Roberts, Lewis R.

Abstract Cholangiocarcinoma (CCA) is an aggressive epithelial malignancy of the bile ducts. Recent reports have suggested a rise in the incidence of CCA globally. Current treatments for CCA have limited effectiveness, with only 20-30% response rates in patients with advanced cancer. Thus, there is a growing need to investigate new therapeutic targets for CCA. The tumor microenvironment (TME) is a potential target for novel therapies. The TME plays an important role in progression and metastasis of cancer through facilitating immune escape. Recent studies have demonstrated potential roles for heparan sulfate proteoglycans (HSPGs) in tumorigenesis. Sulfatase 2 (SULF2) is a heparan sulfate editing sulfatase that removes the 6-O sulfate moiety within the heparan sulfate (HS) chains and alters the affinity of HS chains for growth factors and cytokines and their receptors, thus modulating HSPG function in cell signaling pathways. HSPG specific sulfatases have been recently identified as a potential therapeutic target in CCA. We aimed to assess the effects of anti-Sulfatase-2 antibody on immune cells in the tumor microenvironment of syngeneic CCA xenografts in C57BL6 mice. Mice bearing syngeneic CCA xenografts were treated with an anti-sulf2 antibody, and the tumors compared to untreated control xenografts. After treatment, the tumors were harvested and analyzed by Cytometry by time of flight (Cytof) to identify changes in the types and numbers of immune cells in the tumor xenografts. Treatment with anti-sulf2 antibody resulted in a decrease in immunosuppressive cells such as tumor associated macrophages (TAMs) and myeloid derived suppressor cells (MDSC) compared to the control. There was also an increase in anti-tumor cells such as T-cells and NK cells, suggesting that suppressing sulf-2 in the microenvironment can shift the TME toward an anti-tumorigenic rather than a pro-tumorigenic environment. In summary, our work demonstrates the potential to target Sulfatase 2 as a therapeutic mechanism for immunomodulation of the tumor microenvironment. Future experiments to determine the relationship between specific clinical phenotypes and the number, activities and types of immune cells seen in the TME, and experiments in other hepatobiliary cancers models, such as hepatocellular carcinoma and gallbladder cancer, will be conducted. Citation Format: Tayla R. Brooks, Nellie Campbell, Melanie Keim, Lewis R. Roberts. Modulating the immune response in cholangiocarcinoma: Targeting sulfatase-2 for therapeutic intervention [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6525.

Abstract Background: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. In sub-Saharan Africa, HCC is the second most common cancer in men and the sixth in women. African patients present with HCC at a young age and at advanced stage of disease. Improved surveillance can increase early HCC detection. The GALAD score has good sensitivity in the diagnosis of HCC in Asia, Europe and North America, however, it has not been validated in an African cohort. The aim of this study was to assess the performance of the GALAD score in the diagnosis of HCC in Ghanaian patients. Methods: Clinical data from patients with cirrhosis (n=93) or HCC (n=78) from out-patient hepatology clinics at 3 teaching hospitals in Ghana were abstracted, and serum samples analyzed. A logistic regression model predicting HCC status based on GALAD score was constructed to obtain the Receiver Operating Characteristics (ROC) curve for GALAD. The area under the curve (AUC) with 95% confidence interval was calculated and used to assess the performance of the GALAD score in surveillance for HCC. Results: The median AFP (5010.2 vs. 3.4), L3% (28.3 vs. 0.3) and DCP (507.6 vs. 0.2) levels were all significantly higher among HCC cases than the controls (p<0.0001). The median GALAD score was also higher among HCC patients (8.0 vs. -4.1, p<0.0001). The AUC of the GALAD score in the diagnosis of HCC was 0.86 (95% CI 0.79 - 0.92). At a cut-off value of -0.37, the GALAD score had a sensitivity of 0.81 and a specificity of 0.86. In a re-fit of the logistic regression model, the most significant factors in the GALAD model in our cohort were AFP-L3% and log(DCP). The AUC of the new GALAD model after model selection was 0.89. Conclusion: The GALAD score can be used to detect HCC in Ghana and has the potential to improve HCC surveillance in low-resource settings in sub-Saharan Africa. Citation Format: Yvonne Ayerki Nartey, Ju Dong Yang, Tyler Zemla, Joshua Ayawin, Shadrack Osei Asibey, Mohamed El-Kassas, Sally Afua Bampoh, Amoako Duah, Adwoa Agyei-Nkansah, Yaw Asante Awuku, Mary Yeboah Afihene, Hiroyuki Yamada, Jun Yin, Amelie Plymoth, Lewis Rowland Roberts. Accuracy of the GALAD serologic model in the diagnosis of hepatocellular carcinoma in Ghanaian patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4802.

