Thus, c-MET has been an attractive therapeutic target for HCC. We disclose here for the first time a potent and selective c-MET inhibitor GST-HG161 and show the antitumor efficacy data in preclinical models of HCC. Method: MHCC97H HCC cell line with c-MET overexpression was used to evaluate the anti-proliferative activity of GST-HG161 in a 120-hour viability assay. Selectivity was evaluated with a panel of cell lines without overexpression of c-MET. Daily oral administration of GST-HG161 doses of 1, 3, 10 and 30mg/kg was used to evaluate its in vivo antitumor efficacy in two animal models of HCC with c-MET overexpression, MHCC97H xenograft (CDX) model and LI-03-0317 xenograft (PDX) model. The c-MET protein levels and gene copy number in LI-03-0317 PDX were assessed by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively. High c-MET expression in LI-03-0317 PDX was determined by the presence of tumor cells with membrane staining of 3+ intensity. Effect of GST-HG161 on c-MET signaling inhibition was assessed by western blot analysis of downstream effector proteins including p-MET, p-AKT and p-ERK. Result: GST-HG161 displayed potent anti-proliferative activity in MHCC97H HCC cell line (IC50 = 5 nM) while showed little activity in the cell lines without c-MET overexpression. It significantly inhibited tumor growth at tested doses (3, 10 and 30mg/kg) (P&amp;lt;0.05) in both MHCC97H CDX model and LI-03-0317 PDX model. In MHCC97H CDX model, western blot analysis showed that GST-HG161 potently inhibited p-MET and downstream effector proteins p-AKT and p-ERK in the tumor tissue, indicating that the tumor growth inhibition in this model was mediated through inhibition of c-MET. Conclusion: GST-HG161 is a potent and highly selective c-MET inhibitor. Its excellent antitumor efficacy as shown in the HCC mouse models provide us with confidence that GST-HG161 has high potential in the clinic for treating patients of HCC with high c-MET activity. Citation Format: Xiongbin Xu, Gang Li, Lihong Hu, Junguo Hao, Charles Z. Ding, Shuhui Chen. Preclinical evaluation of GST-HG161, a potent and highly selective c-MET inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4792.

Abstract CT084: HEPANOVA: A phase II trial of tumor treating fields concomitant with sorafenib for advanced hepatocellular carcinoma

Abstract Tumor Treating Fields (TTFields) are a non-invasive, regional antimitotic treatment modality, which has been approved for the treatment of glioblastoma by the FDA. TTFields predominantly act by disrupting the formation of the mitotic spindle during metaphase. TTFields were effective in multiple preclinical models of hepatocellular carcinoma (HCC), leading to a significant increase in cell death. The Phase 2 HEPANOVA study is the first trial testing TTFields in HCC patients, and is designed to test the safety and efficacy of adding TTFields to sorafenib in advanced HCC. Trial Design: Patients (N=25) with unresectable HCC who are not amenable to any local treatment will be enrolled in this prospective, single-arm study. The study enrolls patients with ECOG score of 0-2 and Barcelona clinic liver cancer (BCLC) stage 0-C. Patients must have a measurable disease per RECIST Criteria. Having implanted electronic devices in the torso is exclusionary. Sorafenib will be administered at standard dose (400 mg daily). TTFields (150kHz) will be deilvered for 18 hours/day until local disease progression per RECIST Criteria. Clinical follow up will be performed q4w, and a CT/MRI scan q12w. Following disease progression in the liver, patients will discontinue TTFields and be followed monthly for survival. Overall response rate will be the primary endpoint and in-field control rate, progression-free survival rate at 12 month (PFS12), OS rate at 1 year and toxicity will all be secondary endpoints. Sample size was calculated using an Exact test for proportions considering the weighted average of ORR of patients who had either complete or partial response per RECIST criteria in historical studies with sorafenib is 4.5%. A sample size of 25 patients was required to achieve a power of approximately 80% at a one-sided alpha level of 0.05 using a single sample Exact test for proportions. Citation Format: Anca-Ligia Grosu, Josif Strouthos, Thomas Brunner, Uri Weinberg. HEPANOVA: A phase II trial of tumor treating fields concomitant with sorafenib for advanced hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT084.

SAT-160 - Blocking the CDK1/PDK1/B-Catenin signaling by CDK1 inhibitor RO3306 increased the efficacy of sorafenib treatment with targeting cancer stem cell in preclinical model of hepatocellular carcinoma

SAT-160 - Blocking the CDK1/PDK1/B-Catenin signaling by CDK1 inhibitor RO3306 increased the efficacy of sorafenib treatment with targeting cancer stem cell in preclinical model of hepatocellular carcinoma

An open label phase 1b/2 trial of TRC105 and sorafenib in patient with advanced/metastatic hepatocellular carcinoma (HCC) (NCT01806064).

