Clinical drug screening reveals clofazimine potentiates the efficacy while reducing the toxicity of anti-PD-1 and CTLA-4 immunotherapy

Emerging as the most potent and durable combinational immunotherapy, dual anti-PD-1 and CTLA-4 immune checkpoint blockade (ICB) therapy notoriously increases grade 3-5 immune-related adverse events (irAEs) in patients. Accordingly, attempts to improve the antitumor potency of anti-PD-1+CTLA-4 ICB by including additional therapeutics have been largely discouraged due to concerns of further increasing fatal toxicity. Here, we screened ∼3,000 Food and Drug Administration (FDA)-approved drugs and identified clofazimine as a potential third agent to optimize anti-PD-1+CTLA-4 ICB. Remarkably, clofazimine outperforms ICB dose reduction or steroid treatment in reversing lethality of irAEs, but unlike the detrimental effect of steroids on antitumor efficacy, clofazimine potentiates curative responses in anti-PD-1+CTLA-4 ICB. Mechanistically, clofazimine promotes E2F1 activation in CD8+ T cells to overcome resistance and counteracts pathogenic Th17 cells to abolish irAEs. Collectively, clofazimine potentiates the antitumor efficacy of anti-PD-1+CTLA-4 ICB, curbs intractable irAEs, and may fill a desperate clinical need to improve patient survival.

Immunotherapy and transplantation for hepatocellular carcinoma

Immune checkpoint inhibitors (ICIs) have emerged as the primary treatment for advanced hepatocellular carcinoma (HCC) and have shown promise in the neoadjuvant setting prior to resection. Liver transplantation (LT) is the preferred treatment for unresectable early HCC or locally advanced disease post locoregional therapy, but the need for immunosuppression after LT conflicts with ICIs' immune augmenting effects. Neoadjuvant ICI may benefit select LT candidates, but challenges arise in understanding response indicators and managing post-LT risks. Reports of severe rejection after LT have raised concerns, though liver-specific factors may mitigate rejection risks, prompting exploration of pre-LT ICI usage. While focus has been on PD-1/PD-L1 inhibitors, the optimal pre-LT ICI regimen remains uncertain, and trials must emphasize careful patient selection and management. Living donor LT is advantageous because ICIs can be withheld for a predefined washout period. In the post-LT setting, use of ICIs is generally avoided, though a few reports suggest that PD-L1 expression in the transplanted liver may be a safety biomarker and that, despite the risk, ICI therapy may be better than supportive care for patients with otherwise-untreatable HCC recurrence. This expert opinion highlights the complexities in the management of HCC vis-à-vis LT. Prospective studies and biomarkers are needed to define safe and effective pre- and post-LT immunotherapy protocols.

What Is Hot and New in Basic and Translational Science in Liver Transplantation in 2023? Report of the Basic and Translational Research Committee of the International Liver Transplantation Society

The 2023 Joint Annual Congress of the International Liver Transplantation Society, European Liver and Intestine Transplant Association, and Liver Intensive Care Group of Europe were held in Rotterdam, the Netherlands, from May 3 to 6, 2023. This year, all speakers were invited to attend the Congress in person for the first time since the COVID-19 pandemic. The congress was attended by 1159 registered delegates from 54 countries representing 5 continents, with the 10 countries comprising the bulk of the delegates. Of the 647 abstracts initially submitted, 542 were eventually presented at the meeting, coming from 38 countries (mainly North America, Europe, and Asia) and 85% of them (462 abstracts) came from only 10 countries. Fifty-three (9.8%) abstracts, originated from 17 countries, were submitted under the Basic/Translational Scientific Research category, a similar percentage as in 2022. Abstracts presented at the meeting were classified as (1) ischemia and reperfusion injury, (2) machine perfusion, (3) bioengineering and liver regeneration, (4) transplant oncology, (5) novel biomarkers in liver transplantation, (6) liver immunology (rejection and tolerance), and (7) artificial intelligence and machine learning. Finally, we evaluated the number of abstracts commented in the Basic and Translational Research Committee-International Liver Transplantation Society annual reports over the past 5 y that resulted in publications in peer-reviewed journals to measure their scientific impact in the field of liver transplantation.

Comparative molecular profiling of pancreatic ductal adenocarcinoma of the head versus body and tail

Pancreatic ductal adenocarcinoma (PDAC) of the head (H) and body/tail (B/T) differ in embryonic origin, cell composition, blood supply, lymphatic and venous drainage, and innervation. We aimed to compare the molecular and tumor immune microenvironment (TIME) profiles of PDAC of the H vs. B/T. A total of 3499 PDAC samples were analyzed via next-generation sequencing (NGS) of RNA (whole transcriptome, NovaSeq), DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing), and immunohistochemistry (Caris Life Sciences, Phoenix, AZ). Significance was determined as p values adjusted for multiple corrections (q) of <0.05. Anatomic subsites of PDAC tumors were grouped by primary tumor sites into H (N = 2058) or B/T (N = 1384). There were significantly more metastatic tumors profiled from B/T vs. H (57% vs. 44%, p < 0.001). KRAS mutations (93.8% vs. 90.2%), genomic loss of heterozygosity (12.7% vs. 9.1%), and several copy number alterations (FGF3, FGF4, FGF19, CCND1, ZNF703, FLT4, MUTYH, TNFRS14) trended higher in B/T when compared to H (p < 0.05 but q > 0.05). Expression analysis of immuno-oncology (IO)-related genes showed significantly higher expression of CTLA4 and PDCD1 in H (q < 0.05, fold change 1.2 and 1.3) and IDO1 and PDCD1LG2 expression trended higher in B/T (p < 0.05, fold change 0.95). To our knowledge, this is one of the largest cohorts of PDAC tumors subjected to broad molecular profiling. Differences in IO-related gene expression and TIME cell distribution suggest that response to IO therapies may differ in PDAC arising from H vs. B/T. Subtle differences in the genomic profiles of H vs. B/T tumors were observed.

Molecular profiling in the management of hepatocellular carcinoma

PURPOSE OF REVIEW

The purpose of this review is to both summarize the current knowledge of hepatocellular carcinoma molecular biology and to suggest a framework in which to prospectively translate this knowledge into patient care. This is timely as recent guidelines recommend increased use of these technologies to advance personalized liver cancer care.

RECENT FINDINGS

The main themes covered here address germline and somatic genetic alterations recently discovered in hepatocellular carcinoma, largely owing to next generation sequencing technologies, and nascent efforts to translate these into contemporary practice.

SUMMARY

Early efforts of translating molecular profiling to hepatocellular carcinoma care demonstrate a growing number of potentially actionable alterations. Still lacking are a consensus on what biomarkers and technologies to adopt, at what scale and cost, and how to integrate them most effectively into care.

Bis-indole-derived NR4A1 antagonists inhibit colon tumor and splenic growth and T-cell exhaustion

There is evidence that the orphan nuclear receptor 4A1 (NR4A1, Nur77) is overexpressed in exhausted CD8 + T cells and regulates PD-L1 in tumors. This study investigated the effects of potent bis-indole-derived NR4A1 antagonists on reversing T-cell exhaustion and downregulating PD-L1 in colon tumors/cells. NR4A1 antagonists inhibited colon tumor growth and downregulated expression of PD-L1 in mouse colon MC-38-derived tumors and cells. TILs from MC-38 cell-derived colon tumors and splenic lymphocytes exhibited high levels of the T-cell exhaustion markers including PD-1, 2B4, TIM3+ and TIGIT and similar results were observed in the spleen, and these were inhibited by NR4A1 antagonists. In addition, treatment with NR4A1 antagonists induced cytokine activation markers interferon γ, granzyme B and perforin mRNAs and decreased TOX, TOX2 and NFAT in TIL-derived CD8 + T cells. Thus, NR4A1 antagonists decrease NR4A1-dependent pro-oncogenic activity and PD-L1 expression in colon tumors and inhibit NR4A1-dependent T-cell exhaustion in TILs and spleen and represent a novel class of mechanism-based drugs that enhance immune surveillance in tumors.

Transplant Oncology: An Emerging Discipline of Cancer Treatment

Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The applications of oncology, transplant medicine, and surgery are the core of transplant oncology to improve patients' survival and quality of life. The main concept of transplant oncology is to radically cure cancer by removing the diseased organ and replacing it with a healthy one, aiming to improve the survival outcomes and quality of life of cancer patients. Subsequently, it seeks to expand the treatment options and research for hepatobiliary malignancies, which have seen significantly improved survival outcomes after the implementation of liver transplantation (LT). In the case of colorectal cancer (CRC) in the transplant setting, where the liver is the most common site of metastasis of patients who are considered to have unresectable disease, initial studies have shown improved survival for LT treatment compared to palliative therapy interventions. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years beyond Milan criteria in a stepwise manner. However, the outcome improvements and overall patient survival are limited to the specifics of the setting and systematic intervention options. This review aims to illustrate the representative concepts and history of transplant oncology as an emerging discipline for the management of hepatobiliary malignancies, in addition to other emerging concepts, such as the uses of immunotherapy in a peri-transplant setting as well as the use of circulating tumor DNA (ctDNA) for surveillance post-transplantation.

