The case for immune-based approaches in biliary tract carcinoma

Mapping of the T-cell Landscape of Biliary Tract Cancer Unravels Anatomic Subtype-Specific Heterogeneity

Biliary tract cancer (BTC), encompassing diseases such as intrahepatic (ICC), extrahepatic cholangiocarcinoma (ECC), and gallbladder cancer, is not only increasing but also poses a significant and urgent health threat due to its high malignancy. Genomic differences point to the possibility that these subtypes represent distinct diseases. Elucidation of the specific distribution of T-cell subsets, critical to cancer immunity, across these diseases could provide better insights into the unique biology of BTC subtypes and help identify potential precision medicine strategies. To address this, we conducted single-cell RNA sequencing and T-cell receptor sequencing on CD3+ T cells from 36 samples from 16 patients with BTC across all subtypes and analyzed 355 pathologic slides to examine the spatial distribution of T cells and tertiary lymphoid structures. Compared with ICC and gallbladder cancer, ECC possessed a unique immune profile characterized by T-cell exhaustion, elevated CXCL13 expression in CD4+ T helper-like and CD8+CXCL13+ exhausted T cells, more mature tertiary lymphoid structures, and fewer desert immunophenotypes. Conversely, ICC displayed an inflamed immunophenotype with an enrichment of IFN-related pathways and high expression of LGALS1 in activated regulatory T cells, associated with immunosuppression. Inhibition of LGALS1 reduced tumor growth and regulatory T-cell prevalence in ICC mouse models. Overall, this study unveils T-cell diversity across BTC subtypes at the single-cell and spatial level that could open paths for tailored immunotherapies. Significance: Single-cell and spatial analyses detailed the T-cell characteristics specific to anatomic subtypes of biliary tract cancer, identifying unique immunologic features that could potentially be harnessed to improve patient outcomes.

The Clinical Association Between the Inflammation-Nutritional Condition and Prognosis of Locally Advanced Intrahepatic Cholangiocarcinoma After R0 Resection: Evidence from Competing Risk and Propensity Matching Analysis

Background

Intrahepatic cholangiocarcinoma (ICC) correlates with poor outcomes, necessitating the identification of prognostic factors from an inflammation-nutritional perspective in locally advanced ICC patients after R0 resection.

Methods

We retrospectively reviewed the medical records of 159 locally advanced ICC patients from Sun Yat-sen University Cancer Center. Univariate and multivariate Cox regression analysis, as well as competing risk analysis, were conducted to explore prognostic variables for locally advanced ICC following surgery. To validate the robustness of our findings, we performed propensity score matching (PSM) analyses to evaluate survival differences based on inflammation-nutritional indexes.

Results

Considering non-cancer-specific death as competing risk factors, both systemic immune-inflammation index (SII, HR: 1.934) and prognostic nutrition index (PNI, HR: 0.604) emerged as significant prognostic variables for locally advanced ICC after R0 resection (P < 0.05). After PSM, the survival benefit between the low and high PNI sets remained clear (median survival time: 15.7 months vs 35.1 months, P = 0.002). Although the 5-year overall survival (OS) rate of the low SII group was higher than that of the high SII group, the difference was not statistically significant (17.5% VS 27.4%, P = 0.112). Other influencing factors included tumor number, tumor diameter, preoperative carcinoembryonic antigen (CEA)and carbohydrate antigen 19-9 (CA19-9) levels, and postoperative adjuvant therapy.

Conclusion

Individual inflammatory and nutritional status significantly impact the prognosis of locally advanced ICC undergoing R0 hapectomy. Oncologists should consider incorporating inflammation-nutritional conditions into the decision-making process for this subset of advanced ICC.

Early Decision Making in a Randomized Phase II Trial of Atezolizumab in Biliary Tract Cancer Using a Tumor Growth Inhibition-Survival Modeling Framework

