Anti-PD-1 antibody in combination with radiotherapy as first-line therapy for unresectable intrahepatic cholangiocarcinoma

BACKGROUND

Unresectable intrahepatic cholangiocarcinoma (iCCA) has a poor prognosis despite treatment with standard combination chemotherapy. We aimed to evaluate the efficacy and safety of radiotherapy in combination with an anti-PD-1 antibody in unresectable iCCA without distant metastases.

METHODS

In this phase II study, patients with histopathologically confirmed unresectable primary or postoperative recurrent iCCA without distant metastases were enrolled. Patients received external radiotherapy with a dose of ≥45 Gy (2-2.5 Gy per fraction), followed by anti-PD-1 immunotherapy (camrelizumab 200 mg once, every 3 weeks) initiated within 7 days after completion of radiotherapy as first-line therapy. The primary endpoint was 1-year progression-free survival (PFS) rate. The secondary end points included safety, objective response rate (ORR), disease control rate (DCR), and overall survival (OS).

RESULTS

From December 2019 to March 2021, 36 patients completed radiotherapy and at least one cycle of immunotherapy and were included in efficacy and safety analyses. The median follow-up was 19.0 months (IQR 12.0-24.0), and the one-year PFS rate was 44.4% (95% CI, 30.8-64.0). The median PFS was 12.0 months (95% CI, 7.5-not estimable); the median OS was 22.0 months (95% CI, 15.0-not estimable). The ORR was 61.1% and the DCR was 86.1%. Seventeen of 36 (47.2%) patients experienced treatment-related adverse effects (AEs) of any grade. The most common AE was reactive cutaneous capillary endothelial proliferation (25.0%). Five (13.9%) patients experienced grade ≥3 treatment-related AEs, including decreased lymphocyte (5.6%), bullous dermatitis (2.8%), decreased platelet count (2.8%), and deep-vein thrombosis (2.8%).

CONCLUSIONS

External radiotherapy plus camrelizumab, as first-line therapy, met its primary endpoint and showed antitumor activity and low toxicity levels in patients with unresectable iCCA without distant metastases, warranting further investigation.

TRIAL REGISTRATION

NCT03898895. Registered 2 April 2019.

Immunotherapy for the treatment of biliary tract cancer: an evolving landscape

Biliary tract cancers (BTCs), consisting of intrahepatic and extrahepatic cholangiocarcinoma and gallbladder cancer, are an aggressive, heterogeneous malignancy. They are most often diagnosed in the locally advanced or metastatic setting, at which point treatment consists of systemic therapy or best supportive care. Our understanding of the tumor microenvironment and the molecular classification has led to the identification of targetable mutations, such as isocitrate dehydrogenase 1 and fibroblast growth factor receptor 2. Despite the identification of these genomic alterations, until recently, little advancement had been made in the first-line setting for advanced BTC. While immunotherapy (IO) has revolutionized the treatment of many malignancies, the use of IO in BTC had yielded limited results prior to TOPAZ-1. In this review, we discuss the systemic therapeutic advances for BTC over the past decade, the rationale for immunotherapy in BTC, prior trials utilizing IO in BTC, and current and emerging immune-based therapeutic options. We further analyze the culmination of these advances, which resulted in the approval of durvalumab with gemcitabine and cisplatin for the first-line treatment of BTC per TOPAZ-1. We also discuss the results of KEYNOTE-966, which similarly reported improved clinical outcomes with the use of pembrolizumab in combination with gemcitabine and cisplatin.

A Paradigm Shift in Primary Liver Cancer Therapy Utilizing Genomics, Molecular Biomarkers, and Artificial Intelligence

Primary liver cancer is the sixth most common cancer worldwide and the third leading cause of cancer-related death. Conventional therapies offer limited survival benefit despite improvements in locoregional liver-directed therapies, which highlights the underlying complexity of liver cancers. This review explores the latest research in primary liver cancer therapies, focusing on developments in genomics, molecular biomarkers, and artificial intelligence. Attention is also given to ongoing research and future directions of immunotherapy and locoregional therapies of primary liver cancers.

Moving beyond single-agent checkpoint inhibition in biliary tract cancers: what is the next frontier?

Background: Immunotherapy has been shown to improve outcomes for patients with cancer. Biliary tract cancers are a group of lethal diseases, and immunotherapy is an exciting new strategy to treat patients in advanced stages. Role of immunotherapy in biliary cancers: Durvalumab, an anti-PD-L1 antibody, is a new immunotherapy option for patients with advanced biliary cancers. In a randomized phase III trial, the combination of durvalumab and chemotherapy improved disease outcomes, including overall survival, in patients with advanced biliary cancers regardless of PD-L1 expression. Future perspective: Promising new combinations with new and potent antibodies or antiangiogenics are under development. Combinations with new immunotherapy agents targeting CTLA-4 or OX40 can enhance T-cell activation and improve outcomes compared with single anti-PD-1/PD-L1 agents. Furthermore, ctDNA is being used as an alternative to tissue genomic analysis and can be used to identify actionable targets. In this review, we will discuss the most important studies involving immunotherapy in biliary cancers as well as future perspectives in the field.

Targeting myeloid-derived suppressor cells in tumor immunotherapy: Current, future and beyond

Myeloid-derived suppressor cells (MDSCs) are one of the major negative regulators in tumor microenvironment (TME) due to their potent immunosuppressive capacity. MDSCs are the products of myeloid progenitor abnormal differentiation in bone marrow, which inhibits the immune response mediated by T cells, natural killer cells and dendritic cells; promotes the generation of regulatory T cells and tumor-associated macrophages; drives the immune escape; and finally leads to tumor progression and metastasis. In this review, we highlight key features of MDSCs biology in TME that are being explored as potential targets for tumor immunotherapy. We discuss the therapies and approaches that aim to reprogram TME from immunosuppressive to immunostimulatory circumstance, which prevents MDSC immunosuppression activity; promotes MDSC differentiation; and impacts MDSC recruitment and abundance in tumor site. We also summarize current advances in the identification of rational combinatorial strategies to improve clinical efficacy and outcomes of cancer patients, via deeply understanding and pursuing the mechanisms and characterization of MDSCs generation and suppression in TME.