301 Background: Endoglin plays a critical role in angiogenesis and is implicated in resistance to VEGF inhibition. TRC105, an endoglin antibody potentiates anti-tumor activity of sorafenib (S) in preclinical HCC models. The combination of TRC105 and S demonstrated encouraging evidence of activity, including a 33% partial response rate (5/15 pts) by RECIST, at RP2D doses of TRC105 in HCC ( Clin Can Res 2017). Adverse events characteristic of each drug were not increased in frequency or severity when the two drugs were administered concurrently, and most commonly included epistaxis, fatigue, headache and anemia. Methods: Following dose escalation, 21 pts will be enrolled at the RP2D. Four objective responses are required to reject the null hypothesis that the true response rate probability is &lt; 5% with an alpha level of 0.1 and 80% power. Secondary endpoints: DR, PFS, frequency and severity of AEs, PK, immunogenicity, angiogenic biomarkers. Key inclusion criteria: disease not amendable to surgical or local therapies, ECOG ≤ 1; Child-Pugh A or B (7 points) classification. Results: Four pts have been enrolled in phase 1b at TRC105 10 mg/kg (n=4) weekly for four doses and 15 mg/kg every other week thereafter + S 800 mg daily without DLT. One of 3 evaluable pts achieved PR (41% reduction), ongoing at month 4. Serum levels of TRC105 exceeded the target concentration following 4 weekly doses of TRC105 at 10 mg/kg (mean = 59 µg/ml, range 43-80). Mean trough concentration decreased following every other week dosing (mean = 21 µg/ml, range 17-31). Common TRC105 related AEs included ≤ G2 epistaxis and G1 headache. Common S related AEs included G3 hand foot syndrome, ≤G3 periodontal disease, G2 hypertension, ≤G2 increased lipase, ≤G2 fatigue and G1 epistaxis. Conclusions: TRC105 dosed by a hybrid schedule of 10 mg/kg weekly for four doses followed by every other week dosing at 15 mg/kg was tolerable and did not potentiate the toxicity of S. The combination of TRC105 + S demonstrated additional signs of activity, including a PR in 1/3 evaluable pts. 21 pts will be enrolled at the RP2D to assess the primary endpoint of ORR by RECIST. Clinical trial information: NCT01806064.

Oncolytic Virotherapy and Gene Therapy Strategies for Hepatobiliary Cancers.

Advanced liver cancers and biliary cancers represent diseases with dismal prognosis because of frequent local invasion and metastasis. Effective therapeutic agents for these cancers have not been established. Oncolytic viruses (OVs) constitute a novel class of promising, selective anticancer agents and recent studies have elucidated their unique features. Moreover, clinical trials are demonstrating promising results. Numerous OVs are being tested in preclinical models of hepatocellular carcinoma (HCC). The lead agent Pexa-Vec (pexastimogene devacirepvec, JX-594), a recombinant Wyeth strain vaccinia virus, has demonstrated preliminary evidence of safety and efficacy for HCC in clinical trials. Few other OVs have entered clinical testing. Relatively few preclinical studies and clinical trials exist for biliary cancers. In this review, we introduce various approaches using OVs to treat the intractable hepatobiliary cancers.

Abstract B095: Antitumor activity of lenvatinib mesilate (LEN) via angiogenesis inhibition and tumor FGF signaling pathway in the human hepatocellular carcinoma models