Infliximab for Treatment of Immune Adverse Events and Its Impact on Tumor Response

Background: Immune-related adverse events (irAEs) challenge the use of immune checkpoint inhibitors (ICIs). We performed a retrospective study to evaluate response to infliximab for immune-related adverse event management, and infliximab's effect on progression-free survival (PFS) and overall survival (OS) with a focus on melanoma and genitourinary cancers. Methods: We retrospectively reviewed records of all cancer patients exposed to infliximab after immune checkpoint inhibitor (ICI) treatment from 2004 to 2021 at the MD Anderson Cancer Center. Survival was assessed utilizing the Kaplan-Meier method. Univariate and multivariate logistic regression was utilized to evaluate predictors of infliximab response, OS, and PFS. Results: We identified 185 cancer patients (93 melanoma and 37 genitourinary cancers) treated with ICI and who received infliximab to treat irAEs. Within 3 months of treatment initiation, 71% of the patients responded to infliximab, 27% had no response, and 2% had unknown response. Among different irAEs, colitis was associated with increased response to infliximab at 3 months, irrespective of the type of malignancy. We evaluated best tumor response before and after infliximab in the entire cohort and again in the melanoma and genitourinary (GU); the findings were similar in the melanoma cohort and the entire cohort, where best tumor response before and after infliximab was not significantly different. In the melanoma cohort, acute kidney injury (AKI) was associated with increased risk of death, p = 0.0109, and having response to infliximab was associated with decreased risk of death, p = 0.0383. Interestingly in GU cancer patients, myositis was associated with increased risk of death, p = 0.0041, and having a response to infliximab was marginally associated with decreased risk of death, p = 0.0992. As regards PFS, in a multivariate Cox regression model, having a history of cardiovascular disease remained significantly associated with shorter PFS in the melanoma cohort. For patients with GU cancers, response to infliximab was associated with longer PFS. Conclusions: Our study is among the largest retrospective analyses of infliximab use for irAE management. Patients with colitis were the best responders to infliximab. AKI before initiation of infliximab in the melanoma subcohort and myositis in GU subcohort are associated with higher risk of death. Our results indicate no association between infliximab and cancer progression with the exception of genitourinary cancers.

Case Report: Immune checkpoint inhibitor-induced multiorgan vasculitis successfully treated with rituximab

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer. ICIs have a unique side effect profile, generally caused by inflammatory tissue damage, with clinical features similar to autoimmune conditions. Acute kidney injury from ICIs has been well studied; incidence ranges from 1% to 5%, with higher incidence when combination ICI therapies are used. Although the overall reported incidence of ICI-associated glomerulonephritis is less than 1%, vasculitis is the most commonly reported ICI-related glomerulonephritis. Other biopsy findings include thrombotic microangiopathy, focal segmental glomerulosclerosis, minimal change disease, and IgA nephropathy with secondary amyloidosis. We report a case in which a woman previously treated with the PD-L1 inhibitor durvalumab for locally advanced non-small cell lung cancer with pre-existing antineutrophil cytoplasmic (anti-PR3) antibody who later developed multi-organ vasculitis after ICI exposure, which was successfully treated with rituximab, with continued cancer remission for 3 years.

Immune Checkpoint Inhibitors for Solid Tumors in the Adjuvant Setting: Current Progress, Future Directions, and Role in Transplant Oncology

The rationale for administering immune checkpoint inhibitors (ICIs) in the adjuvant setting is to eradicate micro-metastases and, ultimately, prolong survival. Thus far, clinical trials have demonstrated that 1-year adjuvant courses of ICIs reduce the risk of recurrence in melanoma, urothelial cancer, renal cell carcinoma, non-small cell lung cancer, and esophageal and gastroesophageal junction cancers. Overall survival benefit has been shown in melanoma while survival data are still not mature in other malignancies. Emerging data also show the feasibility of utilizing ICIs in the peri-transplant setting for hepatobiliary malignancies. While ICIs are generally well-tolerated, the development of chronic immune-related adverse events, typically endocrinopathies or neurotoxicities, as well as delayed immune-related adverse events, warrants further scrutiny regarding the optimal duration of adjuvant therapy and requires a thorough risk-benefit determination. The advent of blood-based, dynamic biomarkers such as circulating tumor DNA (ctDNA) can help detect minimal residual disease and identify the subset of patients who would likely benefit from adjuvant treatment. In addition, the characterization of tumor-infiltrating lymphocytes, neutrophil-to-lymphocyte ratio, and ctDNA-adjusted blood tumor mutation burden (bTMB) has also shown promise in predicting response to immunotherapy. Until additional, prospective studies delineate the magnitude of overall survival benefit and validate the use of predictive biomarkers, a tailored, patient-centered approach to adjuvant ICIs that includes extensive patient counseling on potentially irreversible adverse effects should be routinely incorporated into clinical practice.

Impact of Infections in Patients Receiving Pembrolizumab-Based Therapies for Non-Small Cell Lung Cancer

Background: Immune checkpoint inhibitor (ICI) therapy has significantly improved outcomes across a range of malignancies. While infections are a well-known contributor to morbidity and mortality amongst patients receiving systemic chemotherapy regimens, little is known about the impact of infections on patients receiving ICI therapy. This study aims to assess incidence, risk factors, and outcomes in patients who develop infections while on pembrolizumab-based therapies for non-small cell lung cancer (NSCLC). Methods: Patients receiving pembrolizumab for stage III/IV NSCLC from 1/1/2017-8/1/2021 across seven hospitals were identified. Incidence and type of infection were characterized. Covariates including baseline demographics, treatment information, treatment toxicities, and immunosuppressive use were collected and compared between infected and non-infected patients. Outcomes included the rate of infections, all-cause hospital admissions, median number of treatment cycles, overall survival (OS), and progression free survival (PFS). Univariable and multivariable analysis with reported odds ratio (OR) and 95% confidence intervals (CI) were utilized to evaluate infection risks. OS and PFS were analyzed by Kaplan−Meier analysis and tested by log-rank test. p-value < 0.05 was considered statistically significant. Results: There were 243 NSCLC patients that met the inclusion criteria. Of these, 111 (45.7%) had one documented infection, and 36 (14.8%) had two or more. Compared to non-infected patients, infected patients had significantly more all-cause Emergency Department (ED) [37 (33.3%) vs. 26 (19.7%), p = 0.016], hospital [87 (78.4%) vs. 53 (40.1%), p < 0.001], and ICU visits [26 (23.4%) vs. 5 (3.8%), p < 0.001], and had poorer median OS (11.53 [95% CI 6.4−16.7] vs. 21.03 [95% CI: 14.7−24.2] months, p = 0.033). On multivariable analysis, anti-infective therapy (OR 3.32, [95% CI: 1.26−8.76], p = 0.015) and ECOG of >1 (OR 5.79, [95% CI 1.72−19.47], p = 0.005) at ICI initiation conferred an increased risk for infections. At last evaluation, 74 (66.7%) infected and 70 (53.0%) non-infected patients died (p = 0.041). Conclusion: Infections occurred in nearly half of patients receiving pembrolizumab-based therapies for NSCLC. Infected patients had frequent hospitalizations, treatment delays, and poorer survival. ECOG status and anti-infective use at ICI initiation conferred a higher infection risk. Infection prevention and control strategies are needed to ameliorate the risk for infections in patients receiving ICIs.

Case report: Efficacy and safety of regorafenib plus fluorouracil combination therapy in the treatment of refractory metastatic colorectal cancer

Background

More than half of patients with colorectal cancer (CRC) present with metastatic disease or develop recurrent disease on first-line and second-line options. Treatment beyond the second line remains an area of unmet need for patients with progressive or recurrent disease.

Methods

We retrospectively reviewed data of adult (>18 years old) patients with mCRC who received regorafenib + 5FU combination therapy at Houston Methodist Hospital with outcomes of interest including response rate, discontinuation due to side effects, and overall survival.

Results

Seven patients received regorafenib + 5FU combination therapy for mCRC after receiving at least two other lines of therapy (including at least one fluorouracil-based therapy). Four patients (57%) achieved disease control in 7-12 weeks after therapy initiation while three patients developed recurrent disease. In patients who achieved disease control, no new adverse events were reported among patients with this combination.

Conclusion

Regorafenib and Fluorouracil combination could be considered an option beyond the second line for patients with treatment-refractory metastatic colorectal cancer. Further studies, including a prospective trial, are needed to investigate the efficacy and safety of regorafenib plus 5FU therapy compared to other limited available therapies.

Intrahepatic cholangiocarcinoma: The role of liver transplantation, adjunctive treatments, and prognostic biomarkers

Intrahepatic cholangiocarcinoma (iCCA) is a primary epithelial cell malignancy of the liver with rising incidence rate globally. Its insidious presentation, heterogeneous and aggressive biology, and recalcitrance to current therapies results in unacceptably high morbidity and mortality. This has spurred research efforts in the last decade to better characterize it molecularly with translation to improved diagnostic tools and treatments. Much of this has been driven by patient advocacy. This has renewed interest in orthotopic liver transplantation (LT) with adjunctive therapies for iCCA, which was historically disparaged due to poor recipient outcomes and donor organ scarcity. However, the optimal use of LT as a treatment for iCCA care remains unclear. Here, we review the epidemiology of iCCA, the history of LT as a treatment modality, alternative approaches to iCCA local control, the evidence for peri-operative systemic therapies, and the potential roles of biomarkers and targeted agents. In doing so, we hope to prioritize areas for continued research and identify areas where multidisciplinary care can improve outcomes.

Pancreatic Tumorigenesis: Precursors, Genetic Risk Factors and Screening

Pancreatic cancer (PC) is a highly malignant and aggressive tumor. Despite medical advancement, the silent nature of PC results in only 20% of all cases considered resectable at the time of diagnosis. It is projected to become the second leading cause in 2030. Most pancreatic cancer cases are diagnosed in the advanced stages. Such cases are typically unresectable and are associated with a 5-year survival of less than 10%. Although there is no guideline consensus regarding recommendations for screening for pancreatic cancer, early detection has been associated with better outcomes. In addition to continued utilization of imaging and conventional tumor markers, clinicians should be aware of novel testing modalities that may be effective for early detection of pancreatic cancer in individuals with high-risk factors. The pathogenesis of PC is not well understood; however, various modifiable and non-modifiable factors have been implicated in pancreatic oncogenesis. PC detection in the earlier stages is associated with better outcomes; nevertheless, most oncological societies do not recommend universal screening as it may result in a high false-positive rate. Therefore, targeted screening for high-risk individuals represents a reasonable option. In this review, we aimed to summarize the pathogenesis, genetic risk factors, high-risk population, and screening modalities for PC.

Recent Trends and Advancements in the Diagnosis and Management of Gastric Cancer

Gastric cancer is an enigmatic malignancy that has recently been shown to be increasing in incidence globally. There has been recent progress in emerging technologies for the diagnosis and treatment of the disease. Improvements in non-invasive diagnostic techniques with serological tests and biomarkers have led to decreased use of invasive procedures such as endoscopy. A multidisciplinary approach is used to treat gastric cancer, with recent significant advancements in systemic therapies used in combination with cytotoxic chemotherapies. New therapeutic targets have been identified and clinical trials are taking place to assess their efficacy and safety. In this review, we provide an overview of the current and emerging treatment strategies and diagnostic techniques for gastric cancer.

