High PD-L1 expression is associated with therapeutic response to pembrolizumab in patients with advanced biliary tract cancer

Elevated serum soluble programmed death ligand 1 (sPD-L1) level correlate with clinical characteristics in breast cancer patients: A study at Hospital Universiti Sains Malaysia

BACKGROUND

Elevated serum levels of soluble PD-L1 (sPD-L1) have been reported in many cancers; however, there is limited data of sPD-L1 in breast cancer, especially those representing Asian (Malay) women. The purpose of this study was to evaluate sPD-L1 serum levels and analyze its correlation with clinical characteristics in breast cancer patients at Hospital Universiti Sains Malaysia (HUSM).

METHODS

Blood specimens were obtained from 92 malignant, 16 benign breast cancer patients and 23 healthy controls. The serum concentrations of sPD-L1 were assessed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The median serum sPD-L1 concentration of malignant and benign breast cancer patients was significantly elevated compared to the healthy cohorts (12.50 ng/mL vs 13.97 ng/mL vs 8.75 ng/mL, p < 0.05). Optimal cut-off value of serum sPD-L1 for predicting disease progression was 8.84  ng/mL. Elevated serum sPD-L1 levels were significantly associated with menarche age, ethnicity, birth control usage, comorbidity and HER2 status (p < 0.05). Multivariate analysis showed the menarche age and birth control were the independent factors affecting sPD-L1 expression.

CONCLUSION

Elevated serum levels of sPD-L1 were significantly associated with several clinical characteristics and warrant further investigation in evaluating patients pre-diagnosed with breast cancer.

Cholangiocarcinoma of the Middle Bile Duct: A Narrative Review

Resectable cholangiocarcinoma (CCA) arising from the middle of the extrahepatic biliary tree has historically been classified as perihilar or distal CCA, depending on the operation contemplated or performed, namely the associated hepatectomy or pancreaticoduodenectomy, respectively. Segmental bile duct resection is a less invasive alternative for select patients harboring true middle extrahepatic CCA (MCC). A small, yet growing body of literature has emerged detailing institutional experiences with bile duct resection versus pancreaticoduodenectomy or concomitant hepatectomy for MCC. Herein, we provide a brief overview of the epidemiology, preoperative evaluation, and emerging systemic therapies for MCC, and narratively review the existing work comparing segmental resection with pancreaticoduodenectomy or less commonly, hepatectomy, for MCC, with emphasis on the surgical management and oncologic implications of the approach used.

Evaluating the Therapeutic Potential of Durvalumab in Adults with Locally Advanced or Metastatic Biliary Tract Cancer: Evidence to Date

Advanced biliary tract cancers (BTCs) have historically been managed with chemotherapy but, in recent years, this treatment paradigm has begun to shift with the introduction of immune checkpoint inhibitors in addition to standard of care chemotherapy. The tumor microenvironment of BTC may be enriched with regulatory T lymphocytes and immune checkpoint expression in some patients. Durvalumab, an anti-programmed death ligand-1 (PD-L1) antibody, in combination with gemcitabine and cisplatin, has now received United States Food and Drug Administration approval for treatment of advanced BTC. Regulatory approval was based on the Phase III, randomized TOPAZ-1 trial that demonstrated survival benefit with addition of durvalumab to gemcitabine plus cisplatin compared to chemotherapy alone. The combination of chemotherapy and immunotherapy was well tolerated, and a subset of patients were able to achieve a durable response, with a 2-year overall survival rate of 23.6%. However, limitations remain in identifying which patients are most likely to benefit from immune checkpoint inhibition. Future study should aim to identify biomarkers predictive of substantial benefit, as well as the role of immune checkpoint inhibition in combination with targeted therapies and radiotherapy in the management of advanced BTC.

The predictive value of PD-L1 expression in response to anti-PD-1/PD-L1 therapy for biliary tract cancer: a systematic review and meta-analysis

Background

Recently, anti-programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immunotherapy offers promising results for advanced biliary tract cancer (BTC). However, patients show highly heterogeneous responses to treatment, and predictive biomarkers are lacking. We performed a systematic review and meta-analysis to assess the potential of PD-L1 expression as a biomarker for treatment response and survival in patients with BTC undergoing anti-PD-1/PD-L1 therapy.

Methods

We conducted a comprehensive systematic literature search through June 2023, utilizing the PubMed, EMBASE, and Cochrane Library databases. The outcomes of interest included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) according to PD-L1 expression. Subgroup analyses and meta-regression were performed to identify possible sources of heterogeneity.

Results

A total of 30 studies was included in the final analysis. Pooled analysis showed no significant differences in ORR (odds ratio [OR], 1.56; 95% confidence intervals [CIs], 0.94-2.56) and DCR (OR, 1.84; 95% CIs, 0.88-3.82) between PD-L1 (+) and PD-L1 (-) patients. In contrast, survival analysis showed improved PFS (hazard ratio [HR], 0.54, 95% CIs, 0.41-0.71) and OS (HR, 0.58; 95% CI, 0.47-0.72) among PD-L1 (+) patients compared to PD-L1 (-) patients. Sensitivity analysis excluding retrospective studies showed no significant differences with the primary results. Furthermore, meta-regression demonstrated that drug target (PD-1 vs. PD-L1), presence of additional intervention (monotherapy vs. combination therapy), and PD-L1 cut-off level (1% vs. ≥5%) significantly affected the predictive value of PD-L1 expression.

Conclusion

PD-L1 expression might be a helpful biomarker for predicting PFS and OS in patients with BTC undergoing anti-PD-1/PD-L1 therapy. The predictive value of PD-L1 expression can be significantly influenced by diagnostic or treatment variables.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023434114.

Immunogenomics of cholangiocarcinoma

The development of cholangiocarcinoma spans years, if not decades, during which the immune system becomes corrupted and permissive to primary tumor development and metastasis. This involves subversion of local immunity at tumor sites, as well as systemic immunity and the wider host response. While immune dysfunction is a hallmark of all cholangiocarcinoma, the specific steps of the cancer-immunity cycle that are perturbed differ between patients. Heterogeneous immune functionality impacts the evolutionary development, pathobiological behavior, and therapeutic response of these tumors. Integrative genomic analyses of thousands of primary tumors have supported a biological rationale for immune-based stratification of patients, encompassing immune cell composition and functionality. However, discerning immune alterations responsible for promoting tumor initiation, maintenance, and progression from those present as bystander events remains challenging. Functionally uncoupling the tumor-promoting or tumor-suppressing roles of immune profiles will be critical for identifying new immunomodulatory treatment strategies and associated biomarkers for patient stratification. This review will discuss the immunogenomics of cholangiocarcinoma, including the impact of genomic alterations on immune functionality, subversion of the cancer-immunity cycle, as well as clinical implications for existing and novel treatment strategies.

The Expression of Programmed Death-Ligand 1 on Immune Cells Is Related to a Better Prognosis in Biliary Tract Cancer

Background/Aims

Programmed death-ligand 1 (PD-L1) expression in tumor cells is associated with a poor biliary tract cancer (BTC) prognosis; tumor-infiltrating immune cells in the tumor microenvironment are associated with a better prognosis. The effect of PD-L1 expression on immune cells on survival is unclear. We investigated the relationship between PD-L1 expression in immune cells and BTC prognosis.

Methods

PD-L1 expression was evaluated using an anti-PD-L1 22C3 mouse monoclonal primary antibody, and its relationships with clinical characteristics and prognosis were analyzed using the Cox proportional hazard model to investigate the prognostic performance of PD-L1 in BTC.