Biomarker analysis from a phase II multi-institutional study of nivolumab in patients with advanced refractory biliary tract cancer

BACKGROUND

Our previous phase II study demonstrated that nivolumab provides modest but durable clinical efficacy in patients with refractory biliary tract cancer, suggesting the significant clinical benefit of nivolumab in selected patients and the necessity of predictive biomarkers. We evaluated clinicopathological characteristics and tumour microenvironment of the patients who were enrolled the trial to identify potential biomarkers.

METHODS

Baseline clinicopathological characteristics and pretreatment tumour samples were collected. The obtained tumour samples were assessed for whole exome sequencing, RNA sequencing and immunohistochemistry. Their correlations with clinical outcome were analysed.

RESULTS

Pretreatment tumour evaluation revealed PD-L1 expression on tumour, CD8 T cell infiltration and high ratio of CD8 T cell/regulatory T cell in tumour microenvironment were significantly associated with prolonged progression-free survival (PFS), while PD-1 expression on lymphocytes and CD68 macrophages infiltration in tumour microenvironment had no predictive role. Asian patients (N = 3) had improved PFS and disease control rate compared with non-Asian (N = 54). A six-gene predictive model was constructed by evaluation of total 23,550 candidate genes from RNA sequencing of baseline tumour samples using LASSO-Cox regression analysis, and high score of the six-gene prediction model was associated with prolonged PFS.

CONCLUSION

This study suggests that PD-L1 expression on tumour, CD8 T cell infiltration and high ratio of CD8/regulatory T cells and six-gene expression profile in tumour microenvironment may be potential predictive biomarkers of nivolumab in biliary tract cancers. Further studies are needed to confirm these findings.

Verteporfin synergizes the efficacy of anti-PD-1 in cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is one of the primary hepatobiliary malignant neoplasms with only 10% of 5-year survival rate. Promising immunotherapy with the blockade of immune checkpoints has no clear benefit in CCA. The inhibition of YAP1 signaling by verteporfin has shown encouraging results by inhibiting cell proliferation and inducing apoptosis. This study aimed to evaluate the potential benefit of the combination of verteporfin and anti-programmed cell death 1 (PD-1) in CCA mouse model.

METHODS

We assessed the cytotoxicity of verteporfin in human CCA cell lines in vitro, including both intrahepatic CCA and extrahepatic CCA cells. We examined the in vitro effect of verteporfin on cell proliferation, apoptosis, and stemness. We evaluated the in vivo efficacy of verteporfin, anti-PD-1, and a combination of both in subcutaneous CCA mouse model.

RESULTS

Our study showed that verteporfin reduced tumor cell growth and enhanced apoptosis of human CCA tumor cells in vitro in a dose-dependent fashion. Nevertheless, verteporfin impaired stemness evidenced by reduced spheroid formation and colony formation, decreased numbers of cells with aldehyde dehydrogenase activity and positive cancer stem cell markers (all P < 0.05). The combination of verteporfin and anti-PD-1 reduced tumor burden in CCA subcutaneous SB1 tumor model compared to either agent alone.

CONCLUSIONS

Verteporfin exhibits antitumor effects in both intrahepatic and extrahepatic CCA cell lines and the combination with anti-PD-1 inhibited tumor growth.

Current Immune Checkpoint Inhibitor Genetic Biomarker Exploration in Gastrointestinal Tumors

Simple Summary

Immune checkpoint inhibitors (ICIs) are now incorporated into the management of GI tumors. The heterogenous nature of these tumors, however, reveals a lack of ICI consistency in effectiveness. Certain biomarkers have emerged as being potentially predictive for ICI effectiveness. Our review focuses on these biomarkers while discussing the current limitations with these markers.

Abstract

Immune checkpoint inhibitors have revolutionized cancer management. Some patients with gastrointestinal (GI) tract malignancy have experienced remarkable results. Here, in our review, we discuss predictive/prognostic GI tumor biomarkers that appear to correlate with benefits with this strategy. Remarkable progress has been made in certain subsets of patients including the potential for solid tumor patients to avoid local therapies such as radiation and/or surgery (organ preservation), which come with acute and chronic risks that have historically been the only curable strategies for these GI tumors. These results provide new and exciting strategies for solid tumor management. Unfortunately, immune checkpoint inhibitors can correlate with biomarkers, but benefits occur in a small subset of patients with GI malignancies. Most frequently, immune checkpoint inhibitors fail to induce response in GI malignancies due to the “cold” tumor microenvironment that protects cancer. Translational strategies are needed to develop effective combination strategies and novel biomarkers to overcome the intrinsic resistance.

Emerging Systemic Therapies in Advanced Unresectable Biliary Tract Cancer: Review and Canadian Perspective

Biliary tract cancer (BTC) is a group of rare and aggressive malignancies with a dismal prognosis. There is currently a significant lack in effective treatment options for BTC, with gemcitabine-cisplatin remaining the first-line standard of care treatment for over a decade. A wave of investigational therapies, including new chemotherapy combinations, immunotherapy, and biomarker-driven targeted therapy have demonstrated promising results in BTC, and there is hope for many of these therapies to be incorporated into the Canadian treatment landscape in the near future. This review discusses the emerging therapies under investigation for BTC and provides a perspective on how they may fit into Canadian practice, with a focus on the barriers to treatment access.