Gemcitabine Plus Cisplatin Versus Non-Gemcitabine and Cisplatin Regimens as Neoadjuvant Treatment for Cholangiocarcinoma Patients Prior to Liver Transplantation: An Institution Experience

Background

Cholangiocarcinoma management is constantly being updated in view of existing evidence in order to establish practice guidelines and consensus statements. However, the available treatment guidelines to optimize outcomes for cholangiocarcinoma patients who require liver transplantation are still controversial. This study contributing to the cholangiocarcinoma care field by investigating a new promising neoadjuvant therapy that might be help to grant the liver transplant option to the patients with cholangiocarcinoma. Here, we evaluate and compare the potential efficacy of chemotherapy combination of Gemcitabine plus Cisplatin versus non- Gemcitabine and Cisplatin regimens as a neo-adjuvant treatment for cholangiocarcinoma patients prior to liver transplantation.

Methods

In this retrospective study, patients with locally advanced, unresectable, hilar, or intrahepatic cholangiocarcinoma with no evidence of extrahepatic disease or vascular involvement were treated with either the combination of neo-adjuvant Gemcitabine plus Cisplatin with no radiation or other standard options of neo-adjuvant treatment. All patients included received chemotherapy prior to being listed for liver transplantation at a single cancer center in collaboration with the same institution’s transplant center according to an open-labeled, and centers-approved clinical management protocol. Patients were listed for liver transplantation if they had a minimum of six months of scans showing response or confirmation of disease stability. The primary endpoints were the overall survival and recurrence-free survival after liver transplantation. This report, which was censored on March 18, 2022.

Results

Out of a total of 707 liver transplant recipients were screened, 37 patients were confirmed with a diagnosis of cholangiocarcinoma and only 18 patients (11 males and 7 females) with a median age of 61.83 [interquartile range: 58.27-68.74] met inclusion criteria. Of the 18 patients enrolled, 10 received Gemcitabine/Cisplatin, while 8 patients received either Gemcitabine monotherapy or Capecitabine or FOLFIRI. Months for recurrence after transplantation was 20.1 (IRQ: 20.1-20.1) in the Gemcitabine/Cisplatin group and 9.5 (8.9-12.47) months in the non-Gemcitabine/Cisplatin group (p-value=0.18). Median months of follow-up in the Gemcitabine/Cisplatin group was 28.35 (27.1-32.23) months versus 40.12 (20.6-56.22) months in the non-Gemcitabine/Cisplatin group (p-value=0.33). In non-Gemcitabine/Cisplatin patients, overall survival was 75% (95% CI 31-93%) at both years 1 and 2; 63% (95% CI 23-86%) at years 3 to 5. In Gemcitabine/Cisplatin patients, overall survival was 100% (95% CI 100-100%) at both years 1 and 2; 75% (95% CI 13-96%) at years 3 to 5. Three non-Gemcitabine/Cisplatin patients died at 328 days, 340 days, and 896 days, respectively. One Gemcitabine/Cisplatin patient died at 885 days.

Conclusion

Our findings suggest improved overall survival outcomes with Gemcitabine plus Cisplatin as neo-adjuvant treatment with no concomitant radiation compared to non-Gemcitabine/Cisplatin regimens in patients with cholangiocarcinoma prior to liver transplantation.

Immunotherapy as a Neoadjuvant Therapy for a Patient with Hepatocellular Carcinoma in the Pretransplant Setting: A Case Report

Systemic combination therapy of immune checkpoint inhibitors and vascular endothelial growth factors have provided the basis for improved outcomes in select patients with unresectable or metastatic hepatocellular carcinoma. However, for patients with resectable disease, surgery alone or an orthotopic liver transplant remains the standard of care. Within the realms of transplant oncology, neoadjuvant systemic therapy is currently being evaluated as a potential strategy to improve outcomes in patients with HCC. Here, we report excellent response with significant downstaging in a safe manner after neoadjuvant treatment with atezolizumab and bevacizumab in a patient diagnosed with poorly differentiated HCC. As a result of the significant response observed with safe outcomes, the patient was listed for orthotopic liver transplant (OLT) evaluation and transplanted successfully.

Abstract 236: Nuclear receptor 4A1 ligands target T-cell exhaustion in colorectal cancer

Colorectal cancer (CRC) is a highly complex disease with multiple risk factors. The orphan nuclear receptor 4A1 (NR4A1) is overexpressed in several cancers and is a negative prognostic factor for cancer patient survival. Previous reports indicate a potential role for overexpression of NR4A1 in T-cell exhaustion and in this study, we aim to investigate the antitumorigenic activity of two bis-indole derived ligands (DIMs) that act as receptor antagonists. Immune competent C57BL/6 mice and mouse MC-38 colon cancer cells were used and tumor Infiltrating Lymphocytes (TILs) were isolated from mice either untreated or treated with CDIM/NR4A1 antagonists. FACS analysis and Real -Time PCR were performed to determine expression of exhaustion markers in these tumor T-cell population. 1,1-Bis(3΄-indolyl)-1-(3-bromo-5-trifluoromethoxyphenyl)methane (DIM-3-Br-5-OCF3) and the 3,5-dichlorophenyl analog (DIM-3,5-Cl2) at doses of 2.5 and 7.5 mg/kg/d inhibited tumor growth and downregulated expression of PD-L1, an NR4A1-regulated gene in MC-38 - derived tumors and cells. The mouse MC-38 colon cancer cell line was used in a syngeneic mouse model of colon cancer and tumor infiltrating lymphocytes (TILs) from MC-38 cell-derived colon tumors exhibited multiple markers of T-cell exhaustion in both CD8+ and CD4+ T-cells. Lymphocytes from an enlarged spleen in these tumor-bearing animals also exhibited markers of CD8+ and CD4+ T-cell exhaustion. Analysis of CD8+ cells from TILs showed that treatment with the NR4A1 antagonists modulated expression of several genes associated with T-cell exhaustion namely a decrease in TOX, TOX2 and NFAT mRNAs, activation of T-Bet. The percentage of CD8+ and CD4+ T-cells from tumors and spleen expressing PD-1, 2B4 and TIGIT was decreased in the treated vs control mice and TIM3 expression was also decreased in CD8+ (tumors and spleen) and CD4+ (tumors) T-cells. These findings suggest that NR4A1 antagonists are highly effective as anticancer agents in this mouse syngeneic colon tumor model by inactivating the pro-oncogenic activities of NR4A1 in tumors and by remediating NR4A1-regulated T-cell exhaustion in tumor and splenic lymphocytes.

Citation Format: Kumaravel Mohankumar, Gus Wright, Subhashree Kumaravel, Rupesh Shrestha, Lei Zhang, Maen Abdelrahim, Robert S. Chapkin, Stephen Safe. Nuclear receptor 4A1 ligands target T-cell exhaustion in colorectal cancer [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 236.

Immune checkpoint inhibitors for solid organ transplant recipients: clinical updates

Transplant care continues to advance with increasing clinical experience and improvements in immunosuppressive therapy. As the population ages and long-term survival improves, transplant patient care has become more complex due to comorbidities, frailty, and the increased prevalence of cancer posttransplantation. Immune checkpoint inhibitors (ICIs) have become a standard treatment option for many cancers in non-transplant patients, but the use of ICIs in transplant patients is challenging due to the possibility of disrupting immune tolerance. However, over the past few years, ICIs have gradually started to be used in transplant patients as well. In this study, we review the current use of ICIs after all solid organ transplantation procedures (kidney, liver, heart, and lung). Increasing data suggest that the type and number of immunosuppressants may affect the risk of rejection after immunotherapy. Immunotherapy for cancer in transplant patients may be a feasible option for selected patients; however, prospective trials in specific organ transplant recipients are needed.

Feasibility of disease recurrence monitoring in liver post-transplantation for patients with hepatocellular carcinoma via personalized and tumor-informed ctDNA test

e16123

Background: Hepatocellular carcinoma (HCC) is an aggressive malignancy for which liver transplantation can be curative. Unfortunately, ̃8-20% of HCC patients will go on to relapse post-transplantation. Personalized and tumor-informed circulating tumor DNA (ctDNA) testing (Signatera, bespoke mPCR NGS assay) has been validated to accurately predict relapse across solid tumors, ahead of radiological imaging. Here, we demonstrate the feasibility of ctDNA testing for monitoring relapse in HCC patients who underwent liver transplantation with curative intent. Methods: A total of 10 HCC patients, stage I-IV, who underwent curative liver transplantation with longitudinal ctDNA monitoring were included in the analysis. Alpha-fetoprotein (AFP) levels and images were measured during surveillance in a subset of patients. Results: In this cohort of 10 patients, 2 (20%) tested ctDNA positive during surveillance, both of whom relapsed. Of these, one tested ctDNA positive two months prior to imaging. Of the 8 patients who did not test ctDNA positive during surveillance, all remained disease-free by imaging. Two patients had elevated AFP, neither of whom relapsed. Of the 2 patients who relapsed, AFP levels were available for one patient and fell within the normal range. Conclusions: Our study illustrated the feasibility of performing longitudinal ctDNA assessment in patients with HCC (post-transplantation) during surveillance. ctDNA status but not AFP was associated with recurrence and was able to inform disease status ahead of imaging. To facilitate clinical decision-making, specifically with adjuvant therapy and immunosuppression management, additional studies with larger patient cohorts will be needed to validate the clinical utility of ctDNA testing in HCC.