Results

Among 144 analyzed cases, patients with positive PD-L1 expression in tumor cells and negative PD-L1 expression in immune cells showed poorer overall survival rates than those exhibiting other expressions (tumor cells: hazard ratio [HR]=1.023, p<0.001; immune cells: HR=0.983, p=0.021). PD-L1 expression in tumor cells was an independent predictor of poor overall survival (HR=1.024, p<0.001). In contrast, PD-L1 expression in immune cells was a predictive marker of good prognosis (HR=0.983, p=0.018).

Conclusions

PD-L1 expression in immune cells may be used as an independent factor to evaluate the prognosis of patients with BTC.

γ-Secretase Inhibitor Potentiates the Activity of Suberoylanilide Hydroxamic Acid by Inhibiting Its Ability to Induce Epithelial to Mesenchymal Transition and Stemness via Notch Pathway Activation in Triple-Negative Breast Cancer Cells

Histone deacetylase inhibitors, such as suberoylanilide hydroxamic acid (SAHA), possess great therapeutic value for triple-negative breast cancer patients. However, their inherent ability to induce epithelial to mesenchymal transition in various malignancies has been of greater concern. Herein, we hypothesize that SAHA facilitates epithelial to mesenchymal transition (EMT) via activation of the Notch pathway. From the literature survey, it is evident that histone deacetylase mediates the formation of the co-repressor complex upon interacting with the DNA binding domain, thereby inhibiting the transcription of the Notch downstream genes. Hence, we hypothesize that the use of SAHA facilitates the transcriptional activation of the Notch target genes, by disrupting the co-repressor complex and recruiting the coactivator complex, thereby facilitating EMT. In this study, we have observed that SAHA upregulates the expression profile of the Notch downstream proteins (such as Notch intracellular domain, Hes-1, c-Myc, etc.) and the Notch ligands (such as Jagged-1 and Jagged-2), thereby aberrantly activating the signaling pathway. Therefore, we have focused on combination therapy using a γ-secretase inhibitor LY411575 that would enhance the efficacy of SAHA by blocking the canonical Notch pathway mediated via its intracellular domain. It was observed that co-treatment significantly mediates apoptosis, generates cellular reactive oxygen species, depolarizes mitochondria, and diminishes the stemness properties. Besides, it also mediates autophagy-independent cell death and diminishes the expression of inflammatory cytokines, along with the downregulation in the expression of the Notch downstream genes and mesenchymal markers. Altogether, our study provides a mechanistic basis for combating EMT potentiated by SAHA, which could be utilized as a rational strategy for the treatment of solid tumors, especially triple-negative breast cancer.

Lacking Immunotherapy Biomarkers for Biliary Tract Cancer: A Comprehensive Systematic Literature Review and Meta-Analysis

BACKGROUND

Immunotherapy has recently been incorporated into the spectrum of biliary tract cancer (BTC) treatment. The identification of predictive response biomarkers is essential in order to identify those patients who may benefit most from this novel treatment option. Here, we propose a systematic literature review and a meta-analysis of PD-1, PD-L1, and other immune-related biomarker expression levels in patients with BTC.

METHODS

Prisma guidelines were followed for this systematic review and meta-analysis. Eligible studies were searched on PubMed. Studies published between 2017 and 2022, reporting data on PD-1/PD-L1 expression and other immune-related biomarkers in patients with BTC, were considered eligible.

RESULTS

A total of 61 eligible studies were identified. Despite the great heterogeneity between 39 studies reporting data on PD-L1 expression, we found a mean PD-L1 expression percentage (by choosing the lowest cut-off per study) of 25.6% (95% CI 21.0 to 30.3) in BTCs. The mean expression percentages of PD-L1 were 27.3%, 21.3%, and 27.4% in intrahepatic cholangiocarcinomas (iCCAs-15 studies), perihilar-distal CCAs (p/dCCAs-7 studies), and gallbladder cancer (GBC-5 studies), respectively. Furthermore, 4.6% (95% CI 2.38 to 6.97) and 2.5% (95% CI 1.75 to 3.34) of BTCs could be classified as TMB-H and MSI/MMRd tumors, respectively.

CONCLUSION

From our analysis, PD-L1 expression was found to occur approximately in 26% of BTC patients, with minimal differences based on anatomical location. TMB-H and MSI molecular phenotypes occurred less frequently. We still lack a reliable biomarker, especially in patients with mismatch-proficient tumors, and we must need to make an effort to conceive new prospective biomarker discovery studies.

Genomic and Immune Features in an Intrahepatic Cholangiocarcinoma Patient with Microsatellite Instability-High Suffered Rapid Acquired Resistance to PD-1 Inhibitor

Introduction

Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive liver malignancy with poor prognosis. Recently, the development of immune checkpoint inhibitors (ICIs), such as programmed cell death 1 (PD-1) inhibitors, has emerged as a promising strategy in multiple tumor types, including ICC. Microsatellite instability-high (MSI-H) is an important biomarker for ICIs in solid tumors. The response rate in patients with MSI-H is significantly higher than in those with microsatellite stability/microsatellite instability-low. And approximately 80-90% of the patients with MSI-H could maintain sustained clinical benefits once they had an initial response. However, some patients could have primary resistance at the beginning, and some might have acquired resistance after long-term treatment.

Case Presentation

We present the case of an ICC patient with MSI-H who suffered rapid progression after a short-term remission with camrelizumab, a kind of PD-1 inhibitor, as second-line treatment. The patient's genomic and immune features were analyzed by next-generation sequencing and multiplex immunofluorescence staining to explore the possible mechanisms of the rapidly acquired resistance of ICIs in this MSI-H case.

Conclusion

The genomic and immunohistochemical analysis showed that TGFBR2 mutation, loss of HLA B44 supertype, carrying B62 supertype, and increased PD-L1+ cells, macrophages, and Tregs in the tumor microenvironment might be related to the nonsustain benefit of ICIs in this MSI-H patient.

Preclinical evaluation of chimeric antigen receptor T cells targeting the carcinoembryonic antigen as a potential immunotherapy for gallbladder cancer

Gallbladder cancer (GBC) is commonly diagnosed at late stages when conventional treatments achieve only modest clinical benefit. Therefore, effective treatments for advanced GBC are needed. In this context, the administration of T cells genetically engineered with chimeric antigen receptors (CAR) has shown remarkable results in hematological cancers and is being extensively studied for solid tumors. Interestingly, GBC tumors express canonical tumor-associated antigens, including the carcinoembryonic antigen (CEA). However, the potential of CEA as a relevant antigen in GBC to be targeted by CAR-T cell-based immunotherapy has not been addressed. Here we show that CEA was expressed in 88% of GBC tumors, with higher levels associated with advanced disease stages. CAR-T cells specifically recognized plate-bound CEA as evidenced by up-regulation of 4-1BB, CD69 and PD-1, and production of effector cytokines IFN-γ and TNF-α. In addition, CD8+ CAR-T cells up-regulated the cytotoxic molecules granzyme B and perforin. Interestingly, CAR-T cell activation occurred even in the presence of PD-L1. Consistent with these results, CAR-T cells efficiently recognized GBC cell lines expressing CEA and PD-L1, but not a CEA-negative cell line. Furthermore, CAR-T cells exhibited in vitro cytotoxicity and reduced in vivo tumor growth of GB-d1 cells. In summary, we demonstrate that CEA represents a relevant antigen for GBC that can be targeted by CAR-T cells at the preclinical level. This study warrants further development of the adoptive transfer of CEA-specific CAR-T cells as a potential immunotherapy for GBC.