We assess the longitudinal tumor growth inhibition (TGI) metrics and overall survival (OS) predictions applied to patients with advanced biliary tract cancer (BTC) enrolled in IMbrave151 a multicenter randomized phase II, double-blind, placebo-controlled trial evaluating the efficacy and safety of atezolizumab with or without bevacizumab in combination with cisplatin plus gemcitabine. Tumor growth rate (KG) was estimated for patients in IMbrave151. A pre-existing TGI-OS model for patients with hepatocellular carcinoma in IMbrave150 was modified to include available IMbrave151 study covariates and KG estimates and used to simulate IMbrave151 study outcomes. At the interim progression-free survival (PFS) analysis (98 patients, 27 weeks follow-up), clear separation in tumor dynamic profiles with a faster shrinkage rate and slower KG (0.0103 vs. 0.0117 week-1 ; tumor doubling time 67 vs. 59 weeks; KG geometric mean ratio of 0.84) favoring the bevacizumab containing arm was observed. At the first interim analysis for PFS, the simulated OS hazard ratio (HR) 95% prediction interval (PI) of 0.74 (95% PI: 0.58-0.94) offered an early prediction of treatment benefit later confirmed at the final analysis, observed HR of 0.76 based on 159 treated patients and 34 weeks of follow-up. This is the first prospective application of a TGI-OS modeling framework supporting gating of a phase III trial. The findings demonstrate the utility for longitudinal TGI and KG geometric mean ratio as relevant end points in oncology studies to support go/no-go decision making and facilitate interpretation of the IMbrave151 results to support future development efforts for novel therapeutics for patients with advanced BTC.

Immune checkpoint inhibitors in cholangiocarcinoma

Cholangiocarcinoma is an epithelial malignancy originating in the biliary tracts and frequently recurs even with surgical resection. Unresectable disease has a 5-year overall survival of less than 10%. Given this poor prognosis, additional therapies are urgently needed. Chemotherapy has been the mainstay of treatment for many years. However, with the incorporation of immunotherapy into the treatment of other malignancies, there has been a great deal of interest in immunotherapy for biliary cancers. Recently, durvalumab was approved in combination with gemcitabine and cisplatin for the treatment of unresectable cholangiocarcinoma in the first-line setting. However, predicting which patients may respond to immunotherapy remains a challenge due to the lack of a reliable biomarker.

Integrating cytotoxic, targeted and immune therapies for cholangiocarcinoma

Management of biliary tract cancers (BTCs) is rapidly evolving. The majority of patients are diagnosed with advanced disease. In this setting, chemotherapy with cisplatin and gemcitabine (with durvalumab) followed by second-line FOLFOX is the cornerstone of treatment. Targeted therapies for tumours harbouring FGFR2 fusions, IDH1 mutations, BRAF V600E mutations, NTRK fusions and/or HER2 (ERBB2) amplifications, among others, have brought precision medicine to the forefront of management of advanced BTC. This holds especially true for patients with intrahepatic cholangiocarcinoma. Recently, immunotherapy, especially combined with chemoterapy, has also shown promising activity. The field is now moving forward - management is no longer limited to chemotherapy or targeted therapies alone, with increasing research focused on how combination strategies could enhance therapeutic responses. We are therefore facing a change of paradigm, where immunotherapy, cytotoxic chemotherapy and targeted therapies will be administered concomitantly with the aim of harnessing potential synergies. This review will focus on the rationale behind these combinations and summarise current clinical trial data.

Liver Immunology, Immunotherapy, and Liver Cancers: Time for a Rethink?

The complex immune system of the liver has a major role in tumor surveillance, but also partly explains why current immune therapies are poorly effective against liver cancers. Known primarily for its tolerogenic capacity, the hepatic immune repertoire also comprises diverse populations of armored immune cells with tumor surveillant roles. In healthy people, these work together to successfully identify malignant cells and prevent their proliferation, thus halting tumor formation. When frontline hepatic immune surveillance systems fail, compromised hepatic immunity, driven by obesity, infection, or other pathological factors, allows primary or secondary liver cancers to develop. Tumor growth promotes the normal tolerogenic immunological milieu of the liver, perhaps explaining why current immunotherapies fail to work. This review explores the complex local liver immune system with the hope of identifying potential therapeutic targets needed to best overcome immunological barriers in the liver to create an environment no longer hostile to immunotherapy for the treatment of liver cancer.

A Phase II Study of Pembrolizumab in Combination with Capecitabine and Oxaliplatin with Molecular Profiling in Patients with Advanced Biliary Tract Carcinoma

BACKGROUND

We conducted a phase II study of the combination of pembrolizumab with capecitabine and oxaliplatin (CAPOX) in patients with advanced biliary tract carcinoma (BTC) to assess response rate and clinical efficacy. Exploratory objectives included correlative studies of immune marker expression, tumor evolution, and immune infiltration in response to treatment.

