The DNA damage repair (DDR) pathway in biliary tract cancer (BTC): a new Pandora's box?

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.

Pitfalls, challenges, and updates in adjuvant systemic treatment for resected biliary tract cancer

Introduction: Unfortunately, potentially curative surgical resection is possible in approximately the 25% of biliary tract cancer (BTC) patients at diagnosis, and even following radical surgery, relapse rates remain high. Thus, the role of adjuvant systemic treatment has been widely explored in this setting over the last decades, with the hope of lowering recurrence rates and improving outcomes of BTC patients.Areas covered: In this review, we provide an overview of available evidence regarding adjuvant systemic therapy in resected BTC, critically discussing the pros and cons of recently published clinical trials such as the BILCAP, the BCAT, and the PRODIGE-12/ACCORD-18 phase III studies.Expert opinion: Although the BILCAP trial has established adjuvant capecitabine for 6 months following radical resection as a novel standard of care, the role of adjuvant systemic chemotherapy is the object of debate and controversy in the BTC medical community. Although most of the international guidelines on BTC management have not yet been updated, the recently published ASCO guidelines support the use of capecitabine in this setting. Several phase I to III clinical trials are currently evaluating the role of novel therapeutic approaches in patients with resected BTC, and the results of these studies are highly awaited.

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.

Neoadjuvant therapy for cholangiocarcinoma: A comprehensive literature review

Biliary tract cancers (BTCs) comprise a heterogenous group of aggressive and rare malignancies arising in the bile duct outside or within the liver. BTCs include cholangiocarcinoma (CCA), gallbladder cancer (GBC) and ampulla of Vater cancer (AVC); according to the "historical" anatomical classification, CCAs are further subdivided into extrahepatic cholangiocarcinomas (eCCAs) - including distal (dCCA) and perihilar (pCCA) - and intrahepatic cholangiocarcinomas (iCCA). Notably enough, these subtypes reflect distinct features in terms of biology, epidemiology, prognosis and therapeutic strategies. Although surgical resection remains the only potentially curative treatment option for CCA patients, radical surgery is possible for only a small proportion of cases. Moreover, it has been observed that up to 50% of patients deemed resectable at diagnosis are found to be unresectable during exploratory laparotomy. Additionally, even following radical surgery, recurrence rates are high. Neoadjuvant therapy represents an appealing approach in this setting, where this therapeutic strategy has the potential to improve local and distant control, to achieve R0 resection and to prevent distant metastasis. However, few data are currently available supporting neoadjuvant therapy in CCA and several questions remains unanswered, including the activity of systemic therapy in early stages of the disease, the optimal start time of treatment, patient selection and the length of neoadjuvant therapy. In this review, we will discuss available data on neoadjuvant systemic therapy in CCA, highlighting future directions in this setting, with a particular focus on recently published data and ongoing and recruiting trials.

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.

Biochemical predictors of response to immune checkpoint inhibitors in unresectable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the most commonly diagnosed liver cancer worldwide, and the overall survival of patients with unresectable disease is poor. In the last five years, immune checkpoint inhibitors (ICIs) have revolutionized the treatment scenario of several hematological and solid tumors, and these agents have been actively explored in unresectable HCC. Firstly, promising findings of phase I and II clinical studies reporting durable responses and a tolerable safety profile have led to the assessment of ICIs as single agents in phase III clinical studies; however, the latter have provided controversial results, and the activity of ICI monotherapy seems limited to a small subgroup of patients. Conversely, the IMbrave150 trial recently showed that, among patients with previously untreated unresectable HCC, treatment with atezolizumab plus bevacizumab resulted in significantly longer overall survival and progression-free survival compared to sorafenib monotherapy. In addition, the activity of several other ICIs is under investigation, as combination immunotherapy as well as combinations of immunotherapy with antiangiogenic agents. Nonetheless, there are currently no validated predictive biomarkers able to guide treatment choice in this setting, where the identification of specific predictors of response to ICIs represents a major challenge. In this review, we aim to provide a critical overview of recent evidence on biochemical predictors of response to ICIs in patients with unresectable HCC, especially focusing on PD-L1, TMB, MSI, and other emerging biomarkers.

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.

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.

Experimental HER2- targeted therapies for biliary tract cancer

Introduction: Biliary tract cancers (BTCs) constitute a heterogeneous group of poor-prognosis solid tumors with limited treatment options. In the last decade, global efforts have tried to identify therapeutic targets by genomic profiling of BTC, unveiling several genetic aberrations that could play a prognostic and/or a predictive role in these malignancies.Areas covered: In this review, we will present an overview regarding the role of HER2 targeted therapies in BTC, with a particular focus on clinical studies carried out in this field to date and ongoing trials. A literature search was conducted in August 2020 of Pubmed/Medline, Cochrane library and Scopus databases for published preclinical and clinical studies; moreover, abstract of international cancer meetings (AACR, ASCO, and ESMO) were reviewed.Expert opinion: Despite recent advances in medical oncology, the overall survival of BTC patients remains low and there is an urgent need for novel and more effective treatments. Although HER2 blockade has been suggested to induce durable tumor responses in selected subjects with BTC, controversial results have been reported so far and data from ongoing prospective clinical trials are awaited to further clarify the role of anti-HER2 therapies in BTC.

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.