Gemcitabine plus cisplatin versus non-gemcitabine and cisplatin regimens as neoadjuvant treatment for cholangiocarcinoma patients prior to liver transplantation

e16202

Background: Cholangiocarcinoma (CCA)management is constantly being updated in view of existing evidence in order to establish practice guidelines and consensus statements. Here, we evaluate and compare the potential efficacy of chemotherapy combination of Gemcitabine plus Cisplatin versus non- Gemcitabine and Cisplatin regimens as a neo-adjuvant treatment for cholangiocarcinoma patients prior to liver transplantation. Methods: In this prospective study, patients with locally advanced, unresectable, hilar, or intrahepatic CCA with no evidence of extrahepatic disease or vascular involvement were treated with either the combination of neo-adjuvant Gemcitabine plus Cisplatin with no radiation or other standard options of neo-adjuvant treatment. All patients included received chemotherapy prior to being listed for liver transplantation at a single cancer center in collaboration with the same institution’s transplant center according to an open-labeled, and centers-approved clinical management protocol. Patients were listed for liver transplantation if they had a minimum of six months of scans showing response or confirmation of disease stability. This report, which was censored on November 30, 2021, was an initial prospective study of patients treated under this ongoing clinical treatment protocol. Results: Out of a total of 707 liver transplant recipients, 37 patients were confirmed with a diagnosis of CCA and only 18 patients (11 males and 7 females) with a median age of 61.83 [interquartile range (IQR): 58.27-68.74] met inclusion criteria. Of the 18 patients enrolled, 10 received Gemcitabine/Cisplatin, while 8 patients received either Gemcitabine monotherapy or Capecitabine or FOLFIRI alone or with Cetuximab. Days for recurrence after transplantation was 603 (IRQ: 603-603) in the Gemcitabine/Cisplatin group and 285 (267-374) days in the non-Gemcitabine/ Cisplatin group (p-value = 0.18). The median days of follow-up in the Gemcitabine/Cisplatin group were 753 (621-885) days versus 1050 (618-1489) days in the non-Gemcitabine/ Cisplatin group (p-value = 0.25). In the non-Gemcitabine/ Cisplatin group, overall survival was 75% (95% CI 31-93%) at both years 1 and 2; 63% (95% CI 23-86%) at both years 3 and 4. In the Gemcitabine/ Cisplatin group, overall survival was 100% (95% CI 100-100%) at both years 1 and 2; 67% (95% CI 5-95%) at both years 3 and 4. Three patients in the non-Gemcitabine/ Cisplatin group died at 328 days, 340 days, and 896 days, respectively. One patient in the Gemcitabine/ Cisplatin group died at 885 days. Conclusions: To our knowledge, this is the first report to show improved overall survival outcomes with Gemcitabine plus Cisplatin as neo-adjuvant treatment with no concomitant radiation compared to non-Gemcitabine/ Cisplatin regimens in patients with CCA prior to liver transplantation.

Combination of transarterial chemoembolization (TACE) and tyrosine kinase inhibitors (TKIs) compared to TACE alone as bridging therapy transplant recipients with hepatocellular carcinoma: An update

e16201

Background: Hepatocellular carcinoma (HCC) is the world's sixth most prevalent cancer and the third leading cause of cancer-related death. For patients with advanced HCC, trials combining TACE with tyrosine kinase inhibitors (TKIs) such as Sorafenib have given mixed outcomes. (TACE) plus lenvatinib led showed significant improvement in OS compared to lenvatinib alone in the first-line setting in patients with advanced HCC according to phase 3 LAUNCH trial which was presented at the 2022 ASCO Gastrointestinal Cancers Symposium. This study was aimed to compare the outcome of HCC patients who received TACE plus TKI agent versus TACE alone. Methods: Retrospectively all subjects with unresectable HCC were included in this study, who underwent liver transplantation (LT) and were treated by either TACE alone (TA) or TACE plus Sorafenib (TandS) between July 2008–December 2021. For categorical factors, HCC recurrence after LT was reported as frequencies and proportions, while for continuous variables, the median and interquartile range (IQR) or mean was used. For categorical variables, Chi-square or Fisher's exact tests were used, while for continuous variables, Kruskal-Wallis test was used. Results: Seven hundred patients were screened; only 128 patients in total underwent LT with most being males (77%); the median age of 61.5 years. The TA group included 79 (77%) subjects who matched Milan Criteria (MC) and 24 (23%) who did not, but the TandS group had a greater number of cases who did not meet MC: 16 (64%) versus 9 (36%); p = 0.01. There was a significant variation in five-year disease-free survival (DFS) across the therapy groups investigated, with 100% DFS in the TandS group vs 67.2 percent in the TAne group (p = 0.07). The TandS group had a five-year patient survival rate of 77.8% compared to 61.5 percent in the TA group (p = 0.51). However, beyond the MC, patients who were treated with TA had the average percentage of necrotic tumor on resected histology of 43.8 %, 32 % compared to 69.6 %, 32.8 % for cases treated with TandS, p = 0.03. Conclusions: We have found that using TandS is generally well tolerated and demonstrated improved OS compared to TA in patients with unresectable HCC. A prospective clinical study (NCT05171335) is ongoing at our institution to further investigate this concept.

Prognostic value of molecular response via ctDNA measurement in predicating response of systemic therapy in patients with advanced solid cancer

e13001

Background: Molecular profiling of cancer can guide treatment decision, monitor response and predict clinical outcome in the era of precision medicine and individualized treatment. Emerging evidence has suggested that ctDNA change correlates with treatment response and predates radiological relapse. Thus, we aim to provide real-world data regarding the dynamic changes of ctDNA level measured via Guardant 360 Response in advanced solid cancer correlates with clinical outcome. Methods: We retrospectively reviewed data of patients with advanced solid cancer and had at least 2 timepoints of Guardant 360 Response test at Houston Methodist Cancer center from 1/1/2014- 2 /1/2022. Data collected included age, gender, type of solid cancer, mutational values, treatment started date and type of systemic therapy. Personalized mutational profiles derived from tumor tissue via whole-exome sequencing were used to design patient-specific ctDNA assays for variant detection in plasma samples. Blood samples taken at baseline and 8 weeks were analyzed to a 70-gene next-generation sequencing panel. On-therapy changes in circulating tumor DNA levels (molecular response) were measured using a ratio computation, with response defined as a decrease in mean variant allele fraction of 50% or more. Apart from ctDNA analysis, patients were also monitored using tumor markers and radiological imaging. Results: : Of 267 patients, only 93 were met the inclusions criteria with age 58.66 (±12.95) and female were the most with 77 (82.80%). Patients with breast cancer were the dominant with 62 (66.67%), Lung adenocarcinoma 20 (21.51%), Uveal Melanoma 4 (4.30%), Colorectal Cancer and Lung Squamous Cell Carcinoma 2 (2.15 %) each, Large Cell Lung Carcinoma, Sarcoma and Thymic Carcinoma were 1(1.07%) each. Patients who received Chemotherapy /Immunotherapy were 38 (41.30%), Chemotherapy/Immunotherapy/Radiation therapy were 29 (31.52%), Immunotherapy 9 (9.78%), Chemotherapy/Immunotherapy/Targeted Therapy 2 (2.17%) and Targeted Therapy /Chemotherapy 3 (3.26%).Patients samples who correlated with clinical data were 89 (95.70%) and only 4 (4.30%) were not .Follow-up time 2.15 (interquartile range: 1.10-4.12) years, patients who still alive are 24 (25.81%), median survival time 2.4 (95% CI: 1.78-2.76) years. Conclusions: Our data demonstrated that molecular response evaluation using circulating tumor DNA as a noninvasive predictor of response to systemic therapy in addition to standard of care imaging in some solid cancer. Further prospective studies are needed to confirm the validation.

Outcomes of patients with advanced urothelial cancer who develop infection while on treatment with pembrolizumab

4573

Background: Over the past decade, studies have shown the benefit of immune checkpoint inhibitors (IO) in patients with advanced urothelial cancer. These agents work by reconditioning the adaptive anti-cancer immune response within the tumor microenvironment. Immune-related adverse events have been well documented, but there is limited data evaluating infections in patients treated with IO. We performed a retrospective analysis to assess the incidence of infection and its effect on morbidity and mortality in patients treated with pembrolizumab for advanced urothelial cancer. Methods: Data was collected from a network of 7 hospitals for patients who received pembrolizumab for advanced urothelial cancer from 1/1/2017-8/1/2021. Date of last follow up was 12/1/2021. Covariates compared among infected and non-infected cohorts included age, gender, race, comorbidities, ECOG, anti-infective therapy at IO initiation, and line of therapy (1L, 2L, > 2L). Univariable analysis with reported odds ratio (OR) and 95% confidence interval (CI) was used to assess risk factors for infection. Outcome measures included all-cause emergency department (ED) visits, inpatient and intensive care unit (ICU) admissions, median number of IO cycles, and overall survival (OS). OS was evaluated using the Kaplan-Meier model. All analyses were deemed statistically significant if the p-value was < 0.05. Results: A total of 51 patients were identified. Of these, 34 (66.7%) had at least one documented infection and 17 (33.3%) had no reported infections. Baseline characteristics were similar across cohorts. Compared to non-infected patients, infected patients received fewer cycles of IO (median 4 vs 8, p = 0.016). At last follow-up, 20 (58.8%) patients in the infected cohort and 4 (23.5%) in the non-infected cohort died (p = 0.017). Median OS was 7.4 months (95% CI: 3.4-24.9) among patients with infection while not reached in those without infection (p = 0.014). ED visits (p = 1.00), inpatient admissions (p = 0.21), and ICU admissions (p = 0.17) did not significantly differ between cohorts. Univariable analysis did not identify significant risks among covariates. Conclusions: The incidence of infection in patients treated with pembrolizumab for advanced urothelial cancer is high and associated with fewer cycles of IO therapy and shorter OS. Further study of infectious process prevention is of value to maximize immunotherapy benefit.