Clinical presentation and management modalities of gallbladder cancer in Sudan: A single-center study

Background and Aim

Gallbladder cancer (GBC) is a rare and highly aggressive malignancy characterized by late presentation of nonspecific symptoms, poor curability, and high mortality. The gold standard for effective treatment depends on early detection and surgical excision. Hence, the aim of this study was to determine the patterns of clinical presentation and management modalities to reach excellent practice.

Methods

A retrospective study was conducted during the period from May 2021 to April 2022 at Ibn Sina specialized hospital, Khartoum, Sudan, on 50 patients with GBC who underwent a preoperative clinical and radiological evaluation to enable the use of appropriate surgical and oncological approaches.

Results

GBC was more prevalent in females in this series where all had GBC (68%), in the ratio 2:1. Distribution of patients according to age ranged between 61 and 75 years, representing 44% of patients. Abdominal pain, nausea, and vomiting were present in 40% of patients. Fifty-six percent of patients resided in urban areas. Transabdominal ultrasound (TUS) with CT scan diagnosed GBC in 54% of patients. GBC was metastatic (stage IV) in 52% of patients. Based on preoperative decision by a multidisciplinary team (MDT), 62% of patients had palliative nonsurgical oncological treatment. Histopathological analysis of the resected GBC showed adenocarcinoma in 74% of cases. The inoperable patients (42%) were treated palliativelly with endoscopic retrograde cholangiopancreatography/systemic chemotherapy. Finally, the overall mortality rate was 56%.

Conclusions

Accurate early clinical diagnosis and advanced radiological modalities with curative surgical approaches including clear surgical resection margins and systemic oncological therapies will potentially help in improving GBC survival outcomes.

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.

Immunotherapy and Targeted Therapy for Advanced Biliary Tract Cancer: Adding New Flavors to the Pizza

Biliary tract cancers (BTCs) are a rare pathology and can be divided into four major subgroups: intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, hilar cholangiocarcinoma, and gallbladder cancer. In the era of precision oncology, the development of next-generation sequencing (NGS) allowed a better understanding of molecular differences between these subgroups. Thus, the development of drugs that can target these alterations and inhibit the abnormal pathway activation has changed the prognosis of BTC patients. Additionally, the development of immune checkpoint inhibitors and a better understanding of tumor immunogenicity led to the development of clinical trials with immunotherapy for this scenario. The development of biomarkers that can predict how the immune system acts against the tumor cells, and which patients benefit from this activation, are urgently needed. Here, we review the most recent data regarding targeted treatment and immunotherapy in the scenario of BTC treatment, while also discussing the future perspectives for this challenging disease.

Cytotoxic activity of anti-mucin 1 chimeric antigen receptor T cells expressing PD-1-CD28 switch receptor against cholangiocarcinoma cells

BACKGROUND AIMS

Cholangiocarcinoma (CCA) is a lethal bile-duct cancer that is difficult to treat by current standard procedures. This drawback has prompted us to develop adoptive T-cell therapy for CCA, which requires an appropriate target antigen for binding of chimeric antigen receptor (CAR) T cells. Mucin 1 (MUC1), an overexpressed protein in CCA cells, is a potential target antigen for the CAR T-cell development. However, MUC1 overexpression also is associated with the upregulation of programmed death-ligand 1 (PD-L1), an immune checkpoint protein that prohibits anti-tumor functions of T cells, probably causing poor overall survival of patients with CCA.

METHODS

To overcome this problem, we developed anti-MUC1-CAR T cells containing PD-1-CD28 switch receptor (SR), namely αM.CAR/SR T cells, to target MUC1 and switch on the inhibitory signal of PD-1/PD-L1 interaction to activate CD28 signaling. Our lentiviral construct contains the sequences that encode anti-MUC1-single chain variable fragment, CD137 and CD3ζ, linked with P2A, PD-1 and CD28.

RESULTS

Initially, the upregulations of MUC1 and PD-L1 proteins were confirmed in CCA cell lines. αM.CAR and SR were co-expressed in 53.53 ± 13.89% of transduced T cells, mainly CD8⁺ T cells (85.7 ± 0.75%, P<0.0001) with the effector memory phenotype (59.22 ± 16.31%, P < 0.01). αM.CAR/SR T cells produced high levels of intracellular tumor necrosis factor-α and interferon-γ in response to the activation by CCA cells expressing MUC1, including KKU-055 (27.18 ± 4.38% and 27.33 ± 5.55%, respectively, P < 0.05) and KKU-213A (47.37 ± 12.67% and 54.55 ± 8.66%, respectively, P < 0.01). Remarkably, the cytotoxic function of αM.CAR/SR T cells against KKU-213A cells expressing PD-L1 was significantly enhanced compared with the αM.CAR T cells (70.69 ± 14.38% versus 47.15 ± 8.413%, respectively; P = 0.0301), correlated with increased granzyme B production (60.6 ± 9.89% versus 43.2 ± 8.95%, respectively; P = 0.0402). Moreover, the significantly enhanced disruption of KKU-213A spheroids by αM.CAR/SR T cells (P = 0.0027), compared with αM.CAR T cells, was also observed.

CONCLUSION

Taken together, the cytotoxic function of αM.CAR/SR T cells was enhanced over the αM.CAR T cells, which are potential to be further tested for CCA treatment.

Review and Application of Integrin Alpha v Beta 6 in the Diagnosis and Treatment of Cholangiocarcinoma and Pancreatic Ductal Adenocarcinoma

Integrin Alpha v Beta 6 is expressed primarily in solid epithelial tumors, such as cholangiocarcinoma, pancreatic cancer, and colorectal cancer. It has been considered a potential and promising molecular marker for the early diagnosis and treatment of cancer. Cholangiocarcinoma and pancreatic ductal adenocarcinoma share genetic, histological, and pathophysiological similarities due to the shared embryonic origin of the bile duct and pancreas. These cancers share numerous clinicopathological characteristics, including growth pattern, poor response to conventional radiotherapy and chemotherapy, and poor prognosis. This review focuses on the role of integrin Alpha v Beta 6 in cancer progression. It addition, it reviews how the marker can be used in molecular imaging and therapeutic targets. We propose further research explorations and questions that need to be addressed. We conclude that integrin Alpha v Beta 6 may serve as a potential biomarker for cancer disease progression and prognosis.

Radiation-induced PD-L1 expression in tumor and its microenvironment facilitates cancer-immune escape: a narrative review

Background and Objective

Radiotherapy (RT) is one of the fundamental anti-cancer regimens by means of inducing in situ tumor vaccination and driving a systemic anti-tumor immune response. It can affect the tumor microenvironment (TME) components consisting of blood vessels, immunocytes, fibroblasts, and extracellular matrix (ECM), and might subsequently suppress anti-tumor immunity through expression of molecules such as programmed death ligand-1 (PD-L1). Immune checkpoint inhibitors (ICIs), especially anti-programmed cell death 1 (PD-1)/PD-L1 therapies, have been regarded as effective in the reinvigoration of the immune system and another major cancer treatment. Experimentally, combination of RT and ICIs therapy shows a greater synergistic effect than either therapy alone.