Safety and Efficacy of Allogeneic Natural Killer Cells in Combination with Pembrolizumab in Patients with Chemotherapy-Refractory Biliary Tract Cancer: A Multicenter Open-Label Phase 1/2a Trial

Background and Aim: This study investigated the administration of combination therapy, allogeneic natural killer (NK) cells and pembrolizumab in the treatment of advanced biliary tract cancer to determine the safety and tolerability (phase 1) and the efficacy and safety (phase 2a). Methods: Forty patients (phase 1, n = 6; phase 2a, n = 34) were enrolled between December 2019 and June 2021. The patients received highly activated allogeneic NK cells (“SMT-NK”) on weeks 1 and 2 and pembrolizumab on week 1. This 3-week schedule (one cycle) was repeated until confirmed disease progression, intolerable adverse events (AEs), patient withdrawal, or finishing the maximum treatment schedule. The tumor response was evaluated after every three cycles. Results: In phase 1, four patients (66.7%) experienced seven AEs, but no severe AE was observed. In phase 2a, 126 AEs occurred in 29 patients (85.3%). Severe AEs (≥grade 3) were reported in 16 patients (47.1%). The overall response rate (ORR) was 17.4% in the full analysis set and 50.0% in the per-protocol set. Conclusions: SMT-NKs plus pembrolizumab resulted in no severe AEs directly related to the drug combination. The combination therapy also exerted antitumor activity with improved efficacy compared to the recent monotherapy with pembrolizumab in patients with advanced biliary tract cancer.

Immunotherapy in biliary tract cancers: Current evidence and future perspectives

Bile duct tumors are comprised of tumors that originate from both intrahepatic and extrahepatic bile ducts and gallbladder tumors. These are aggressive tumors and chemotherapy is still the main treatment for advanced-stage disease and most of these cases have a poor overall survival. Strategies are aimed at treatments with better outcomes and less toxicity which makes immunotherapy an area of ​​significant importance. Recent Food and Drug Administration approvals of immune checkpoint inhibitors (ICI) for agnostic tumors based on biomarkers such as microsatellite instability-high and tumor mutation burden-high are important steps in the treatment of patients with advanced bile duct tumors. Despite limited responses with isolated checkpoint inhibitors in later lines of systemic treatment in advanced disease, drug combination strategies have been demonstrating encouraging results to enhance ICI efficacy.

The path to personalized treatment in advanced and metastatic biliary tract cancers: a review of new targeted therapies and immunotherapy

PURPOSE OF REVIEW

To summarize targeted therapies and immunotherapy as treatment for advanced/metastatic biliary tract cancers and discuss ongoing clinical trials.

RECENT FINDINGS

For the first time since gemcitabine-cisplatin was set as the standard of care in first-line advanced/metastatic biliary tract cancers in the ABC-02 trial, the combination of durvalumab and gemcitabine-cisplatin has demonstrated a statistically significant improvement of median overall survival in the TOPAZ-1 phase 3 trial. The ABC-06 trial showed a significant increase of median overall survival for FOLFOX and active symptom control compared with active symptom control alone in second-line regardless of molecular and genetic alterations. However, faced with a heterogeneous cancer, patient prognosis remains poor, leaving room for new, personalized, treatment options such as targeted therapies. Efficacy of fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitors has been demonstrated in different phase 2 trials for previously treated intrahepatic cholangiocarcinomas harboring FGFR2 fusions. Ivosidenib increases significantly median progression-free survival in previously treated cholangiocarcinomas with isocitrate dehydrogenase-1 (IDH-1) mutation. Other targeted therapies are tested for tumors with HER2 amplifications/mutations, BRAFV600E mutations or KRASG12C mutations.

SUMMARY

In this review, we aim to follow the changes in the treatment of these tumors, moving from very few chemotherapy options to immunotherapy and targeted therapies in the context of molecular selection of biliary tract cancers subtypes.

The emerging role of immunotherapy in biliary tract cancer: a review of new evidence and predictive biomarkers

Biliary tract cancers (BTCs) are frequently diagnosed in advanced stages and are highly lethal. Immunotherapy may play a role in the treatment of these patients. Promising results come from monotherapy or combination therapy studies in pretreated patients. In addition, several studies have demonstrated the safety and efficacy of immune checkpoint inhibitors (ICIs) in combination with chemotherapy in treatment-naive patients. Numerous biomarkers have been investigated to define their predictive role in response to ICIs. However, the full extent of the benefit of immunotherapies has not yet been fully established and, except for high microsatellite instability status, no other biomarkers were uniquely predictive of response to ICIs.

Advanced Bile Duct Cancers: A Focused Review on Current and Emerging Systemic Treatments

Cancers arising in the biliary tract are rare, with varied incidence depending on geographical location. As clinical presentation is typically vague with non-specific symptoms, a large proportion of patients present with unresectable or metastatic disease at diagnosis. When unresectable, the mainstay of treatment is cytotoxic chemotherapy; however, despite this, 5-year overall survival remains incredibly poor. Diagnostic molecular pathology, using next-generation sequencing, has identified a high prevalence of targetable alterations in bile duct cancers, which is transforming care. Substantial genomic heterogeneity has been identified depending on both the anatomical location and etiology of disease, with certain alterations enriched for subtypes. In addition, immune checkpoint inhibitors with anti-PD-1/PD-L1 antibodies in combination with chemotherapy are now poised to become the standard first-line treatment option in this disease. Here, we describe the established role of cytotoxic chemotherapy, targeted precision treatments and immunotherapy in what is a rapidly evolving treatment paradigm for advanced biliary tract cancer.