PATIENTS AND METHODS

Adult patients with histologically confirmed BTC were enrolled and received oxaliplatin and pembrolizumab on day 1 of cycles 1-6. Capecitabine was administered orally twice daily as intermittent treatment, with the first dose on day 1 and the last dose on day 14 of cycles 1-6. Starting on cycle 7, pembrolizumab monotherapy was continued until disease progression. The primary endpoint was progression-free survival (PFS). Secondary endpoints were safety, tolerability, feasibility, and response rate. Immunohistochemistry (IHC) for PD-L1 and immune infiltrates was analyzed in paired tumor biopsies, as well as bulk transcriptome and exome profiling for five patients and single-cell RNA sequencing for one partial responder.

RESULTS

Eleven patients enrolled, three of whom had received no prior systemic therapy. Treatment was well tolerated, and the most common treatment-related grade 3 or 4 adverse events were lymphocytopenia, anemia, and decreased platelet count. Three patients (27.3%) achieved a partial response, and six (54%) had stable disease. The disease control rate was 81.8%. The median PFS was 4.1 months with a 6-month PFS rate of 45.5%. Molecular profiling suggests qualitative differences in immune infiltration and clonal evolution based on response.

CONCLUSION

Capecitabine and oxaliplatin in combination with pembrolizumab is tolerable and a potentially effective treatment for refractory advanced BTC. This study highlights a design framework for the precise characterization of individual BTC tumors.

TRIAL REGISTRATION

This study was registered in ClinicalTrials.gov (NCT03111732).

Biliary tract cancers: moving from the present standards of care towards the use of immune checkpoint inhibitors

Biliary tract cancers (BTCs) are aggressive and chemoresistant tumors associated with poor prognosis. Thus, more active and effective treatments are urgently needed, among which immunotherapy holds promise for the near future. Preclinical data show that BTCs are mainly immunosuppressed cancers, thus suggesting that their immunogenic potential may be unleashed with the appropriate strategy. Immune checkpoint inhibitors (ICIs) could theoretically be effective in BTCs by blocking those inhibitory checkpoints that limit the activation and the expansion of the effector cells of the immune response. Many currently ongoing trials aim to demonstrate the efficacy of ICIs and to incorporate immunotherapy into the routine management of BTCs. Presently available results are controversial and there is no consensus on the role of ICIs in monotherapy, while combinations of immunotherapy with chemotherapy look more promising. Nevertheless, despite the many proposed over time, there are no predictive biomarkers presently available, thus, the early identification of those patients showing a good response is of great significance.

Integrating Machine Learning and Tumor Immune Signature to Predict Oncologic Outcomes in Resected Biliary Tract Cancer

BACKGROUND

Improved methods are needed to predict outcomes in biliary tract cancers (BTCs). We aimed to build an immune-related signature and establish holistic models using machine learning.

METHODS

Samples were from 305 BTC patients treated with curative-intent resection, divided into derivation and validation cohorts in a two-to-one ratio. Spatial resolution of T cell infiltration and PD-1/PD-L1 expression was assessed by immunohistochemistry. An immune signature was constructed using classification and regression tree. Machine learning was applied to develop prediction models for disease-specific survival (DSS) and recurrence-free survival (RFS).

RESULTS

The immune signature composed of CD3+, CD8+, and PD-1+ cell densities and PD-L1 expression within tumor epithelium significantly stratified patients into three clusters, with median DSS varying from 11.7 to 80.8 months and median RFS varying from 6.2 to 62.0 months. Gradient boosting machines (GBM) outperformed rival machine-learning algorithms and selected the same 11 covariates for DSS and RFS prediction: immune signature, tumor site, age, bilirubin, albumin, carcinoembryonic antigen, cancer antigen 19-9, tumor size, tumor differentiation, resection margin, and nodal metastasis. The clinical-immune GBM models accurately predicted DSS and RFS, with respective concordance index of 0.776-0.816 and 0.741-0.781. GBM models showed significantly improved performance compared with tumor-node-metastasis staging system.

CONCLUSIONS

The immune signature promises to stratify prognosis and allocate treatment in resected BTC. The clinical-immune GBM models accurately predict recurrence and death from BTC following surgery.