Abstract Background: LEN is an oral multi-targeted tyrosine kinase inhibitor that selectively inhibits vascular endothelial growth factor receptor (VEGFR)1-3, fibroblast growth factor receptor (FGFR)1-4, platelet-derived growth factor receptor α, RET, and KIT. LEN was noninferior to sorafenib (SOR) in overall survival (OS) in a phase 3 study in patients with unresectable hepatocellular carcinoma (HCC) (medians: LEN, 13.6 vs SOR, 12.3 months; hazard ratio: 0.92; 95% confidence interval, 0.79-1.06) and statistically superior to SOR in progression-free survival (PFS), time to progression (TTP), and objective response rate (ORR). We previously reported that LEN showed antitumor activity in multiple HCC xenograft models including patient-derived xenograft (PDx) models. Here, we investigated the mode of action of LEN in preclinical human HCC models to examine antitumor angiogenesis activity in vivo and the effects on FGF signaling pathways both in vitro and in vivo in the preclinical HCC models. Methods: Antiproliferative activity of LEN and SOR was examined using human HCC cells (Hep 3B2.1-7, HuH-7, SNU398, and PLC/PRF/5) in vitro, and antitumor and anti-angiogenesis activity were examined using these HCC cell lines and PDx models. The effect on the FGF signaling pathway was evaluated by determining the phosphorylation of FRS2, a direct substrate of FGFRs, with immunoblotting analysis in both cultured cells and tumor xenografts. Anti-angiogenesis activity was evaluated by determining microvessel density (MVD) within tumor xenografts by immunohistochemical analysis using anti-CD31 antibody. Result: LEN decreased the phosphorylation of FRS2 in FGF19-overexpressing Hep3B2.1-7 and HuH-7 cells at 0.03 to 3 μmol/L in a concentration-dependent manner. LEN showed selective antiproliferative activity against these cells with half-maximal inhibitory concentration (IC50) values of 0.23 and 0.42 μmol/L, respectively, and those concentrations were consistent with ones for inhibitions of the phosphorylation of FRS2. In tumor xenografts, LEN also decreased the phosphorylation of FRS2 by the single administration of LEN between 3 and 30 mg/kg. SNU398 cells are known to have a relatively weak dependence on the FGF signaling pathway without FGF19 expression. LEN inhibited in vitro proliferation of SNU398 cells, and the phosphorylation of FRS2 both in vitro and in vivo at higher doses than in Hep 3B2.1-7 and HuH-7 cells. SOR did not selectively inhibit in vitro proliferation or the phosphorylation of FRS2 in HCC cells with FGF activation in vitro and in vivo. In HCC PDx and PLC/PRF/5 xenograft models, LEN significantly decreased the MVD in a dose-dependent manner between 3 and 30 mg/kg, and it was correlated with tumor growth inhibition in each models. SOR showed clear anti-angiogenesis activity at 30 mg/kg, but not at 10 mg/kg. Conclusion: These results suggest that inhibition of the FGF signaling pathway via FGFR with LEN affects proliferation of HCC cells with activation of the FGF signaling pathway, and the potent anti-angiogenic activity underlies the antitumor activity of LEN in preclinical HCC xenograft models. Citation Format: Taisuke Hoshi, Masahiro Matsuki, Yuji Yamamoto, Yukinori Minoshima, Junji Matsui, Yasuhiro Funahashi. Antitumor activity of lenvatinib mesilate (LEN) via angiogenesis inhibition and tumor FGF signaling pathway in the human hepatocellular carcinoma models [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B095.

Blocking CDK1/PDK1/β-Catenin signaling by CDK1 inhibitor RO3306 increased the efficacy of sorafenib treatment by targeting cancer stem cells in a preclinical model of hepatocellular carcinoma.

Rationale: Hepatocellular carcinoma (HCC) is an aggressive malignant solid tumor wherein CDK1/PDK1/β-Catenin is activated, suggesting that inhibition of this pathway may have therapeutic potential.Methods: CDK1 overexpression and clinicopathological parameters were analyzed. HCC patient-derived xenograft (PDX) tumor models were treated with RO3306 (4 mg/kg) or sorafenib (30 mg/kg), alone or in combination. The relevant signaling of CDK1/PDK1/β-Catenin was measured by western blot. Silencing of CDK1 with shRNA and corresponding inhibitors was performed for mechanism and functional studies.Results: We found that CDK1 was frequently augmented in up to 46% (18/39) of HCC tissues, which was significantly associated with poor overall survival (p=0.008). CDK1 inhibitor RO3306 in combination with sorafenib treatment significantly decreased tumor growth in PDX tumor models. Furthermore, the combinatorial treatment could overcome sorafenib resistance in the HCC case #10 PDX model. Western blot results demonstrated the combined administration resulted in synergistic down-regulation of CDK1, PDK1 and β-Catenin as well as concurrent decreases of pluripotency proteins Oct4, Sox2 and Nanog. Decreased CDK1/PDK1/β-Catenin was associated with suppression of epithelial mesenchymal transition (EMT). In addition, a low dose of RO3306 and sorafenib combination could inhibit 97H CSC growth via decreasing the S phase and promoting cells to enter into a Sub-G1 phase. Mechanistic and functional studies silencing CDK1 with shRNA and RO3306 combined with sorafenib abolished oncogenic function via downregulating CDK1, with downstream PDK1 and β-Catenin inactivation.Conclusion: Anti-CDK1 treatment can boost sorafenib antitumor responses in PDX tumor models, providing a rational combined treatment to increase sorafenib efficacy in the clinic.

A microRNA-7/growth arrest specific 6/TYRO3 axis regulates the growth and invasiveness of sorafenib-resistant cells in human hepatocellular carcinoma.

We identified a mechanism for acquiring SR in HCC that is through the aberrant expression of the TYRO3/phosphoinositide 3-kinase/protein kinase B signal transduction pathway, and that can be overcome by miR-7 overexpression. Taken together, these data suggest a potential role for miR-7 as an RNA-based therapeutic to treat refractory and drug-resistant HCC. (Hepatology 2018;67:216-231).