Systemic Therapy for Advanced Hepatocellular Carcinoma: ASCO Guideline Update

PURPOSE

To update an evidence-based guideline to assist in clinical decision-making for patients with advanced hepatocellular carcinoma (HCC).

METHODS

ASCO convened an Expert Panel to update the 2020 guideline on systemic therapy for HCC. The panel updated the systematic review to include randomized controlled trials (RCTs) published through October 2023 and updated recommendations.

RESULTS

Ten new RCTs met the inclusion criteria and were added to the evidence base.

RECOMMENDATIONS

Atezolizumab + bevacizumab (atezo + bev) or durvalumab + tremelimumab (durva + treme) may be offered first-line for patients with advanced HCC, Child-Pugh class A liver disease, and Eastern Cooperative Oncology Group performance status 0-1. Where there are contraindications to these therapies, sorafenib, lenvatinib, or durvalumab may be offered first-line. Following first-line treatment with atezo + bev, second-line therapy with a tyrosine kinase inhibitor (TKI), ramucirumab (for patients with alpha-fetoprotein [AFP] ≥400 ng/mL), durva + treme, or nivolumab + ipilimumab (nivo + ipi) may be recommended for appropriate candidates. Following first-line therapy with durva + treme, second-line therapy with a TKI is recommended. Following first-line treatment with sorafenib or lenvatinib, second-line therapy options include cabozantinib, regorafenib for patients who previously tolerated sorafenib, ramucirumab (AFP ≥400 ng/mL), nivo + ipi, or durvalumab; atezo + bev or durva + treme may be considered for patients who did not have access to these therapies in the first-line setting, and do not have contraindications. Pembrolizumab or nivolumab are also options for appropriate patients following sorafenib or lenvatinib. Third-line therapy may be considered in Child-Pugh class A patients with good PS, using one of the agents listed previously that has a nonidentical mechanism of action with previously received therapy. A cautious approach to systemic therapy is recommended for patients with Child-Pugh class B advanced HCC. Further guidance on choosing between options is included within the guideline.Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines.

A synergistic two-drug therapy specifically targets a DNA repair dysregulation that occurs in p53-deficient colorectal and pancreatic cancers

The tumor-suppressor p53 is commonly inactivated in colorectal cancer and pancreatic ductal adenocarcinoma, but existing treatment options for p53-mutant (p53Mut) cancer are largely ineffective. Here, we report a therapeutic strategy for p53Mut tumors based on abnormalities in the DNA repair response. Investigation of DNA repair upon challenge with thymidine analogs reveals a dysregulation in DNA repair response in p53Mut cells that leads to accumulation of DNA breaks. Thymidine analogs do not interrupt DNA synthesis but induce DNA repair that involves a p53-dependent checkpoint. Inhibitors of poly(ADP-ribose) polymerase (PARPis) markedly enhance DNA double-strand breaks and cell death induced by thymidine analogs in p53Mut cells, whereas p53 wild-type cells respond with p53-dependent inhibition of the cell cycle. Combinations of trifluorothymidine and PARPi agents demonstrate superior anti-neoplastic activity in p53Mut cancer models. These findings support a two-drug combination strategy to improve outcomes for patients with p53Mut cancer.

Body mass index's effect on CRSwNP extends to pathological endotype and recurrence

BACKGROUND

Elevated body mass index (BMI) has been recognized as an important contributor to corticosteroid insensitivity in chronic rhinosinusitis with nasal polyps (CRSwNP). We aimed to delineate the effects of elevated BMI on immunological endotype and recurrence in CRSwNP individuals.

METHODOLOGY

A total of 325 patients with CRSwNP undergoing FESS were recruited and stratified by BMI. H&E staining was employed for histological evaluation. Characteristics of inflammatory patterns were identified by immunohistochemical staining. The predictive factors for recurrence were determined and evaluated by multivariable logistic regression analysis and the receiver operating characteristic (ROC) curves across all subjects and by weight group.

RESULTS

In all patients with CRSwNP, 26.15% subjects were classified as overweight/obese group across BMI categories and exhibited a higher symptom burden. The upregulated eosinophil/neutrophil-dominant cellular endotype and amplified type 2/ type 3 coexisting inflammation was present in overweight/obese compared to underweight/normal weight controls. Additionally, a higher recurrent proportion was shown in overweight/obese patients than that in underweight/normal weight cohorts. Multivariable logistic regression analysis identified BMI as an independent predictor for recurrence. The predictive capacity of each conventional parameter (tissue eosinophil and CLCs count, and blood eosinophil percentage) alone or in combination was poor in overweight/obese subjects.

CONCLUSIONS

Overweight/obese CRSwNP stands for a unique phenotype and endotype. Conventional parameters predicting recurrence are compromised in overweight/obese CRSwNP, and there is an urgent need for novel biomarkers that predict recurrence for these patients.

The extracellular matrix in hepatocellular carcinoma: Mechanisms and therapeutic vulnerability

The tumor microenvironment (TME) is influenced by a "disorganized" extracellular matrix (ECM) that sensitizes cancer cells toward mechanical stress, signaling, and structural alterations. In hepatocellular carcinoma (HCC), lack of knowledge about key ECM proteins driving the TME refractory to targeted therapies poses a barrier to the identification of new therapeutic targets. Herein, we discuss the contributions of various ECM components that impact hepatocytes and their surrounding support network during tumorigenesis. In addition, the underpinnings by which ECM proteins transduce mechanical signals to the liver TME are detailed. Finally, in view of the bidirectional feedback between the ECM, transformed hepatocytes, and immune cells, we highlight the potential role of the ECM disorganization process in shaping responses to immune checkpoint inhibitors and targeted therapies. Our comprehensive characterization of these ECM components may provide a roadmap for innovative therapeutic approaches to restrain HCC.

NCCN Guidelines® Insights: Biliary Tract Cancers, Version 2.2023

In 2023, the NCCN Guidelines for Hepatobiliary Cancers were divided into 2 separate guidelines: Hepatocellular Carcinoma and Biliary Tract Cancers. The NCCN Guidelines for Biliary Tract Cancers provide recommendations for the evaluation and comprehensive care of patients with gallbladder cancer, intrahepatic cholangiocarcinoma, and extrahepatic cholangiocarcinoma. The multidisciplinary panel of experts meets at least on an annual basis to review requests from internal and external entities as well as to evaluate new data on current and emerging therapies. These Guidelines Insights focus on some of the recent updates to the NCCN Guidelines for Biliary Tract Cancers as well as the newly published section on principles of molecular testing.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of gastrointestinal cancer

Gastrointestinal (GI) cancers, including esophageal, gastroesophageal junction, gastric, duodenal and distal small bowel, biliary tract, pancreatic, colon, rectal, and anal cancer, comprise a heterogeneous group of malignancies that impose a significant global burden. Immunotherapy has transformed the treatment landscape for several GI cancers, offering some patients durable responses and prolonged survival. Specifically, immune checkpoint inhibitors (ICIs) directed against programmed cell death protein 1 (PD-1), either as monotherapies or in combination regimens, have gained tissue site-specific regulatory approvals for the treatment of metastatic disease and in the resectable setting. Indications for ICIs in GI cancer, however, have differing biomarker and histology requirements depending on the anatomic site of origin. Furthermore, ICIs are associated with unique toxicity profiles compared with other systemic treatments that have long been the mainstay for GI cancer, such as chemotherapy. With the goal of improving patient care by providing guidance to the oncology community, the Society for Immunotherapy of Cancer (SITC) convened a panel of experts to develop this clinical practice guideline on immunotherapy for the treatment of GI cancer. Drawing from published data and clinical experience, the expert panel developed evidence- and consensus-based recommendations for healthcare professionals using ICIs to treat GI cancers, with topics including biomarker testing, therapy selection, and patient education and quality of life considerations, among others.

Abstract 1934: Incidence and survival outcomes of younger adults with colorectal cancers by age group: a SEER analysis

Background: The incidence of colorectal cancer (CRC) is increasing in younger adults (<50 years). Most cases occur between 40 and 49 years. Adolescents and young adults (AYA,15-39 years) with CRC have more aggressive disease. We sought to compare the incidence and outcomes of CRC in AYA with patients in the 40-49 age group.

Methods: Surveillance, Epidemiology, and End Result (SEER) was analyzed from 2000-2019. Survival outcomes were analyzed using Kaplan-Meier methods, and comparisons were made using the log-rank test. Cox regression models were used to evaluate univariate and multivariate associations with survival outcomes. SAS v9.4 (Cary, NC) and SEER*Stat v8.4 were used, with a significance level of 0.05.Results: A total of 13,877 AYA patients and 43,771 patients in the age group 40-49 years were identified. The annual incidence rate per 100,000 AYA patients increased from 3.1 in 2000 to 5.3 in 2019. In the 40-49 cohort, the annual incidence rate per 100,000 increased from 21.6 in 2000 to 28.0 in 2019. The annual percent change for incidence for the AYA cohort was higher 3.1% (95% CI 2.8,3.4) than the 40-49 cohort 1.4% (95% CI 1.2,1.6). The 2-year overall survival (OS) rate was not different among the two groups. Disease-specific survival (DSS) was slightly but significantly inferior in the AYA group, 83% (95%CI 0.82,0.83) compared to in the 40-49 cohort, 84% (95%CI 0.83,0.84). Factors associated with inferior DSS in the AYA group were male sex, black race, advanced stage, lack of chemotherapy, and longer time to treatment.

