Targeted Therapies in Advanced Biliary Tract Cancer: An Evolving Paradigm

Unresectable biliary tract cancer: Current and future systemic therapy

For decades, treatment of advanced biliary tract cancer (BTC) was confined to the use of chemotherapy. In recent years however, the number of therapeutic options available for patients with unresectable BTC have drastically increased, with immunotherapy and targeted treatment gradually joining the ranks of guideline-recommended treatment regimens. The aim of the present review is to summarise the current knowledge on unresectable BTC focusing on epidemiology, anatomical distribution and current strategies for systemic treatment. We further outline ongoing clinical trials and provide an outlook on future therapeutic interventions. In the realm of gastrointestinal malignancies, the increasing number of systemic treatment options for BTC is finally delivering on the longstanding commitment to personalised oncology. This emphasises the need for considering a comprehensive genomic-based pathology assessment right from the initial diagnosis to fully leverage the expanding array of therapeutic options that have recently become accessible.

KRAS Allelic Variants in Biliary Tract Cancers

Importance

Biliary tract cancers (BTCs) contain several actionable molecular alterations, including FGFR2, IDH1, ERBB2 (formerly HER2), and KRAS. KRAS allelic variants are found in 20% to 30% of BTCs, and multiple KRAS inhibitors are currently under clinical investigation.

Objectives

To describe the genomic landscape, co-sequence variations, immunophenotype, genomic ancestry, and survival outcomes of KRAS-mutated BTCs and to calculate the median overall survival (mOS) for the most common allelic variants.

Design, Setting, and Participants

This retrospective, multicenter, pooled cohort study obtained clinical and next-generation sequencing data from multiple databases between January 1, 2017, and December 31, 2022. These databases included Princess Margaret Cancer Centre, MD Anderson Cancer Center, Foundation Medicine, American Association for Cancer Research Project GENIE, and cBioPortal for Cancer Genomics. The cohort comprised patients with BTCs who underwent genomic testing.

Main Outcome and Measure

The main outcome was mOS, defined as date of diagnosis to date of death, which was measured in months.

Results

A total of 7457 patients (n = 3773 males [50.6%]; mean [SD] age, 63 [5] years) with BTCs and genomic testing were included. Of these patients, 5813 had clinical outcome data available, in whom 1000 KRAS-mutated BTCs were identified. KRAS allelic variants were highly prevalent in perihilar cholangiocarcinoma (28.6%) and extrahepatic cholangiocarcinoma (36.1%). Thirty-six KRAS allelic variants were identified, and the prevalence rates in descending order were G12D (41%), G12V (23%), and Q61H (8%). The variant G12D had the highest mOS of 25.1 (95% CI, 22.0-33.0) months compared with 22.8 (95% CI, 19.6-31.4) months for Q61H and 17.8 (95% CI, 16.3-23.1) months for G12V variants. The majority of KRAS-mutated BTCs (98.9%) were not microsatellite instability-high and had low tumor mutational burden (ranging from a median [IQR] of 1.2 (1.2-2.5) to a mean [SD] of 3.3 [1.3]). Immune profiling through RNA sequencing of KRAS and NRAS-mutated samples showed a pattern toward a more immune-inflamed microenvironment with higher M1 macrophage activation (0.16 vs 0.12; P = .047) and interferon-γ expression compared with wild-type tumors. The G12D variant remained the most common KRAS allelic variant in all patient ancestries. Patients with admixed American ancestry had the highest proportion of G12D variant (45.0%).

Conclusions and Relevance

This cohort study found that KRAS allelic variants were relatively common and may be potentially actionable genomic alterations in patients with BTCs, especially perihilar cholangiocarcinoma and extrahepatic cholangiocarcinoma. The findings add to the growing data on genomic and immune landscapes of KRAS allelic variants in BTCs and are potentially of value to the planning of specific therapies for this heterogeneous patient group.

Intrahepatic cholangiocarcinoma biomarkers: Towards early detection and personalized pharmacological treatments

Cholangiocarcinoma (CCA) is a rare malignancy originating from the biliary tree and is anatomically categorized as intrahepatic (iCCA), perihilar, and extrahepatic or distal. iCCA, the second most prevalent hepatobiliary cancer following hepatocellular carcinoma (HCC), constitutes 5-20 % of all liver malignancies, with an increasing incidence. The challenging nature of iCCA, combined with nonspecific symptoms, often leads to late diagnoses, resulting in unfavorable outcomes. The advanced phase of this neoplasm is difficult to treat with dismal results. Early diagnosis could significantly reduce mortality attributed to iCCA but remains an elusive goal. The identification of biomarkers specific to iCCA and their translation into clinical practice could facilitate diagnosis, monitor therapy response, and potentially reveal novel interventions and personalized medicine. In this review, we present the current landscape of biomarkers in each of these contexts. In addition to CA19.9, a widely recognized biomarker for iCCA, others such as A1BG, CYFRA 21-1, FAM19A5, MMP-7, RBAK, SSP411, TuM2-PK, WFA, etc., as well as circulating tumor DNA, RNA, cells, and exosomes, are under investigation. Advancing our knowledge and monitoring of biomarkers may enable us to improve diagnosis, prognostication, and apply treatments dynamically and in a more personalized manner.

Molecular Profile of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a relatively uncommon but highly aggressive primary liver cancer that originates within the liver. The aim of this study is to review the molecular profile of intrahepatic cholangiocarcinoma and its implications for prognostication and decision-making. This comprehensive characterization of ICC tumors sheds light on the disease's underlying biology and offers a foundation for more personalized treatment strategies. This is a narrative review of the prognostic and therapeutic role of the molecular profile of ICC. Knowing the molecular profile of tumors helps determine prognosis and support certain target therapies. The molecular panel in ICC helps to select patients for specific therapies, predict treatment responses, and monitor treatment responses. Precision medicine in ICC can promote improvement in prognosis and reduce unnecessary toxicity and might have a significant role in the management of ICC in the following years. The main mutations in ICC are in tumor protein p53 (TP53), Kirsten rat sarcoma virus (KRAS), isocitrate dehydrogenase 1 (IDH1), and AT-rich interactive domain-containing protein 1A (ARID1A). The rate of mutations varies significantly for each population. Targeting TP53 and KRAS is challenging due to the natural characteristics of these genes. Different stages of clinical studies have shown encouraging results with inhibitors of mutated IDH1 and target therapy for ARID1A downstream effectors. Fibroblast growth factor receptor 2 (FGFR2) fusions are an important target in patients with ICC. Immune checkpoint blockade can be applied to a small percentage of ICC patients. Molecular profiling in ICC represents a groundbreaking approach to understanding and managing this complex liver cancer. As our comprehension of ICC's molecular intricacies continues to expand, so does the potential for offering patients more precise and effective treatments. The integration of molecular profiling into clinical practice signifies the dawn of a new era in ICC care, emphasizing personalized medicine in the ongoing battle against this malignancy.