Methods

We performed a narrative review of the literature in the PubMed database. The research string comprised various combinations of "radiotherapy", "programmed death-ligand 1", "microenvironment", "exosome", "myeloid cell", "tumor cell", "tumor immunity". The database was searched independently by two authors. A third reviewer mediated any discordance of the results of the two screeners.

Key Content and Findings

RT upregulates PD-L1 expression in tumor cells, tumor-derived exosomes (TEXs), myeloid-derived suppressor cells (MDSCs), and macrophages. The signaling pathways correlated to PD-L1 expression in tumor cells include the DNA damage signaling pathway, epidermal growth factor receptor (EGFR) pathway, interferon gamma (IFN-γ) pathway, cGAS-STING pathway, and JAK/STATs pathway.

Conclusions

PD-L1 upregulation post-RT is found not only in tumor cells but also in the TME and is one of the mechanisms of tumor evasion. Therefore, further studies are necessary to fully comprehend this biological process. Meanwhile, combination of therapies has been shown to be effective, and novel approaches are to be developed as adjuvant to RT and ICIs therapy.

PD-1 inhibitors plus nab-paclitaxel-containing chemotherapy for advanced gallbladder cancer in a second-line setting: A retrospective analysis of a case series

Background

Gallbladder cancer (GBC) is a fatal cancer, and the efficacy of the current standard second-line chemotherapy for GBC is limited. Novel therapies need to be explored. This retrospective analysis was aimed to investigate the outcomes of patients treated at West China Hospital with PD-1 inhibitors combined with nab-paclitaxel-based chemotherapy (nab-paclitaxel monotherapy or nab-paclitaxel plus other cytotoxic agents) in a second-line setting.

Methods

Between April 2020 and May 2022, the patients with advanced GBC receiving PD-1 inhibitors combined with nab-paclitaxel-based chemotherapy after resistance to first-line gemcitabine-based chemotherapy at West China Hospital were retrospectively screened.

Results

Eleven patients were included, and all received gemcitabine-based chemotherapy as first-line therapy. Eight patients underwent next-generation sequencing (NGS), and all had microsatellite stability (MSS) and a low tumor mutation burden (TMB). Six patients were negative for PD-L1 expression and one patient was positive for PD-L1. Therapeutically relevant genetic alterations were not found. All patients received PD-1 inhibitors in combination with nab-paclitaxel-based chemotherapy as second-line therapy. Pembrolizumab was administered in 3 patients, and sintilimab was administered in eight patients. One patient had no measurable target lesion. Complete response (CR) was observed in one (10.0%) patient, partial response (PR) in four (40%) patients, and stable disease (SD) in four (40%) patients. The median progression-free survival (PFS) was 7.5 (95% CI: 2.5-12.5) months, and the median overall survival (OS) was 12.7 (95% CI: 5.5-19.9) months. The adverse events (AEs) were manageable.

Conclusion

Our results suggest that PD-1 inhibitors combined with nab-paclitaxel-based chemotherapy as second-line therapy for advanced GBC might be a potential treatment and deserves further evaluation.

Newest Therapies for Cholangiocarcinoma: An Updated Overview of Approved Treatments with Transplant Oncology Vision

Simple Summary

Cholangiocarcinoma is a relatively rare but deadly disease with traditionally limited treatment options. The disease can be categorized by anatomic location within the biliary tree, with different associated risk factors and molecular profiles. Recent years have seen a burgeoning of targeted therapies that have enhanced survival in subsets of patients with certain mutations. We herein discuss these more recent advances as well as providing an overview of more well-known treatment modalities, with the goal of providing an accessible source for practicing clinicians.

Abstract

A minority of cholangiocarcinoma (CCA) can be cured by surgical intervention (i.e., liver resection (LR) and liver transplantation (LT)). When modern criteria for LT are met, this intervention along with neoadjuvant treatments may achieve unprecedented survival in selected patients. Liver resection is associated with a median overall survival (OS) of 40 months, this number drastically decreases for unresectable advanced cholangiocarcinoma (CCA), which is treated with systemic therapy. The first-line chemotherapy regimen of gemcitabine and cisplatin is associated with a median overall survival of only 11.7 months. Since the Food and Drug Administration (FDA)’s approval of the isocitrate dehydrogenase (IDH) 1 inhibitor ivosidenib in August 2021, there has been increasing interest in targeted therapy for CCA patients harboring mutations in fibroblast growth factor receptor (FGFR) 2, neurotrophic receptor tyrosine kinase (NTRK), B-raf kinase (BRAF), and HER2. At the same time, immunotherapy with immune checkpoint inhibitors isalso being used in relapsed CCA. This review looks into the most recently completed and ongoing studies of targeted therapy as monotherapy or in combination with chemo- and/or immunotherapy. Whether it is resection, liver transplant, radiotherapy, chemotherapy, immunotherapy, targeted therapy, or any combination of these treatment modalities, great strides are being made to improve outcomes for this challenging disease.

Feasibility and Efficacy of Adjuvant Chemotherapy With Gemcitabine After Liver Transplantation for Perihilar Cholangiocarcinoma - A Multi-Center, Randomized, Controlled Trial (pro-duct001)

Background

Liver transplantation (LT) is considered a therapeutic option for unresectable perihilar cholangiocarcinoma (PHC) within defined criteria. It remains uncertain whether patients can safely receive adjuvant chemotherapy after LT.

Methods

We performed a prospective, multi-center, randomized, non-blinded two-arm trial (pro-duct001). Patients after LT for unresectable PHC within defined criteria were randomized to adjuvant gemcitabine (LT-Gem group) and LT alone (LT alone group). The primary objective was to investigate if adjuvant chemotherapy is feasible in ≥ 85% of patients after LT. The primary endpoint was the percentage of patients completing the 24 weeks course of adjuvant chemotherapy. Secondary endpoints included overall survival (OS) and disease-free (DFS), and complication rates.

Results

Twelve patients underwent LT for PHC, of which six (50%) were eligible for randomization (LT-Gem: three patients, LT alone: three patients). Two out of three patients discontinued adjuvant chemotherapy after LT due to intolerance. The study was prematurely terminated due to slow enrollment. One patient with PHC had underlying primary sclerosing cholangitis (PSC). Tumor-free margins could be achieved in all patients. In both the LT-Gem and the LT alone group, the cumulative 1-, 3-, and 5-year OS and DFS rates were 100%, 100%, 67%, and 100%, 67% and 67%, respectively.

Conclusions

This prospective, multi-center study was prematurely terminated due to slow enrollment and a statement on the defined endpoints cannot be made. Nevertheless, long-term survival data are consistent with available retrospective data and confirm defined criteria for LT. Since more evidence of LT per se in unresectable PHC is urgently needed, a prospective, non-randomized follow-up study (pro-duct002) has since been launched.