Conclusion: Our study shows that the annual percent change in incidence rate was higher in AYA patients compared to those in the 40-49 age group from 2000-2019. DSS was slightly lower in AYA patients; OS was similar in both groups. Further studies are needed to understand the discrepancies.

Table 1: Baseline characteristics of AYA and 40-49yr patients AYA 13877(24.1%) 40-49yr 43771(75.9%) Overall 57648(100%) P value Age at diagnosis Mean/Standard deviation 34/4.6 45.5/2.8 42.7/5.9 <0.001 Gender Male 51.9% 53.6% 53.2% <0.001 Race Non-Hispanic White 54.2% 59.4% 58.2% <0.001 Non-Hispanic Black 12.1% 13.3% 13% Asian or Pacific Islander 33% 26.7% 28.2% Unknown 0.6% 0.6% 0.6% Stage Localized 22.2% 26.5% 25.5% <0.001 Regional 31.6% 30.2% 30.6% Distant 20% 19.2% 19.4% Unstaged 1.8% 1.7% 1.7% Blank 24.4% 22.3% 22.8% Chemotherapy No/Unknown 33.8% 39.4% 38.1% <0.001

Citation Format: Sheeba Ba Aqeel, Adrienne Groman, Kristopher Attwood, Renuka Iyer, Sarabjit Mukherjee, Deepak Vadehra. Incidence and survival outcomes of younger adults with colorectal cancers by age group: a SEER analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1934.

Immunotherapy in malignant peritoneal mesothelioma (Review)

Over the last decade, there has been a movement in cancer treatment away from cytotoxic therapies toward strategies that enhance the immune system against cancer. Immune checkpoint inhibitors (ICIs) have been incorporated into the treatment regimens for patients with various solid tumors. Mesothelioma trials revealed encouraging efficacy; however, patients with peritoneal mesothelioma are usually excluded, slowing the progress of improving the treatment of this aggressive cancer and compelling oncologist to rely on retrospective studies despite their flaws and limitations. Currently, there is no consensus on the role of ICIs in the treatment of malignant peritoneal mesothelioma (MPeM). The present review discusses data from clinical studies that examined immunotherapy in MPeM and evaluates what is known about the relevance of the tumor microenvironment and clinically validated biomarkers for ICIs efficacy. Furthermore, a proposed strategy for utilizing immunotherapy in treating MPeM is discussed.

PET Imaging of Hepatocellular Carcinoma Using ZD2-(68Ga-NOTA)

Purpose

We tested a recently developed short peptide radioligand for PET imaging of hepatocellular carcinoma (HCC) by targeting an oncoprotein, extra-domain B fibronectin (EDB-FN) in the tumor microenvironment.

Methods

The radioligand consists of a small linear peptide ZD2 with 68Ga-NOTA chelator, and specifically binds to EDB-FN. PET images were acquired dynamically for 1 hour after intravenously (i.v.) injecting 37 MBq (1.0 mCi) of the radioligand into the woodchuck model of naturally occurring HCC. Woodchuck HCC originated from chronic viral hepatitis infection, which recapitulates the corresponding human primary liver cancer. The animals were euthanized post-imaging for tissue collection and validation.

Results

For ZD2 avid liver tumors, the radioligand accumulation plateaued a few minutes after injection, while the liver background uptake stabilized 20 min post-injection. The status of EDB-FN in woodchuck HCC was confirmed by histology and validated by PCR and western blocking.

Conclusion

We have showed the viability of using the ZD2 short peptide radioligand targeting EDB-FN in liver tumor tissue for PET imaging of HCC, which can potentially impact the clinical care for HCC patients.

Phase 1 Randomized Trial of Stereotactic Body Radiation Therapy Followed by Nivolumab plus Ipilimumab or Nivolumab Alone in Advanced/Unresectable Hepatocellular Carcinoma

PURPOSE

Immunotherapy has emerged as a promising therapeutic option for advanced or unresectable hepatocellular carcinoma (HCC). However, survival remains poor with only a subset of patients deriving benefit. This trial investigated the safety and efficacy of stereotactic body radiation therapy (SBRT) with immunotherapy in HCC.

METHODS AND MATERIALS

In this multicenter phase 1 randomized trial, patients with advanced or unresectable HCC received liver SBRT (40 Gy in 5 fractions) followed by either nivolumab alone or nivolumab plus ipilimumab. The primary endpoint was dose-limiting toxicity occurring within 6 months of SBRT. Secondary endpoints included overall response rate, progression-free survival, overall survival (OS), distant disease control, and local control of the irradiated tumor. Disease status and response endpoints were assessed radiographically every 8 weeks until progression or initiation of nonprotocol therapy. Response was determined using both RECIST (Response Evaluation Criteria in Solid Tumors) 1.1 and iRECIST.

RESULTS

Fourteen patients were enrolled across 3 centers. Thirteen patients were evaluated for study endpoints. The study was closed early because of slow accrual. The median follow-up time was 42.7 months. Dose-limiting toxicities within 6 months occurred in 2 (15.4%) of 13 patients: 1 of 6 patients in the nivolumab arm (16.7%; 90% confidence interval [CI], 0.9%-58.2%) and 1 of 7 patients in the nivolumab plus ipilimumab arm (14.3%; 90% CI, 0.7%-52.1%). Grade 3 adverse events occurred in 8 (61.6%), 5 (71.4%), and 3 (50.0%) patients in the overall nivolumab plus ipilimumab and nivolumab cohorts. Grade 3 hepatotoxicity occurred in 4 (30.8%), 3 (42.9%), and 1 (16.7%) patients in the respective cohorts. Clinical outcomes favored the nivolumab plus ipilimumab arm compared with nivolumab alone, including an overall response rate of 57% (4 of 7 patients; 90% CI, 23%-87%) versus 0% (0 of 6 patients; 90% CI, 0%-39%), median progression-free survival of 11.6 months (90% CI, 4.5 months to not reached) versus 2.7 months (90% CI, 1.3-4.7 months), and median OS of 41.6 months (90% CI, 4.5 months to not reached) versus 4.7 months (90% CI, 2.0-16.2 months) (all P < .05). With combination immunotherapy, 3-year OS was 57% (90% CI, 23%-81%), with 2 patients alive after 42.7 months without progression and negative PET.

CONCLUSIONS

In this first prospective trial investigating the combination of SBRT and immunotherapy for HCC, multimodal therapy demonstrated acceptable safety. SBRT with nivolumab plus ipilimumab compared favorably to outcomes of immunotherapy alone and warrants further investigation.

A multicenter, phase Ib/II, open-label study of tivozanib with durvalumab in advanced hepatocellular carcinoma (DEDUCTIVE)

Durvalumab, a PD-L1 inhibitor, is part of an immunotherapeutic drug class shown to have prolonged survival benefit in patients with advanced stage hepatocellular carcinoma (HCC). Tivozanib is a potent and selective VEGFR 1, 2 and 3 tyrosine kinase inhibitor. While these medications have both demonstrated single-agent activity in HCC and have been combined safely with other therapies, there is no data on their concurrent therapeutic effects. In the phase Ib DEDUCTIVE trial, the combination of tivozanib plus durvalumab is evaluated for safety and tolerability. Here, the design of and rationale for this trial in both treatment naive patients and those who progress on atezolizumab and bevacizumab for advanced or metastatic HCC are described. Clinical Trial Registration: NCT03970616.

Abstract CT105: Initial results of a phase II study evaluating a chemokine-modulatory (CKM) regimen in patients with colorectal cancer metastatic to the liver

Background: Liver metastases develop in 20-50% of colorectal cancer (CRC) patients, being typically resistant to immune checkpoint inhibitors (ICIs) and having a poor prognosis. Our preliminary data showed synergy between IFNα and TLR3 ligands in selectively enhancing the intratumoral production of CD8+ T cell (CTL) attracting chemokines (but not Treg attractants) in ex vivo-treated CRC explants and preferential impact of this combination on liver-metastatic CRC tumor tissues (rather than surrounding liver tissues). Based on these data and previous reports showing the prognostic value of intratumoral CTLs in the CRC outcomes, we hypothesized that systemic infusion of the combination of IFNα2b with rintatolimod (selective TLR3 ligand for i.v. use) can reprogram local balance between the CTL- and regulatory T cell (Treg)-attracting chemokines and the resulting patterns of immune infiltrate in liver lesions.