Tumor in the Crossfire: Inhibiting TGF-β to Enhance Cancer Immunotherapy

Cancer immunotherapy using monoclonal antibodies targeting immune checkpoints has undoubtedly revolutionized the cancer treatment landscape in the last decade. Immune checkpoint inhibitors can elicit long-lasting, previously unheard-of responses in a number of tumor entities. Yet, even in such tumors as metastatic melanoma and non-small cell-lung cancer, in which immune checkpoint inhibition has become the first-line treatment of choice, only a minority of patients will benefit considerably from these treatments. This has been attributed to a number of factors, including an immune-suppressive tumor microenvironment (TME). Using different modalities to break these barriers is of utmost importance to expand the population of patients that benefit from immune checkpoint inhibition. The multifunctional cytokine transforming growth factor-β (TGF-β) has long been recognized as an immune-suppressive factor in the TME. A considerable number of drugs have been developed to target TGF-β, yet most of these have since been discontinued. The combination of anti-TGF-β agents with immune checkpoint inhibitors now has the potential to revive this target as a viable immunomodulatory therapeutic approach. Currently, a limited number of small molecular inhibitor and monoclonal antibody candidates that target TGF-β are in clinical development in combination with the following immune checkpoint inhibitors: SRK 181, an antibody inhibiting the activation of latent TGF-β1; NIS 793, a monoclonal antibody targeting TGF-β; and SHR 1701, a fusion protein consisting of an anti-PD-L1 monoclonal antibody fused with the extracellular domain of human TGF-β receptor II. Several small molecular inhibitors are also in development and are briefly reviewed: LY364947, a pyrazole-based small molecular inhibitor of the serine-threonine kinase activity of TGFβRI; SB-431542, an inhibitor targeting several TGF-β superfamily Type I activin receptor-like kinases as well as TGF-β1-induced nuclear Smad3 localization; and galunisertib, an oral small molecular inhibitor of the TGFβRI kinase. One of the most advanced agents in this area is bintrafusp alfa, a bifunctional fusion protein composed of the extracellular domain of TGF-β receptor II fused to a human IgG1 mAb blocking PD-L1. Bintrafusp alfa is currently in advanced clinical development and as an agent in this space with the most clinical experience, is a focused highlight of this review.

Novel and emerging targets for cholangiocarcinoma progression: therapeutic implications

INTRODUCTION

Cholangiocarcinoma (CCA) is a heterogeneous group of aggressive biliary malignancies. While surgery and liver transplantation are the only potentially curative modalities for early-stage disease, limited options are available for most patients with incurable-stage disease. Survival outcomes remain dismal. Recent molecular profiling efforts have led to improved understanding of the genomic landscape of CCA and to the identification of subgroups with distinct diagnostic, prognostic, and therapeutic implications.

AREAS COVERED

: We provide an updated review and future perspectives on features of cholangiocarcinogenesis that can be translated into therapeutic biomarkers and targets. We highlight the critical studies that have established current systemic chemotherapy and targeted therapeutics, while elaborating on novel targeted and immunotherapeutic approaches in development. Relevant literature and clinical studies were identified by searching PubMed and www.ClinicalTrials.gov.

EXPERT OPINION

: While therapies targeting the various molecular subgroups of CCA are rapidly emerging and changing treatment paradigms, their success has been limited by the genetic heterogeneity of CCA and the plasticity of the targets. Novel strategies aiming to combine immunotherapy, chemotherapy, and molecularly-targeted therapeutics will be required to offer durable clinical benefit and maximize survival.

Low prevalence of biliary tract cancer with defective mismatch repair genes in a Japanese hospital-based population

Recent studies have reported that immune checkpoint inhibitors are effective against various defective mismatch repair (dMMR)/microsatellite instability-high (MSI-H) cancers. A limited number of reports are available on the frequency of dMMR/MSI-H carcinoma in biliary tract cancer (BTC), describing its clinicopathological characteristics and prognosis. The latter carcinoma is also associated with Lynch syndrome (LS). The present study was performed to investigate the frequency of patients with dMMR/MSI-H in BTC and the clinical characteristics of BTC with dMMR/MSI-H in a single institution in Japan. A total of 116 patients with BTC who underwent curative surgical resection at Kagawa University Hospital between January 2008 and December 2017 were included. The protein expression levels of the mismatch repair (MMR) genes [mutL homolog 1 (MLH1), mismatch repair endonuclease PMS2 (PMS2), MutS homolog (MSH)2 and MSH6] were assessed by immunohistochemistry (IHC) using formalin-fixed paraffin-embedded tissue specimens. Subsequently, MSI testing was performed on patients who exhibited loss of MMR protein expression. Loss of expression of one or more proteins was detected in five cases (4.3%). Loss of MLH1/PMS2 expression was observed in one case of intrahepatic cholangiocarcinoma, whereas loss of PMS2 expression was noted in one case of perihilar cholangiocarcinoma. Loss of MSH2/MSH6 and MSH6 expression was noted in two cases of distal cholangiocarcinoma and loss of PMS2 expression in one case of ampullary carcinoma. Out of the five patients, two demonstrated MSI-H. Microsatellite stability was observed in two cases and for one case, no data were available. Two MSI-H cases were patients with loss of expression of MLH1/PMS2 and MSH2/MSH6. None of the five patients exhibited a past medical history or family history of suspected LS. The frequency of dMMR in BTC was ~5%, which was similar to that reported by similar studies performed in other countries. In the present study, IHC appeared to be more useful than MSI testing for detecting MMR abnormalities with regards to the detection rate. Furthermore, there may only be a limited number of patients with BTCs who are likely to benefit from the therapeutic effects of treatment with immune checkpoint inhibitors.

Successful Treatment of Advanced Intrahepatic Cholangiocarcinoma With a High Tumor Mutational Burden and PD-L1 Expression by PD-1 Blockade Combined With Tyrosine Kinase Inhibitors: A Case Report

Advanced intrahepatic cholangiocarcinoma (iCCA) is not suitable for surgical treatment. Guided by the concept of precision medicine, preoperative systematic treatment may reshape the clinical outcomes of advanced intrahepatic cholangiocarcinoma patients. We describe the case of a 38-year-old female who has been diagnosed with stage IV intrahepatic cholangiocarcinoma with a high tumor mutational burden and positively programmed death-ligand 1 (PD-L1) expression. The patient was treated with programmed cell death 1 (PD-1) inhibitors combined with tyrosine kinase inhibitors (TKIs). After 7 cycles of combination therapy, she underwent radical resection and no tumor cells were found in the postoperative histopathological examination. In addition, the patient’s survival time had reached 25 months, as of August 2021. To date, this is the first case of successful radical resection after combined immunotherapy with TKIs for advanced PD-L1-positive intrahepatic cholangiocarcinoma with a high tumor mutational burden (TMB). The case provides a new approach to the treatment of advanced intrahepatic cholangiocarcinoma.