Anti-PD-1 in Combination With Trametinib Suppresses Tumor Growth and Improves Survival of Intrahepatic Cholangiocarcinoma in Mice

BACKGROUND & AIMS

Intrahepatic cholangiocarcinoma (iCCA) accounts for a fraction of primary liver cancers but has a 5-year survival rate of only 10%. Immune checkpoint inhibitors are effective in treating many solid cancers, but immune checkpoint inhibitor monotherapy has no clear benefit in iCCA. Mitogen-activated kinase (MEK) inhibitors, such as trametinib, have shown promising results in preclinical studies for iCCA by inhibiting cell proliferation and modifying the tumor microenvironment. This study aimed to show the potential benefit of combining trametinib with anti-programmed cell death protein 1 (PD-1) therapy in different iCCA mouse models.

METHODS

Here, we assessed the in vitro cytotoxicity of trametinib in mouse (SB1 and LD-1) and human (EGI-1) cholangiocarcinoma cell lines. We examined the efficacy of single-agent trametinib, anti-PD-1, and a combination of both in subcutaneous, orthotopic, and plasmid-induced iCCA mouse models. Flow cytometry analysis was used to elucidate changes in the tumor immune microenvironment upon treatment. Whole-exome sequencing (WES) was performed on the SB1 tumor cell line to correlate this preclinical model with iCCAs in patients.

RESULTS

Trametinib reduced tumor cell growth of SB1, LD-1, and EGI-1 tumor cells in vitro. Trametinib treatment led to up-regulation of major histocompatibility complex (MHC-I) and programmed cell death ligand 1 (PD-L-1) (programmed cell death ligand 1) on tumor cells in vitro. The combination of trametinib and anti-PD-1 reduced tumor burden in several iCCA tumor models and improved survival in SB1 tumor-bearing mice compared with either agent alone. Immunoprofiling of tumor-bearing mice showed an increase of hepatic effector memory CD8⁺ and CD4⁺ T cells, as well as an increased degranulation of CD8⁺ T cells, indicating enhanced cytotoxicity. WES and somatic mutational analysis showed no mutations of KRAS, BRAF, and ERK in SB1 tumor cells, and showed a similar genetic signature of SB1 found in a cohort of patients with iCCA.

CONCLUSIONS

Altogether, our study shows that trametinib improves the immunogenicity of tumor cells by up-regulating MHC-I surface expression. The combination with anti-PD-1 results in optimal treatment efficacy for iCCA. WES of SB1 cells suggests that KRAS wild-type iCCAs also respond to this combination therapy.

CD40-mediated immune cell activation enhances response to anti-PD-1 in murine intrahepatic cholangiocarcinoma

BACKGROUND & AIMS

While cholangiocarcinomas (CCAs) commonly express programmed cell death 1 (PD-1) and its ligand (PD-L1), they respond poorly to immune checkpoint inhibitors (ICIs). We aimed to determine whether stimulating antigen-presenting cells, including macrophages and dendritic cells, using a CD40 agonist could improve this response.

METHODS

We compared treatment responses in subcutaneous, orthotopic, and 2 plasmid-based murine intrahepatic CCA (iCCA) models. Mice were treated for 4 weeks with weekly IgG control, a CD40 agonistic antibody, anti-PD-1, or the combination of both (anti-CD40/PD-1). Flow cytometric (FACS) analysis of lymphocytes and myeloid cell populations (including activation status) was performed. We used dendritic cell knockout mice, and macrophage, CD4⁺ and CD8⁺ T cell depletion models to identify effector cells. Anti-CD40/PD-1 was combined with chemotherapy (gemcitabine/cisplatin) to test for improved therapeutic efficacy.

RESULTS

In all 4 models, anti-PD-1 alone was minimally efficacious. Mice exhibited a moderate response to CD40 agonist monotherapy. Combination anti-CD40/PD-1 therapy led to a significantly greater reduction in tumor burden. FACS demonstrated increased number and activation of CD4⁺ and CD8⁺ T cells, natural killer cells, and myeloid cells in tumor and non-tumor liver tissue of tumor-bearing mice treated with anti-CD40/PD-1. Depletion of macrophages, dendritic cells, CD4+ T cells, or CD8+ T cells abrogated treatment efficacy. Combining anti-CD40/PD-1 with gemcitabine/cisplatin resulted in a significant survival benefit compared to gemcitabine/cisplatin alone.

CONCLUSION

CD40-mediated activation of macrophages and dendritic cells in iCCA significantly enhances response to anti-PD-1 therapy. This regimen may enhance the efficacy of first-line chemotherapy.