Methods: Recurrent/metastatic CRC patients with unresectable liver metastases amenable to biopsy were eligible. Patients had prior treatment (Rx) with fluoropyrimidine, irinotecan, oxaliplatin, and an anti-EGFR targeted therapy (if RAS wt), or contra-indication to such. Patients received IFNα2b IV (20 million units/m2 IV daily) and rintatolimod (200 mg IV daily) plus oral celecoxib (200 mg twice daily) on days 1, 2, 3, 8, 9, 10, 15, 16, and 17. Response assessment was done via liver biopsies (pre-Rx and on day 24 ± 4 days) and CT imaging (RECIST v1.1) on D46. The primary endpoint was the change in CD8+ T-cells before Rx, with that seen post-Rx (measured by quantitative RT-PCR as a ratio of CD8α to a housekeeping gene, HPRT). With a sample size of N=12 evaluable pts, the study design had a 90% power to detect a 0.77 standard deviation increase (pre- to post Rx) at a significance level of 0.1 (ClinicalTrials.gov Identifier: NCT03403634).

Results: Nineteen patients with microsatellite stable (MSS) CRC were enrolled between Apr 2018 and Oct 2020, 15 were treated and 12 were evaluable for the primary endpoint. Most were male (75%, N=9) and Caucasian (92%, N=11). The median age at diagnosis was 65 years. Most had previously received three or more prior lines of therapy (58%, N=7). The study's primary endpoint was met, evidenced by increased CD8a expression post-treatment (p=0.046). An increase in ratios of CD8a/CD4 (p=0.03), CD8a/FOXP3 (p&lt;0.01) and GZMB/FOXP3 (p&lt;0.01) was observed. The expression of CTL-attracting chemokines CCL5 (p=0.08), CXCL9 (p=0.05), and CXCL10 (p=0.06) were increased, while expression of the Treg/MDSC attractant CXCL12 (p=0.07) was decreased post-Rx. Median OS was 10.5 (90% CI 2.2-15.2) months, and the median PFS was 1.5 (90% CI 1.4, 1.8) months. No objective response was seen. The treatment was well tolerated. Of all enrolled patients (N=19), adverse events were noted in 74% of patients, with the most common being fatigue (58%). Grade 3 or higher adverse events were rare (5%). Age, gender, line of treatment, RAS mutational status, and tumor location did not significantly impact CD8a change or PFS.

Conclusion: Our study demonstrated that a combinatorial CKM regimen could re-program the immunosuppressive tumor microenvironment in MSS CRC patients with liver metastasis, raising the possibility that the CKM regimen can be used to enhance the effectiveness of ICIs in this group of patients.

Citation Format: Sarbajit Mukherjee, Patrick M. Boland, Melissa Grimm, Ronald Slomba, Kristopher Attwood, Renuka Iyer, Pawel Kalinski. Initial results of a phase II study evaluating a chemokine-modulatory (CKM) regimen in patients with colorectal cancer metastatic to the liver [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT105.

Imaging of Tumor-Associated Vascular Prostate-Specific Membrane Antigen in Woodchuck Model of Hepatocellular Carcinoma

BACKGROUND AND AIMS

Radiolabeled short peptide ligands targeting prostate-specific membrane antigen (PSMA) were developed initially for imaging and treatment of prostate cancers. While many nonprostate solid tumors including hepatocellular carcinoma (HCC) express little PSMA, their neovasculature expresses a high level of PSMA, which is avid for Gallium-68-labeled PSMA-targeting radio-ligand (⁶⁸Ga-PSMA-11) for positron emission tomography (PET). However, the lack of a spontaneous animal model of tumor-associated vascular PSMA overexpression has hindered the development and assessment of PSMA-targeting radioligands for imaging and therapy of the nonprostatic cancers. We identified detectable indigenous PSMA expression on tumor neovascular endothelia in a naturally occurring woodchuck model of HCC.

METHODS

Molecular docking was performed with 3 bait PSMA ligands and compared between human and woodchuck PSMA. Initially, PET images were acquired dynamically after intravenously injecting 37 MBq (1.0 mCi) of ⁶⁸Ga-PSMA-11 into woodchuck models of HCC. Subsequently, 10-minute static PET scans were conducted for other animals 1-hour after injection due to HCC and liver background uptake stabilization at 30-45 minutes after injection. Liver tissue samples were harvested after imaging, fresh-frozen for quantitative reverse transcription polymerase chain reaction and western blot for validation, or fixed for histology for correlation.

RESULTS

Our preclinical studies confirmed the initial clinical findings of ⁶⁸Ga-PSMA-11 uptake in HCC. The agents (ligands and antibodies) developed against human PSMA were found to be reactive against the woodchuck PSMA.

CONCLUSION

This animal model offers a unique opportunity for investigating the biogenesis of tumor-associated vascular PSMA, its functional role(s), and potentials for future treatment strategies targeting tumor vascular PSMA using already developed PSMA-targeting agents.

Mutant PPM1D- and TP53-Driven Hematopoiesis Populates the Hematopoietic Compartment in Response to Peptide Receptor Radionuclide Therapy

PURPOSE

Hematologic toxic effects of peptide receptor radionuclide therapy (PRRT) can be permanent. Patients with underlying clonal hematopoiesis (CH) may be more inclined to develop hematologic toxicity after PRRT. However, this association remains understudied.

MATERIALS AND METHODS

We evaluated pre- and post-PRRT blood samples of patients with neuroendocrine tumors. After initial screening, 13 cases of interest were selected. Serial blood samples were obtained on 4 of 13 patients. Genomic DNA was analyzed using a 100-gene panel. A variant allele frequency cutoff of 1% was used to call CH.

RESULT

Sixty-two percent of patients had CH at baseline. Persistent cytopenias were noted in 64% (7 of 11) of the patients. Serial sample analysis demonstrated that PRRT exposure resulted in clonal expansion of mutant DNA damage response genes (TP53, CHEK2, and PPM1D) and accompanying cytopenias in 75% (3 of 4) of the patients. One patient who had a normal baseline hemogram and developed persistent cytopenias after PRRT exposure showed expansion of mutant PPM1D (variant allele frequency increased to 20% after exposure from < 1% at baseline). In the other two patients, expansion of mutant TP53, CHEK2, and PPM1D clones was also noted along with cytopenia development.

CONCLUSION

The shifts in hematopoietic clonal dynamics in our study were accompanied by emergence and persistence of cytopenias. These cytopenias likely represent premalignant state, as PPM1D-, CHEK2-, and TP53-mutant clones by themselves carry a high risk for transformation to therapy-related myeloid neoplasms. Future studies should consider CH screening and longitudinal monitoring as a key risk mitigation strategy for patients with neuroendocrine tumors receiving PRRT.

Phase Ib/II Study of Cetuximab plus Pembrolizumab in Patients with Advanced RAS Wild-Type Colorectal Cancer

PURPOSE

We evaluated the antitumor efficacy of cetuximab in combination with pembrolizumab in patients with RAS wild-type (RASwt), metastatic colorectal adenocarcinoma (mCRC).

PATIENTS AND METHODS

In this phase Ib/II study, cetuximab was combined with pembrolizumab in patients with RASwt mCRC with ≥ one prior line of therapy for advanced disease. We analyzed baseline on-treatment tumor tissues for changes in the tumor microenvironment (TME), using flow cytometry and multispectral immunofluorescence.

RESULTS

Forty-four patients were evaluable for efficacy. The study was negative for the primary efficacy endpoint [overall response rate: 2.6%, 6-month progression-free survival (PFS): 31%; P = 0.52]. Median PFS was 4.1 months [95% confidence interval (CI): 3.9-5.5 months]. No increase in adverse effects was identified. We observed favorable immunomodulation with 47% increase in the number of intratumoral CTLs posttreatment (P = 0.035). These changes were more pronounced in patients with tumor shrinkage (P = 0.05). The TME was characterized by high numbers of TIM3⁺ and CTLA4⁺ cells; there were few activated OX40⁺ cells. PD-L1 expression was higher in pretreatment tumor cells from metastatic sites versus primary tumor samples (P < 0.05). Higher numbers of PD-L1⁺ tumor cells at baseline were associated with tumor shrinkage (P = 0.04). Analysis of immune populations in the blood demonstrated decreases in PD-1⁺ memory effector cells (P = 0.04) and granulocytic myeloid-derived suppressor cells (P = 0.03), with simultaneous increases in CD4⁺/CTLA4⁺ cells (P = 0.01).

CONCLUSIONS

The combination of cetuximab and pembrolizumab is inactive in patients with RASwt mCRC, despite its partial local immunologic efficacy. Further development of immuno-oncology combinations with enhanced efficacy and/or targeting additional or alternative immune checkpoints merits investigation.