Clinical treatment of cholangiocarcinoma: an updated comprehensive review

Cholangiocarcinoma (CCA) is a heterogeneous group of neoplasms of the bile ducts and represents the second most common hepatic cancer after hepatocellular carcinoma; it is sub-classified as intrahepatic cholangiocarcinoma (iCCA) and extrahepatic cholangiocarcinoma (eCCA), the latter comprising both perihilar cholangiocarcinoma (pCCA or Klatskin tumor), and distal cholangiocarcinoma (dCCA). The global incidence of CCA has increased worldwide in recent decades. Chronic inflammation of biliary epithelium and bile stasis represent the main risk factors shared by all CCA sub-types. When feasible, liver resection is the treatment of choice for CCA, followed by systemic chemotherapy with capecitabine. Liver transplants represent a treatment option in patients with very early iCCA, in referral centers only. CCA diagnosis is often performed at an advanced stage when CCA is unresectable. In this setting, systemic chemotherapy with gemcitabine and cisplatin represents the first treatment option, but the prognosis remains poor. In order to ameliorate patients' survival, new drugs have been studied in the last few years. Target therapies are directed against different molecules, which are altered in CCA cells. These therapies have been studied as second-line therapy, alone or in combination with chemotherapy. In the same setting, the immune checkpoints inhibitors targeting programmed death 1 (PD-1), programmed death-ligand 1 (PD-L1), cytotoxic T-lymphocyte antigen-4 (CTLA-4), have been proposed, as well as cancer vaccines and adoptive cell therapy (ACT). These experimental treatments showed promising results and have been proposed as second- or third-line treatment, alone or in combination with chemotherapy or target therapies.

Prognostic Factors in Patients Treated with Pembrolizumab as a Second-Line Treatment for Advanced Biliary Tract Cancer

Some BTC types respond to pembrolizumab, but there are no known prognostic factors to predict its treatment benefits. In this study, we attempted to identify the prognostic factors associated with pembrolizumab as a second-line treatment for gemcitabine-refractory BTC. This retrospective and single tertiary-center study involved all the consecutive patients (n = 80) with refractory advanced BTC, who were diagnosed as programmed cell death ligand 1-positive and treated with pembrolizumab between August 2017 and February 2021. The overall survival (OS) was analyzed using Cox regression analysis. The median OS was 6.0 months [95% confidence interval (CI): 3.87−8.20]; median progression-free survival was 1.9 months (95% CI: 1.82−1.98); and the response rate was 15.9%. In the multivariate Cox regression analysis, the TB [adjusted hazard ratio (HR) = 2.286; 95% CI: 1.177−4.440; p = 0.015), albumin levels (adjusted HR = 0.392; 95% CI: 0.211−0.725; p = 0.003), ALP levels (adjusted HR = 1.938; 95% CI: 1.105−3.400; p = 0.021), and LMR (adjusted HR = 0.325; 95% CI: 0.173−0.609; p < 0.001) were identified as significant variables associated with the OS. High albumin levels and LMR and low ALP levels and TB were significantly associated with better OS in patients treated with pembrolizumab.

Targeted therapy for breast cancer: An overview of drug classes and outcomes

The last 25 years have seen significant growth in new therapeutic options for breast cancer, termed targeted therapies based on their ability to block specific pathways known to drive breast tumor growth and survival. Introduction of these drugs has been made possible through advances in the understanding of breast cancer biology. While the promise of targeted therapy for breast cancer has been clear for some time, the experience of the clinical use of multiple drugs and drug classes allows us to now present a summary and perspective as to the success and impact of this endeavor. Here we will review breast cancer targeted therapeutics in clinical use. We will provide the rationale for their indications and summarize clinical data in patients with different breast cancer subtypes, their impact on breast cancer progression and survival and their major adverse effects. The focus of this review will be on the development that has occurred within classes of targeted therapies and subsequent impact on breast cancer patient outcomes. We will conclude with a perspective on the role of targeted therapy in breast cancer treatment and highlight future areas of development.

Lenvatinib Plus Programmed Cell Death Protein-1 Inhibitor Beyond First-Line Systemic Therapy in Refractory Advanced Biliary Tract Cancer: A Real-World Retrospective Study in China

Background

Currently, no second-line systemic treatment regimen has been recommended in advanced biliary tract cancer (BTC). Cumulative clinical evidence showed that systemic treatment with tyrosine kinase inhibitors (TKIs) in combination with immunotherapy may shed light on the dim clinical outcome in advanced BTC.

Objective

The aim of this study is to evaluate the anticancer efficacy of lenvatinib plus programmed cell death protein-1 (PD-1) antibody in patients with BTC who progressed after first-line cisplatin/gemcitabine (CisGem) chemotherapy.

Methods

Patients with advanced BTCs who progressed after CisGem were recruited. A combination regimen of lenvatinib (8/12 mg daily) plus PD-1 antibody (200/240 mg injection every 3 weeks) was prescribed. Clinicopathological information and therapeutic outcome, including tumor subtypes, biomarkers, treatment duration, adverse events (AE), progression-free survival (PFS), and overall survival (OS), were recorded and estimated.

Results

A total of 351 patients with BTCs were reviewed and 74 were recruited eventually: 35 had intrahepatic cholangiocarcinoma (47.3%), 4 had extrahepatic cholangiocarcinoma (5.4%), and 35 had gallbladder cancer (47.3%). The median administered cycles of PD-1 antibody were 6.43 (95% CI: 5.83–7.04) cycles, and the median duration of lenvatinib medication was 21.0 weeks (95% CI: 18.04–23.93). Twenty-eight patients (37.83%) experienced detectable objective response per RECIST1.1 within a median follow-up duration of 15.0 months. The objective response rate (ORR) was 20.27% (95% CI: 10.89%–29.65%), and the disease control rate (DCR) was 71.62% (95% CI: 61.11%–82.14%). The median PFS and OS were 4.0 months (95% CI: 3.5–5.0) and 9.50 months (95% CI: 9.0–11.0), respectively. Seventy-three patients (98.64%) reported AEs and 39 (52.70%) experienced ≥grade 3 AEs. In subgroup analyses, tumoral PD-L1 expression ≥50% and tumor mutation burden (TMB) ≥2.5 Muts/Mb were associated with prolonged PFS.

Conclusion

Lenvatinib plus PD-1 antibody treatment shows an active trend towards improving survival in patients with advanced BTCs after failure with CisGem chemotherapy. The treatment-related AEs are worthy of attention and are manageable.

Triple therapy in biliary tract cancers: GemOX plus immune checkpoint inhibitor in combination with lenvatinib or NGS-guided targeted therapy

PURPOSE

The combination of gemcitabine-based chemotherapy and immune checkpoint inhibitors has a good efficacy in advanced biliary tract cancer (BTC). The multi-target TKI lenvatinib and NGS-guided targeted therapy are also promising in BTC treatment. This study aimed to explore the performance of GemOX plus sintilimab and TKI (either lenvatinib or by NGS-guided targeted therapy) for local advanced or metastatic BTCs.

METHODS

This prospective single-arm study included patients with local advanced or metastatic BTCs and applied intravenous infusion of standard GemOX plus sintilimab and lenvatinib (no targetable gene alterations) or targeted therapy based on NGS (olaparib for BRCA1/2 mutation, dasatinib for IDH1/2 mutation, afatinib for EGFR amplification, lenvatinib for PDGFR and KIT mutation, and lenvatinib for FGFR/KIT mutation).

RESULTS

From November 2020 to December 2021, 22 patients BTCs (6 GBC, 14 iCCA, 1 pCCA and 1 dCCA cases) were enrolled, with an average age of 58.4 years. Partial response (PR) was achieved in 10 cases, stable disease (SD) in 9 cases and progression disease (PD) in 3 cases (13.6%). The objective response rate (ORR) was 45.5%, and the disease control rate (DCR) was 86.4%. During the treatment, the incidence of adverse reactions was 81.8%, and the incidence of grade 3/4 adverse events was 9.09%. For 14 patients with NGS, 5 patients were treated by targeted therapy and there were 1 SD and 4 PR cases. For four patients with positive PD-L1 expression, the ORR was 100%. While among the three patients with super-progression markers such as RET, MDM2 and FGF14/STK24, there were two SD and one PD cases.