Tucatinib and Trastuzumab for Previously Treated Human Epidermal Growth Factor Receptor 2-Positive Metastatic Biliary Tract Cancer (SGNTUC-019): A Phase II Basket Study

PURPOSE

To evaluate the efficacy and safety of tucatinib and trastuzumab in patients with previously treated human epidermal growth factor receptor 2-positive (HER2+) metastatic biliary tract cancer (mBTC).

METHODS

SGNTUC-019 (ClinicalTrials.gov identifier: NCT04579380) is an open-label phase II basket study evaluating the efficacy and safety of tucatinib and trastuzumab in patients with HER2-altered solid tumors. In the biliary tract cancer cohort, patients had previously treated HER2 overexpressing or amplified (HER2+) tumors (identified with local testing) with no prior HER2-directed therapy. The primary end point was confirmed objective response rate (cORR) per investigator assessment. Patients were treated on a 21-day cycle with tucatinib (300 mg orally twice daily) and trastuzumab (8 mg/kg intravenously followed by 6 mg/kg every 3 weeks).

RESULTS

Thirty patients were enrolled. As of data cutoff (January 30, 2023), the median duration of follow-up was 10.8 months. The cORR was 46.7% (90% CI, 30.8 to 63.0), with a disease control rate of 76.7% (90% CI, 60.6 to 88.5). The median duration of response and progression-free survival were 6.0 months (90% CI, 5.5 to 6.9) and 5.5 months (90% CI, 3.9 to 8.1), respectively. At data cutoff, 15 patients (50.0%) had died, and the estimated 12-month overall survival rate was 53.6% (90% CI, 36.8 to 67.8). The two most common treatment-emergent adverse events (TEAEs) were pyrexia (43.3%) and diarrhea (40.0%). Grade ≥3 TEAEs were reported in 18 patients (60.0%), with the most common being cholangitis, decreased appetite, and nausea (all 10.0%), which were generally not treatment related. TEAEs led to treatment regimen discontinuation in one patient, and there were no deaths due to TEAEs.

CONCLUSION

Tucatinib combined with trastuzumab had clinically significant antitumor activity and was well tolerated in patients with previously treated HER2+ mBTC.

Case Report: A novel mixture of dose-fractioned radiation and immunotherapy for treatment of cholangiocarcinoma

Malignant tumors of the biliary tract exhibit a high degree of malignancy and heterogeneity with a poor overall prognosis. Immunotherapy has limited benefits for patients with cholangiocarcinoma. Radiation therapy can change the tumor microenvironment, but its effect heavily depends on radiation dose and fraction. We report a case of advanced intrahepatic cholangiocarcinoma in a 43-year-old male patient, with a huge liver mass of 16.5 cm in diameter, with bone and liver metastases at the first diagnosis. First-line treatment with chemotherapy and PD1 inhibitor was sustained only for 8 months. In second-line treatment, radiotherapy was administered, with 5 Gy in 5 fractions administered to the entire tumor area and 25 Gy in 5 fractions to the solid lesions of the tumor. After the completion of radiotherapy, programmed cell death 1 inhibitor combined with tyrosine kinase inhibitor was maintained. The patient achieved a progression-free-survival time of 12 months and an overall survival time of 25 months. The success of our case suggests that mixed low- and high-dose radiation can significantly improve tumor control and survival time. In clinical practice, based on the characteristics of the tumor and existing treatment options, the rational combination of existing treatment regimens can improve the prognosis of cholangiocarcinoma.

Current status and issues in genomic analysis using EUS-FNA/FNB specimens in hepatobiliary-pancreatic cancers

Comprehensive genomic profiling based on next-generation sequencing has recently been used to provide precision medicine for various advanced cancers. Endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA) and EUS-guided fine-needle biopsy (EUS-FNB) play essential roles in the diagnosis of abdominal masses, mainly pancreatic cancers. In recent years, CGP analysis using EUS-FNA/FNB specimens for hepatobiliary-pancreatic cancers has increased; however, the success rate of CGP analysis is not clinically satisfactory, and many issues need to be resolved to improve the success rate of CGP analysis. In this article, we review the transition from EUS-FNA to FNB, compare each test, and discuss the current status and issues in genomic analysis of hepatobiliary-pancreatic cancers using EUS-FNA/FNB specimens.

Targeted Therapies in Advanced Cholangiocarcinoma

Primary tumor resection and liver transplantation are the only curative treatment options for the management of cholangiocarcinoma (CCA). However, for patients with advanced or metastatic disease, palliative systemic therapy remains the only treatment option. The development of targeted therapeutics has begun to shift the treatment paradigm in CCA. Targets of interest in CCA include mutated isocitrate dehydrogenase-1 (mIDH-1), human epidermal growth factor receptor 2 (HER2) overexpression/amplification, and fibroblast growth factor receptor 2 (FGFR2) fusion, in addition to less frequently observed targets such as BRAF V600E, deficient mismatch repair/high microsatellite instability (dMMR/MSI-H), and high tumor mutation burden (TMB-H). These targets are observed in varying frequency among patients with intrahepatic CCA and extrahepatic CCA. Multiple novel therapies have been developed to exploit each of these targets, with some having received United States Food and Drug Administration approval for use in the second-line setting. In the current review, we discuss targets of interest in CCA and summarize current evidence evaluating available therapies directed at these targets.

Phase 2 trial of bintrafusp alfa as second-line therapy for patients with locally advanced/metastatic biliary tract cancers

BACKGROUND AND AIMS

Biliary tract cancers are rare, heterogeneous cancers with poor prognoses. Bintrafusp alfa, a first-in-class bifunctional fusion protein composed of the extracellular domain of TGF-βRII (a TGF-β "trap") fused to a human IgG1 monoclonal antibody blocking programmed death ligand 1, was evaluated in patients with locally advanced/metastatic chemorefractory biliary tract cancers.

APPROACH AND RESULTS

This multicenter, single-arm, open-label, phase 2 study (NCT03833661) enrolled adults with locally advanced or metastatic biliary tract cancer that was intolerant to or had failed first-line systemic platinum-based chemotherapy. Patients received 1200 mg bintrafusp alfa intravenously Q2W. The primary endpoint was confirmed objective response according to Response Evaluation Criteria in Solid Tumors 1.1 assessed by IRC. Secondary endpoints included duration of response, durable response rate, safety, progression-free survival, and overall survival.Between March 2019 and January 2020, 159 patients were enrolled. Median follow-up was 16.1 (range, 0.0-19.3) months; 17 patients (10.7%; 95% CI: 6.4%-16.6%) achieved an objective response. Median duration of response was 10.0 (range, 1.9-15.7) months; 10 patients (6.3%; 95% CI: 3.1%-11.3%) had a durable response (≥6 mo). Median progression-free survival was 1.8 months (95% CI: 1.7-1.8 mo); median overall survival was 7.6 months (95% CI: 5.8-9.7 mo). Overall survival rates were 57.9% (6 mo) and 38.8% (12 mo). Grade ≥3 adverse events occurred in 26.4% of patients, including one treatment-related death (hepatic failure). Frequent grade ≥3 adverse events included anemia (3.8%), pruritus (1.9%), and increased alanine aminotransferase (1.9%).