An Assessment of Combination of the Camrelizumab With Chemotherapy in Metastatic Biliary Tract Cancers

BACKGROUND

Monoclonal antibodies that target the PD-1 receptor are emerging as promising therapeutic candidates for the treatment of biliary tract cancers (BTCs). The purpose of the current study was to assess the combination of the camrelizumab with chemotherapy as a first-line treatment for metastatic BTCs.

METHODS

We conducted a prospective single-arm pilot study of PD-1 antibody (camrelizumab 3 mg/kg d1, Q2 W or Q3 W) combined with different chemotherapy regimens as first-line treatment for BTCs. Efficacy endpoints were objective response rate (ORR), disease control rate (DCR), progression free survival (PFS), and overall survival (OS). Treatment-related adverse events (TRAEs) were also evaluated.

RESULTS

Fourteen patients with histologically confirmed BTCs were evaluated. The ORR was 14.3% (95% CI: 1.8 to 42.8) and the DCR was 64.3% (95%CI: 41.7 to 86.9). The median PFS was 6.5 months (95% CI: 3.8 to 9.2), and the 6- and 12-month PFS rates were 61.6% and 12.3%, respectively. The median OS was 9.9 months (95% CI: 7.6 to 12.2), and the 6-and 12-month OS rates were 74.5% and 26.6%, respectively. All patients displayed at least 1 TRAE., and Grade 3 or 4 TRAEs occurred in 6 (42.86%) patients.

CONCLUSIONS

Camrelizumab combined with chemotherapy as first-line treatment for metastatic BTCs demonstrated acceptable safety and efficacy in our pilot study. These findings warrant prospective controlled clinical trials comparing combinations of camrelizumab and chemotherapy to standard regimens.

The Emerging Role of Immunotherapy in Intrahepatic Cholangiocarcinoma

Biliary tract cancer, and intrahepatic cholangiocarcinoma (iCC) in particular, represents a rather uncommon, highly aggressive malignancy with unfavorable prognosis. Therapeutic options remain scarce, with platinum-based chemotherapy is being considered as the gold standard for the management of advanced disease. Comprehensive molecular profiling of tumor tissue biopsies, utilizing multi-omics approaches, enabled the identification of iCC’s intratumor heterogeneity and paved the way for the introduction of novel targeted therapies under the scope of precision medicine. Yet, the unmet need for optimal care of patients with chemo-refractory disease or without targetable mutations still exists. Immunotherapy has provided a paradigm shift in cancer care over the past decade. Currently, immunotherapeutic strategies for the management of iCC are under intense research. Intrinsic factors of the tumor, including programmed death-ligand 1 (PD-L1) expression and mismatch repair (MMR) status, are simply the tip of the proverbial iceberg with regard to resistance to immunotherapy. Acknowledging the significance of the tumor microenvironment (TME) in both cancer growth and drug response, we broadly discuss about its diverse immune components. We further review the emerging role of immunotherapy in this rare disease, summarizing the results of completed and ongoing phase I–III clinical trials, expounding current challenges and future directions.

Durable response after discontinuation of pembrolizumab therapy for intrahepatic cholangiocarcinoma: a case report

Although it has recently been reported that immune checkpoint inhibitors (ICIs) constitute effective treatment for solid tumors, the success rate in patients with intrahepatic cholangiocarcinoma is limited. We administered pembrolizumab to a patient as treatment for liver and lymph node metastases of intrahepatic cholangiocarcinoma. The patient had abundant infiltration of programmed death ligand 1-positive macrophages, cytotoxic T cells (CD8-positive lymphocytes), and programmed death 1-positive lymphocytes as well as a high combined positive score of 33.1, high-frequency microsatellite instability, and mismatch repair deficiency. These characteristics are predictive biomarkers of the efficacy of ICIs. After pembrolizumab was administered four times (triweekly administration), the carbohydrate antigen 19-9 serum level fell within the normal range, and computed tomography revealed that the size of the metastatic liver tumors and enlarged hilar lymph node had markedly decreased. However, the patient developed pruritus and exanthema on the trunk and limbs after 14 administrations and was diagnosed with bullous pemphigoid. We discontinued pembrolizumab therapy and started treatment for bullous pemphigoid. Nine months after discontinuation of pembrolizumab therapy, the patient remains alive without tumor relapse. This patient had durable response even after discontinuation of pembrolizumab therapy for multiple metastases of intrahepatic cholangiocarcinoma.

Current and New Biomarkers for Early Detection, Prognostic Stratification, and Management of Gallbladder Cancer Patients

Gallbladder cancer (GBC) is an aggressive disease that shows evident geographic variation and is characterized by a poor prognosis, mainly due to the late diagnosis and ineffective treatment. Genetic variants associated with GBC susceptibility, including polymorphisms within the toll-like receptors TLR2 and TLR4, the cytochrome P450 1A1 (CYP1A1), and the ATP-binding cassette (ABC) transporter ABCG8 genes, represent promising biomarkers for the stratification of patients at higher risk of GBC; thus, showing potential to prioritize cholecystectomy, particularly considering that early diagnosis is difficult due to the absence of specific signs and symptoms. Similarly, our better understanding of the gallbladder carcinogenic processes has led to identify several cellular and molecular events that may influence patient management, including HER2 aberrations, high tumor mutational burden, microsatellite instability, among others. Despite these reports on interesting and promising markers for risk assessment, diagnosis, and prognosis; there is an unmet need for reliable and validated biomarkers that can improve the management of GBC patients and support clinical decision-making. This review article examines the most potentially significant biomarkers of susceptibility, diagnosis, prognosis, and therapy selection for GBC patients, highlighting the need to find and validate existing and new molecular biomarkers to improve patient outcomes.

Camrelizumab plus gemcitabine and oxaliplatin (GEMOX) in patients with advanced biliary tract cancer: a single-arm, open-label, phase II trial

Background

Immune checkpoint inhibitors monotherapy has been studied in patients with advanced biliary tract cancer (BTC). The aim of this study was to assess the efficacy and safety of camrelizumab, plus gemcitabine and oxaliplatin (GEMOX) as first-line treatment in advanced BTC and explored the potential biomarkers associated with response.