CONCLUSION

In patients with advanced BTCs, the combination of GemOX plus sintilimab and lenvatinib or NGS-guided targeted therapy showed promising ORR and DCR, especially for the patients with positive PD-L1 expression and targetable gene alterations.

Therapeutic Effect and Prognosis of Biliary Tract Tumor Transformation

Biliary tract tumor is a common malignant disease in clinical practice. Its incidence rate and mortality rate are high, which seriously endangers the health of the people. At present, gastrointestinal surgery is mainly used to treat patients at home and abroad. This paper discusses the main risk factors of biliary tract cancer transformation, analyzes its prognostic characteristics and clinical efficacy, and compares them by comprehensive evaluation methods such as observation group control method, blood routine examination and treatment. The results are as follows: the postoperative adverse reactions in the control group are more obvious than those in the experimental group. There were no obvious clinical manifestations or adverse reactions in the experimental group. The therapeutic effect of biliary tumor transformation can effectively help patients improve their quality of life. Through the prognosis recovery of biliary tract tumor transformation treatment, the health level of patients in the experimental group was higher than that in the control group.

Evolving Role of Immunotherapy in Advanced Biliary Tract Cancers

Biliary tract cancers (BTC) comprise a rare and diverse group of malignancies that involve the gallbladder and biliary tree. These cancers typically present in later stages because they are aggressive in nature and affected patients are often asymptomatic in earlier stages of disease. Moreover, BTCs are generally refractory to cytotoxic chemotherapy, which further contributes to their associated poor survival outcomes. Novel therapy approaches are clearly needed. Molecular targeted agents have been developed based on our expanding knowledge of the genetic mutations underlying BTCs and represent a promising treatment strategy in molecularly selected subgroups of patients. In addition, the advent of immunotherapy over recent years has dramatically changed the bleak outcomes observed in malignancies such as melanoma. Our growing understanding of the complex tumor microenvironment in BTC has identified mechanisms of tumor immune evasion that could potentially be targeted with immunotherapy. As a result, different immunotherapeutic approaches including immune checkpoint inhibitors, cancer vaccines, and adoptive cell therapy, have been investigated. The use of immunotherapeutic agents is currently only approved for a small subset of treatment-refractory BTCs based on microsatellite instability (MSI) status and tumor mutational burden (TMB), but this will likely change with the potential approval of immunotherapy plus chemotherapy as a result of the TOPAZ-1 trial.

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).

Immune Checkpoint Inhibitors for Advanced Biliary Tract Cancer

BTC is a rare and aggressive cancer disease bearing an overall dismal prognosis with only finite therapy options. Only combination chemotherapy regimens achieve disease control which is often only short-lived since the tumor tissue exhibits a high resistance to chemotherapy. The emergence of immune checkpoint inhibitors in recent years has significantly improved the survival of cancer patients and thus, has been integrated in the therapeutic management of several solid tumors, including melanoma, colorectal carcinoma (CRC), hepatocellular carcinoma (HCC), triple-negative breast cancer (TNBC), non-small-cell lung cancer (NSCLC). Investigation of the tumor biology of BTC and results of preliminary studies have shown that BTC may also be amenable to immunomodulation. In this review, we seek to give a comprehensive overview about the role, potential and clinical significance of ICPI in the management of BTC.

Common DNA methylation changes in biliary tract cancers identify subtypes with different immune characteristics and clinical outcomes

BACKGROUND

DNA methylation-associated studies on biliary tract cancer (BTC), including cholangiocarcinoma (CCA) and gallbladder cancer (GBC), may improve the BTC classification scheme. We proposed to identify the shared methylation changes of BTCs and investigate their associations with genomic aberrations, immune characteristics, and survival outcomes.

METHODS

Multi-dimensional data concerning mutation, DNA methylation, immune-related features, and clinical data of 57 CCAs and 48 GBCs from Eastern Hepatobiliary Surgery Hospital (EHSH) and 36 CCAs in the TCGA-CHOL cohort were analyzed.

RESULTS

In our cohort including 24 intrahepatic CCAs (iCCAs), 20 perihilar CCAs (pCCAs), 13 distal CCAs (dCCAs), and 48 GBCs, 3369 common differentially methylated regions (DMRs) were identified by comparing tumor and non-tumor samples. A lower level of methylation changes of these common DMRs was associated with fewer copy number variations, fewer mutational burden, and remarkably longer overall survival (OS, hazard ratio [HR] = 0.07, 95% confidence interval [CI] 0.01-0.65, P = 0.017). Additionally, a 12-marker model was developed and validated for prognostication after curative surgery (HR = 0.21, 95% CI 0.10-0.43, P < 0.001), which exhibited undifferentiated prognostic effects in subgroups defined by anatomic location (iCCAs, d/pCCAs, GBCs), TNM stage, and tumor purity. Its prognostic utility remained significant in multivariable analysis (HR = 0.26, 95% CI 0.11-0.59, P = 0.001). Moreover, the BTCs with minimal methylation changes exhibited higher immune-related signatures, infiltration of CD8⁺ lymphocytes, and programmed death-ligand 1 (PD-L1) expression, indicating an inflamed tumor immune microenvironment (TIME) with PD-L1 expression elicited by immune attack, potentially suggesting better immunotherapy efficacy.

CONCLUSIONS

In BTCs, DNA methylation is a powerful tool for molecular classification, serving as a robust indicator of genomic aberrations, survival outcomes, and tumor immune microenvironment. Our integrative analysis provides insights into the prognostication after curative surgery and patient selection for immunotherapy.

Intron-Retention Neoantigen Load Predicts Favorable Prognosis in Pancreatic Cancer

PURPOSE

High tumor mutation burden (TMB) in many cancer types is associated with the production of tumor-specific neoantigens, a favorable outcome and response to immune checkpoint blockade (ICB) therapy. Besides mutation-derived neoantigens, aberrant intron retention also produces tumor neopeptides that could trigger an immune response. The relationship between intron-retention-derived tumor neoantigens (IR-neoAg) and clinical outcomes in pancreatic cancer remains uncertain. Here, we quantify IR-neoAg in pancreatic cancer and evaluate whether IR-neoAg load might serve as a biomarker for selecting patients who may benefit from ICB therapy.

METHODS

We developed a computational approach to estimate patient-specific IR-neoAg load from transcriptome data available in The Cancer Genome Atlas pancreatic cancer cohort. Associations between IR-neoAg load and patient overall survival were evaluated using Kaplan-Meier estimates and Cox regression. Differential expression of immune checkpoint and HLA-I genes was evaluated in tumors with high IR-neoAg load.

RESULTS

High IR-neoAg load predicted better overall survival in pancreatic cancer, although no association was found for TMB. IR-neoAg load remained a significant prognostic factor after adjusting for patient age, sex, tumor stage and grade, and TMB. Moreover, pancreatic tumors with both high IR-neoAg load and high HLA-I gene expression had similar gene expression profiles as other tumor types that showed response to anti-programmed cell death protein 1 therapy.

CONCLUSION

IR-neoAg load is associated with favorable survival in pancreatic cancer. These findings provide strong evidence for considering IR-neoAgs when selecting patients who might benefit from ICB therapy.