CONCLUSIONS

Although this study did not meet its prespecified primary endpoint, bintrafusp alfa demonstrated clinical activity as second-line treatment in this hard-to-treat cancer, with durable responses and a manageable safety profile.

Paradigm shift of chemotherapy and systemic treatment for biliary tract cancer

Biliary tract cancers (BTC) are frequently identified at late stages and have a poor prognosis due to limited systemic treatment regimens. For more than a decade, the combination of gemcitabine and cis-platin has served as the first-line standard treatment. There are few choices for second-line chemo-therapy. Targeted treatment with fibroblast growth factor receptor 2 inhibitors, neurotrophic tyrosine receptor kinase inhibitors, and isocitrate dehydrogenase 1 inhibitors has had important results. Immune checkpoint inhibitors (ICI) such as pembrolizumab are only used in first-line treatment for microsatellite instability high patients. The TOPAZ-1 trial's outcome is encouraging, and there are several trials underway that might soon put targeted treatment and ICI combos into first-line options. Newer targets and agents for existing goals are being studied, which may represent a paradigm shift in BTC management. Due to a scarcity of targetable mutations and the higher toxicity profile of the current medications, the new category of drugs may occupy a significant role in BTC therapies.

The Role of HER2 Status in the Biliary Tract Cancers

Despite recent advances, biliary tract cancer (BTC) is traditionally known as being hard to treat with a poor prognosis. Recent state-of-the-art genomic technologies such as next-generation sequencing (NGS) revolutionized cancer management and shed light on the genomic landscape of BTCs. There are ongoing clinical trials to assess the efficacy of HER2-blocking antibodies or drug conjugates in BTCs with HER2 amplifications. However, HER2 amplifications may not be the sole eligibility factor for these clinical trials. In this review, we aimed to comprehensively examine the role of somatic HER2 alterations and amplifications in patient stratification and provide an overview of the current state of ongoing clinical trials.

A phase 1/2a safety, pharmacokinetics, and efficacy study of the novel nucleoside analog FF-10502-01 for the treatment of advanced solid tumors

BACKGROUND

The nucleoside FF-10502-01, structurally similar to but with different biologic effects than gemcitabine, shows promising activity both alone and combined with cisplatin in preclinical gemcitabine-resistant tumor models. We conducted an open-label, single-arm, 3 + 3 first-in-human trial to explore the safety, tolerability, and antitumor activity of FF-10502-01 in patients with solid tumors.

METHODS

Patients with inoperable metastatic tumors refractory to standard therapies were enrolled. Escalating intravenous FF-10502-01 doses (8-135 mg/m² ) were administered weekly for 3 weeks in 28-day cycles until progressive disease or unacceptable toxicity was observed. Three expansion cohorts were subsequently evaluated.

RESULTS

A phase 2 dose of 90 mg/m² was determined after evaluating 40 patients. Dose-limiting toxicities included hypotension and nausea. Phase 2a enrolled patients with cholangiocarcinoma (36), gallbladder cancer (10), and pancreatic/other tumors (20). Common adverse events were grade 1-2 rash, pruritus, fever, and fatigue. Grade 3 or 4 hematologic toxicities were observed at low incidences, including thrombocytopenia (5.1%) and neutropenia (2%). Confirmed partial responses (PRs) occurred in five patients with gemcitabine-refractory tumors, including three with cholangiocarcinoma and one each with gallbladder and urothelial cancer. Median progression-free and overall survival rates in patients with cholangiocarcinoma were 24.7 and 39.1 weeks, respectively. Prolonged progression-free survival in patients with cholangiocarcinoma was associated with BAP1 and PBRM1 mutations.

CONCLUSION

FF-10502-01 was well tolerated with manageable side effects and limited hematologic toxicity. Durable PRs and disease stabilizations were observed in heavily pretreated biliary tract patients who had received prior gemcitabine. FF-10502-01 is distinct from gemcitabine and may represent an effective therapy.

Developments in FGFR and IDH inhibitors for cholangiocarcinoma therapy

INTRODUCTION

Cholangiocarcinoma (CCA) is an uncommon malignancy originating from epithelial cells of the biliary tract. Regardless of the site of origin within the biliary tree, CCAs are generally aggressive with a poor survival. Surgical resection remains the only chance for cure, yet a majority of patients are not surgical candidates at presentation. Unfortunately, systemic therapies are often ineffective and complicated by side effects. As such, more effective targeted therapies are required in order to improve survival.

AREA COVERED

Genetic analysis of CCA has allowed for a better understanding of the genomic landscape of CCA. Isocitrate dehydrogenase (IDH) and fibroblast growth factor receptor (FGFR) mutations have emerged as the most promising molecular targets for CCA. Inhibitors of IDH and FGFR have proven to have therapeutic benefit with an acceptable safety profile. However, patients often develop resistance rendering the therapy ineffective.

EXPERT OPINION

Understanding the molecular pathways of IDH and FGFR may lead to a better understanding of the mechanisms of resistance. Thus, novel therapies may be developed to improve the efficacy of these therapies. Developing novel biomarkers may improve patient selection and further enhance effectiveness of targeted therapies.

Emerging treatment strategies in hepatobiliary cancer

INTRODUCTION

There have been significant advances in the treatment of hepatobiliary cancers, especially for advanced-stage disease. However, data is limited for optimal therapy selection in the first line and sequencing of available options.

AREAS COVERED

This review covers the systemic treatment of hepatobiliary cancers with an emphasis on the advanced stage. The previously published and ongoing trials will be discussed to create an algorithm for the current practice and to give future perspectives on how the field could go forward.

EXPERT OPINION

While there is no standard-of-care option in the adjuvant treatment of hepatocellular cancer, capecitabine is the standard of care for biliary tract cancer. The efficacy of adjuvant gemcitabine and cisplatin and the added benefit of radiotherapy to chemotherapy are yet to be defined. For the advanced stage, immunotherapy-based combinations became the standard of care for both hepatocellular and biliary tract cancers. The molecularly targeted therapy has profoundly changed the second-line and later treatment for biliary tract cancers, while the optimal second-line treatment for advanced hepatocellular cancer is yet to be defined due to rapid advances in the first-line setting.

Effects of Metformin on Risk and Prognosis of Biliary Tract Cancer: A Systematic Review and Meta-Analysis

Background and Objectives: Metformin has been found to potentially reduce the risk and improve the prognosis of a variety of tumors, but these findings remain controversial in biliary tract cancer (BTC). Therefore, this systematic review and meta-analysis was conducted to investigate the association between metformin and BTC. Materials and Methods: Two independent researchers comprehensively searched PubMed, Embase, the Cochrane Library, and Web of Science for eligible studies published from their inception to 31 March 2022. Comparisons of risk, overall survival (OS), and disease-free survival (DFS) for patients with BTC were selected as the endpoints of interest and pooled by random or fixed-effects models. Results: Eleven studies with a total of 24,788,738 participants were eligible for this analysis. The overall pooled effects showed no significant differences in biliary tract cancer risk (hazard ratio (HR) = 0.82, 95% confidence interval (CI): 0.50-1.35, p = 0.436), OS (HR = 0.88, 95% CI: 0.74-1.04, p = 0.135), or DFS (HR = 1.03, 95% CI: 0.79-1.34, p = 0.829) between metformin users and non-users. When restricting participants to those with diabetes, a similar negative result was found, demonstrating that metformin use was not significantly associated with a lower risk of developing BTC compared with a lack of metformin use (HR = 0.65, 95% CI: 0.39-1.07, p = 0.089); notably, the included studies exhibited significant heterogeneity in the selection of participants and the definition of metformin users. Conclusions: Metformin may not be able to reduce the risk of BTC and improve prognosis in certain populations. Based on the limited quantity and quality of the included studies, the present results should be interpreted within their limitations, and further studies are warranted to determine the optimal timing, dose, duration, and scenario of metformin administration.