LAY SUMMARY

Checkpoint inhibition, a common form of immune therapy, is generally ineffective for the treatment of cholangiocarcinoma. These tumors suppress the infiltration and function of surrounding immune cells. Stimulating immune cells such as macrophages and dendritic cells via the CD40 receptor activates downstream immune cells and enhances the response to checkpoint inhibitors.

Serum microRNAs as Biomarkers for the Noninvasive Early Diagnosis of Biliary Tract Cancer

Background

Biliary tract cancers (BTCs) are aggressive malignancies with difficult early diagnosis and poor prognosis. Studies have shown that microRNAs (miRNAs) are expected to be biomarkers of the disease, which indicates that we can diagnose cancers according to the miRNAs that have significant changes. The aim of this study was to explore miRNA biomarkers of BTCs.

Methods

A total of 163 samples were collected and divided into the control group, the benign group and the malignant group. High-throughput low-density chips were used to screen miRNAs with significant changes. Then, the preliminary screening test and the verification test were performed by quantitative real time PCR (qRT-PCR). Finally, the level of miRNAs in serum exosomes was measured.

Results

MiR-10a, miR-21, miR-135b, miR-221, and miR-214 were upregulated in the BTCs group compared to the control group. The change in the miR-221 level was statistically significant when the malignant group was compared with the benign group (P<0.01). Meanwhile, miR-135b and miR-214 were enriched in serum exosomes.

Conclusion

Five miRNAs in the serum were found to be significantly upregulated in patients with BTCs. Among them, miR-221 can serve as an early diagnostic marker for BTCs patients. MiR-10a, miR-21, miR-135b and miR-214 can be used as biomarkers for the diagnosis of biliary diseases.

Therapy for advanced cholangiocarcinoma: Current knowledge and future potential

Cholangiocarcinoma (CCA) is a biliary epithelial tumour that can emerge at any point in the biliary tree. It is commonly classified based on its anatomical site of development into intrahepatic cholangiocarcinoma (ICC), perihilar cholangiocarcinoma (PCC) and distal cholangiocarcinoma (DCC), each of which is associated with varying patient demographics, molecular characteristics and treatment options. CCA patients have poor overall prognoses and 5‐year survival rates. Additionally, CCA is often diagnosed at an advanced stage, with surgical treatment restricted to early‐stage disease. Owing to an increase in the incidence of ICC, that of CCA is also on the rise, with a corresponding increase in the associated mortality, particularly in South America and Asia. Therefore, the development of an effective treatment is crucial to improve the survival of CCA patients. We aimed to systematically review the current understanding of advanced CCA treatment and discuss potential effective strategies.

Suppressive myeloid cells are expanded by biliary tract cancer-derived cytokines in vitro and associate with aggressive disease

Background

BTC is an aggressive disease exacerbated by inflammation and immune suppression. Expansion of immunosuppressive cells occurs in biliary tract cancer (BTC), yet the role of BTC-derived cytokines in this process is unclear.

Methods

Activated signalling pathways and cytokine production were evaluated in a panel of human BTC cell lines. Human peripheral blood mononuclear cells (PBMCs) were cultured with BTC supernatants, with and without cytokine neutralising antibodies, and analysed by flow cytometry or immunoblot. A human BTC tissue microarray (TMA, n = 69) was stained for IL-6, GM-CSF, and CD33⁺S100a9⁺ cells and correlated with clinical outcomes.

Results

Immunomodulatory factors (IL-6, GM-CSF, MCP-1) were present in BTC supernatants. BTC supernatants expanded CD33^dimCD11b⁺HLA-DR^low/− myeloid-derived suppressor cells (MDSCs) from human PBMCs. Neutralisation of IL-6 and GM-CSF in BTC supernatants inhibited activation of STAT3/5, respectively, in PBMCs, with heterogeneous effects on MDSC expansion in vitro. Staining of a BTC TMA revealed a positive correlation between IL-6 and GM-CSF, with each cytokine and more CD33⁺S100a9⁺ cells. Increased CD33⁺S100a9⁺ staining positively correlated with higher tumour grade, differentiation and the presence of satellite lesions.

Conclusion

BTC-derived factors promote suppressive myeloid cell expansion, and higher numbers of CD33⁺S100a9⁺ cells in resectable BTC tumours correlates with more aggressive disease.