Methods

In this single-arm, open-label, phase II study, we enrolled stage IV BTC patients. Participants received camrelizumab (3 mg/kg) plus gemcitabine (800 mg/m²) and oxaliplatin (85 mg/m²). Primary endpoints were 6-month progression-free survival (PFS) rate and safety. Secondary endpoints were objective response rate (ORR), PFS and overall survival (OS). Exploratory endpoints included association between response and tumor mutational burden (TMB), blood TMB, dynamic change of ctDNA and immune microenvironment.

Results

54 patients with advanced BTC were screened, of whom 38 eligible patients were enrolled. One patient withdrew informed consent before first dose treatment. Median follow-up was 11.8 months. The 6-month PFS rate was 50% (95% CI 33 to 65). Twenty (54%) out of 37 patients had an objective response. The median PFS was 6.1 months and median OS was 11.8 months. The most common treatment-related adverse events (TRAEs) were fatigue (27 (73%)) and fever (27 (73%)). The most frequent grade 3 or worse TRAEs were hypokalemia (7 (19%)) and fatigue (6 (16%)). The ORR was 80% in patients with programmed cell death ligand-1 (PD-L1) tumor proportion score (TPS) ≥1% versus 53.8% in PD-L1 TPS <1%. There was no association between response and TMB, blood TMB, immune proportion score or immune cells (p>0.05), except that PFS was associated with blood TMB. Patients with positive post-treatment ctDNA had shorter PFS (p=0.007; HR, 2.83; 95% CI 1.27 to 6.28).

Conclusion

Camrelizumab plus GEMOX showed a promising antitumor activity and acceptable safety profile as first-line treatment in advanced BTC patients. Potential biomarkers are needed to identify patients who might respond to camrelizumab plus GEMOX.

Trial registration number

NCT03486678.

FIGHT-302: first-line pemigatinib vs gemcitabine plus cisplatin for advanced cholangiocarcinoma with FGFR2 rearrangements

FGFR2 rearrangements resulting in dysregulated signaling are drivers of cholangiocarcinoma (CCA) tumorigenesis, and occur almost exclusively in intrahepatic CCA. Pemigatinib, a selective, potent, oral inhibitor of FGFR1-3, has demonstrated efficacy and safety in a Phase II study of patients with previously treated locally advanced/metastatic CCA harboring FGFR2 fusions/rearrangements. We describe the study design of FIGHT-302, an open-label, randomized, active-controlled, multicenter, global, Phase III study comparing the efficacy and safety of first-line pemigatinib versus gemcitabine plus cisplatin in patients with advanced CCA with FGFR2 rearrangements (NCT03656536). The primary end point is progression-free survival; secondary end points are objective response rate, overall survival, duration of response, disease control rate, safety and quality of life. Clinical Trial Registration: NCT03656536 (ClinicalTrials.gov).

Microsatellite Instability-high Intrahepatic Cholangiocarcinoma with Portal Vein Tumor Thrombosis Successfully Treated with Pembrolizumab

A 60-year-old man presented with postoperative recurrence of intrahepatic cholangiocarcinoma with right portal vein tumor thrombosis (PVTT). After failure of standard chemotherapy, a liver biopsy showed that his microsatellite instability (MSI) status was high. Treatment with the immune checkpoint inhibitor (ICI) pembrolizumab was commenced, which resulted in a partial response and resolution of the PVTT. There were no significant immune-related adverse events. According to recently published reports, the frequency of MSI-high biliary tract cancer (BTC) is about 0-2.1%, which is extremely rare. However, ICIs may be effective in patients with MSI-high BTC, such as the present patient.

Current status of treatment with immune checkpoint inhibitors for gastrointestinal, hepatobiliary, and pancreatic cancers

The development of immune checkpoint inhibitors (ICIs) targeting cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), or programmed cell death protein ligand 1 (PD-L1) has revolutionized the treatment strategy in various types of cancers. In addition, recent studies have revealed that tumor microsatellite instability (MSI) status and tumor mutation burden (TMB) contribute significantly to the therapeutic response to anti-PD-1 monoclonal antibody (mAb), which led to an accelerated approval to pembrolizumab for the treatment of MSI-high or mismatch-repair-deficient solid tumors after conventional chemotherapies in 2017 and for the treatment of TMB-high solid tumors in 2020 by the United States Food and Drug Administration (FDA). In the field of gastrointestinal cancers, many clinical trials evaluating the safety and efficacy of various regimens such as ICI monotherapy, the combination of anti-CTLA-4 mAb and anti-PD-1/PD-L1 mAb, and combination of ICI and conventional chemotherapy or tyrosine kinase inhibitor have been reported or are in progress. This review summarizes MSI status and TMB in gastrointestinal, hepatobiliary, and pancreatic cancers, and provides the results of most relevant clinical trials evaluating ICIs. We also discuss the development of biomarkers required for improving the selection of patients with a high probability of benefiting from treatment with ICIs, and potential therapeutic strategies that could help to enhance anticancer responses of ICIs.