Brain Metastases from Biliary Tract Cancer: Case Series and Clinicogenomic Analysis

BACKGROUND

Limited data from small series have suggested that brain metastases from biliary tract cancers (BrM-BTC) affect ≤2% of patients with BTC. We sought to review our experience with patients with BrM-BTC and to identify associations of tumor-related molecular alterations with outcomes.

MATERIALS AND METHODS

A retrospective review of patients with BTC seen at a tertiary referral center from 2005 to 2021 was performed; patients with BrM-BTC were identified, and clinical and molecular data were collected.

RESULTS

Twenty-one of 823 patients with BTC (2.6%) developed BrM. For patients with BrM-BTC, median follow-up time was 27.9 months after primary BTC diagnosis and 3.1 months after BrM diagnosis. Median time from primary diagnosis to diagnosis of BrM was 14.4 [range, 1.1-66.0] months. Median overall survival (OS) from primary diagnosis was 31.5 [2.9-99.8] months and median OS from BrM diagnosis was 4.2 [0.2-33.8] months. Patients who underwent BrM-directed therapy trended toward longer OS following BrM diagnosis than patients receiving supportive care only (median 6.5 vs 0.8 months, P = .060). The BrM-BTC cohort was enriched for BRAF (30%), PIK3CA (25%), and GNAS (20%) mutations. patients with BrM-BTC with BRAF mutations trended toward longer OS following BrM diagnosis (median 13.1 vs 4.2 months, P = .131).

CONCLUSION

This is the largest series of patients with BrM-BTC to date and provides molecular characterization of this rare subgroup of patients with BTC. Patients with BrM-BTC may be more likely to have BRAF mutations. With advances in targeted therapy for patients with BTC with actionable mutations, continued examination of shifting patterns of failure, with emphasis on BrM, is warranted.

The multidisciplinary management of cholangiocarcinoma

Cholangiocarcinoma is a lethal malignancy of the biliary epithelium that can arise anywhere along the biliary tract. Surgical resection confers the greatest likelihood of long-term survivability. However, its insidious onset, difficult diagnostics, and resultant advanced presentation render the majority of patients unresectable, highlighting the importance of early detection with novel biomarkers. Developing liver-directed therapies and emerging targeted therapeutics may offer improved survivability for patients with unresectable or advanced disease. In this article, the authors review the current multidisciplinary standards of care in resectable and unresectable cholangiocarcinoma, with an emphasis on novel biomarkers for early detection and nonsurgical locoregional therapy options.

Pemigatinib in cholangiocarcinoma with a FGFR2 rearrangement or fusion

INTRODUCTION

Cholangiocarcinoma (CCA) accounts for approximately 3% of gastrointestinal malignancies and is associated with a high mortality rate. Recent progress in the understanding of cholangiocarcinoma tumorigenesis and molecular markers has led to the development of several targeted therapies applicable to this disease. Fibroblast growth factor receptor 2 (FGFR2) gene fusion or translocation, resulting in constitutive activation of the FGFR tyrosine kinase, has been identified as a driver of oncogenesis in 10-15% of intrahepatic CCA. Pemigatinib is an FGFR inhibitor that has demonstrated survival benefit in the second line setting for treatment of CCA with FGFR2 fusion or rearrangement refractory to chemotherapy. Pemigatinib was the first targeted therapy to be approved by the FDA for treatment of cholangiocarcinoma.

AREAS COVERED

This article reviews FGFR and its dysregulation in oncogenesis, FGFR inhibitors, especially pemigatinib, utilized in treatment of CCA, common adverse events associated with FGFR inhibitors, and future directions in the field of targeted drug development for CCA.

EXPERT OPINION

FGFR inhibitors, including pemigatinib, have shown promise in the management of CCA with FGFR2 fusion or rearrangement; however, acquired resistance remains a major barrier in the field of FGFR inhibitors and requires further study.

Epidemiologic patterns of biliary tract cancer in the United States: 2001–2015

Background

Biliary tract cancer (BTC) includes intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer (AVC). Although BTC is rare in the US, incidence is increasing and elevated in certain populations. This study examined BTC epidemiology in the US by age, sex, race/ethnicity, geographic region, and anatomic site.

Methods

BTC incidence, prevalence, mortality, and survival from 2001 to 2015 were evaluated using the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program and the Centers for Disease Control and Prevention’s National Program of Cancer Registries databases. Incidence and mortality rates were calculated and reported as age-standardized rates. Data were assessed by age, anatomic sites, geographic region, and race/ethnicity, and a joinpoint regression model was used to predict trends for age-adjusted BTC incidence and mortality rates.

Results

BTC incidence increased during the study period (annual percent change = 1.76, 95% confidence interval [1.59–1.92]), with the highest increase in ICC (6.65 [6.11–7.19]). Incidence of unspecified BTC initially increased but has recently begun to drop. Hispanic, Asian/Pacific Islander, Black, or American Indian/Alaska Native race/ethnicity was associated with higher BTC mortality rates than White race/ethnicity. Patients with ICC had the highest mortality rate (age-standardized rate = 1.87/100,000 person-years [1.85–1.88]). Five-year survival was 15.2% for all BTC, ranging from 8.5% (ICC) to 34.5% (AVC), and patients with distant disease at diagnosis had lower survival (3%) compared with those with regional (19.1%) or locally advanced disease (31.5%).

Conclusions

BTC incidence increased, survival was low across all subtypes, and mortality was greatest in patients with ICC. This underscores the serious, increasing unmet need among patients with BTC. Treatment options are limited, although clinical studies investigating immunotherapy, targeted therapies, and alternative chemotherapy combinations are ongoing. Epidemiological insights may improve patient care and inform the integration of novel therapies for BTC.

Tumor Mutational Burden Is a Potential Predictive Biomarker for Response to Immune Checkpoint Inhibitors in Patients With Advanced Biliary Tract Cancer

PURPOSE

Patients with advanced biliary tract cancers (BTCs) have a dismal prognosis. This multisite, single-institution study analyzed the efficacy and safety of immune checkpoint inhibitors (ICIs) in patients with advanced BTC.