New and Emerging Systemic Therapeutic Options for Advanced Cholangiocarcinoma

Cholangiocarcinoma (CCA) represents a disease entity that comprises a heterogeneous group of biliary malignant neoplasms, with variable clinical presentation and severity. It may be classified according to its anatomical location and distinguished in intrahepatic (iCCA), perihilar (pCCA), or distal (dCCA), each subtype implying distinct epidemiology, biology, prognosis, and strategy for clinical management. Its incidence has increased globally over the past few decades, and its mortality rate remains high due to both its biological aggressiveness and resistance to medical therapy. Surgery is the only potentially curative treatment and is the standard approach for resectable CCA; however, more than half of the patients have locally advanced or metastatic disease at presentation. For patients with unresectable CCA, the available systemic therapies are of limited effectiveness. However, the advances of the comprehension of the complex molecular landscape of CCA and its tumor microenvironment could provide new keys to better understand the pathogenesis, the mechanisms of resistance and ultimately to identify promising new therapeutic targets. Recently, clinical trials targeting isocitrate dehydrogenase (IDH)-1 mutations and fibroblast growth factor receptor (FGFR)-2 fusions, as well as immunotherapy showed promising results. All these new and emerging therapeutic options are herein discussed.

Nivolumab alone or in combination with cisplatin plus gemcitabine in Japanese patients with unresectable or recurrent biliary tract cancer: a non-randomised, multicentre, open-label, phase 1 study

BACKGROUND

This study aimed to assess the safety and tolerability of the immune checkpoint inhibitor nivolumab, as monotherapy or combined with chemotherapy, in Japanese patients with biliary tract cancer.

METHODS

This multicentre, open-label, phase 1 trial was done at four cancer centres in Japan. Eligible patients were aged 20-79 years, had biliary tract adenocarcinoma (intrahepatic bile duct cancer, extrahepatic bile duct cancer, gallbladder cancer, or ampullary cancer), Eastern Cooperative Oncology Group performance status 0 or 1, adequate hepatic, renal, and haematological function, and tumour tissue samples for PD-L1 expression analysis. Patients with unresectable or recurrent biliary tract cancer that was refractory or intolerant to gemcitabine-based treatment regimens received nivolumab monotherapy (240 mg every 2 weeks [monotherapy cohort]). Chemotherapy-naive patients with unresectable or recurrent biliary tract cancer received nivolumab (240 mg every 2 weeks) and cisplatin (25 mg/m²) plus gemcitabine (1000 mg/m²) chemotherapy (combined therapy cohort). The primary objective was to assess tolerability and safety. The primary objective was assessed in the safety population of all patients who had received at least one dose of nivolumab. This study is registered with www.clinicaltrials.jp, number JapicCTI-153098, and follow-up is ongoing.

FINDINGS

30 patients were enrolled into each cohort between Jan 13, 2016, and April 19, 2017. Data cutoff was Aug 31, 2017. In the monotherapy cohort, the most frequently reported treatment-related adverse events were decreased appetite (five [17%]), malaise (four [13%]), and pruritus (four [13%]). Grade 3-4 treatment-related adverse events were reported by three (10%) patients (rash, maculopapular rash, and amylase increase) and treatment-related serious adverse events were reported by one (3%) patient (pleurisy). In the combined therapy cohort, the most frequently reported treatment-related adverse events were neutrophil count decrease (any grade 25 [83%]; grade 3-4 in 23 [77%] patients) and platelet count decrease (any grade 25 [83%] of 30; grade 3-4 in 15 [50%] patients). Six (20%) patients reported 11 treatment-related serious adverse events (platelet count decrease [three patients], febrile neutropenia [two patients], neutrophil count decrease, anaemia, anaphylactic reaction, decreased appetite, pyrexia, and myocarditis [one patient each]). In the monotherapy cohort, median overall survival was 5·2 months (90% CI 4·5-8·7), median progression-free survival was 1·4 months (90% CI 1·4-1·4), and one of 30 patients had an objective response. In the combined therapy cohort, median overall survival was 15·4 months (90% CI 11·8-not estimable), median progression-free survival was 4·2 months (90% CI 2·8-5·6), and 11 of 30 patients had an objective response.

INTERPRETATION

Nivolumab had a manageable safety profile and signs of clinical activity in patients with unresectable or recurrent biliary tract cancer. This initial assessment of nivolumab for the treatment of advanced biliary tract cancer provides supportive evidence for future larger randomised studies of nivolumab in this difficult to treat cancer.