A phase I study of the anaplastic lymphoma kinase inhibitor ceritinib in combination with gemcitabine-based chemotherapy in patients with advanced solid tumors

In this phase I, dose-escalation study, we sought to determine the maximum tolerated dose (MTD) of the anaplastic lymphoma kinase/c-ROS oncogene 1 receptor (ALK/ROS1) inhibitor ceritinib in combination with gemcitabine-based chemotherapy in patients with advanced solid tumors. Secondary objectives were characterization of the safety profile, pharmacokinetics and preliminary efficacy of these combinations, and identification of potential biomarkers of efficacy. Ceritinib was combined with gemcitabine (Arm 1), gemcitabine/nab-paclitaxel (Arm 2) or gemcitabine/cisplatin (Arm 3). Drug concentrations in plasma were measured by tandem mass spectrometric detection (LC-MS/MS). We analyzed archival tumor tissue for ALK, ROS1, hepatocyte growth factor receptor (c-MET) and c-Jun N-terminal kinase (JNK) expression by immunohistochemistry. Arm 2 closed early secondary to toxicity. Twenty-one patients were evaluable for dose-limiting toxicity (DLT). There was one DLT in Arm 1 (grade 3 ALT increase) and three DLTs in Arm 3 (grade 3 acute renal failure, grade 3 thrombocytopenia, grade 3 dyspnea). The MTD of ceritinib was determined to be 600 mg (Arm 1) and 450 mg orally daily (Arm 3). Main toxicities were hematologic, constitutional and gastrointestinal as expected by the chemotherapy backbone. The apparent clearance for ceritinib decreased substantially after repeated dosing; cisplatin did not significantly affect the pharmacokinetics of ceritinib. The overall response rate was 20%; the median progression-free survival was 4.8 months. Three out of five response-evaluable cholangiocarcinoma patients had clinical benefit. Increased expression of c-MET was associated with a lack of clinical benefit. Ceritinib in combination with gemcitabine and gemcitabine/cisplatin has a manageable toxicity profile. Further development of this strategy in tumors with ALK or ROS1 fusions is warranted.

Selective therapeutic strategy for p53-deficient cancer by targeting dysregulation in DNA repair

Breast carcinomas commonly carry mutations in the tumor suppressor p53, although therapeutic efforts to target mutant p53 have previously been unfruitful. Here we report a selective combination therapy strategy for treatment of p53 mutant cancers. Genomic data revealed that p53 mutant cancers exhibit high replication activity and express high levels of the Base-Excision Repair (BER) pathway, whereas experimental testing showed substantial dysregulation in BER. This defect rendered accumulation of DNA damage in p53 mutant cells upon treatment with deoxyuridine analogues. Notably, inhibition of poly (ADP-ribose) polymerase (PARP) greatly enhanced this response, whereas normal cells responded with activation of the p53-p21 axis and cell cycle arrest. Inactivation of either p53 or p21/CDKN1A conferred the p53 mutant phenotype. Preclinical animal studies demonstrated a greater anti-neoplastic efficacy of the drug combination (deoxyuridine analogue and PARP inhibitor) than either drug alone. This work illustrates a selective combination therapy strategy for p53 mutant cancers that will improve survival rates and outcomes for thousands of breast cancer patients.

Abstract 1180: A novel synthetic lethality treatment strategy for metastatic breast cancer

Breast carcinomas commonly carry mutations in the tumor suppressor p53, while therapeutic efforts to target mutant p53 were largely unfruitful. Here we present preclinical data supporting a novel combination therapy strategy for treatment of p53-deficient cancers. Genomic data revealed a high expression activity of Base-Excision Repair (BER) pathways in p53-deficient breast cancers. However, we found that BER-mediated repair was significantly dysregulated in p53-mutant cancer cells. Treatment with deoxyuridine analogues induced accumulation of DNA damage in p53-mutant cells and inhibitors of poly (ADP-ribose) polymerase (PARPi) greatly enhanced this response. In contrast, normal cells responded to PARPi with activation of the p53-p21 axis and cell cycle arrest. Inactivation of either p53 or p21/CDKN1A in p53 wild-type cells conferred the p53-mutant phenotype. Preclinical breast cancer studies revealed that the combination of deoxyuridine analogue with PARPi was more effective in inhibition of tumor growth and metastases than either drug alone. This work illustrates a novel combination therapy strategy that may improve survival rates and outcomes for thousands of breast cancer patients.

Citation Format: Justin Zonneville, Moyi Wang, Mohammed Alruwaili, Kevin Eng, Thomas Melendy, Ben Ho Park, Renuka Iyer, Christos Fountzilas, Andrei V. Bakin. A novel synthetic lethality treatment strategy for metastatic breast cancer [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 1180.

Hepatobiliary Cancers, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Hepatobiliary Cancers focus on the screening, diagnosis, staging, treatment, and management of hepatocellular carcinoma (HCC), gallbladder cancer, and cancer of the bile ducts (intrahepatic and extrahepatic cholangiocarcinoma). Due to the multiple modalities that can be used to treat the disease and the complications that can arise from comorbid liver dysfunction, a multidisciplinary evaluation is essential for determining an optimal treatment strategy. A multidisciplinary team should include hepatologists, diagnostic radiologists, interventional radiologists, surgeons, medical oncologists, and pathologists with hepatobiliary cancer expertise. In addition to surgery, transplant, and intra-arterial therapies, there have been great advances in the systemic treatment of HCC. Until recently, sorafenib was the only systemic therapy option for patients with advanced HCC. In 2020, the combination of atezolizumab and bevacizumab became the first regimen to show superior survival to sorafenib, gaining it FDA approval as a new frontline standard regimen for unresectable or metastatic HCC. This article discusses the NCCN Guidelines recommendations for HCC.

Immunotherapy in hepatocellular cancer

Hepatocellular carcinoma is a major global healthcare problem. It is closely related to chronic liver inflammation triggered by viral and non-viral insults, that can lead to exhaustion of effector T-cells. Furthermore, immune cells within the normal liver itself tend to be more immune tolerant in order to support the essential function of liver as the first processing station of molecules absorbed in the gastrointestinal tract. Dysregulation of the immune system is a hallmark of hepatocellular carcinoma. Immune checkpoint inhibitors targeting the programmed death-1 axis have shown promise as monotherapy in the management of advanced disease, but still most patients do not benefit from treatment. Most recently, combinatorial strategies with other immune checkpoint inhibitors or agents targeting the second hallmark of hepatocellular carcinoma, i.e., the activation of the vascular epithelial growth factor axis have been studied. In this paper, we review the current immunotherapy approaches for hepatocellular carcinoma and discuss novel immunotherapy approaches and optimal patient selection.

Targeting the NTRK Fusion Gene in Pancreatic Acinar Cell Carcinoma: A Case Report and Review of the Literature

Pancreatic acinar cell carcinoma (PACC) is a rare pancreatic exocrine malignancy. Compared with the more common pancreatic ductal adenocarcinoma (PDAC), PACC is more common in younger White men, has earlier stages and a lower mean age (56 vs 70 years) at the time of presentation, and has a better prognosis. In addition to differences in demographic, histologic, and clinical characteristics, PACC has a genomic profile distinct from PDAC, with only rare mutations in TP53, KRAS, and p16 that are commonly found in PDAC. This case report presents a man aged 81 years who presented with a pancreatic body mass with peripancreatic lymph node enlargement. Biopsy of the mass showed acinar cell carcinoma. The patient underwent upfront surgical resection, followed by one cycle of adjuvant gemcitabine, with stoppage of therapy due to poor tolerance. Lower-dose gemcitabine was reintroduced after disease progression 6 months later. Nab-paclitaxel was added to gemcitabine after 6 cycles because of a continued increase in the size of peripancreatic lymph nodes. Combination chemotherapy was stopped after 4 cycles because of further disease progression with new liver metastasis. Molecular testing showed the presence of an SEL1L-NTRK1 fusion. Targeted therapy was started with the oral neurotrophic tropomyosin receptor kinase (NTRK) inhibitor larotrectinib at a dosage of 100 mg twice daily. At the time of writing, the patient has been on therapy for 13 months with an exceptional radiographic response and has not experienced any grade 3 adverse effects. To our knowledge, this is the first clinical report of an NTRK gene fusion in a patient with PACC. This case study highlights the significance of tumor molecular profiling in patients with pancreatic tumors, especially rare histologies.

Systemic Therapy for Advanced Hepatocellular Carcinoma: ASCO Guideline

PURPOSE

To develop an evidence-based clinical practice guideline to assist in clinical decision making for patients with advanced hepatocellular carcinoma (HCC).

METHODS

ASCO convened an Expert Panel to conduct a systematic review of published phase III randomized controlled trials (2007-2020) on systemic therapy for advanced HCC and provide recommended care options for this patient population.

RESULTS

Nine phase III randomized controlled trials met the inclusion criteria.

RECOMMENDATIONS

Atezolizumab + bevacizumab (atezo + bev) may be offered as first-line treatment of most patients with advanced HCC, Child-Pugh class A liver disease, Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0-1, and following management of esophageal varices, when present, according to institutional guidelines. Where there are contraindications to atezolizumab and/or bevacizumab, tyrosine kinase inhibitors sorafenib or lenvatinib may be offered as first-line treatment of patients with advanced HCC, Child-Pugh class A liver disease, and ECOG PS 0-1. Following first-line treatment with atezo + bev, and until better data are available, second-line therapy with a tyrosine kinase inhibitor may be recommended for appropriate candidates. Following first-line therapy with sorafenib or lenvatinib, second-line therapy options for appropriate candidates include cabozantinib, regorafenib for patients who previously tolerated sorafenib, or ramucirumab (for patients with α-fetoprotein ≥ 400 ng/mL), or atezo + bev where patients did not have access to this option as first-line therapy. Pembrolizumab or nivolumab are also reasonable options for appropriate patients following sorafenib or lenvatinib. Consideration of nivolumab + ipilimumab as an option for second-line therapy and third-line therapy is discussed. Further guidance on choosing between therapy options is included within the guideline. Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines.