MATERIALS AND METHODS

The prospectively maintained institutional database was searched for patients with advanced BTC. Electronic medical records of the patients with advanced BTC treated with an ICI that included programmed death-1 or programmed death-ligand 1 blockers were retrospectively reviewed to obtain data on patient characteristics, tumor characteristics including molecular biomarkers, detailed treatment, response characteristics, survival, and toxicities. The analysis included overall response rate, survival, and correlation between survival and molecular biomarkers.

RESULTS

The institutional database query identified 47 patients with advanced BTC who received at least one dose of an ICI; 11 (24%) patients in the first-line setting and the rest of the patients had refractory disease. The median age of the cohort was 62 years, and 51% were female. The overall response rate was 10.6%, with a disease control rate of 53.2%. The median progression-free survival (PFS) and overall survival were 3.6 months and 6.9 months, respectively. Biomarker analysis revealed improved PFS in patients with tumor mutational burden > 5 mutations per megabase (median PFS: 6.4 v 2.2 months; P = .0027). No unexpected adverse events were observed.

CONCLUSION

ICIs are well tolerated and have modest antitumor activity in patients with advanced BTC. The study result supports the exploration of tumor mutational burden as a potential predictive biomarker for response to ICIs in patients with advanced BTC.

Systemic Treatment for Metastatic Biliary Tract Cancer: State of the Art and a Glimpse to the Future

Recent years have seen some breakthroughs in the therapeutic landscape of advanced biliary tract cancer (BTC). Firstly, a better understanding of the molecular background of BTC has led to important improvements in the management of these hepatobiliary malignancies, with the advent of targeted agents representing an unprecedented paradigm shift, as witnessed by the FDA approval of pemigatinib and infigratinib for FGFR2-rearranged and ivosidenib in IDH1-mutant cholangiocarcinoma. In addition, several novel treatments are under assessment, including immune checkpoint inhibitors and combination chemotherapies. In the current review, we provide an overview of systemic treatment for metastatic BTC, summarizing recent clinical data on chemotherapy as well as the main results of targeted therapies and immunotherapy.

Immunotherapy for Biliary Tract Cancer in the Era of Precision Medicine: Current Knowledge and Future Perspectives

Biliary tract cancers (BTC) represent a heterogeneous and aggressive group of tumors with dismal prognosis. For a long time, BTC has been considered an orphan disease with very limited therapeutic options. In recent years a better understanding of the complex molecular landscape of biology is rapidly changing the therapeutic armamentarium. However, while 40-50% of patients there are molecular drivers susceptible to target therapy, for the remaining population new therapeutic options represent an unsatisfied clinical need. The role of immunotherapy in the continuum of treatment of patients with BTC is still debated. Despite initial signs of antitumor-activity, single-agent immune checkpoint inhibitors (ICIs) demonstrated limited efficacy in an unselected population. Therefore, identifying the best partner to combine ICIs and predictive biomarkers represents a key challenge to optimize the efficacy of immunotherapy. This review provides a critical analysis of completed trials, with an eye on future perspectives and possible biomarkers of response.

Comparison of Clinical Features and Outcomes Between Intrahepatic Cholangiocarcinoma and Hepatocellular Carcinoma in the United States

BACKGROUND AND AIMS

Intrahepatic cholangiocarcinoma (iCCA) and hepatocellular carcinoma (HCC) are the most common primary liver cancers (PLCs). Differences in their clinical features and outcomes are open for investigation in a large-scale study. We aim to investigate the differences in clinical features and outcomes between iCCA and HCC.

APPROACH AND RESULTS

The Surveillance, Epidemiology, and End Results Program 18 Database (2000-2017) was used to extract demographic and clinical features of HCC and iCCA patients. Logistic regression analysis was performed to identify factors associated with iCCA diagnosis versus HCC. Cox regression analysis was used to assess factors affecting overall survival (OS). There were 13,611 iCCA and 96,151 HCC patients. Half of iCCA (50.7%) and three quarters of HCC (76.3%) patients were male. Diagnosis in recent year, age (<50 or ≥65), female sex, non-Hispanic White race, higher income, rural area, and higher tumor burden were independently associated with iCCA diagnosis versus HCC. Patients with iCCA had worse OS than those with HCC (9 vs. 13 months; P < 0.001). However, OS was comparable between iCCA and HCC in multivariable analysis (adjusted hazard ratio [aHR] = 1.02; 95% CI = 0.99-1.05). In subgroup analyses, iCCA was associated with better OS than HCC in patients with tumor ≥5 cm (aHR = 0.83; 95% CI = 0.80-0.86), lymph node involvement (aHR = 0.76; 95% CI = 0.72-0.81), distant metastasis (aHR = 0.76; 95% CI = 0.73-0.79), poorly/undifferentiated tumors (aHR = 0.88; 95% CI = 0.83-0.94), and those receiving noncurative treatment (aHR = 0.96; 95% CI = 0.93-0.98).

CONCLUSIONS

We identified the demographic, socioeconomic, and clinical features associated with iCCA diagnosis over HCC among patients with PLC. Although iCCA patients presented at an advanced stage, OS was similar between iCCA and HCC in multivariable analysis. iCCA was associated with longer OS for subgroups with poor prognostic features.

A review of molecularly targeted therapy in biliary tract carcinoma: what is the next step?

Patients with unresectable biliary tract carcinomas (BTCs) have a poor prognosis with a median overall survival of fewer than 12 months following systemic chemotherapy. In recent years, the identification of distinct molecular alterations with corresponding targeted therapies is modifying this therapeutic algorithm. The aim of this review is to present an overview of targeted therapy for BTCs, describing published available data and potential future challenges in ongoing trials. From clinicaltrials.gov online database all ongoing trials for BTCs (any stage) was examinated in July 2021, and data regarding study design, disease characteristics and type of treatments were registered. Oncogenic-driven therapy (targeted therapy) was investigated in 67 trials. According to research, 15 ongoing trials (22.4%) are investigating fibroblast growth factor (FGF) receptor (FGFR)-inhibitors in BTCs. Three (18.7%) are open-label randomized multicenter phase 3 trials, 8 (50%) are single-arm phase two trials, and 4 (25%) are phase one studies. Twelve (17.9%) clinical trials dealt with isocitrate dehydrogenase (IDH) 1/2 targeting therapy either in combination with cisplatin (Cis) and gemcitabine (Gem) as first-line treatment for BTCs or in monotherapy in patients with IDH1 mutant advanced malignancies, including cholangiocarcinoma (CCA). Nine (13.4%) clinical trials tested human epidermal growth factor receptor (HER) 2 targeting therapy. Four (44.4%) studies are phase I trials, two (22.2%) are phase I/II trials, and three (33.3%) phase II trials. Rare molecular alterations in BTCs, such as anaplastic lymphoma kinase (ALK), c-ros oncogene1 receptor tyrosine kinase (ROS1), and v-RAF murine sarcoma viral oncogene homologue B1 (BRAF), are also under investigation in a few trials. Forty-four clinical trials (17.2%) are investigating not oncogenic-driven multitarget therapy like multireceptor tyrosin kinase inhibitors and antiangiogenetic agents. In conclusion, this review shows that BTCs management is experiencing important innovations, especially in biomarker-based patient selection and in the new emerging therapeutic approach. Many ongoing trials could answer questions regarding the role of molecular inhibitors leading to new therapeutic frontiers for molecular subcategories of BTCs.