Efficacy and Safety of Pembrolizumab for Gemcitabine/Cisplatin-Refractory Biliary Tract Cancer: A Multicenter Retrospective Study

Pembrolizumab, an anti-programmed cell death (PD)-1 monoclonal antibody, is an anticancer agent showing substantial benefit in lung cancer and melanoma treatment. Biliary tract cancer (BTC) has been shown to respond to pembrolizumab; however, no credible data of such treatment outcomes exist. Therefore, we assessed the clinical outcomes and safety of pembrolizumab in patients with gemcitabine/cisplatin-refractory BTC. In this multicenter study, we retrospectively analyzed 51 patients with programmed cell death 1-ligand 1 (PD-L1)-positive gemcitabine/cisplatin-refractory BTC treated with pembrolizumab in four tertiary hospitals in Korea. PD-L1 positivity was defined as the expression of PD-L1 in ≥1% of tumor cells based on immunohistochemical staining (22C3, SP263, and E1L3N assays). The median age of the patients was 66 (range, 43–83) years and 29 (56.9%) were male. Extrahepatic cholangiocarcinoma was the most common cancer type (n = 30, 58.8%). Partial response and stable disease were achieved in 5 (9.8%) and 13 (25.5%) patients, respectively. Median progression-free survival and overall survival were 2.1 (95% CI, 1.7–2.4) and 6.9 (95% CI, 5.4–8.3) months, respectively. Overall, 30 (58.8%) patients experienced treatment-related adverse events (AEs). Only four (7.8%) patients experienced grades 3 and 4 AEs. In PD-L1-positive gemcitabine/cisplatin-refractory BTC, pembrolizumab presented durable efficacy, with a 9.8% response rate and manageable toxicity.

Broadening the therapeutic horizon of advanced biliary tract cancer through molecular characterisation

Biliary tract cancers (BTC) comprise a group of rare and heterogeneous poor-prognosis tumours with the incidence of intrahepatic cholangiocarcinoma increasing over recent years. Combination chemotherapy with gemcitabine and cisplatin is the established first-line treatment for advanced BTC with a significant but modest survival advantage over monotherapy. There remains no accepted standard treatment in the second-line setting, although recent results from a randomised study have shown a survival benefit with 5-fluorouracil and oxaliplatin chemotherapy. Historically, clinical trials investigating targeted therapies in unselected BTC have failed to demonstrate significant clinical benefit. More recently, advancement in molecular exploration of BTC has shed light on the complex biological heterogeneity within these tumours and has also identified actionable genomic aberrations, such as fibroblast growth factor receptor 2 (FGFR2) gene fusions, isocitrate dehydrogenase (IDH) and BRAF mutations, which offer promise with the anticipation of increased responses and durable clinical benefit in selected patients. Several targeted drugs have now entered clinical development with some encouraging results being seen. Here we review the current and rapidly evolving therapeutic landscape of advanced BTC, including targeted therapies and immunotherapy. We also discuss how recent efforts and successes in BTC are overcoming the obstacles typically associated with precision medicine in rare cancers. Ultimately, the management of advanced BTC is likely to become molecularly selected in the near future with the hope of finally improving the bleak prognosis of patients with this disease.

A metastatic intrahepatic cholangiocarcinoma treated with programmed cell death 1 inhibitor: a case report and literature review

Intrahepatic cholangiocarcinoma is a disease with grave prognosis due to limited therapeutic regimens. Programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitor have shown dramatic clinical effectiveness in multiple solid tumors. Here, we report the case that a patient with metastasis intrahepatic cholangiocarcinoma, being failure of first-line chemotherapy, was enrolled into the Phase I study of a PD-1 inhibitor, sintilimab. The patient achieved complete remission after three cycles of treatment with mild adverse reaction. In addition, the tumor mutational burden and the microsatellite instability status were low in the present case. Hence, PD-1 inhibitor might be a promising therapeutic approach for patients with advanced cholangiocarcinoma.

Phase I study of bintrafusp alfa, a bifunctional fusion protein targeting TGF-β and PD-L1, in patients with pretreated biliary tract cancer

BACKGROUND

Patients with biliary tract cancer (BTC) have poor prognosis with few treatment options. Bintrafusp alfa, a first-in-class bifunctional fusion protein composed of the extracellular domain of the transforming growth factor (TGF)-βRII receptor (a TGF-β 'trap') fused to a human IgG1 antibody blocking programmed death ligand 1 (PD-L1), has shown clinical efficacy in multiple solid tumors.

METHODS

In this phase I, open-label trial expansion cohort, Asian patients with BTC whose disease progressed after first-line chemotherapy received bintrafusp alfa 1200 mg every 2 weeks until disease progression, unacceptable toxicity, or withdrawal. The primary endpoint is safety/tolerability, while the secondary endpoints include best overall response per Response Evaluation Criteria in Solid Tumors version 1.1.

RESULTS

As of August 24, 2018, 30 patients have received bintrafusp alfa for a median of 8.9 (IQR 5.7-32.1) weeks; 3 patients remained on treatment for >59.7 weeks. Nineteen (63%) patients experienced treatment-related adverse events (TRAEs), most commonly rash (17%), maculopapular rash and fever (13% each), and increased lipase (10%). Eleven (37%) patients had grade ≥3 TRAEs; three patients had grade 5 events (septic shock due to bacteremia, n=1; interstitial lung disease (reported term: interstitial pneumonitis), n=2). The objective response rate was 20% (95% CI 8 to 39) per independent review committee (IRC), with five of six responses ongoing (12.5+ to 14.5+ months) at data cut-off. Two additional patients with durable stable disease had a partial response per investigator. Median progression-free survival assessed by IRC and overall survival were 2.5 months (95% CI 1.3 to 5.6) and 12.7 months (95% CI 6.7 to 15.7), respectively. Clinical activity was observed irrespective of PD-L1 expression and microsatellite instability-high status.

CONCLUSIONS

Bintrafusp alfa had clinical activity in Asian patients with pretreated BTC, with durable responses. Based on these results, bintrafusp alfa is under further investigation in patients with BTC (NCT03833661 and NCT04066491).

TRIAL REGISTRATION NUMBER

NCT02699515.