Decreased Expression of Programmed Death Ligand-L1 by Seven in Absentia Homolog 2 in Cholangiocarcinoma Enhances T-Cell-Mediated Antitumor Activity

N6-methyladenosine (m6A) has been reported as an important mechanism of post-transcriptional regulation. Programmed death ligand 1 (PD-L1) is a primary immune inhibitory molecule expressed on tumor cells that promotes immune evasion. In addition, seven in absentia homolog 2 (Siah2), a RING E3 ubiquitin ligase, has been involved in tumorigenesis and cancer progression. However, the role of m6A-METTL14-Siah2-PD-L1 axis in immunotherapy remains to be elucidated. In this study, we showed that METTL14, a component of the m⁶A methyltransferase complex, induced Siah2 expression in cholangiocarcinoma (CCA). METTL14 was shown to enrich m⁶A modifications in the 3'UTR region of the Siah2 mRNA, thereby promoting its degradation in an YTHDF2-dependent manner. Furthermore, co-immunoprecipitation experiments demonstrated that Siah2 interacted with PD-L1 by promoting its K63-linked ubiquitination. We also observed that in vitro and in vivo Siah2 knockdown inhibited T cells expansion and cytotoxicity by sustaining tumor cell PD-L1 expression. The METTL14-Siah2-PD-L1-regulating axis was further confirmed in human CCA specimens. Analysis of specimens from patients receiving anti-PD1 immunotherapy suggested that tumors with low Siah2 levels were more sensitive to anti-PD1 immunotherapy. Taken together, our results evidenced a new regulatory mechanism of Siah2 by METTL14-induced mRNA epigenetic modification and the potential role of Siah2 in cancer immunotherapy.

Regorafenib-avelumab combination in patients with biliary tract cancer (REGOMUNE): a single-arm, open-label, phase II trial

BACKGROUND

Regorafenib has shown substantial clinical activity in patients with advanced biliary tract cancers (BTCs). Preclinical data suggested that this drug modulates antitumour immunity and is synergistic with immune checkpoint inhibition.

PATIENTS AND METHODS

This is a single-arm, multicentric phase II trial. Regorafenib was given 3 weeks/4, 160 mg quaque die (once a day) (QD); avelumab 10 mg/kg IV was given every two weeks, beginning at C1D15 until progression or unacceptable toxicity. The primary end-point was the confirmed objective response rate under treatment, as per Response Evaluation Criteria in Solid Tumours 1.1. The secondary end-points included the following: 1-year non-progression rate; progression-free survival (PFS) and overall survival; safety and biomarkers studies performed on sequential tumour samples obtained at baseline and at cycle 2 day 1.

RESULTS

Thirty-four patients were enrolled in four centres. Twenty-nine patients were assessable for efficacy after central radiological review. The best response was partial response for four patients (13.8%), stable disease for 11 patients (37.9%) and progressive disease for 14 patients (48.3%). The median PFS and overall survival were 2.5 months (95% confidence interval [CI] [1.9-5.5]) and 11.9 months (95%CI [6.2-NA]) respectively. The most common grade 3 or 4 clinical adverse events related to treatment were hypertension (17.6%), fatigue (14.7%) and maculopapular rash (11.8%). High baseline levels of programmed cell death ligand 1 and of indoleamine 2, 3-dioxygénase expression were associated with improved outcomes.

CONCLUSIONS

Regorafenib combined with avelumab has antitumour activity in a subset of heavily pretreated biliary tract cancer population. Further investigations are needed in patients selected based on tumour microenvironment features.

CLINICAL TRIAL REGISTRATION

NCT03475953.

Moving forward in the treatment of cholangiocarcinoma

Despite being the second most frequent primary liver tumor in humans, early diagnosis and treatment of cholangiocarcinoma (CCA) are still unsatisfactory. In fact, survival after 5 years is expected in less than one fourth of patients diagnosed with this disease. Rare incidence, late appearance of symptoms and heterogeneous biology are all factors contributing to our limited knowledge of this cancer and determining its poor prognosis in the clinical setting. Several efforts have been made in the last decades in order to achieve an improved classification/understanding with regard to the diverse CCA forms. Location within the biliary tree has helped to distinguish between intrahepatic, perihilar and distal CCA types. Sequence analysis contributed to identifying several characteristic genetic aberrations in CCA that may also serve as possible targets for therapy. Novel findings are expected to significantly improve the management of this malignancy in the near future. In this changing scenario our review focuses on the current and future strategies for CCA treatment. Both systemic and surgical treatments are discussed in detail. The results of the main studies in this field are reported, together with the ongoing trials. The current findings suggest that an integrated multidisciplinary approach to this malignancy would be helpful to improve its outcome.

Gallbladder cancer: Historical treatment and new management options

Gallbladder cancer is a rare, aggressive malignancy that has a poor overall prognosis. Effective treatment consists of early detection and surgical treatment. With the wide spread treatment of gallbladder disease with minimally invasive techniques, the rate of incidental gallbladder cancer has seen an equitable rise along with stage migration towards earlier disease. Although the treatment remains mostly surgical, newer modalities such as regional therapy as well as directed therapy based on molecular medicine has led to improved outcomes in patients with advanced disease. We aim to summarize the management of gallbladder cancer along with the newer developments in this formidable disease process.

M6A Demethylase ALKBH5 Regulates PD-L1 Expression and Tumor Immunoenvironment in Intrahepatic Cholangiocarcinoma

N6-methyladenosine (m6A) has been reported as an important mechanism of post-transcriptional regulation. Programmed death-ligand 1 (PD-L1) is a primary immune inhibitory molecule expressed on tumor cells that promotes immune evasion. Here we report ALKBH5 as an important m6A demethylase that orchestrates PD-L1 expression in intrahepatic cholangiocarcinoma (ICC). Regulation of PD-L1 expression by ALKBH5 was confirmed in human ICC cell lines. Sequencing of the m6A methylome identified PD-L1 mRNA as a direct target of m6A modification whose levels were regulated by ALKBH5. Furthermore, ALKBH5 and PD-L1 mRNA were shown to interact. ALKBH5 deficiency enriched m6A modification in the 3'UTR region of PD-L1 mRNA, thereby promoting its degradation in a YTHDF2-dependent manner. In vitro and in vivo, tumor-intrinsic ALKBH5 inhibited the expansion and cytotoxicity of T cells by sustaining tumor cell PD-L1 expression. The ALKBH5-PD-L1-regulating axis was further confirmed in human ICC specimens. Single-cell mass cytometry analysis unveiled a complex role of ALKBH5 in the tumor immune microenvironment by promoting the expression of PD-L1 on monocytes/macrophages and decreasing the infiltration of myeloid-derived suppressor-like cells. Analysis of specimens from patients receiving anti-PD1 immunotherapy suggested that tumors with strong nuclear expression patterns of ALKBH5 are more sensitive to anti-PD1 immunotherapy. Collectively, these results describe a new regulatory mechanism of PD-L1 by mRNA epigenetic modification by ALKBH5 and the potential role of ALKBH5 in immunotherapy response, which might provide insights for cancer immunotherapies.