Phase Ib Study of Enzalutamide with or Without Sorafenib in Patients with Advanced Hepatocellular Carcinoma

LESSONS LEARNED

Androgen receptor as assessed by immunohistochemistry is expressed in a high proportion of patients with hepatocellular carcinoma (HCC). Enzalutamide at 160 mg orally daily is safe and tolerable in patients with advanced HCC but has no single-agent antitumor activity. Enzalutamide, a CYP3A4 inducer, at a standard dose of 160 mg reduces the exposure of sorafenib, a CYP3A4 substrate. Enzalutamide and sorafenib is safe and tolerable in patients with advanced HCC, but the addition of enzalutamide to sorafenib did not enhance the antitumor activity of sorafenib.

BACKGROUND

Androgen receptor (AR) interference is deleterious to hepatocellular carcinoma (HCC) in preclinical models.

METHODS

This is a multicenter, phase Ib study of enzalutamide ± sorafenib in patients with advanced HCC. In part 1, a 3 + 3 dose de-escalation design with expansion established the recommended phase II dose (RP2D) of enzalutamide in patients in whom sorafenib treatment had failed. In part 2, a 3 + 3 dose escalation with expansion established the safety of enzalutamide with sorafenib in treatment-naive patients with HCC. Secondary objectives included objective response rate (ORR), progression-free survival (PFS), overall survival (OS), pharmacokinetics (PK), and determination of AR expression by immunohistochemistry. A 7-day run-in with sorafenib alone in part 2 allowed assessment of the impact of enzalutamide on sorafenib pharmacokinetics.

RESULTS

In part 1, 16 patients received enzalutamide 160 mg daily. No dose-limiting toxicity (DLT) occurred; 1 patient required dose reduction. Responses were not observed; median PFS and OS were 1.8 (95% confidence interval [CI]: 1.6-3.6) and 7 (95% CI: 3.6 to not reached [NR]) months, respectively. In part 2, patients received sorafenib 400 mg daily (4) or twice a day (8) both with enzalutamide at the recommended phase II dose-no DLTs were observed. ORR was 10% (95% CI: 0.3-44.5), and median PFS and OS were 2.9 (95% CI: 1.6 to NR) and 6.7 (95% CI: 4.6 to NR) months, respectively. Enzalutamide reduced sorafenib exposure by 60%. Tumor AR expression did not associate with outcome.

CONCLUSION

Enzalutamide is ineffective in HCC; further development is not supported by this study.

Liver background uptake of [18F]FLT in PET imaging

High liver uptake presents a problem for 3'-deoxy-3'-[¹⁸F]fluorothymidine ([¹⁸F]FLT) as a radiotracer for imaging cellular proliferation in the liver with positron emission tomography (PET). This investigation re-visited some issues related to the high liver background uptake of [¹⁸F]FLT with an animal model of woodchucks. Several enzymes involved in the hepatic catabolism of FLT, thymidine phosphorylase (TP, TYMP), uridine 5'-diphospho-glucuronosyl-transferases (UDP-GTs, short for UGTs), and β-glucuronidase (GUSB), their homology as well as hepatic expression between the human and the woodchuck was examined. Inhibitors of these enzymes, TP inhibitor (TPI) tipiracil hydrochloride, UGT inhibitor probenecid, β-glucuronidase inhibitor L-aspartate, were administered to the animals at human equivalent doses either intravenously (i.v.) and orally before the injection of tracer-dose [¹⁸F]FLT for PET imaging to examine any changes in liver uptake. Liver tissue samples were harvested from the animals after PET imaging and used to perform polymerase chain reaction (PCR) for TP expression or assays for enzymatic activities of TP and β-glucuronidase. Non-radiolabeled (cold) FLT was also applied for enzyme saturation. Animals administered with TPI displayed lower radioactivity in the liver in comparison with the baseline scan. The application of probenecid did not change [¹⁸F]FLT liver uptake even though it reduced renal uptake. L-aspartate reduced the liver background uptake of [¹⁸F]FLT slightly. The application of cold FLT reduced overall uptake of [¹⁸F]FLT including the liver background. Therefore, the combined application of cold FLT and [¹⁸F]FLT merits further clinical investigation for reducing liver background uptake of [¹⁸F]FLT.

Tivozanib mediated inhibition of c-Kit/SCF signaling on Tregs and MDSCs and reversal of tumor induced immune suppression correlates with survival of HCC patients

The immune modulatory effect of tivozanib, a tyrosine kinase inhibitor, and the underlying immune mechanisms impacting survival of HCC patients have not been investigated. Pre-clinical studies have shown that tivozanib reduces Tregs and MDSCs accumulation through inhibition of c-Kit/SCF axis. We rationalized that c-Kit/SCF axis antagonism by tivozanib may reverse tumor-induced immune suppression in HCC patients. The frequency of circulating Tregs, MDSCs, CTLA-4⁺Tregs, PD-1⁺T cells, c-Kit⁺pERK-2⁺Tregs, and c-Kit⁺pERK-2⁺MDSCs were quantified in HCC patients at baseline and two time points during tivozanib treatment. We report for the first time that reduction in Tregs after tivozanib treatment and increased levels of baseline CD4⁺PD-1⁺T cells correlated with significant improvement in overall survival (OS) of the patients and these signatures may be potential biomarkers of prognostic significance. This immune modulation resulted from tivozanib-mediated blockade of c-Kit/SCF signaling, impacting ERK2 phosphorylation on Tregs and MDSCs. Low pre-treatment CD4⁺T cells: Treg ratio and reduction in the frequencies of Foxp3⁺c-Kit⁺pERK⁺Tregs after tivozanib treatment correlated significantly with progression free survival. In a comparative analysis of tivozanib vs sorafenib treatment in HCC patients, we demonstrate that decrease in the baseline numbers or frequencies of Foxp3⁺Tregs, MDSCs and exhausted T cells was significantly greater following tivozanib treatment. Additionally, greater increase in CD4⁺T cell: Treg ratio after tivozanib treatment was associated with significant improvement in OS compared to sorafenib treatment, highlighting the greater efficacy of tivozanib. These insights may help identify patients who likely would benefit from c-Kit/SCF antagonism and inform efforts to improve the efficacy of tivozanib in combination with immunotherapy.

Sequencing Systemic Therapy Pathways for Advanced Hepatocellular Carcinoma: A Cost Effectiveness Analysis

INTRODUCTION

Hepatocellular carcinoma (HCC) is the most common form of liver cancer worldwide and carries a poor prognosis. Historically, sorafenib was the only available systemic treatment for advanced HCC. However, in recent years, 6 new treatments have been approved by the US Food and Drug Administration (FDA): regorafenib, lenvatinib, cabozantinib, pembrolizumab, ramucirumab, and nivolumab. Data are lacking regarding the most appropriate sequencing pathway for these agents. Our objective was to conduct a comprehensive cost effectiveness analysis (CEA) of different 1st- and 2nd-line treatment pathways for HCC reflecting all new drug approvals, and then use our data to provide guidance for clinicians on which pathway is the most cost-effective.

MATERIALS AND METHODS

Markov models were used to evaluate the cost effectiveness of 8 different 1st- and 2nd-line treatment sequences. The model allowed for 9 possible states. Cost effectiveness ratios (CER) and incremental CER (ICER) were calculated to compare costs between different pathways and against a willingness-to-pay (WTP) threshold. Efficacy and toxicity data were extracted from the landmark trials for each agent. All agents except ramucirumab were included. The cost of each agent was based on the wholesale acquisition cost (WAC) in USD as of June 2019. Monte-Carlo methods were used to simulate the experience of 1,000,000 patients per treatment sequence for a 12-month period.

RESULTS

The pathway with the lowest CER was sorafenib, followed by pembrolizumab (USD 227,741.03/quality-adjusted life year [QALY]). ICER analysis supported implementing 2nd-line pembrolizumab-based pathways at a higher WTP threshold of 300,000/quality-adjusted life year. Sensitivity analysis did not substantially change these results.

CONCLUSIONS

The most cost-effective strategy was 1st-line tyrosine kinase inhibitor therapy followed by 2nd-line immunotherapy. All pathways exceeded a commonly accepted WTP of USD 100-150,000/QALY. Our preliminary results warrant further studies to best inform real-world practices.