FUNDING

Ono Pharmaceutical Co Ltd and Bristol-Myers Squibb Inc.

Tremelimumab in Combination With Microwave Ablation in Patients With Refractory Biliary Tract Cancer

Treatment options for patients with advanced biliary tract cancer are limited. Dysregulation of the immune system plays an important role in the pathogenesis of biliary tract cancer (BTC). This study aimed to investigate whether tremelimumab, an anti-CTLA4 (cytotoxic T-lymphocyte-associated protein 4) inhibitor, could be combined safely with microwave ablation to enhance the effect of anti-CTLA4 treatment in patients with advanced BTC. Patients were enrolled to receive monthly tremelimumab (10 mg/kg, intravenously) for six doses, followed by infusions every 3 months until off-treatment criteria were met. Thirty-six days after the first tremelimumab dose, patients underwent subtotal microwave ablation. Interval imaging studies were performed every 8 weeks. Adverse events (AEs) were noted and managed. Tumor and peripheral blood samples were collected to perform immune monitoring and whole-exome sequencing (WES). Twenty patients with refractory BTC were enrolled (median age, 56.5 years). No dose-limiting toxicities were encountered. The common treatment-related AEs included lymphopenia, diarrhea, and elevated transaminases. Among 16 patients evaluable for efficacy analysis, 2 (12.5%) patients achieved a confirmed partial response (lasting for 8.0 and 18.1 months, respectively) and 5 patients (31.3%) achieved stable disease. Median progression free survival (PFS) and overall survival (OS) were 3.4 months (95% confidence interval [CI], 2.5-5.2) and 6.0 months (95% CI, 3.8-8.8), respectively. Peripheral blood immune cell subset profiling showed increased circulating activated human leukocyte antigen, DR isotype ([HLA-DR] positive) CD8⁺ T cells. T-cell receptor (TCR)β screening showed tremelimumab expanded TCR repertoire, but not reaching statistical significance (P = 0.057). Conclusion: Tremelimumab in combination with tumor ablation is a potential treatment strategy for patients with advanced BTC. Increased circulating activated CD8⁺ T cells and TCR repertoire expansion induced by tremelimumab may contribute to treatment benefit.

Cholangiocarcinoma: the quest for a second-line systemic treatment

Biliary tract cancers (BTC) are a heterogeneous group of epithelial neoplasms, with a poor prognosis. Advanced BTC remains a challenging, non-curable disease. Gemcitabine plus platinum chemotherapy is the standard of care as first-line (L1) therapy in this setting. Beyond failure of L1, available evidence to guide therapeutic decisions is scarce. Data from phase III studies are lacking and there is no validated strategy to date. In this review, we provide an overview of the systemic therapeutic options that can be proposed and unsolved questions in the management of patients with advanced BTC in the second-line (L2) setting. Criteria to select which patients should receive L2 therapy are ill defined and reliable prognostic tools and models to help estimate individual patient survival at the beginning of L2 are needed. Chemotherapy, mainly fluoropyrimidine-based yields modest survival results. There is insufficient evidence level to recommend a specific L2 chemotherapy regimen, and anti-epidermal growth factor receptor and antiangiogenic agents failed to demonstrate any survival improvement in a non-selected patient population. In recent years, knowledge about BTC molecular heterogeneity has considerably increased with the advent of high-throughput genomic and transcriptomic analyses, opening new avenues for targeted therapies. Patients with BTC may be particularly good candidates for biomarker-driven therapy in clinical practice. Among the ongoing developments, targeting of FGFR and IDH mutations and immune therapies hold many promises for the next future. In future L2 clinical trials, patients should be carefully characterized and stratified according to prognostic factors, disease subtype, and genetic drivers.