The impact of pembrolizumab on patients with pre-existing autoimmune diseases

2660

Background: Immune checkpoint inhibitors (ICI) have changed the therapeutic landscape across a range of solid and hematologic malignancies. With the mechanistic activation of the adaptive immune response and known unique development of immune-related adverse effects (irAE), there is a theoretical risk of causing detrimental effects on patients with pre-existing autoimmune diseases (AID). However, this patient population was excluded from many clinical trials, and there is limited and conflicting retrospective data speculating upon the impacts of using ICI therapy in patients with AID. This study aims to report the impact of pembrolizumab in patients with AID. Methods: Patients who received pembrolizumab for treatment of any type of cancer between 1/1/2017-8/1/2021 were retrospectively reviewed, and patients with AID (rheumatologic or non-rheumatologic) were identified. Data including age, gender, race, ECOG, and primary cancer diagnosis were collected. AID was characterized by type, activity (symptomatic vs. asymptomatic at ICI initiation), and immunosuppressive treatment (IST) use. Outcomes included flare of AID, irAE, and ICI discontinuation. Results: Out of 810 patients, 12 with pre-existing AID were found and being treated for non-small cell lung cancer (NSCLC) (58% N=7), renal cell carcinoma (RCC) (16.6% N=2), colorectal cancer (CRC) (8% N=1), head and neck cancer (8% N=1), and cervical cancer (8% N=1). Around 67% of these patients were females with a median age of 65 years (50-77). Median ECOG was 1 (0-2). 9 patients (75%) had rheumatologic disease (5 rheumatoid arthritis (RA), 1 systemic lupus erythematosus (SLE), 2 psoriatic arthritis, and 1 systemic sclerosis (SS)). 3 patients (25%) had non-rheumatologic AID (1 multiple sclerosis (MS), 1 autoimmune hepatitis, and 1 Evan’s syndrome). All patients were asymptomatic prior to initiation of therapy. At the time of ICI initiation, 11 patients (92%) were on therapy, including steroids, methotrexate, and other IST. Due to concern for severe flare, pembrolizumab was discontinued in 3 (25%) MS, RA, and SS patients treated for RCC, CRC, and NSCLC, respectively. 3 patients (25%) developed irAE unrelated to their AID (pneumonitis, dermatitis, arthritis, gastritis) and received steroids. 4 patients (33.3%) had documented flares while on pembrolizumab requiring escalation of their ongoing therapy, and 1 NSCLC patient had a severe exacerbation of SS requiring cyclophosphamide and rituximab infusions. Conclusions: This analysis adds to the limited available literature that patients with an AID and on IST appear to have minimal AID-associated flares requiring intervention and tolerate pembrolizumab with a similar rate of irAE compared to patients without AID. Additional larger studies are needed to assess the efficacy of treatment in this population.

Timeline of FDA-Approved Targeted Therapy for Cholangiocarcinoma

Simple Summary

Cholangiocarcinoma constitutes around 3% of gastrointestinal cancers, and mortality from this cancer has been rising in the recent decades. Many cases of cholangiocarcinoma are unfortunately discovered in their advanced stages which cannot be treated with surgical resection alone. Targeted therapy is a type of medical treatment that has garnered significant interest due to its ability to specifically target cancer cells while sparing normal healthy cells. A few targeted therapies have just recently been approved by the United States FDA for the treatment of cholangiocarcinoma specifically. This manuscript seeks to explore the timeline of targeted therapies with either FDA approval or FDA breakthrough therapy designation. The official approval of these therapies marks a new age for the treatment of cholangiocarcinoma and brings new options for clinicians across the nation for this unfortunate disease.

Abstract

Cholangiocarcinoma (CCA) represents approximately 3% of gastrointestinal malignancies worldwide and constitutes around 10–15% of all primary liver cancers, being only second to hepatocellular carcinoma. Mortality from CCA has been on the rise in recent decades, and in the United States alone there has been a 36% increase in CCA from 1999 to 2014, with over 7000 CCA mortalities since 2013. Targeted therapies, which have been gaining interest due to their greater specificity toward cancer cells, have only recently started gaining FDA approval for the treatment of CCA. In this manuscript, we will go through the timeline of current FDA-approved targeted therapies as well as those that have gained FDA breakthrough therapy designation.

Gemcitabine and Cisplatin as Neo-Adjuvant for Cholangiocarcinoma Patients Prior to Liver Transplantation: Case-Series

Background: The management of cholangiocarcinoma is continually reviewed on a current evidence basis to develop practice guidelines and consensus statements. However, the standardized treatment guidelines are still unclear for cholangiocarcinoma patients who are listed for liver transplantation. We aimed to validate and evaluate the potential efficacy of chemotherapy combination of Gemcitabine and Cisplatin as a neo-adjuvant treatment for cholangiocarcinoma patients before liver transplantation. Methods: In this prospective case series, patients with locally advanced, unresectable, hilar, or intrahepatic cholangiocarcinoma with no evidence of extrahepatic disease or vascular involvement were treated with a combination of neoadjuvant gemcitabine and cisplatin with no radiation. All patients included received chemotherapy prior to being listed for liver transplantation at a single cancer center according to an open-labeled, and center-approved clinical management protocol. The primary endpoints were the overall survival and recurrence-free survival after liver transplantation. Results: Between 1 March 2016, and 15 March 2022, 10 patients (8 males and 2 females) with a median age of 62.71(interquartile range: 60.02–71.87) had a confirmed diagnosis of intrahepatic or hilar cholangiocarcinoma and underwent liver transplantation. Median days of neoadjuvant therapy for a given combination of gemcitabine and cisplatin were 181 (IRQ: 120–250). Nine patients (90%) were reported with no recurrence or metastasis, and only 1 patient had confirmed metastasis (10%); days for metastasis after transplantation were 612 for this patient. All patients received a combination of gemcitabine and cisplatin as neo-adjuvant while awaiting liver transplantation. The median days of follow-up were 851 (813–967). Overall survival was 100% (95% CI 100–100%) at both years one and two; 75% (95% CI 13–96%) at years three to five. One patient died at eight hundred and eighty-five days. No adverse events were reported after liver transplantation including the patient who was confirmed with recurrence. Conclusions: Our finding demonstrated that neo-adjuvant gemcitabine and cisplatin with no radiation prior to liver transplantation resulted in excellent outcomes for patients with cholangiocarcinoma.

Thymoquinone's Antiviral Effects: It is Time to be Proven in the Covid-19 Pandemic Era and its Omicron Variant Surge

The COVID-19 pandemic has impacted every country in the world. With more than 400 million cases and more than 5.5 million deaths. The FDA either approved or authorized the emergency use for three vaccines against COVID-19. The treatment options of COVID-19 are very limited. Multiple complementary and alternative medicine modalities were suggested to be efficacious in the treatment of COVID-19 such as Thymoquinone. The effects of Thymoquinone have been examined and multiple studies indicate a promising beneficial effect. However, the current body of research is limited in terms of its scope, quality, and quantity. While higher-quality studies are required, physicians do not routinely recommend the use of marketed supplements of natural products, including Thymoquinone for COVID-19. Given the numerous suggested positive effects of Thymoquinone, including anti-inflammatory and antimicrobial properties, additional research is required to confirm or refute these promising benefits. Complementary and alternative medicine is an area that requires additional evidence-based practice and research to confirm effects observed in clinical practice.

Utilization of Immunotherapy for the Treatment of Hepatocellular Carcinoma in the Peri-Transplant Setting: Transplant Oncology View

Simple Summary

Hepatocellular carcinoma is the second most common cause of cancer-related deaths and accounts for over eighty percent of primary liver cancers worldwide. Regarding the Milan Criteria, only a small portion of HCC patients are eligible for liver transplantation due to advanced-stage disease and large tumor size preventing/delaying organ allocation. Recently, the use of anti-programmed cell death protein 1 and programmed cell death ligand 1 (PD-1 and PD-L1) checkpoint inhibitors in the treatment of cancers have evolved rapidly and these therapies have been approved for the treatment of HCC, however, the main concerns about organ rejection in liver transplant patients who will be treated with ICPIs are still the same in both pre-and post-transplant setting. To alleviate those concerns, more global collaborations to explore the safety and efficacy of ICPIs in both the pre-and post-organ transplantation settings are required. The decision to administer ICPI treatment in liver transplant patients should be made on a case-by-case basis according to the goal of care and the availability and efficacy of other treatment options.

Abstract

Hepatocellular carcinoma (HCC) represents the second most common cause of cancer-related deaths and accounts for over eighty percent of primary liver cancers worldwide. Surgical resection and radiofrequency ablation in small tumors are included in the treatment options for HCC patients with good liver function profiles. According to the Milan Criteria, only a small portion of HCC patients are eligible for liver transplantation due to advanced-stage disease and large tumor size preventing/delaying organ allocation. Recently, the use of anti-programmed cell death protein 1 and programmed cell death ligand 1 (PD-1 and PD-L1) checkpoint inhibitors in the treatment of cancers have evolved rapidly and these therapies have been approved for the treatment of HCC. Immune checkpoint inhibitors have resulted in good clinical outcomes in pre-and post-transplant HCC patients, although, some reports showed that certain recipients may face rejection and graft loss. In this review, we aim to illustrate and summarize the utilization of immune checkpoint inhibitor therapies in pre-and post-liver transplants for HCC patients and discuss the assessment of immune checkpoint inhibitor regulators that might determine liver transplant outcomes.

Pancreatic head vs pancreatic body/tail cancer: Are they different?

BACKGROUND

The impact of pancreatic tumor location on patient survival has been studied in large national data-based analyses which yielded controversial results.

AIM

To explore if pancreatic head cancer (PHC) and pancreatic body/tail cancer (PBTC) have different overall survival (OS), molecular signature and response to chemotherapy.

METHODS

We retrospectively queried patient records from July 2016 to June 2020 in our institution. Patient demographics, cancer stage on diagnosis, tumor location, somatic mutations, treatment, and survival are recorded and analyzed. A test is considered statistically significant if the P value was < 0.05.

RESULTS

We reviewed 101 patients with complete records, among which 67 (66.34%) were PHC and 34 (33.66%) were PBTC. More PHC were diagnosed at younger age [61.49 vs 68.97, P = 0.010], earlier stages (P = 0.006) and underwent surgical resection (P = 0.025). There were no significant differences among all mutations and pathways studied except for TP53 mutations (37.0% in PHC vs 70.0% in PBTC, P = 0.03). OS was not statistically different between PHC and PBTC (P = 0.636) in the overall population and in subgroups according to surgical resection status or stages. In terms of response to chemotherapy, chemotherapy regimens (FOLFIRINOX-based vs gemcitabine-based) didn’t impact disease free interval in those who had surgical resection in either PHC (P = 0.546) or PBTC (P = 0.654), or the duration of response to first line palliative treatment in those with advanced disease in PHC (P = 0.915) or PBTC (P = 0.524).