Abstract CT139: Ceritinib (Cer) in combination with gemcitabine (Gem)-based chemotherapy in patients (pts) with advanced solid tumors, a phase I study

Introduction: Cer is an oral ALK/ROS1 inhibitor. Aberrancies in ALK and ROS1 have been observed in many cancer types and ALK inhibition has synergistic effects with chemotherapy in ALK or ROS1 rearranged tumors in preclinical models. We launched a Phase I study of Cer in combination with Gem-based chemotherapy in advanced solid tumors. Herein we present initial results of this study. Methods: Phase I, dose-escalation study of Cer in combination with A1: Gem 1000 mg IV D1/8/15 q28 days; A2: Gem 1000 mg IV + nanoparticle albumin-bound Paclitaxel 125 mg IV both D1/8/15 q28 days; A3: Gem 1000 mg IV + Cisplatin 60 mg IV D1/8 q21 days in pts with advanced, solid malignancies until disease progression, intolerable toxicity or withdrawal. A 3 + 3 dose-escalation design was used starting at Cer 450 mg once daily (DL1) in all arms; DL2 was 600 mg once daily. Primary objective was to determine the maximum tolerated dose (MTD) of Cer. Key inclusion criteria: diagnosis of advanced solid malignancy for which Gem-based treatment was appropriate, &gt;18 years old, ECOG PS 0/1, adequate bone marrow/renal/liver function. Key exclusion criteria: interstitial lung fibrosis/disease, recent acute coronary event, CHF NYHA III/IV, corrected QTc &gt; 450 ms. Pts in A3 could have up to 2 prior lines of therapy. Prior use of ALK inhibitors allowed. Plasma was collected for PK on C1D1, C2D1, and C1D15. Archival tumor tissue was tested for ALK/ROS1/JNK/MET by IHC. Results: Thirty-eight patients were enrolled with 21 evaluable for dose-limiting toxicity (DLT) in A1 and A3. A2 (n=4) closed to accrual for toxicity. Median age was 61 years. Seven pts (41%) had cholangiocarcinoma. A1 had one DLT (G3 ALT increase) in DL2; MTD was 600 mg. A3 had one DLT in DL1 (G3 acute renal failure) and two DLTs in DL2 (G3 thrombocytopenia and G3 dyspnea); MTD was 450 mg. G3-5 AEs in all pts: anemia (A1: 3/19, A3: 2/15), nausea (A1: 1/19, A3: 2/15), emesis (A1: 1/19, A3: 1/15), neutropenia (A1: 2/19, A3: 8/15), thrombocytopenia (A1: 1/19, A3: 4/15), hyperbilirubinemia (A3: 3/15), pneumonia (A1: 2/19), acute renal failure (A3: 1/15), fatigue (A3: 2/15). Fifteen patients were evaluable for response; the overall response rate was 20% with two PR (pt with head and neck carcinoma in A1 and pt with carcinoma of unknown primary in A3) - and one CR in a pt with cholangiocarcinoma (A3) lasting 10.3 months. Overall, disease control rate was 47%. Of 5 evaluable pts with cholangiocarcinoma 3 had clinical benefit. Median PFS 3.4 mo (A1)/4.8 mo (A3) and OS 13.7 mo (A1)/29.1 mo (A3). PK and IHC data will be presented at the conference. Conclusions: The MTD of Cer is 600 mg in combination with Gem and 450 mg in combination with Gem/Cisplatin. Further evaluation of Cer plus Gem-based chemotherapy is planned in ALK/ROS1 positive cholangiocarcinomas.

Citation Format: Christos Fountzilas, Alex Adjei, Mateusz Opyrchal, Rachel Evans, Kristopher Attwood, Andrew Goey, John Wilton, Wen Wee Ma, Renuka Iyer. Ceritinib (Cer) in combination with gemcitabine (Gem)-based chemotherapy in patients (pts) with advanced solid tumors, a phase I study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT139.

Guidelines Insights: Hepatobiliary Cancers, Version 2.2019

The NCCN Guidelines for Hepatobiliary Cancers provide treatment recommendations for cancers of the liver, gallbladder, and bile ducts. The NCCN Hepatobiliary Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel's discussion and updated recommendations regarding systemic therapy for first-line and subsequent-line treatment of patients with hepatocellular carcinoma.

Exploring the role of survivin in neuroendocrine neoplasms

Neuroendocrine tumors (NETs) are a heterogenous group of tumors. While most NETs have excellent prognosis, certain subsets have aggressive biology and have limited treatment options. We explored the role of survivin in NET as a prognostic and potentially therapeutic marker. Tissue microarrays of 132 patients were stained for survivin using immunohistochemistry (IHC) and correlated with outcomes. Using genomic database, we then correlated survivin (BIRC5) mRNA expression with radiosensitivity index (RSI) in 52 samples of NET. Finally, we studied the effect of radiation on survivin expression in human cell lines and the impact of knock-down of BIRC5 on cell proliferation and radiation sensitivity. We found that survivin positivity by IHC correlated with a shorter survival (overall survival 8.5 years vs. 18.3 years, p < 0.001). There was a positive correlation between BIRC5 expression and RSI (r = 0.234, p < 0.0001). Radiation exposure increased BIRC5 gene expression in a human carcinoid cell line. Knockout of BIRC5 using siRNA reduced proliferation of neuroendocrine cells but did not increase radiation sensitivity. We conclude that survivin expression in NET correlates with an inferior survival and survivin expression in human carcinoid cell lines increases after exposure to ionizing radiation.

Does dual-energy CT differentiate benign and malignant ovarian tumours?

AIM

To assess the ability of dual-energy computed tomography (DECT) to distinguish benign from malignant ovarian tumours (OTs).

MATERIALS AND METHODS

Following approval of the institutional review board, the institutional database was mined for treatment-naive patients who underwent primary cytoreduction for OT. Thirty-seven patients were included and divided into those with benign OTs (n = 11) and malignant OTs (n = 26), including high-grade (n = 20) and low-grade (n = 6) malignant OTs. Advanced processing and region of interest delineation on the ovarian mass were performed using the preoperative staging DECT examination using the Advantage Workstation. The pixel-level data of the CT attenuation values at 50, 70, and 120 keV and the effective atomic number (Z_eff), water content (WC), and iodine content (IC) in the ovarian mass were recorded. The Wilcoxon rank-sum test was used to compare CT attenuation data at different voltages, Z_eff, and WC and IC levels between benign and malignant OTs and between high- and low-grade malignant OTs. Simple logistic regression was used to correlate the imaging characteristics with malignant status and grade.

RESULTS

Malignant OTs had significantly higher Z_eff and IC compared with benign OTs. The threshold values for the diagnosis of malignant OT were IC≥9.74 (100 μg/cm³) with 81% sensitivity and 73% specificity and Z_eff ≥8.16 with 85% sensitivity and 73% specificity. High-grade OTs had significantly higher WC compared with low-grade OTs, and a threshold of ≥1,013.92 mg/cm³ differentiated them with 80% sensitivity and 83% specificity.

CONCLUSION

DECT may be a tool to help distinguish malignant and benign OTs and predict tumour grade.

Delayed response to proton beam treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has become one of the leading causes of cancer death worldwide. There has been anecdotal report regarding the effectiveness of proton beam treatment for HCC. In this pre-clinical investigation, the woodchuck model of viral hepatitis infection-induced HCC was used for proton beam treatment experiment. The radiopaque fiducial markers that are biodegradable were injected around the tumor under ultrasound guidance to facilitate positioning in sequential treatments. An α cradle mode was used to ensure reproducibility of animal positioning on the treatment couch. A CT scan was performed first for contouring by a radiation oncologist. The CT data set with contours was then exported for dose planning. Three fractionations, each 750 CcGyE, were applied every other day with a Mevion S250 passive scattering proton therapy system. Multiphase contrast-enhanced CT scans were performed after the treatment and at later times for follow-ups. 3 weeks post-treatment, shrinking of the HCC nodule was detected and constituted to a partial response (30% reduction along the long axis). By week nine after treatment, the nodule disappeared during the arterial phase of multiphase contrast-enhanced CT scan. Pathological evaluation corroborated with this imaging response. A delayed, but complete imaging response to proton beam treatment applied to HCC was achieved with this unique and clinically relevant animal model of HCC.

Phase I Study of Irinotecan/5-Fluorouracil/Leucovorin (FOLFIRI) with Sunitinib for Advanced Gastric or Gastroesophageal Junction Adenocarcinoma

BACKGROUND

Sunitinib (S) is a multi-targeted tyrosine kinase inhibitor. It is synergistic with chemotherapy in preclinical models. We hypothesized that sunitinib in combination with fluorouracil, leucovorin, and irinotecan (FOLFIRI) would be a tolerable and effective regimen in advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma.

OBJECTIVE

Since the outcomes of advanced gastric and GEJ adenocarcinoma patients are poor, we decided to study a combination of FOLFIRI + S, to establish tolerability and efficacy.

PATIENTS AND METHODS

This was a phase I study for patients with advanced chemo-naïve gastric or GEJ adenocarcinoma. Dose escalation used a standard 3 + 3 design. The primary objective was to determine the tolerability and safety of FOLFIRI + S. Secondary objectives were overall survival (OS), progression-free survival (PFS), and objective response rate (ORR).