Neoplastic Transformation of the Peribiliary Stem Cell Niche in Cholangiocarcinoma Arisen in Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is a chronic inflammatory cholangiopathy frequently complicated by cholangiocarcinoma (CCA). Massive proliferation of biliary tree stem/progenitor cells (BTSCs), expansion of peribiliary glands (PBGs), and dysplasia were observed in PSC. The aims of the present study were to evaluate the involvement of PBGs and BTSCs in CCA which emerged in PSC patients. Specimens from normal liver (n = 5), PSC (n = 20), and PSC-associated CCA (n = 20) were included. Samples were processed for histology, immunohistochemistry, and immunofluorescence. In vitro experiments were performed on human BTSCs, human mucinous primary CCA cell cultures, and human cholangiocyte cell lines (H69). Our results indicated that all CCAs emerging in PSC patients were mucin-producing tumors characterized by PBG involvement and a high expression of stem/progenitor cell markers. Ducts with neoplastic lesions showed higher inflammation, wall thickness, and PBG activation compared to nonneoplastic PSC-affected ducts. CCA showed higher microvascular density and higher expression of nuclear factor kappa B, interleukin-6, interleukin-8, transforming growth factor β, and vascular endothelial growth factor-1 compared to nonneoplastic ducts. CCA cells were characterized by a higher expression of epithelial-to-mesenchymal transition (EMT) traits and by the absence of primary cilia compared to bile ducts and PBG cells in controls and patients with PSC. Our in vitro study demonstrated that lipopolysaccharide and oxysterols (PSC-related stressors) induced the expression of EMT traits, the nuclear factor kappa B pathway, autophagy, and the loss of primary cilia in human BTSCs. Conclusion: CCA arising in patients with PSC is characterized by extensive PBG involvement and by activation of the BTSC niche in these patients, the presence of duct lesions at different stages suggests a progressive tumorigenesis.

Activation of Fas/FasL pathway and the role of c-FLIP in primary culture of human cholangiocarcinoma cells

Intrahepatic cholangiocarcinoma (iCCA) represents a heterogeneous group of malignancies emerging from the biliary tree, often in the context of chronic bile ducts inflammation. The immunological features of iCCA cells and their capability to control the lymphocytes response have not yet been investigated. The aims of the present study were to evaluate the interaction between iCCA cells and human peripheral blood mononuclear cells (PBMCs) and the role of Fas/FasL in modulating T-cells and NK-cells response after direct co-culture. iCCA cells express high levels of Fas and FasL that increase after co-culture with PBMCs inducing apoptosis in CD4⁺, CD8⁺ T-cells and in CD56⁺ NK-cells. In vitro, c-FLIP is expressed in iCCA cells and the co-culture with PBMCs induces an increase of c-FLIP in both iCCA cells and biliary tree stem cells. This c-FLIP increase does not trigger the caspase cascade, thus hindering apoptotis of iCCA cells which, instead, underwent proliferation. The increased expression of Fas, FasL and c-FLIP is confirmed in situ, in human CCA and in primary sclerosing cholangitis. In conclusion our data indicated that iCCA cells have immune-modulatory properties by which they induce apoptosis of T and NK cells, via Fas/FasL pathway, and escape inflammatory response by up-regulating c-FLIP system.

Emerging molecular therapeutic targets for cholangiocarcinoma

Cholangiocarcinomas (CCAs) are diverse epithelial tumors arising from the liver or large bile ducts with features of cholangiocyte differentiation. CCAs are classified anatomically into intrahepatic (iCCA), perihilar (pCCA), and distal CCA (dCCA). Each subtype has distinct risk factors, molecular pathogenesis, therapeutic options, and prognosis. CCA is an aggressive malignancy with a poor overall prognosis and median survival of less than 2years in patients with advanced disease. Potentially curative surgical treatment options are limited to the subset of patients with early-stage disease. Presently, the available systemic medical therapies for advanced or metastatic CCA have limited therapeutic efficacy. Molecular alterations define the differences in biological behavior of each CCA subtype. Recent comprehensive genetic analysis has better characterized the genomic and transcriptomic landscape of each CCA subtype. Promising candidates for targeted, personalized therapy have emerged, including potential driver fibroblast growth factor receptor (FGFR) gene fusions and somatic mutations in isocitrate dehydrogenase (IDH)1/2 in iCCA, protein kinase cAMP-activated catalytic subunit alpha (PRKACA) or beta (PRKACB) gene fusions in pCCA, and ELF3 mutations in dCCA/ampullary carcinoma. A precision genomic medicine approach is dependent on an enhanced understanding of driver mutations in each subtype and stratification of patients according to their genetic drivers. We review the current genomic landscape of CCA, the potentially actionable molecular aberrations in each CCA subtype, and the role of immunotherapy in CCA.

New molecular and immunotherapeutic approaches in biliary cancer

Biliary tract carcinoma is a collective term for a group of rare gastrointestinal cancers. This overview outlines the key pathways and specialised therapeutics in biliary cancer and the emerging role of immunotherapy by highlighting the rationale and selected examples of studies in each area.