Upamostat is an orally available small-molecule serine protease inhibitor that is a highly potent inhibitor of trypsin 1, trypsin 2, trypsin 3 (PRSS1/2/3), and the urokinase-type plasminogen activator (uPA). These enzymes are expressed in many cancers, especially during tissue remodeling and subsequent tumor cell invasion. Opaganib (ABC294640), a novel, orally available small molecule is a selective inhibitor of the phosphorylation of sphingosine to sphingosine-1-phosphate (S-1-P) by sphingosine kinase 2 (SPHK2). Both sphingosine kinase 1 (SPHK1) and SPHK2 are known to regulate the proliferation-inducing compound S-1-P. However, SPHK2 is more critical in cancer pathogenesis. The goal of this project was to investigate the potential antitumor effects of upamostat and opaganib, individually and in combination, on cholangiocarcinoma (CCA) xenografts in nude mice. PAX165, a patient-derived xenograft (PDX) from a surgically resected CCA, expresses substantial levels of SPHK2, PRSS1, PRSS2, and PRSS3. Four groups of 18 mice each were treated with upamostat, opaganib, both, or vehicle. Mouse weights and PAX165 tumor volumes were measured. Tumor volumes in the upamostat, opaganib, and upamostat plus opaganib groups were significantly decreased compared to the control group.

Background and Aims: Despite the substantial impact of environmental factors, individuals with a family history of liver cancer have an increased risk for HCC. However, genetic factors have not been studied systematically by genome-wide approaches in large numbers of individuals from European descent populations (EDP). Approach and Results: We conducted a 2-stage genome-wide association study (GWAS) on HCC not affected by HBV infections. A total of 1872 HCC cases and 2907 controls were included in the discovery stage, and 1200 HCC cases and 1832 controls in the validation. We analyzed the discovery and validation samples separately and then conducted a meta-analysis. All analyses were conducted in the presence and absence of HCV. The liability-scale heritability was 24.4% for overall HCC. Five regions with significant ORs (95% CI) were identified for nonviral HCC: 3p22.1, MOBP, rs9842969, (0.51, [0.40–0.65]); 5p15.33, TERT, rs2242652, (0.70, (0.62–0.79]); 19q13.11, TM6SF2, rs58542926, (1.49, [1.29–1.72]); 19p13.11 MAU2, rs58489806, (1.53, (1.33–1.75]); and 22q13.31, PNPLA3, rs738409, (1.66, [1.51–1.83]). One region was identified for HCV-induced HCC: 6p21.31, human leukocyte antigen DQ beta 1, rs9275224, (0.79, [0.74–0.84]). A combination of homozygous variants of PNPLA3 and TERT showing a 6.5-fold higher risk for nonviral-related HCC compared to individuals lacking these genotypes. This observation suggests that gene-gene interactions may identify individuals at elevated risk for developing HCC. Conclusions: Our GWAS highlights novel genetic susceptibility of nonviral HCC among European descent populations from North America with substantial heritability. Selected genetic influences were observed for HCV-positive HCC. Our findings indicate the importance of genetic susceptibility to HCC development.