[Personalized treatment of cholangiocellular carcinoma (CCA)]

Cholangiocellular carcinoma (CCA) is one of the primary liver tumors and overall represents a rare malignancy; however, in recent years the incidence, particularly of intrahepatic CCA (iCCA) has increased worldwide. Due to the high mortality, CCAs cause a significant proportion of cancer-related deaths also in Germany. Because the diagnosis is often made in advanced stages of the disease, in many cases a surgical approach with curative intention is not possible. For locally advanced or metastatic CCA the combination of gemcitabine and cisplatin currently remains the only approved systemic treatment. As the average survival time is only approximately 12 months even under first-line treatment with gemcitabine/cisplatin, research is focused on developing new molecularly targeted and immunological treatment options. Various studies are currently being carried out to investigate approval options for targeted treatment, which could be considered for genetically altered tumors, e.g. in fibroblast growth factor receptor (FGFR) fusion and isocitrate dehydrogenase (IDH) mutations. Additionally, initial clinical data on immune checkpoint inhibitors are available for CCA. Due to the complex selection and partially limited applicability of current treatment options in patients with CCA, an early collaboration with a gastroenterology and oncology center with the possibility of supervision by a tumor board consisting of gastroenterological oncologists, surgeons, radiologists and radio-oncologists or in advanced stages by a molecular tumor board is essential.

Microsatellite instability and immune checkpoint inhibitors: toward precision medicine against gastrointestinal and hepatobiliary cancers

Recent innovations in the next-generation sequencing technologies have unveiled that the accumulation of genetic alterations results in the transformation of normal cells into cancer cells. Accurate and timely repair of DNA is, therefore, essential for maintaining genetic stability. Among various DNA repair pathways, the mismatch repair (MMR) pathway plays a pivotal role. MMR deficiency leads to a molecular feature of microsatellite instability (MSI) and predisposes to cancer. Recent studies revealed that MSI-high (MSI-H) or mismatch repair-deficient (dMMR) tumors, regardless of their primary site, have a promising response to immune checkpoint inhibitors (ICIs), leading to the approval of the anti-programmed cell death protein 1 monoclonal antibody pembrolizumab for the treatment of advanced or recurrent MSI-H/dMMR solid tumors that continue to progress after conventional chemotherapies. This new indication marks a paradigm shift in the therapeutic strategy of cancers; however, when considering the optimum indication for ICIs and their safe and effective usage, it is important for clinicians to understand the genetic and immunologic features of each tumor. In this review, we describe the molecular basis of the MMR pathway, diagnostics of MSI status, and the clinical importance of MSI status and the tumor mutation burden in developing therapeutic strategies against gastrointestinal and hepatobiliary malignancies.

Immune Therapy for Liver Cancers

Hepatocellular carcinoma (HCC) and biliary tract cancers (BTC) display a poor prognosis with 5-year overall survival rates around 15%, all stages taken together. These primary liver malignancies are often diagnosed at advanced stages where therapeutic options are limited. Recently, immune therapy has opened new opportunities in oncology. Based on their high programmed death-ligand 1 expression and tumor-infiltrating lymphocytes, HCC and BTC are theoretically good candidates for immune checkpoint blockade. However, clinical activity of single agent immunotherapy appears limited to a subset of patients, which is still ill-defined, and combinations are under investigation. In this review, we provide an overview of (i) the biological rationale for immunotherapies in HCC and BTC, (ii) the current state of their clinical development, and (iii) the predictive value of immune signatures for both clinical outcome and response to these therapies.

Contemporary Tailored Oncology Treatment of Biliary Tract Cancers

Biliary tract cancers (BTCs) are poor prognosis malignancies with limited treatment options. Capecitabine has recently emerged as an effective agent in the adjuvant setting; however, treatment of advanced disease is still limited to first-line cisplatin and gemcitabine chemotherapy. Recent global efforts in genomic profiling and molecular subtyping of BTCs have uncovered a wealth of genomic aberrations which may carry prognostic significance and/or predict response to treatment, and several targeted agents have shown promising results in clinical trials. As such, the uptake of comprehensive genomic profiling for patients with BTCs and the expansion of basket trials to include these patients are growing. This review describes the currently approved systemic therapies for BTCs and provides insight into the emerging targeted and immunotherapeutic agents, as well as conventional chemotherapeutic regimes, currently being investigated in clinical trials.

Pharmacotherapeutic options for biliary tract cancer: current standard of care and new perspectives

Introduction: Biliary tract cancer (BTC), which comprises gallbladder cancer, ampullary cancer, and cholangiocarcinoma, is a rare and heterogeneous entity, with limited approved therapeutic options. However, interest in this disease has grown exponentially in recent years, as a mounting body of evidence has shed light on the complex molecular and microenvironmental background of BTC, and clinical investigations have explored a variety of new agents and combinations, with promising results.Areas covered: This review describes the standard of care in advanced BTC and summarizes the most recent evidence available on the pharmacological treatment of resected and advanced disease, focusing on chemotherapy, targeted therapy, and immunotherapy.Expert opinion: The therapeutic armamentarium of BTC has made radical progress after almost a decade of very few positive results. Phase-III evidence now supports the use of adjuvant capecitabine after resection of localized disease, while investigations into improved regimens in the advanced setting are underway, exploring alternative options to the standard gemcitabine-cisplatin doublet. The first positive phase-III trial supports the use of the mFOLFOX6 regimen as a second-line chemotherapy. Targeted therapy against specific genomic alterations can combine with chemotherapy in specific subsets of patients. Despite recent advancements, conducting clinical trials for BTC is still a real challenge.

Genotyping of circulating tumor DNA in cholangiocarcinoma reveals diagnostic and prognostic information

Diagnosis of Cholangiocarcinoma (CCA) is difficult, thus a noninvasive approach towards (i) assessing and (ii) monitoring the tumor-specific mutational profile is desirable to improve diagnosis and tailor treatment. Tumor tissue and corresponding ctDNA samples were collected from patients with CCA prior to and during chemotherapy and were subjected to deep sequencing of 15 genes frequently mutated in CCA. A set of ctDNA samples was also submitted for 710 gene oncopanel sequencing to identify progression signatures. The blood/tissue concordance was 74% overall and 92% for intrahepatic tumors only. Variant allele frequency (VAF) in ctDNA correlated with tumor load and in the group of intrahepatic CCA with PFS. 63% of therapy naive patients had their mutational profile changed during chemotherapy. A set of 76 potential progression driver genes was identified among 710 candidates. The molecular landscape of CCA is accessible via ctDNA. This could be helpful to facilitate diagnosis and personalize and adapt therapeutic strategies.

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.