Intrahepatic Cholangiocarcinoma: A Summative Review of Biomarkers and Targeted Therapies

Simple Summary

Intrahepatic cholangiocarcinoma is the second most common primary liver malignancy. Among patients with operable disease, surgical resection is the cornerstone of therapy. Among the majority of patients who present with advanced disease treatment, systemic or targeted therapy is indicated. Recent advancements have provided more novel therapeutic approaches to a subset of patients with intrahepatic cholangiocarcinoma.

Abstract

Although rare, intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy and the incidence of ICC has increased 14% per year in recent decades. Treatment of ICC remains difficult as most people present with advanced disease not amenable to curative-intent surgical resection. Even among patients with operable disease, margin-negative surgical resection can be difficult to achieve and the incidence of recurrence remains high. As such, there has been considerable interest in systemic chemotherapy and targeted therapy for ICC. Over the last decade, the understanding of the molecular and genetic foundations of ICC has reshaped treatment approaches and strategies. Next-generation sequencing has revealed that most ICC tumors have at least one targetable mutation. These advancements have led to multiple clinical trials to examine the safety and efficacy of novel therapeutics that target tumor-specific molecular and genetic aberrations. While these advancements have demonstrated survival benefit in early phase clinical trials, continued investigation in randomized larger-scale trials is needed to further define the potential clinical impact of such therapy.

Intrahepatic Cholangiocarcinoma: A Summative Review of Biomarkers and Targeted Therapies

Although rare, intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy and the incidence of ICC has increased 14% per year in recent decades. Treatment of ICC remains difficult as most people present with advanced disease not amenable to curative-intent surgical resection. Even among patients with operable disease, margin-negative surgical resection can be difficult to achieve and the incidence of recurrence remains high. As such, there has been considerable interest in systemic chemotherapy and targeted therapy for ICC. Over the last decade, the understanding of the molecular and genetic foundations of ICC has reshaped treatment approaches and strategies. Next-generation sequencing has revealed that most ICC tumors have at least one targetable mutation. These advancements have led to multiple clinical trials to examine the safety and efficacy of novel therapeutics that target tumor-specific molecular and genetic aberrations. While these advancements have demonstrated survival benefit in early phase clinical trials, continued investigation in randomized larger-scale trials is needed to further define the potential clinical impact of such therapy.

Quality of Life and Symptom Management in Advanced Biliary Tract Cancers

Simple Summary

Patients with advanced BTC have poor prognosis and frequently experience symptoms that adversely impact their quality of life. In this review, we explore the potential complications of advanced BTC and its treatments. We also review the possible strategies and interventions available to manage these adverse events.

Abstract

Biliary tract carcinomas (BTCs) account for less than 1% of all cancers but are increasing in incidence. Prognosis is poor for BTC patients, with 5-year survival rates of less than 10%. While chemotherapy has been the mainstay treatment for patients with advanced BTC, immunotherapy and targeted therapies are being evaluated in numerous clinical trials and rapidly incorporated into clinical practice. As patients with BTC have reduced health-related quality of life (HRQoL) due to both tumor- and treatment-related symptoms, it is important for clinicians to recognize and manage these symptoms early. This review will highlight the anticipated complications from BTC and its systemic treatment, as well as their effects on HRQoL.

Potential utility of liquid biopsies in the management of patients with biliary tract cancers: A review

Biliary tract cancer, comprising gallbladder cancer, cholangiocarcinoma and ampullary cancer, represents a more uncommon entity outside high-endemic areas, though global incidence is rising. The majority of patients present at a late stage, and 5-year survival remains poor. Advanced stage disease is incurable, and though palliative chemotherapy has been shown to improve survival, further diagnostic and therapeutic options are required in order to improve patient outcomes. Although certain subtypes of biliary tract cancer are relatively rich in targetable mutations, attaining tumour tissue for histological diagnosis and treatment monitoring is challenging due to locoregional anatomical constraints and patient fitness. Liquid biopsies offer a safe and convenient alternative to invasive procedures and have great potential as diagnostic, predictive and prognostic biomarkers. In this review, the current standard of care for patients with biliary tract cancer, future treatment horizons and the possible utility of liquid biopsies within a variety of contexts will be discussed. Circulating tumour DNA, circulating microRNA and circulating tumour cells are discussed with an overview of their potential applications in management of biliary tract cancer. A summary is also provided of currently recruiting clinical trials incorporating liquid biopsies within biliary tract cancer research.

Next-Generation Biomarkers for Cholangiocarcinoma

Simple Summary

Early and non-invasive diagnosis of cholangiocarcinoma (CCA) is still challenging, thus largely contributing to the increased mortality rates observed worldwide. Consequently, several efforts have been made in order to report novel biomarkers for CCA, that would aid on diagnosis and also to predict prognosis and therapy response. We herein aim to provide an in-depth and critical revision on the next-generation biomarkers for CCA that have been recently proposed.

Abstract

The increasing mortality rates of cholangiocarcinoma (CCA) registered during the last decades are, at least in part, a result of the lack of accurate non-invasive biomarkers for early disease diagnosis, making the identification of patients who might benefit from potentially curative approaches (i.e., surgery) extremely challenging. The obscure CCA pathogenesis and associated etiological factors, as well as the lack of symptoms in patients with early tumor stages, highly compromises CCA identification and to predict tumor development in at-risk populations. Currently, CCA diagnosis is accomplished by the combination of clinical/biochemical features, radiological imaging and non-specific serum tumor biomarkers, although a tumor biopsy is still needed to confirm disease diagnosis. Furthermore, prognostic and predictive biomarkers are still lacking and urgently needed. During the recent years, high-throughput omics-based approaches have identified novel circulating biomarkers (diagnostic and prognostic) that might be included in large, international validation studies in the near future. In this review, we summarize and discuss the most recent advances in the field of biomarker discovery in CCA, providing new insights and future research directions.

Targeted Therapies in Advanced Cholangiocarcinoma: A Focus on FGFR Inhibitors

Despite advanced diseases continuing to be associated with grim prognoses, the past decade has witnessed the advent of several novel treatment options for cholangiocarcinoma (CCA) patients. In fact, CCA has emerged as a heterogeneous group of malignancies harboring potentially druggable mutations in approximately 50% of cases, and thus, molecularly targeted therapies have been actively explored in this setting. Among these, fibroblast growth factor receptor (FGFR) inhibitors have reported important results, as witnessed by the FDA approval of pemigatinib in previously treated metastatic CCA patients harboring FGFR2 fusion or other rearrangements. Herein, we provide an overview of available evidence on FGFR inhibitors in CCA, especially focusing on the development, pitfalls and challenges of emerging treatments in this setting.