507 Background: Navitoclax (ABT-263) is an oral Bcl-2 homology-3 mimetic that binds with high affinity to pro-survival Bcl-2 proteins, resulting in apoptosis. Sorafenib, an oral multi kinase inhibitor inhibits tumor angiogenesis and also promotes apoptosis. The efficacy of either agent alone is limited; however, preclinical studies demonstrate synergy with the combination of navitoclax and sorafenib. Methods: In this phase 1 pharmacokinetic and pharmacodynamic study (NCT01364051), we evaluated the combination of navitoclax and sorafenib in a dose escalation cohort of patients with refractory solid tumors, with an expansion cohort in hepatocellular carcinoma (HCC). The study agents were provided by the Cancer Therapy Evaluation Program at National Cancer Institute under CRADA. Navitoclax and sorafenib were administered continuously on days 1 through 21 of 21-day cycles. The maximum tolerated dose (MTD) was determined using the continual reassessment method. Results: Ten patients were enrolled in the dose escalation cohort and 15 patients with HCC were enrolled in the expansion cohort. Two dose levels were tested, dose level 1 (navitoclax 150 mg daily plus sorafenib 400 mg twice daily) and dose level 2 (navitoclax 200 mg daily plus sorafenib 400 mg twice daily). At dose level 1, one dose limiting toxicity (DLT) [grade 3 aspartate aminotransferase elevation] was observed among 6 patients treated at this dose level. In a cohort of 3 patients treated at dose level 2, two DLTs were observed (grade 3 hypertension, and grade 3 rash), hence dose level 1 was identified as the MTD. Among all patients, the most common grade 3 toxicity was thrombocytopenia (5 patients, 20%): there were no grade 4 or 5 toxicities (Table). Patients received a median of 2 cycles (range 1-36 cycles) and all patients were off study treatment at data cut off. Six patients in the expansion cohort had stable disease, 5 had progressive disease and 4 with unavailable data. There were no partial or complete responses. Drug-drug interaction between navitoclax and sorafenib was not observed. The combination of navitoclax and sorafenib did not increase induction of apoptosis compared with navitoclax alone. Conclusions: Navitoclax plus sorafenib resulted in manageable, but not ideal toxicities for continuous oral administration which precluded dose escalation. The lack of clinical benefit in the HCC expansion cohort does not support further development of this combination for the treatment of advanced HCC. Clinical trial information: NCT01364051 . [Table: see text]

SummaryBackgroundRacial and ethnic disparities exist for hepatitis C virus (HCV) treatment and hepatocellular carcinoma (HCC) survival.AimTo evaluate the impact of HCV treatment on such disparities.MethodsIn a retrospective cohort study, we analysed 6069 patients with HCV‐related HCC (54.2% Asian, 30.1% White, 8.5% Black, and 7.3% Hispanic) from centres in the United States and Asia.ResultsThe mean age was 61, 60, 59 and 68, respectively, for White, Black, Hispanic and Asian patients. Black patients were most likely to have Barcelona Clinic Liver Cancer stage D, vascular invasion and distant metastasis (23% vs. 5%–15%, 20% vs. 10%–17% and 10% vs. 5%–7%, respectively; all p < 0.0001). Treatment rate with direct‐acting antiviral agents (DAA) was 35.9% for Asian, 34.9% for White, 30.3% for Hispanic (30.3%), and 18.7% for Black patients (p < 0.0001). Among those untreated or without sustained virologic response (SVR), 10‐year survival rates were 35.4, 27.5, 19.3 and 14.0, respectively, for Asian, Hispanic, White and Black patients (p < 0.0001). There were no statistically significant differences among those with SVR (p = 0.44). On multivariable analysis adjusted for relevant confounders, there was no statistically significant association between survival and being Hispanic (aHR: 0.68, p = 0.26) or Black (aHR: 1.18, p = 0.60) versus White. There was a significant association between being Asian American and survival (aHR: 0.24, p = 0.001; non‐U.S. Asian: aHR: 0.66, p = 0.05), and for SVR (aHR: 0.30, p < 0.0001).ConclusionDAA treatment rates were suboptimal. Racial and ethnic disparities resolved with HCV cure. Early diagnosis and improved access to HCV treatment is needed for all patients with HCV infection.