CONCLUSION

Even though PHC and PBTC have similar poor OS and response to chemotherapy, the different presentations and molecular profiles indicate they are different diseases. Utilization of molecular profiling to develop targeted therapy for individualization of treatment is needed.

Survival following liver transplantation for locally advanced, unresectable intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) has previously been considered a contraindication to liver transplantation (LT). However, recent series showed favorable outcomes for LT after neoadjuvant therapy. Our center developed a protocol for neoadjuvant therapy and LT for patients with locally advanced, unresectable iCCA in 2010. Patients undergoing LT were required to demonstrate disease stability for 6 months on neoadjuvant therapy with no extrahepatic disease. During the study period, 32 patients were listed for LT and 18 patients underwent LT. For transplanted patients, the median number of iCCA tumors was 2, and the median cumulative tumor diameter was 10.4 cm. Patients receiving LT had an overall survival at 1-, 3-, and 5-years of 100%, 71%, and 57%. Recurrences occurred in seven patients and were treated with systemic therapy and resection. The study population had a higher than expected proportion of patients with genetic alterations in fibroblast growth factor receptor (FGFR) and DNA damage repair pathways. These data support LT as a treatment for highly selected patients with locally advanced, unresectable iCCA. Further studies to identify criteria for LT in iCCA and factors predicting survival are warranted.

Minimal residual disease assessment in colorectal cancer (MiRDA-C)

TPS236

Background: Detection of circulating tumor DNA (ctDNA) in the bloodstream is emerging as a novel marker for identifying of radiographically occult microscopic or minimal residual disease (MRD) in colorectal cancer (CRC) patients (pts) after curative intent treatments. Accumulating data suggest that ct-DNA defined MRD is a highly specific prognostic biomarker for future recurrences with a lead time of several months and prospective clinical trials are being conducted using ct-DNA defined MRD as an integral biomarker for improving risk stratification for adjuvant chemotherapy decision making. However, large scale, prospective data regarding kinetics of ctDNA-defined MRD with accurate pre-analytical methodology for plasma isolation and paired clinical data are limited. Methods: In this multi-center, prospective observational study, 1,000 pts with resectable CRC (stages II – IV) without other active malignancies undergoing therapy with curative intent will be enrolled any time from time of diagnosis up to start of adjuvant therapy (or ≤ 3 months post curative surgery, whichever is earlier). All therapeutic and surveillance visits decisions are at the discretion of the treating physicians. Serial biospecimens including blood (in Cell-Free DNA BCT tubes) to be processed to plasma and buffy coat in ≤ 2 days and formalin fixed tumor tissue will be collected at key time points until the time of radiographic recurrence or up to 5 years of surveillance. Blood draws will be at study entry, after each line of neoadjuvant therapy, post-surgery, during and after adjuvant therapy in addition to each surveillance visit. These blood draws will be coordinated with pts’ standard of care visits in order to minimize additional venipunctures. Relevant clinical data including demographics, cancer history, treatment details and outcomes, serum tumor markers and genomic data will be collected at each time point. Samples will be evaluated retrospectively with a primary objective of evaluating sensitivity and specificity of post-operative MRD for radiographic recurrences utilizing Guardant Health’s Reveal assay. Other key objectives include evaluating ctDNA kinetics with neoadjuvant and adjuvant therapies and to correlate with outcomes. The study is active, and enrollment is ongoing. Clinical trial information: NCT04739072.

Association of personalized and tumor-informed ctDNA with patient survival outcomes in pancreatic adenocarcinoma

517

Background: Pancreatic adenocarcinoma (PDAC) is the third leading cause of cancer-related death, with a recurrence rate of 85% after curative surgery and a 5-year survival rate of 10%. Serum biomarkers like CA 19-9 lack sensitivity and specificity (10% of patients fail to produce CA 19-9), and are poor indicators of molecular residual disease (MRD). Circulating tumor DNA (ctDNA) detection allows for MRD identification months ahead of radiological findings, and may assess molecular response and patient outcomes. Methods: A personalized and tumor-informed multiplex PCR assay (Signatera™ bespoke mPCR NGS assay) was used for the detection and quantification of ctDNA in a prospective clinical cohort of patients. Serial time points were collected for unresectable, borderline resectable, and resectable subsets of patients to monitor ctDNA levels in response to treatment (see Table). Results: 93 patients were included, with a median age of 67.3 yrs and 45% female. 285 timepoints were analyzed for ctDNA presence, with each patient having between 1 and 7 timepoints (median 3 timepoints per patient). 46 patients had one or more samples positive for ctDNA, resulting in an anytime ctDNA positivity rate of 49.5%. Anytime positivity correlated with the stage of disease (p<0.001). Within ctDNA-positive samples, observed levels were 0.04-1227 mean tumor molecules per mL of plasma (mean 35.1, median 1.02 MTM/mL). During the follow-up period (median 13.5 months, range 1-80 months), 36 patients had recurrence or disease progression events. Recurrence-free survival (RFS) strongly correlated with post-operative anytime ctDNA positivity: Hazards Ratio 8.0 (95% CI 3.4-18.7), p =1.6e-6. For 49 patients, CA 19-9 measurements were available. Elevated CA 19-9 was not correlated with RFS (p=0.35). Conclusions: Our study demonstrates the feasibility of tumor-informed ctDNA-based MRD testing in PDAC, in 93 patients of all stages. ctDNA positivity correlated with patient survival outcomes more strongly than CA19-9. Our data suggests patients can benefit from personalized and tumor-informed MRD testing.[Table: see text]

Comparative molecular profiling of pancreatic ductal adenocarcinoma (PDAC) of the head (H) versus body/tail (B/T) and the tumor immune microenvironment (TIME)

598

Background: PDAC of the H and B/T differ in embryonic origin, cell composition, blood supply, lymphatic and venous drainage, and innervation. H tumors tend cause symptoms earlier and to present at earlier stages compared to B/T cancers. The impact of PDAC tumor location on patient presentation and survival has been shown in large national data-based analyses, although with conflicting results. We aimed to compare the molecular and tumor immune microenvironment (TIME) profiles of PDAC of the H vs. B/T. Methods: A total of 3499 PDAC samples were analyzed via next-generation sequencing (NGS) of RNA (whole transcriptome, NovaSeq), DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing) and immunohistochemistry (IHC, Caris Life Sciences, Phoenix, AZ). RNA deconvolution was performed using QuantiSeq (Finotello 2019, Genome Medicine) to quantify the immune cell infiltration. Pathway gene enrichment analyses were done using Gene Set Enrichment Analysis (GSEA, Subramaniam 2015, PNAS). Significance was determined as p values adjusted for multiple correction (q) of < 0.05. Results: Anatomic subsites of PDAC tumors were grouped by primary tumor sites into H (N = 2058) or B/T (N = 1384). There were significantly more metastatic tumors profiled from H vs. B/T (57% vs. 44%, p < 0.001). KRAS mutations (93.8% vs. 90.2%), genomic loss of heterozygosity (12.7% vs. 9.1%), and several copy number alterations ( FGF3, FGF4, FGF19, CCND1, ZNF703, FLT4, MUTYH, TNFRS14) trended higher in B/T when compared to H (p < 0.05 but q > 0.05). GNAS mutations (2.2% vs. 0.7%) trended higher in H vs. B/T (p < 0.05). No significant difference in immuno-oncology (IO) markers (TMB, PD-L1, MSI-H) were observed, but expression analysis of IO-related genes showed significantly higher expression of CTLA4 and PDCD1 in H (q < 0.05, fold change 1.2 and 1.3) and IDO1 and PDCD1LG2 expression trended higher in B/T (p < 0.05, fold change 0.95). When comparing median cell abundance values as part of TIME analysis, H had increased immune infiltration of B cells (0.045 vs. 0.043), M2 macrophages (0.035 vs. 0.032), neutrophils (0.056 vs. 0.052), NK cells (0.027 vs. 0.026), CD8+ T cells (% > 0: 48.2% vs. 43.2%), while B/T had increased infiltration of M1 macrophages (0.035 vs. 0.032) (all q < 0.05). GSEA showed enrichment of CTLA4 (normalized enrichment score (NES) 1.6, false discovery rate (FDR) 0.19) and primary immunodeficiency pathway enrichment (NES 1.7, FDR 0.11) in H. Conclusions: To our knowledge, this is one of the largest cohort of PDAC tumors subjected to broad molecular profiling. Differences in IO-related gene expression and TIME cell distribution suggest that response to IO therapies may differ in PDAC arising from H vs B/T. Subtle differences in the genomic profliles of H vs. B/T tumors were also observed.

Utility of Cell-Free DNA Detection in Transplant Oncology

Simple Summary

Transplant oncology is an emerging field in cancer treatment that applies transplant medicine, surgery, and oncology to improve cancer patient survival and quality of life. This review aims to provide a comprehensive overview of the history and emergence of cfDNA technology, its applications to specifically monitor tumor burden at pre-and post-liver transplant stages, and evaluate transplant rejection. The use of ctDNA to evaluate transplant rejection has been extensively studied in non-hepatocellular carcinoma (HCC) diseases. Emerging studies have also investigated the use of ctDNA detection in evaluating HCC tumor burden pre-and post-surgery as well as transplant rejection. However, extensive studies still need to be conducted to evaluate the role of ctDNA detection in the medical management of transplant oncology patients.

Abstract

Transplant oncology is an emerging field in cancer treatment that applies transplant medicine, surgery, and oncology to improve cancer patient survival and quality of life. A critical concept that must be addressed to ensure the successful application of transplant oncology to patient care is efficient monitoring of tumor burden pre-and post-transplant and transplant rejection. Cell-free DNA (cfDNA) detection has emerged as a vital tool in revolutionizing the management of cancer patients who undergo organ transplantation. The advances in cfDNA technology have provided options to perform a pre-transplant evaluation of minimal residual disease (MRD) and post-transplant evaluation of cancer recurrence and transplant rejection. This review aims to provide a comprehensive overview of the history and emergence of cfDNA technology, its applications to specifically monitor tumor burden at pre-and post-transplant stages, and evaluate transplant rejection.