FGFR inhibitors in elderly patients with advanced biliary tract cancer: an unsolved issue

Background: Despite recent advances in the understanding of the molecular landscape of biliary tract cancer (BTC), advanced disease continues to carry a poor prognosis, and the benefit from systemic treatments remains modest. However, BTCs have emerged as malignancies harboring specific potentially druggable aberrations, and thus, several molecularly targeted treatments have been recently tested. Among these, fibroblast growth factor receptor (FGFR) inhibitors have shown interesting results in previously treated BTC patients with advanced diseaseAreas covered: In this review, we aimed to provide an overview of available evidence on FGFR inhibitors in elderly patients with metastatic BTC, especially focusing on subgroup analyses of recently published trials exploring this novel therapeutic approach in these aggressive malignancies.Expert opinion: The FGFR1, FGFR2, and FGFR3 inhibitor pemigatinib has been recently approved by the United States Food and Drug Administration (FDA) in metastatic BTCs harboring FGFR2 fusion or other rearrangement. However, few data are available regarding the use of FGFR inhibitors in elderly BTCs, a patient population that remains seriously under-represented in clinical trials.

Recent advances of immunotherapy for biliary tract cancer

Introduction: Biliary tract cancer (BTC) is a heterogeneous group of aggressive malignancies comprising intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer. Although recent years have witnessed the emergence of novel treatment targets, medical therapy remains a compelling challenge in these hepatobiliary malignancies. In order to provide more effective treatment options, immune checkpoint inhibitors (ICIs) are currently under investigation in advanced BTC, with controversial results reported so far.Areas covered: This review provides an overview regarding current scenario of ICIs and immune-based combinations in advanced BTC, where several novel treatments are currently being developed, some of which have suggested interesting efficacy in recent clinical trials. In addition, we provide a report of ongoing Phase I to III clinical trials assessing ICIs and new immunotherapeutic strategies for advanced BTC.Expert opinion: Although immunotherapy has revolutionized the treatment landscape of several hematological and solid tumors, the role of ICIs and immune-based combinations in advanced BTC is still unclear. Despite ICI monotherapy has reported limited efficacy in this setting, the durable responses observed in sporadic cases suggest that testing patients for MMR, MSI, TMB, and PD-L1 expression is warranted. Results of currently ongoing trials are highly awaited.

Olaparib Treatment in a Patient with Advanced Gallbladder Cancer Harboring BRCA1 Mutation

Gallbladder cancer is a highly aggressive malignancy with an extremely poor prognosis. Germline BRCA1 mutation in gallbladder cancer is very rare. Herein, we present a case of a 73-year-old Asian patient diagnosed with lymph nodes and peritoneal metastases just two months after surgery for primary gallbladder cancer. The patient had a past history of early-stage breast cancer and received a left radical mastectomy 27 years ago. Next-generation sequencing (NGS) was performed as the patient refused to receive systemic chemotherapy. According to NGS result of germline BRCA1 mutation, the patient was administered first-line Olaparib and obtained a progression-free survival of about 6 months. Furthermore, we briefly summarized the current targeted treatment of gallbladder cancer. To the best of our knowledge, this is the first report of germline BRCA1 p. S451Lfs*20 mutation and first-line Olaparib treatment in a metastatic gallbladder cancer patient. As a highly heterogeneous and aggressive malignancy, we suggest making clinical decisions according to a precision medicine concept based on gene sequencing in advanced gallbladder cancer.

IDH inhibitors in advanced cholangiocarcinoma: Another arrow in the quiver?

Cholangiocarcinomas (CCAs) are a heterogenous group of hepatobiliary tumors with poor prognosis and limited therapeutic options. In the last decade, the advent of genomic profiling has led to the identification of several putative actionable aberrations in CCAs, and genomic characterization is playing an increasing role in the management of these malignancies. Thus, a wide number of targetable mutations are currently under investigation, and early studies on this approach in CCAs have been recently presented or published. Among these, isocitrate dehydrogenase (IDH) mutations have been reported in approximately 15-20% of intrahepatic cholangiocarcinoma (iCCA) patients, while these aberrations are considered to be less frequent in perihilar CCA (pCCA), distal CCA (dCCA), and gallbladder cancer. Of note, the recent findings of the ClarIDHy phase III trial add to mounting evidence showing the potential advantages of molecularly targeted therapies in CCA, on the basis of a benefit in previously treated IDH1-mutant patients receiving ivosidenib versus placebo. However, although the results of this trial showed a statistically significant improvement in progression-free survival and overall survival for IDH-mutant CCAs treated with ivosidenib, several questions regarding the real impact of IDH inhibitors in this setting remain open. In this review, we will provide an overview on the biological rationale behind the use of IDH inhibitors in CCA patients and current clinical implications of these molecularly targeted agents. The recently published results of the ClarIDHy - as well as ongoing clinical trials in this setting - are highlighted and critically discussed.

Systemic treatment of HCC in special populations

Recent years have seen significant progress in the systemic treatment of hepatocellular carcinoma (HCC), including the advent of immunotherapy. While several large phase III trials have provided the evidence for a multi-line treatment paradigm, they have focused on a highly selected group of patients by excluding potentially confounding comorbidities. As a result, high quality evidence for the systemic treatment of HCC in patients with various comorbidities is missing. This review summarises current knowledge on the use of approved medicines in patients with HIV, autoimmune disease, cardiovascular disease, diabetes, fibrolamellar HCC, mixed HCC-cholangiocarcinoma, decompensated cirrhosis (Child-Pugh B and C), a significant bleeding history, vascular invasion or portal vein thrombosis, as well as the elderly, those on haemodialysis, and those after solid organ transplantation. The article highlights relevant knowledge gaps and current clinical challenges. To improve the safety and efficacy of HCC treatment in these subgroups, future trials should be designed to specifically include patients with comorbidities.

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.

Novel Targeted Therapies for Advanced Cholangiocarcinoma

Cholangiocarcinoma (CCA) includes a group of rare and aggressive hepatobiliary malignancies, including extrahepatic cholangiocarcinoma (eCCA) and intrahepatic cholangiocarcinoma (iCCA), with the former further subdivided into distal (dCCA) and perihilar cholangiocarcinoma (pCCA) [...].

Pemigatinib: Hot topics behind the first approval of a targeted therapy in cholangiocarcinoma

Cholangiocarcinoma (CCA) includes a heterogeneous group of malignancies with limited treatment options. Despite recent advances in medical oncology, the prognosis of CCA patients with metastatic disease remains poor, with a median overall survival of less than a year. In the last decade, notable efforts have been made by the CCA medical community in an attempt to improve clinical outcomes of patients, with the development of molecularly targeted therapies in this setting. Among these treatments, the fibroblast growth factor receptor (FGFR) 2 inhibitor pemigatinib has received accelerated approval in April 2020 by the US Food and Drug Administration (FDA) in CCA patients harboring FGFR2 gene fusions or other rearrangements, on the basis of the results of the FIGHT-202 trial, and thus, representing the first molecularly targeted therapy to be approved for the treatment of CCA. However, several issues remain, including the emergence of polyclonal mutations determining resistance to pemigatinib, the identification of biomarkers predictive of response, and the knowledge gaps regarding the role of other FGFR gene aberrations. This review aims to provide an overview of recent development of pemigatinib, especially focusing on the results of the pivotal FIGHT-202 trial, the approval of this FGFR inhibitor, and the future challenges concerning the use of FGFR-directed treatments in CCA patients.