Cholangiocarcinoma (CCA), the second most common primary liver tumor, is associated with a dismal outcome, and useful prognostic markers are not currently available in clinical practice. SerpinB3, a serine protease inhibitor, was recently found to play a relevant role in malignant transformation in different cancers. The aim of the present study was to determine the expression of SerpinB3/4 in tissue and serum samples of patients with CCA in relation to clinical outcomes. SerpinB3/4 was assessed in the tissue microarrays (TMAs) of 123 surgically resected CCAs. ELISA assays were carried out in 188 patients with CCA to detect the free and IgM-linked forms of SerpinB3/4. Overall survival was analyzed in relation to SerpinB3/4 expression, and Cox models were used to identify the variables associated with survival. High levels of SerpinB3/4 (TMA score 2+/3+) were detected in 15 tumors (12.2%), characterized by a more advanced TNM stage (III/IV: 64.3% vs. 31.3%; p = 0.031) and lower overall patient survival, independently of CCA subclass (intrahepatic CCA: median 1.1 (0.8—Not Estimable, NE) vs. 2.4 (1.8–3.4) years; p = 0.0007; extrahepatic CCA: median 0.8 (0.2—NE) vs. 2.2 (1.5–5.4) years; p = 0.011). Vascular invasion (p = 0.027) and SerpinB3/4 scores (p = 0.0016) were independently associated with mortality in multivariate analysis. Patients who had detectable free or IgM-linked SerpinB3/4 in their serum showed poorer survival (1 vs. 2.4 years, p = 0.015, for free SerpinB3/4, and 1 vs. 2.6 years, p = 0.0026, for SerpinB3/4–IgM). In conclusion, high levels of SerpinB3/4 in tissue and serum in CCA are associated with poor outcomes after surgery, regardless of tumor subclass.

Abstract Although immune checkpoint inhibition (ICI) has produced profound survival benefits in a broad variety of tumors, a proportion of patients do not respond. Treatment failure is in part due to immune suppressive tumor microenvironments (TME), which is particularly true of hepatocellular carcinoma (HCC). Since oncolytic viruses (OV) can generate a highly immune-infiltrated, inflammatory TME, we developed a vesicular stomatitis virus expressing interferon-ß (VSV-IFNß) as a viro-immunotherapy against HCC. Since HCC standard of care atezolizumab/bevacizumab incorporates ICI, we tested the hypothesis that pro-inflammatory VSV-IFNß would recruit, prime, and activate anti-tumor T cells, whose activity anti-PD-L1 ICI would potentiate. However, in a partially anti-PD-L1-responsive model of HCC, addition of VSV-IFNß abolished anti-PD-L1 therapy. Cytometry by Time of Flight showed that VSV-IFNß expanded dominant anti-viral effector CD8 T cells with concomitant, relative disappearance of anti-tumor T cell populations which are the target of anti-PD-L1. However, by expressing a range of HCC tumor antigens within VSV, the potent anti-viral response became amalgamated with an anti-tumor T cell response generating highly significant cures compared to anti-PD-L1 ICI alone. Our data provide a cautionary message for the use of highly immunogenic viruses as tumor-specific immune-therapeutics by showing that dominant anti-viral T cell responses can inhibit sub-dominant anti-tumor T cell responses. However, by chimerizing anti-viral and anti-tumor T cell responses through encoding tumor antigens within the virus, oncolytic virotherapy can be purposed for very effective immune driven tumor clearance and can generate anti-tumor T cell populations upon which immune checkpoint blockade can effectively work.

PURPOSE Hepatocellular carcinoma (HCC), the fourth most common cancer in Africa, has a dismal overall survival of only 3 months like in sub-Saharan Africa. This is affected by the low gross domestic product and human development index, absence of coherent guidelines, and other factors. METHODS An open forum for HCC-experienced health care workers from Africa and the rest of the world was held in October 2021. Participants completed a survey to help assess the real-life access to screening, diagnoses, and treatment in the North and Southern Africa (NS), East and West Africa (EW), Central Africa (C), and the rest of the world. RESULTS Of 461 participants from all relevant subspecialties, 372 were from Africa. Most African participants provided hepatitis B vaccination and treatment for hepatitis B and C. More than half of the participants use serum alpha-fetoprotein and ultrasound for surveillance. Only 20% reported using image-guided diagnostic liver biopsy. The Barcelona Clinic Liver Cancer is the most used staging system (52%). Liver transplant is available for only 28% of NS and 3% EW. C reported a significantly lower availability of resection. Availability of local therapy ranged from 94% in NS to 62% in C. Sorafenib is the most commonly used systemic therapy (66%). Only 12.9% reported access to other medications including immune checkpoint inhibitors. Besides 42% access to regorafenib in NS, second-line treatments were not provided. CONCLUSION Similarities and differences in the care for patients with HCC in Africa are reported. This reconfirms the major gaps in access and availability especially in C and marginally less so in EW. This is a call for concerted multidisciplinary efforts to achieve and sustain a reduction in incidence and mortality from HCC in Africa.