Triple-Regimen of Vemurafenib, Irinotecan, and Cetuximab for the Treatment of BRAFV600E-Mutant CRC: A Case Report and Review

Mutation of the BRAF proto-oncogene is found in approximately 10% of colorectal cancers (CRC), with much of the mutation conferred by a V600E mutation. Unlike other CRC subtypes, BRAF-mutant CRC have had relatively limited response to conventional therapies and overall poor survival. We present the case of a 75-year-old man with severe nonischemic cardiomyopathy on a LifeVest who was found to have a transverse colonic mass with widespread hepatic metastatic disease and was subsequently found to have BRAF^V600E-mutant CRC (MSI High/dMMR). After a failed therapy with FOLFOX and pembrolizumab, the patient was started on a regimen of vemurafenib, irinotecan, and cetuximab (VIC) based on the SWOG 1406 trial which had shown improved progression-free survival and response rate for the treatment of BRAF^V600E-mutant metastatic CRC. After 40 cycles of VIC, the patient attained complete response and is in remission off chemotherapy with significant improvement. This case highlights the effectiveness of the triple-regimen of vemurafenib, irinotecan, and cetuximab as a treatment option for BRAF^V600E-mutant CRC, which is a treatment regimen based on the SWOG 1406 trial, and also demonstrates the synergistic role of BRAF^V600E inhibitors and EGFR inhibitors in the treatment of BRAF^V600E-mutant CRC.

Renal Toxicity

With the increasing use of immunotherapy, there has been an associated increased survival in many cancers but has also resulted in unregulated organ-specific toxicities. In this review, we will discuss the renal toxicities associated with a checkpoint inhibitor (CPI) from the typical acute tubulointerstitial nephritis to glomerulonephritis and their proposed mechanisms and treatments. We also discuss the use of CPI and reactivation of preexisting autoimmune disease with a focus on renal cell cancer in setting of chronic kidney disease (CKD). Transplant rejection in setting of CPI use has been further evaluated with single-center and multicenter retrospective studies, and available data will be presented in this chapter.

808 Tertiary lymphoid structure gene signature detected in immune checkpoint inhibitor-associated renal immune related adverse event

Background

Tertiary lymphoid structures (TLSs) have been previously associated with ICI induced response in patients with cancer, but a commensurate observation has not been made in ICI associated immune related adverse events (irAEs). Acute interstitial nephritis (AIN) is the predominant lesion reported in patients with renal irAEs, but various etiologies can also trigger the development of AIN including non-ICI drugs (e.g. non-steroidal anti-inflammatory drugs, antibiotics, proton pump inhibitors, etc.), and it is unknown whether these mechanisms are similar. With increasing indications for ICIs in cancer therapy, there is a critical need to define immune pathways driving the emergence of irAEs. To address this critical knowledge gap, we performed gene expression profiling on ICI-AIN, drug-AIN, and control (non-AIN) kidney biopsy specimens.

Methods

Total RNA extracted from ICI-AIN (n = 6), drug-AIN (n = 4), and control (n = 4) fixed formalin paraffin embedded archival kidney biopsy samples was analyzed by Nanostring nCounter PanCancer Immune Profiling Panel using NanoString nCounter FLEX Analysis System.

Results

Three comparisons were conducted:

ICI-AIN vs control, drug-AIN vs control, and ICI-AIN vs drug-AIN. A total of 147 genes were differentially expressed in ICI-AIN vs control and the most differentially expressed genes were CXCL 9, 10, and 11. Similarly, cell marker gene expression signatures (GES) revealed significant upregulation of T and B cell markers in ICI-AIN vs control (P < 0.01) and ICI-AIN vs drug-AIN (T cell P < 0.05; B cell P < 0.01). Differences in T and B cell score were not detected in drug-AIN vs control. Since irAEs have been associated with anti-tumor efficacy, we investigated whether a TLS signature could be detected in ICI-AIN using a four GES (CD79A, MS4A1, LAMP3 and POU2AF1). The ICI-AIN group had significantly higher TLS score compared to both control and drug-AIN groups. Since several TLS signatures have been reported, we also calculated a 12-chemokine TLS GES which was also found to be statistically significant (P < 0.05). Th1 and Th17 cells have been associated with the formation of TLS, differential upregulation of Th1 associated genes but not Th17 associated genes were detected. Furthermore, differential expression IFN-y and TNF signature was also observed in ICI-AIN group.

Conclusions

This study is the first to demonstrate the presence of TLS immune signature in irAEs. Further investigations into the prognostic significance and strategies to uncouple ICI-associated anti-tumor benefits from ICI-induced irAEs should be explored.

Ethics Approval

The study was approved by The University of Texas MD Anderson Cancer Center intuition's Ethics Board, approval number PA16-1016

725 Immunomodulation by targeting PDL-1 in colon cancer using nuclear receptor 4A1 (NR4A1) antagonists

Background

The nuclear orphan receptor 4A1 (NR4A1, Nur77, TR3) is overexpressed in multiple solid tumors including colorectal tumors and is a negative prognostic factor for patient survival.1–3 NR4A1 is expressed in colon cancer cells and exhibit pro-oncogenic activity4 and results of examination of several colon cancer cell lines show that PD-L1 expression is limited and NR4A1 and PD-L1 are co-expressed in SW480 and RKO colon cancer cell lines. Previous studies showed that PD-L1 was regulated by NR4A1 which activates transcription factor Sp1 bound to the PD-L1 gene promoter.5–7 Knockdown of NR4A1 or Sp1 by RNA interference or treatment with mithramycin an inhibitor of Sp-mediated transcription decreased expression of PD-L1 in RKO and SW480 colon cancer cell lines.

Methods

SW480, RKO and MC-38 cells were used in this study. Cells were treated for 24 hrs with DIM series of compounds.

Results

Current data coupled with ongoing gene expression and PD-L1 promoter studies demonstrate that PD-L1 expression is regulated by NR4A1/Sp1 in colon cancer cells (figures 1–3). Bis-indole derived NR4A1 ligand that act as receptor antagonists have been developed in this laboratory and these compounds block pro-oncogenic NR4A1-regulated genes/pathways. Treatment of RKO and SW480 colon cancer cell lines with a series of potent 1,1-bis(3′-indolyl)-1-(3,5-disubstitutedphenyl) analogs decreased expression of PD-L1. These results show that bis-indole derived NR4A1 antagonists act as small molecule mimics of immunotherapeutics that target PD-L1. In vivo applications of NR4A1 ligands that target PD-L1 and their effects on tumor growth and immune surveillance are currently being investigated.

Conclusions

Bis-indole derived NR4A1 antagonists inhibit PD-L1 expression. NR4A1/SP1 regulates PD-L1 and is inhibited by NR4A1 antagonist. NR4A1 ligands such as DIM-3-Br-5-OCF3 were among the most potent of the substituted DIM compounds and ongoing in vivo studies show that this DIM compound also inhibits tumor growth in a syngenic mouse model (data not shown). Data from this study demonstrate the pro-oncogenic activity of NR4A1 and show that the synthetic buttressed analog DIM-3-Br-5-OCF3 acts as an NR4A1 antagonist and inhibits PD-L1 expression. These drugs can be developed for future clinical applications.

References

www.cancer.org/cancer/colon-rectal-cancer/about/key-statistics.html.

Garcia-Villatoro et al., Effects of high-fat diet and intestinal aryl hydrocarbon receptor deletion on colon carcinogenesis. Am J Physiol Gastrointest Liver Physiol 2020;318(3):G451–G463.

Safe S, Jin UH, Hedrick E, et al. Minireview: role of orphan nuclear receptors in cancer and potential as drug targets. Mol Endocrinol 2014;28(2):157–72.

Maxwell MA, Muscat GE. The NR4A subgroup: immediate early response genes with pleiotropic physiological roles. Nucl Recept Signal 2006;4:e002.

Lee SO, Li X, Hedrick E, et al. Diindolylmethane analogs bind NR4A1 and are NR4A1 antagonists in colon cancer cells. Mol Endocrinol 2014;28(10):1729–39.

Safe S, Kim K. Non-classical genomic estrogen receptor (ER)/specificity protein and ER/activating protein-1 signaling pathways. J Mol Endocrinol 2008;41(5):263–75.

Tao LH, Zhou XR, Li FC, Chen Q, Meng FY, Mao Y, et al. A polymorphism in the promoter region of PD-L1 serves as a binding-site for SP1 and is associated with PD-L1 overexpression and increased occurrence of gastric cancer. Cancer Immunol Immunother 2017;66(3):309–18.

Abstract 725 Figure 1

NR4A1 inactivation inhibits PD-L1 expression. SW480, RKO and MC-38 cells were transfected with siCtrl (non-specific oligonucleotide) and two oligonucleotides targeting NR4A1 (siNR4A1(1) and siNR4A1(2)) or PD-L1 (siPD-L1(1) and siPD-L1(2)) for 72 hrss. Protein expression from whole cell lysates were analyzed by western blots and effects on PD-L1 expression were determined

Abstract 725 Figure 2

Sp1 inactivation inhibits PD-L1 expression. SW480, RKO and MC-38 cells were transfected with siCtrl and oligonucleotides targeting Sp1 (siSp1(1) and siSp1(2)) for 72 hrs as well as treated with Mithrsamycin (150 and 300 nM) for 24 hrs. Protein expression from was analyzed by western blots and effects on PD-L1 levels were determined.

Abstract 725 Figure 3

Role of NR4A1/Sp in regulation of PD-L1. SW480, RKO and MC-38 cells were treated with DIM-3-Br-5-OCF3 for 24 hrss and protein interactions with the GC-rich PD-L1 promoter region were analyzed by ChIP using primers encompassing GC-rich region of the promoter

732 A novel nuclear receptor 4A1 (NR4A1) antagonists attenuates T-cell exhaustion in colorectal cancer

Background

Colorectal cancer (CRC) is a highly complex disease with multiple risk factors and both genetic and environmental components contribute to disease incidence.1 2 Cancer immunotherapy using immune-checkpoint blockades represents a major advance in treatment strategy.3 4 The orphan nuclear receptor 4A1 (NR4A1) is overexpressed in lung, colon, liver and breast cancers and in Rhabdomyosarcoma and is a negative prognostic factor for cancer patient survival.5–8 Previous studies in breast cancer cells showed that PD-L1 was regulated by NR4A1 which activates transcription factor Sp1 bound to the PD-L1 gene promoter. Genome-wide studies have identified NR4A1 as a key mediator of T-cell dysfunction and NR4A1 also plays an important role in regulating genes which are involved in tumor-induced T-cell exhaustion.9 Bis-indole derived NR4A1 ligand that act as receptor antagonists have been developed in this laboratory and these compounds block pro-oncogenic NR4A1-regulated genes/pathways.