Adjuvant systemic treatment in resected biliary tract cancer: State of the art, controversies, and future directions

Biliary tract cancer (BTC) includes a heterogeneous group of aggressive malignancies comprising gallbladder cancer (GBC), ampulla of Vater cancer (AVC), intrahepatic cholangiocarcinoma (iCCA), and extrahepatic cholangiocarcinoma (eCCA). Unfortunately, potentially curative resection is possible in approximately the 25% of presenting patients, and relapse rates are high, with a notable proportion of BTCs experiencing disease recurrence. Recent years have seen the publication of several prospective clinical trials evaluating the role of adjuvant systemic treatments, and among these, the phase III BILCAP study provided evidence supporting the use of capecitabine after radical surgery in BTC patients; in fact, although the study failed to meet its primary endpoint, the capecitabine arm showed improved clinical outcomes in terms of overall survival (pre-planned sensitivity analysis in the intention-to-treat population and in the per-protocol analysis) and relapse-free survival. However, the BILCAP has been widely criticized, with several authors that have not accepted adjuvant capecitabine as novel standard of care. In this review, we summarize current state of the art regarding adjuvant systemic treatment in BTC, highlighting advantages and disadvantages of recent clinical trials, and suggesting new research directions in this setting.

First-line Chemotherapy in Advanced Biliary Tract Cancer Ten Years After the ABC-02 Trial: "And Yet It Moves!"

Biliary tract cancers (BTCs) include a heterogeneous group of highly aggressive hepatobiliary malignancies, representing the 3% of all gastrointestinal cancers and the second most frequent type of primary liver cancer after hepatocellular carcinoma. Ten years after the publication of the phase III, randomized, ABC-02 trial, the combination of cisplatin plus gemcitabine remains the standard first-line treatment for patients with advanced BTC. In the last decade, a large number of attempts has been made to improve the efficacy of the reference doublet by using novel drugs or adding a third agent to cisplatin-gemcitabine. Unfortunately, despite the addition of different cytotoxic drugs failed to improve clinical outcomes in several studies, recently published clinical trials have provided interesting results, and other first-line chemotherapy options are currently under investigation in randomized phase III studies. Moreover, recent years have witnessed the parallel emergence of molecularly targeted therapies and immune checkpoint inhibitors, with these novel agents having the potential to revolutionize the therapeutic algorithm of advanced BTC. In this review, we will provide an overview on first-line therapeutic opportunities currently available in the management of advanced BTCs, especially focusing on recently published data and ongoing clinical trials in this setting.

PD-L1, TMB, MSI, and Other Predictors of Response to Immune Checkpoint Inhibitors in Biliary Tract Cancer

Biliary tract cancer (BTC) represents the second most frequently diagnosed primary liver cancer worldwide following hepatocellular carcinoma, and the overall survival of patients with unresectable disease remains poor. In recent years, the advent of immune checkpoint inhibitors (ICIs) has revolutionized the therapeutic landscape of several malignancies with these agents, which have also been explored in advanced BTC, as monotherapy or in combination with other anticancer agents. However, clinical trials evaluating ICIs in BTC have shown conflicting results, and the clinical benefit provided by immunotherapy seems limited to a small subgroup of BTC patients. Thus, the identification of reliable predictors of the response to immunotherapy represents a significant challenge in this setting. This review provides an overview of the available evidence on the biomarkers predictive of the response to ICIs in patients with advanced BTC, especially focusing on programmed death-ligand 1 (PD-L1), tumor mutational burden (TMB), microsatellite instability (MSI), and other emerging biomarkers.

Intrahepatic Cholangiocarcinoma: State of the Art of FGFR Inhibitors

OBJECTIVE

Intrahepatic cholangiocarcinoma (iCCA), the second most common type of primary liver tumor, has an increasing incidence in the past few decades. iCCA is highly malignant, with a 5-year survival rate of approximately 5-10%. Surgical resection is usually the prescribed treatment for patients with early stage iCCA; however, patients are usually in an advanced stage iCCA upon diagnosis. Currently, targeted therapy combined with chemotherapy and other comprehensive treatment measures have been mainly adopted as palliative treatment measures. As a common candidate of targeted therapy, FGFR inhibitors have demonstrated their unique advantages in clinical trials. At present, the prospect of FGFR targeted therapy is encouraging. The landscape of FGFR inhibitors in iCCA is needed to be showed urgently.

METHODS

We searched relative reports of clinical trials on FGFR inhibitors in PubMed as well as Web of Science. We also concluded other available clinical trials of FGFR inhibitors (Data were collected from clinicaltrials.gov).

RESULTS

Several relatively effective targeted drugs are being used in clinical trials. Some preliminary results indicate the outlook of targeted therapy such as BGJ398, TAS120, and HSP90 inhibitors.

CONCLUSIONS

In summary, FGFR targeted therapy has broad prospects for the treatment of iCCA.

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.

Molecular Features and Targeted Therapies in Extrahepatic Cholangiocarcinoma: Promises and Failures

Biliary tract cancers (BTCs) include a heterogenous group of aggressive malignancies with limited therapeutic options. According to their anatomical location, these hepatobiliary tumors are usually classified into intrahepatic cholangiocarcinoma (iCCA), extrahepatic cholangiocarcinoma (eCCA), and gallbladder cancer (GBC). Unfortunately, BTCs are often diagnosed when already metastatic, and although the advent of genomic sequencing has led to a deeper understanding of iCCA pathogenesis, very little data are currently available about the molecular landscape of eCCA. Moreover, despite novel systemic treatments emerging in BTC, the grim prognosis of eCCA patients has not changed in the past decade, and no targeted therapies have been approved so far. The aim of the current review is to provide an overview regarding molecular features and potential targeted therapies in eCCA, together with novel therapeutic approaches and future directions of translational and clinical research on this highly aggressive disease that poses many unanswered questions.

Targeting BRAF-Mutant Biliary Tract Cancer: Recent Advances and Future Challenges

BACKGROUND

Biliary tract cancers (BTCs) represent a heterogeneous group of aggressive solid tumors with limited therapeutic options, and include gallbladder cancer (GBC), ampulla of Vater cancer (AVC), intrahepatic cholangiocarcinoma (iCCA) and extrahepatic cholangiocarcinoma (eCCA).

METHODS & RESULTS

In the current review, we will discuss recent results of clinical trials testing targeted therapies in BRAF-mutant BTCs, with a particular focus on the recently published Phase II ROAR trial and ongoing active and recruiting clinical trials.

CONCLUSIONS

Although the extended use of molecular profiling has paved the way toward a new era in BTC management, targeted therapies are limited to iCCA so far, and the prognosis of patients with metastatic disease has substantially not changed in the last decade. In this discouraging scenario, BRAF inhibition is currently emerging as a novel treatment option in patients harboring BRAF mutations.