RESULTS

A total of 23 patients participated in the study (male 78%, female 22%). The median age was 61 (range: 38-77) years. Median follow-up time was 67.5 (95% CI 58.9-76) months. The most frequently reported adverse events were anemia (78%; G3/4: 4%), neutropenia (78%; G3/4: 43%), nausea (74%; G3/4:13%), diarrhea (65%; G3/4: 4%), vomiting (61%, G3/4: 9%) lymphopenia (52%; G3/4: 13%), and fatigue (52%; G3/4:17%). Two dose-limiting toxicities were noted each at dose level (DL) 1 and 1A, one at DL 1B, and three at DL 2. Maximum tolerated dose was determined at DL 1B. At the time of data reporting, 21 patients had died. The median OS and PFS were 12.4 (95% CI 8.9, 16.5) months and 6.2 (95% CI 3.4, 13.5) months, respectively. Of all patients, 35% (eight out of 23) had a partial response.

CONCLUSIONS

FOLFIRI + S has signs of clinical activity in patients with advanced gastric and GEJ adenocarcinoma, and the side-effect profile was similar to previously reported studies. Current treatment paradigms in gastric cancer probably negate further study of this regimen. ClinicalTrials.gov identifier: NCT00524186.

Role of Adjuvant Chemotherapy in Pulmonary Carcinoids: An NCDB Analysis

BACKGROUND/AIM

Typical carcinoids (TC) and atypical carcinoids (AC) are rare diseases. A paucity of randomized studies and disagreements among various guidelines makes the management challenging.

PATIENTS AND METHODS

Using codes for TC (8240) and AC (8249) in the National Cancer Database (NCDB), all surgically resected cases from 2004-2014 were included to evaluate the need for adjuvant chemotherapy.

RESULTS

A total of 6,673 cases were included, 88% were TCs and 12% were ACs. From 2004 to 2014, the proportion of TCs went up from 1.3% to 1.8% and ACs from 0.1% to 0.3% of all lung malignancies. TC patients did well with surgery alone in all stages. AC patients with stage I [5-year overall survival (OS) - 84% vs. 52%; S vs. S+CT] and stage II disease (5-year OS - 81% vs. 55%; S vs. S+CT) showed better OS trend with surgery alone, while stage III patients showed some benefit with the use of adjuvant chemotherapy (5-year OS - 46% vs. 54%; S vs. S+CT). These results supported the National Comprehensive Cancer Network (NCCN) guidelines.

CONCLUSION

No benefit was seen from adjuvant chemotherapy in TCs. While the adjuvant therapy may add benefit in stage III AC, the numbers are small and did not reach statistical significance.

Poly(ADP-Ribose) Polymerase Inhibitors in Pancreatic Cancer: A New Treatment Paradigms and Future Implications

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy. Most of the patients of PDAC present at later stages of disease and have a five-year survival rate of less than 10%. About 5-10% PDAC cases are hereditary in nature and have DNA damage repair (DDR) mutations such as BRCA 1 and 2. Besides having implications on screening and prevention strategies, these mutations can confer sensitivity to platinum-based therapies and determine eligibility for poly(ADP-ribose) polymerase inhibitors (PARPi). In the presence of DDR mutations and PARPi, the cells are unable to utilize the error-free process of homologous recombination repair, leading to accumulation of double stranded DNA breaks and cell death eventually. Various PARPi are in clinical development in PDAC in different subgroup of patients as monotherapies and in combination with other therapeutics. This review would focus on the mechanism of action of PARPi, history of development in PDAC, resistance mechanisms and future directions.

[18F] Clofarabine for PET Imaging of Hepatocellular Carcinoma

Clinical diagnosis of hepatocellular carcinoma (HCC) relies heavily on radiological imaging. However, information pertaining to liver cancer treatment such as the proliferation status is lacking. Imaging tumor proliferation can be valuable in patient management. This study investigated ¹⁸F-labeled clofarabine ([¹⁸F]CFA) targeting deoxycytidine kinase (dCK) for PET imaging of dCK-dependent proliferation in HCC. Since clinical PET scans showed a high liver background uptake of [¹⁸F]CFA, the aim of this study was to reduce this liver background uptake. A clinically relevant animal model of spontaneously developed HCC in the woodchucks was used for imaging experiments. Several modifiers were tested and compared with the baseline PET scan: Forodesine, probenecid, and cold clofarabine, all applied before the hot [¹⁸F]CFA injection to evaluate the reduction in liver background uptake. Application of forodesine before hot [¹⁸F]CFA injection did not reduce the background uptake. Instead, it increased the background by 11.6–36.3%. Application of probenecid also increased the liver background uptake by 16.6–32.1%. Cold CFA application did reduce the liver background uptake of [¹⁸F]CFA, comparing to the baseline scan. Combining cold CFA with [¹⁸F]CFA for PET imaging of liver cancers is a promising strategy, worthy of further clinical evaluation.

Augmentation of IFN-γ+ CD8+ T cell responses correlates with survival of HCC patients on sorafenib therapy

BACKGROUNDSorafenib has been shown to reduce the extent of immunosuppression in patients with hepatocellular carcinoma (HCC). The rationale of this investigation was to identify biomarkers that can predict treatment efficacy of sorafenib in HCC patients and to unravel the mechanism by which sorafenib impedes immune suppression mediated by distinct immunosuppressive cell subsets.METHODSWith informed consent, blood samples were collected from 30 patients with advanced HCC, at baseline and 2 time points after initiation of sorafenib treatment. The frequency of PD-1+ T cells, ERK2 phosphorylation on flt-3+ Tregs and MDSCs, and T effector cell function were quantified by using flow cytometry.RESULTSElevated levels of CD8+Ki67+ T cells producing IFN-γ were associated with improved progression-free survival and overall survival (OS). High frequencies of these T cells were correlated with significantly reduced risk of death over time. Patients with an increased pretreatment T effector/Treg ratio showed significant improvement in OS. ERK+flt-3+ Tregs and MDSCs were significantly decreased after sorafenib therapy. Increased numbers of baseline flt-3+p-ERK+ MDSCs were associated with survival benefit of patients.CONCLUSIONA high baseline CD4+ T effector/Treg ratio is a potential biomarker of prognostic significance in HCC. CD8+Ki67+ T cells producing IFN-γ are a key biomarker of response to sorafenib therapy resulting in survival benefit. The immune modulation resulted from sorafenib-mediated blockade of signaling through the VEGF/VEGFR/flt-3 pathway, affecting ERK phosphorylation. These insights may help identify patients who likely would benefit from VEGFR antagonism and inform efforts to improve the efficacy of sorafenib in combination with immunotherapy.TRIAL REGISTRATIONNCT02072486.FUNDINGNational Comprehensive Cancer Network Oncology Research Program from general research support provided by Bayer US LLC (NCCNSORA0002), National Cancer Institute grant P30CA016056, and pilot funds from Roswell Park Alliance Foundation.

Abstract 4530: An independent validation of a screening test using mass spectrometry for detection of hepatocellular carcinoma

Background: Early detection is critical to improve outcome in hepatocellular carcinoma (HCC). Despite inadequate sensitivity (SS) and specificity (SP), abdominal ultrasound and alpha-fetoprotein (AFP) are considered methods of choice for HCC surveillance. As less than 30% of patients (pts) are diagnosed early enough for resection or transplantation, a test with improved SS and SP is needed. A test to detect HCC in a high-risk population from 10 uL serum, combining MALDI mass spectrometry and AFP data was developed using a dropout-regularized hierarchical machine learning approach designed to minimize overfitting in small development sets. It was previously validated in 293 high risk pts (158 HCC, 135 non-HCC) with SS/SP of 83%/84% in development and 81%/79% in validation across various etiologies and Child-Pugh classification [1].

Methods: The test was applied to an independent validation cohort of 156 pts (97 HCC, 59 non-HCC healthy controls), blinded to clinical data, the performance was assessed by SS, SP. Sub-group analyses were performed by grade and stage. Performance was compared with that of AFP by area under the curve (AUC), using the test output prior to the predefined thresholding which yields the final binary cancer/benign test result.

Results:

Table 1.HCC patient demographics in the independent validation setClinical characteristicsIndependent validationPatients with HCC (N=97)Median age (range), years62 (38 - 89)Median AFP (range), ng/mL4.0 (less than 1.5 - 10,000)Gender, male / female85% / 16%Hepatitis B / C / No virus / not available (NA)3% / 27% / 20% / 51%Grade I / II / III / NA17% / 22% / 12% / 50%Stage I / II / III / IV / NA12% / 14% / 33% / 26% / 14%Previous liver directed or systemic therapy yes/no44% / 54%ECOG PS 0 / 1 / 2 / 3 / NA13% / 20% / 11% / 5% / 51%

In independent validation, AUC for the test output prior to thresholding was 0.979, significantly better than AFP AUC 0.915 (P&lt;0.001). SS and SP were 88% and 100%. SS in grade I, II, and III was 75%, 76%, and 92% and in stage I, II, III, and IV was 75%, 86%, 94%, and 92%. Conclusion: Results in the independent cohort confirm performance of the test, with better SS and SP than AFP and historical ultrasound. The SS was also high in low grade and early stage disease, indicating the test’s potential to improve early detection of HCC when curative approaches are feasible. Data and samples from Data Bank and BioRepository, Roswell Park; funding by the NCI grant P30CA016056 [1] D Mahalingam et al. Hepatology 62(S1): 1135A (2015)

Citation Format: Sunyoung S. Lee, Kristopher Attwood, Heinrich Roder, Senait Asmellash, Krista Meyer, Stylianos Kakolyris, Carlos Oliveira, Joanna Roder, Julia Grigorieva, Leonidas Chelis, Renuka Iyer, Devalingam Mahalingam. An independent validation of a screening test using mass spectrometry for detection 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 4530.