Potential experimental immune checkpoint inhibitors for the treatment of cancer of the liver

Introduction: Traditional systemic therapies offer limited benefit for advanced cancers of the liver. Immune checkpoints are inhibitory regulators of the immune system and the success of immune checkpoint inhibitors (ICIs) in the treatment of other cancers has led to clinical trials investigating the use of ICIs alone or in combination with other therapies for liver cancers.Area covered: Clinical trials involving ICIs for the treatment of liver cancer were broadly reviewed. Hepatocellular carcinoma and intrahepatic cholangiocarcinoma were examined. Phase I/II trials were prioritized, and relevant phase III trials were discussed. MEDLINE, PubMed, ASCO meeting library, and Web of Science databases were searched with the keywords 'immune checkpoint inhibitor' or 'targeted therapy' in combination with 'hepatocellular carcinoma,' or 'intrahepatic cholangiocarcinoma'. Major outcomes were safety and efficacy defined by response rate, progression-free survival, or overall survival.Expert opinion: ICIs can improve progression-free and overall survival among patients with advanced disease with an acceptable safety profile. Given the heterogeneity of liver disease, ideal strategies will likely include a combination of ICIs with additional therapies to achieve the most robust and durable response. Additional biomarkers will be needed to guide combination therapy to personalize treatment regimen for patients with primary liver cancers.

Cholangiocarcinoma: bridging the translational gap from preclinical to clinical development and implications for future therapy

Introduction: Cholangiocarcinoma (CCA) is a devastating liver tumor with a poor prognosis. While less than 50% of the patients with CCA may benefit from surgical resection, the rest undergoes chemotherapy with disappointing results (mean survival <2 years). Alternative pharmacological treatments are needed to improve the outcomes in patients with CCA.Areas covered: In this review, we discuss CCA-related (1) experimental systems used in preclinical studies; (2) pharmacological targets identified by genetic analysis; (3) results obtained in preliminary trials in human with their pros and cons; and (4) possible targeting of endocrinal modulation. A PubMed bibliographic search matching the term 'cholangiocarcinoma' with 'experimental model', 'preclinical model', 'genetic target', 'targeted therapy', 'clinical trial', or 'translational research' was conducted and manuscripts published between 2010 and 2020 were retrieved for reading and reviewing.Expert opinion: Several factors contribute to the translational gap between bench research and clinical practice in CCA. The tumor heterogeneity, lack of a preclinical model recapitulating the different features of CCA, and difficult patient enrollment in clinical trials are elements to consider for basic and clinical research in CCA. Establishment of international networks formed by experts in the field of CCA may improve future research and its translational findings on patients.

Ultrasensitive detection of programmed death-ligand 1 (PD-L1) in whole blood using dispersible electrodes

The direct quantification of programmed death-ligand 1 (PD-L1) as a biomarker for cancer diagnosis, prognosis and treatment efficacy is an unmet clinical need. Herein, we demonstrate the first report of rapid, ultrasensitive and selective electrochemical detection of PD-L1 directly in undiluted whole blood using modified gold-coated magnetic nanoparticles as "dispersible electrodes" with an ultralow detection limit of 15 attomolar and a response time of only 15 minutes.

Durvalumab: an investigational anti-PD-L1 antibody for the treatment of biliary tract cancer

Introduction: The prognosis of patients with advanced biliary tract cancer (BTC) remains dismal, with a 5-year overall survival rate of less than 10%. Although immune checkpoint inhibitors (ICIs) have revolutionized the treatment landscape of several hematological and solid tumors, controversial results have been reported in BTC. In this setting, the anti-PD-L1 inhibitor durvalumab is currently under investigation in several clinical trials as monotherapy, or in combination with other pharmacological agents.Areas covered: We offer an overview of immunotherapies for BTC, discuss recently published or presented data on durvalumab pharmacology, safety, and efficacy in the treatment of BTC and consider future research directions for the agent in this setting.Expert opinion: The promising antitumor activity shown by durvalumab in early trials warrants further investigation because it may provide more effective, much needed treatment options. The results of clinical trials of this PD-L1 inhibitor, as a monotherapy or in combination, are eagerly awaited. Future efforts should focus on the identification and development of reliable biomarkers of response to durvalumab in BTC, clarifying the role of PD-L1 expression, microsatellite instability (MSI), mismatch repair (MMR), tumor mutational burden (TMB) and other emerging predictors.

Development of Possible Next Line of Systemic Therapies for Gemcitabine-Resistant Biliary Tract Cancers: A Perspective from Clinical Trials

Biliary tract cancer (BTC) compromises a heterogenous group of tumors with poor prognoses. Curative surgery remains the first choice for localized disease; however, most BTC patients have had unresectable or metastatic disease. The gold standard therapy for these patients is chemotherapy with gemcitabine and cisplatin. There are no consensus guidelines for standard treatment in a second-line setting, although the data of the ABC-06 trial showed a slight survival benefit from oxaliplatin and 5-fluorouracil combination chemotherapy. Recent progress in comprehensive genomic profiling for advanced BTC (ABTC) has helped to clarify tumorigenesis and facilitate the coming era of precision medicine. Generally, targeted agents fail to show significant clinical benefits in unselected populations. Only fibroblast growth factor receptor 2 (FGFR2) fusion and isocitrate dehydrogenase (IDH)- and BRAF mutation-enriched populations have survival benefits from the corresponding inhibitors. Several interesting targeted agents for monotherapies or combination therapies with other compounds are currently ongoing or recruiting. Here, we review the published data from clinical trials of second-line therapies after the failure of gemcitabine-based chemotherapy in ABTC. The results were stratified by different genetic alternations, as well as by chemotherapy, targeted therapy and immunotherapy.

Immunotherapies in clinical development for biliary tract cancer

Introduction: Cancers of the biliary tract (BTC) are aggressive malignancies with limited treatment options and an overall dismal prognosis. In recent years, two concepts, namely precision oncology and immune oncology (IO) have profoundly influenced and, in some cancers, even revolutionized tumor treatments. While positive data from randomized trials have led to the incorporation of targeted concepts for genetically select BTC patients, IO is not yet implemented in clinical practice.Areas covered: We discuss published results from completed, as well as from ongoing studies on IO in BTC, based on a literature search on Pubmed and information provided by clinicaltrials.gov in October 2020. Apart from monotherapy, we outline IO-based combination approaches and highlight pivotal studies whose results will likely influence the future development of relevant concepts in BTC.Expert opinion: Despite partially positive signals, IO thus far disappointed in unselected BTC populations and should currently not be considered as a preferred systemic treatment in patients with microsatellite stable disease outside of clinical trials. In the coming years, a better understanding of the molecular mechanisms underlying resistance to checkpoint inhibition, and the identification of positive predictive biomarkers will be important for the successful integration of IO into treatment concepts for BTC patients.

Nivolumab: an investigational agent for the treatment of biliary tract cancer

Introduction: Biliary tract cancers (BTCs) include four uncommon primary biliary malignancies characterized by poor prognosis: intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer. To date, the available therapeutic options are limited; nevertheless, with the advent of targeted therapy and immunotherapy, the treatment scenario is constantly changing, opening toward future possibilities for the personalized treatment of BTC. Among these treatments, nivolumab is currently being investigated in BTC.Areas covered: This review provides a comprehensive overview of the recent progress and future perspectives of immunotherapy for the treatment of BTC, with a particular focus on nivolumab, which has demonstrated its effectiveness in many malignancies and is in its initial phase of evaluation in BTC.Expert opinion: BTCs are not among those tumors that demonstrated remarkable sensitivity to immunotherapy, such as melanoma or non-small-cell lung cancer. However, the results obtained with nivolumab are not disappointing if we analyze the population of the trials testing its efficacy, including pretreated patients, unselected for PD-L1 expression and with different BTCs. In our opinion, ICIs such as nivolumab could fill an empty spot in the treatment of selected BTC patients, especially in combination with other agents, and the results of ongoing clinical trials are awaited.