Methods

Immune competent C57BL/6 mice and mouse MC-38 colon cancer cells were used and tumor Infiltrating Lymphocytes (TILs) were isolated from mice either untreated or treated with CDIM/NR4A1 antagonists. FACS analysis and Real -Time PCR were performed to determine expression of exhaustion markers in these tumor T-cell population.

Results

Two compounds:

1,1-bis(3′-indolyl)-1-(3-bromo-5-trifluoromethoxyphenyl)methane (DIM-3-Br-5-OCF3) and 3,5-dichlorophenyl analog (DIM-3,5-Cl2) inhibited tumor growth and weight at doses of 2.5 and 7.5mg/kg/day (figure 1). Tumor CD8+ T-cells isolated from mice treated with DIM-3,5-Cl2 and DIM-3-Br-5-OCF3 exhibited decreased mRNA expression of NR4A1 and high mobility group – box transcription factors NFAT, TOX and TOX2 and increased mRNA levels of Interferon-γ (IFNγ), granzyme β (GzB) and perforin compared to control animals (figure 2). As TOX and TOX2 cooperate with NR4A1 to modulate CD8+ T-cell exhaustion, we investigated the expression of several inhibitory receptors of T-cell exhaustion in CD8+ TILs, including PD-1, 2B4, TIGIT and TIM3. Following treatment with DIM-3,5-Cl2 or DIM-3-Br-5-OCF3, there was a significant decrease in the percentage of PD1 and 2B4 cells and a decrease in TIGIT and TIM3 (figure 3). These results indicate that NR4A1 antagonists reverses T-cell exhaustion.

Conclusions

NR4A1 plays a critical role in T-cell dysfunction, and this includes T-cell exhaustion.10 11 Our results demonstrate that the NR4A1 antagonists reverse many markers of T-cell exhaustion including activation of cytokines. The combined effects of NR4A1 antagonists in both tumors and T-cells result in inhibition of colon tumorigenesis by targeting pathways/genes in tumor cells and by enhancing immune surveillance via reversal of T-cell exhaustion.

References

Ahmed M. Colon cancer: a Clinician's perspective in 2019. Gastroenterology Res 2020;13(1):1–10. Epub 2020/02/26. doi: 10.14740/gr1239.

Keum N, Giovannucci E. Global burden of colorectal cancer: emerging trends, risk factors and prevention strategies. Nat Rev Gastroenterol Hepatol 2019;16(12):713–32. Epub 2019/08/29. doi: 10.1038/s41575-019-0189-8.

Pardoll DM. The blockade of immune checkpoints in cancer immunotherapy. Nat Rev Cancer 2012;12(4):252–64. Epub 2012/03/23. doi: 10.1038/nrc3239.

Ribas A, Wolchok JD. Cancer immunotherapy using checkpoint blockade. Science 2018;359(6382):1350–1355.

Yang et al. Distinct epigenetic features of tumor-reactive CD8+ T cells in colorectal cancer patients revealed by genome-wide DNA methylation analysis. Genome Biol 2019;21(1):2. doi: 10.1186/s13059-019-1921-y.

Safe S, Karki K. The paradoxical roles of orphan nuclear receptor 4A (NR4A) in cancer. Mol Can Res 2020. Epub 2020/10/28. doi: 10.1158/1541-7786.MCR-20-0707.

Lee SO, et al. Diindolylmethane analogs bind NR4A1 and are NR4A1 antagonists in colon cancer cells. Molecular Endocrinology. 2014;28(10):1729–39. doi: 10.1210/me.2014-1102.

Hedrick E, et al. The nuclear orphan receptor NR4A1 regulates β1-integrin expression in pancreatic and colon cancer cells and can be targeted by NR4A1 antagonists. Mol Carcinog 2017;56(9):2066–2075.

Liu X, et al. Genome-wide analysis identifies NR4A1 as a key mediator of T cell dysfunction. Nature 2019;567(7749):525–9. Epub 2019/03/01. doi: 10.1038/s41586-019-0979-8.

Chen J et al. NR4A transcription factors limit CAR T cell function in solid tumours. Nature. 2019;567(7749):530–4. Epub 2019/03/01. doi: 10.1038/s41586-019-0985-x. PubMed PMID: 30814732; PMCID: PMC6546093.

Seo H, et al. TOX and TOX2 transcription factors cooperate with NR4A transcription factors to impose CD8(+) T cell exhaustion. Proc Natl Acad Sci USA 2019;116(25):12410–5.

Ethics Approval

All animal studies were carried out according to the ethical procedures approved by the Texas A&M University Institutional Animal Care and Use Committee. Approval number is 2020-0138.

Abstract 732 Figure 1

CDIM/NR4A1 antagonists inhibit colon tumor growth. Model for regulation of genes with GC-rich promoters by NR4A1/SP1 (A). C57BL/6 mice bearing MC-38 cells as xenografts were treated for 21 days with corn oil (control), DIM-3-Br-5-OCF3 (2.5 and 7.5 mg/kg/d), DIM-3,5-Cl2 (2.5 and 7.5 mg/kg/d) and effects on tumor volume (B), and tumor weights (C) were determined.

Abstract 732 Figure 2

CDIM analogs alter transcription factors expression. FACS analysis and CD4 and CD8 – specific antibodies were used to determine T-cell population in tumors of mice treated with corn oil (control), DIM-3-Br-5-OCF3 (2.5 and 7.5 mg/kg/d) and DIM-3,5-Cl2 (2.5 and 7.5 mg/kg/d) (A). Real time PCR was used to determine expression of nuclear factors (B) and cytokine (C) mRNA levels in CD8+ T-cells isolated from tumors. Results are expressed as means ± SD replicates from each treatment group and significant (p<0.05) induction or inhibition is indicated (*)

Abstract 732 Figure 3

NR4A1 ligands decreases T-cell exhaustion markers. FACS analysis in tumors derived from mice treated with corn oil (control), DIM-3-Br-5-OCF3 (2.5 and 7.5 mg/kg/d) and DIM-3,5-Cl2 (2.5 and 7.5 mg/kg/d) using specific antibodies was carried out to determine percentage of CD8+ T-cells expressing T-cell exhaustion markers - PD1 (A), 2B4 (B), TIGIT (C) and TIM3 (D). Significant (p<0.05) induction or inhibition is indicated (*) and results are expressed as means ± SD for at least 4 separate mice per treatment group.

Transcription factors specificity protein and nuclear receptor 4A1 in pancreatic cancer

Specificity protein (Sp) transcription factors (TFs) Sp1, Sp3 and Sp4, and the orphan nuclear receptor 4A1 (NR4A1) are highly expressed in pancreatic tumors and Sp1 is a negative prognostic factor for pancreatic cancer patient survival. Results of knockdown and overexpression of Sp1, Sp3 and Sp4 in pancreatic and other cancer lines show that these TFs are individually pro-oncogenic factors and loss of one Sp TF is not compensated by other members. NR4A1 is also a pro-oncogenic factor and both NR4A1 and Sp TFs exhibit similar functions in pancreatic cancer cells and regulate cell growth, survival, migration and invasion. There is also evidence that Sp TFs and NR4A1 regulate some of the same genes including survivin, epidermal growth factor receptor, PAX3-FOXO1, α5- and α6-integrins, β1-, β3- and β4-integrins; this is due to NR4A1 acting as a cofactor and mediating NR4A1/Sp1/4-regulated gene expression through GC-rich gene promoter sites. Several studies show that drugs targeting Sp downregulation or NR4A1 antagonists are highly effective inhibitors of Sp/NR4A1-regulated pathways and genes in pancreatic and other cancer cells, and the triterpenoid celastrol is a novel dual-acting agent that targets both Sp TFs and NR4A1.

Clinical Outcomes Among Patients With Metastatic Pancreatic Ductal Adenocarcinoma Treated With Liposomal Irinotecan

Background

The NAPOLI-1 trial demonstrated that liposomal irinotecan in combination with fluorouracil (5-FU) and leucovorin (LV) prolonged survival with a manageable safety profile in patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) previously treated with gemcitabine-based therapy. Real-world data on clinical outcomes associated with liposomal irinotecan in NAPOLI-1-based regimens is needed to further substantiate this.

Methods

This real-world, retrospective chart review study included patients with mPDAC who received NAPOLI-1-based regimens from six academic centers in the United States. Liposomal irinotecan initiation defined the index date. Overall survival (OS) and progression-free survival (PFS) were assessed with Kaplan-Meier methodology.

Results

There were 374 patients evaluated; median age was 68 years, and 51% were female. Among 326 patients with baseline ECOG information, approximately 74% had ECOG score <2. Liposomal irinotecan was administered as a doublet with 5-FU in a NAPOLI-1-based regimen in the first line (1L; 16%), 2L (42%), and 3L+ (42%) of the metastatic setting. For patients treated in 1L, 2L, and 3L+, median [95% confidence interval (CI)] OS was 8.0 [5.1, 11.2], 7.3 [5.3, 8.8], and 4.6 [4.0, 5.7] months, and median [95% CI] PFS was 4.2 [2.2, 6.6], 3.0 [2.6, 3.7], and 2.0 [1.7, 2.2] months, respectively.

Conclusions

Patients in a real-world setting treated with NAPOLI-1-based liposomal irinotecan doublet regimens at academic centers were older with poorer performance status compared to trial patients yet had similar outcomes and efficacy. Furthermore, liposomal irinotecan was frequently used in the 3L+ setting where no treatment has been approved and provided clinical benefit.