Abstract 136: Modeling of prognostication and immune profiling, based on genomic analysis in the tumor microenvironment of pancreatic adenocarcinoma via machine learning

The extensive tumor microenvironment (TME) in pancreatic adenocarcinoma (PAD) modulates cancer progression and impact prognosis. Although gene analysis has enhanced understanding of cancer biology, few models exist to model prognosis in association with mRNA expression in the TME. Clinical outcomes data and mRNA-seq of 156 and 64 patients (pts) were obtained from TCGA and Bailey at el. [1] for testing and validation, respectively. Expressivity of 191 genes enriched in cellular and structural elements of TME and clinical data were analyzed by multivariate nonlinear regression aided by machine learning for confined optimization with model-data error minimization. Statistics including Kaplan-Meier (KM), Cox Hazard (CH), and correlation analysis was used. Most pts (85.89% and 85.94%, respectively) were in stage II, and pts in stage I/III/IV were excluded. Prognostication was modeled with higher risk score (RS) representing worse prognosis: RS = -7.6526 x (Age-5.5679) + 0.0813 x (P/G0.3677) + 0.7069, where P/G is a ratio of genes associated with poor to good prognosis (Table 1). Based on RS, pts were clustered into 2 groups (high and low RS) with 2 KM curves showing p&lt;0.0001 and p=0.014 in test and validation sets. Immune profiling of high and low RS groups in both test and validation sets shows that in low RS group, genes related to both immune activation (IA) and inhibition (II) (Table 2) are highly co-expressed, implying that co-expression of IA and II contributes to PAD’s poor prognosis even in pts with immune system activation. In high RS group, genes related to cancer stem cells (CD44 and EPCAM) significantly contributed to poor prognosis. Machine learning-assisted modeling of RS and gene analysis suggest that IA genes are suppressed by co-expression of high degree of II, contributing to poor prognosis in PAD. RS enables prognostication of pts encountered in the clinic when genomic profiles are provided. [1] Nature 531, 47-52 (2016).

Table 1genes associated with good and poor prognosis out of 191 genes (identification via KM and CH with p&lt;0.05)Good prognosisFCRL3, LILRA4, IL3RA, IL10, CCL22, DOK3, CXCR4, PDGFA, ICOSLG, TNFRSF4Poor prognosisTNFSF10, CD44

Table 2gene groups of immune activation (IA) and immune inhibition (II)IA gene groupscytotoxic T, B, NK, T-helper 1 cells, IFN, cytolytic activity, T cell co-stimulation, and antigen presentationII gene groupsregulatory T cells, desmoplasia, immunosuppressive chemokines, immune checkpoints, angiogenesis, cancer stem cells, epithelial-mesenchymal transition, and neutrophils

Note: This abstract was not presented at the meeting.

Citation Format: Sunyoung S. Lee, Seok Joon Kwon, Ahmed Elkhanany, Andrew Baird, Seongwon Lee, Jillian Dolan, Stuart Baird, Shinyoung Park, Renuka Iyer. Modeling of prognostication and immune profiling, based on genomic analysis in the tumor microenvironment of pancreatic adenocarcinoma via machine learning [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 136.

Interleukin-6 as a biomarker in patients with hepatobiliary cancers

Background

The role of inflammation has been well established in many cancers, including hepatobiliary cancers. Elevated levels of interleukin-6 (IL-6), a pro-inflammatory marker, are associated with poor overall survival (OS) in hepatocellular carcinoma (HCC) patients.

Methods

We performed a study to establish the role of IL-6 as a prognostic biomarker in both HCC and biliary cancer patients and further assessed the impact of IL-6 on pain score and performance status, two parameters that affect the quality of life. We evaluated 91 patients with newly diagnosed unresectable hepatobiliary cancer and compared them with age, gender and BMI matched healthy controls.

Results

We found that IL-6 levels were elevated in hepatobiliary cancer patients compared to healthy controls. Higher levels of IL-6 were associated with poor prognosis, elevated pain scores and poor performance status in patients. Interestingly, we found an association between elevated IL-6 levels and the presence of portal vein thrombosis (PVT) at the time of cancer diagnosis.

Conclusions

This study suggests that IL-6 is an important prognostic biomarker in hepatobiliary cancers, where elevated levels are not only associated with a worse survival but also linked to an inferior quality of life.

PET imaging of hepatocellular carcinoma with anti-1-amino-3-[18F]fluorocyclobutanecarboxylic acid in comparison with L-[S-methyl-11C]methionine

PURPOSE

[11C]methionine ([11C]Met) was used for cancer imaging based on upregulated amino acid transport and protein synthesis in different tumor types. However, the short half-life of 11C decay limited further clinical development of [11C]Met. Synthetic amino acid analog anti-1-amino-3-[18F]fluoro-cyclobutyl-1-carboxylic acid ([18F]FCABC) was developed and FDA-approved for PET imaging of recurrent prostate cancer. This study investigated "repurposed" [18F]FACBC for PET imaging of primary liver cancer such as hepatocellular carcinoma (HCC) in comparison with [11C]Met.

METHODS

[11C]Met was synthesized in the lab, and [18F]FACBC was purchased from a commercial outlet. A clinically relevant animal model of spontaneously developed HCC in the woodchucks was used for PET imaging. Bioinformatics analysis was performed for the expression of amino acid transporters responsible for radiotracer uptake and validated by PCR. Dynamic PET scans of [11C]Met and [18F]FACBC were acquired within 1 week. Standardized uptake value (SUV) was calculated for regions of interest (ROIs) defined over HCC and a liver background region. H&E staining and immunohistochemical (IHC) staining were performed with harvested tissues post-imaging.

RESULTS

Higher expression of ACST2 and LAT1 was found in HCC than in the surrounding liver tissues. PCR validated this differential expression. [11C]Met and [18F]FACBC displayed some differences in their uptake and retention in HCC. Both peaked in HCC with an SUV of 3.5 after 10 min post-injection. Met maintained a plateaued contrast uptake in HCC to that in the liver while [18F]FCABC declined in HCC and liver after peak uptake. The pathological assessment revealed the liver tumor as moderately differentiated similar to the human HCC and proliferative.

CONCLUSION

Both [18F]FACBC and [11C]Met showed uptake in HCC through the use of a clinically relevant animal model of woodchuck HCC. The uptake and retention of [18F]FACBC and [11C]Met depend on their metabolism and also rely on the distribution of their principal amino acid transporters.

Efficacy, Safety, and Potential Biomarkers of Sunitinib and Transarterial Chemoembolization (TACE) Combination in Advanced Hepatocellular Carcinoma (HCC): Phase II Trial

OBJECTIVES

To evaluate the safety/efficacy and explore biomarkers for a rationally designed combination of sunitinib and transarterial chemoembolization (TACE) in a prospective phase 2 study of advanced hepatocellular carcinoma (HCC).

METHODS

Inoperable HCC patients with Child-Pugh A disease received 37.5 mg sunitinib from days 1 to 7 followed by TACE on day 8. Sunitinib was resumed from days 15 to 36 followed by 2 weeks off. Patients received subsequent sunitinib cycles of 4 weeks on and 2 weeks off. Dynamic contrast-enhanced magnetic resonance imaging and circulating soluble biomarkers were assessed at baseline, day 8, day 10, and day 36.

RESULTS

Sixteen patients with liver only (n=10) and extrahepatic disease (n=6) were enrolled. After a median follow-up of 12.8 months, 2 partial responses, 11 stable disease, and 3 clinical deteriorations were seen for a clinical benefit rate of 81%. Median progression-free survival (PFS) was 8 months (95% CI, 4.3-9.3) and overall survival was 14.9 months (95% CI, 6.3-27.1). Eleven of 16 patients (69%) had grade 3/4 toxicities attributable to sunitinib, the most frequent being thrombocytopenia, amylase/lipase elevations, lymphopenia, and fatigue. Mean K (volume transfer constant) and viable tumor percent in consented patients decreased by 27% and 14.8%, respectively, with combination therapy. Soluble vascular endothelial growth factor receptor-2 (sVEGFR2) levels, cytokines (interleukin-8, interleukin-21), and monocytes decreased with combination therapy. Estimated sunitinib IC50 values of 15 and 10 ng/mL modulated K and AUC90. sVEGFR2 levels decreased with K and AUC90.

CONCLUSIONS

Encouraging progression-free survival and overall survival were seen with acceptable toxicity in our study of sunitinib and TACE combination in advanced HCC. Potential imaging and serum biomarkers showed increased benefit with combination therapy.