Targeting FGFR inhibition in cholangiocarcinoma

A new promising oncogenic target (p.C382R) for treatment with pemigatinib in patients with cholangiocarcinoma

Point mutations of the fibroblast growth factor receptor (FGFR)2 receptor in intrahepatic cholangiocarcinoma (iCC) are mainly of unknown functional significance compared to FGFR2 fusions. Pemigatinib, a tyrosine kinase inhibitor, is approved for the treatment of cholangiocarcinoma with FGFR2 fusion/rearrangement. Although it is hypothesized that FGFR2 mutations may cause uncontrolled activation of the signaling pathway, the data for targeted therapies for FGFR2 mutations remain unclear. In vitro analyses demonstrated the importance of the p.C382R mutation for ligand-independent constitutive activation of FGFR2 with transforming potential. The following report describes the clinical case of a patient diagnosed with an iCC carrying a FGFR2 p.C382R point mutation which was detected in liquid, as well as in tissue-based biopsies. The patient was treated with pemigatinib, resulting in a sustained complete functional remission in fluorodeoxyglucose-positron emission tomography/computed tomography over 10 months to date. The reported case is the first description of a complete functional remission under the treatment with pemigatinib in a patient with p.C383R mutation.

Combined MEK/PD-L1 Inhibition Alters Peripheral Cytokines and Lymphocyte Populations Correlating with Improved Clinical Outcomes in Advanced Biliary Tract Cancer

PURPOSE

Biliary tract cancers (BTC) are aggressive malignancies refractory to chemotherapy and immunotherapy. MEK inhibition (MEKi)-based regimens may have utility in this disease when combined with PD-L1 blockade. We hypothesize that dual MEK/PD-L1 inhibition alters circulating soluble and cellular immune mediators to improve clinical outcomes in patients with advanced BTC.

EXPERIMENTAL DESIGN

We examined immune features in peripheral blood from 77 patients with advanced BTC enrolled in a phase II clinical trial investigating atezolizumab with or without cobimetinib. Plasma and peripheral blood mononuclear cells (PBMC) were isolated from whole blood to evaluate soluble factors and immune cell populations. Baseline blood samples were additionally compared with healthy donors to identify immune signatures unique to BTC.

RESULTS

At baseline, the soluble factors platelet-derived growth factor B (PDGF)-BB, placental growth factor (PlGF)-1, IL5, and IL17A were elevated in patients with BTC compared with healthy adult donors, and higher baseline frequencies of CD8+BTLA+ T cells correlated with better overall survival (OS) in this trial. There were also significant treatment-related alterations in several factors, including decreased PDGF-BB following combination treatment, that correlated with improved OS and progression-free survival (PFS). Higher baseline levels of IL23 and RANTES corresponded to improved clinical outcomes following combination treatment. Dual MEK/PD-L1 inhibition increased populations of CD4+TIM3+ and decreased CD8+VISTA+ T cells, correlating with worse OS and better PFS, respectively.

CONCLUSIONS

This work represents a comprehensive analysis of peripheral immune features in patients with BTC and systemic responses to dual MEK/PD-L1 inhibition. These data support further investigation to understand how MEKi combines with immunotherapeutic approaches to improve clinical outcomes for patients with advanced BTC.

An Expert, Multidisciplinary Perspective on Best Practices in Biomarker Testing in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is a rare and aggressive malignancy that arises from the intrahepatic biliary tree and is associated with a poor prognosis. Until recently, the treatment landscape of advanced/metastatic iCCA has been limited primarily to chemotherapy. In recent years, the advent of biomarker testing has identified actionable genetic alterations in 40%-50% of patients with iCCA, heralding an era of precision medicine for these patients. Biomarker testing using next-generation sequencing (NGS) has since become increasingly relevant in iCCA; however, several challenges and gaps in standard image-guided liver biopsy and processing have been identified. These include variability in tissue acquisition relating to the imaging modality used for biopsy guidance, the biopsy method used, number of passes, needle choice, specimen preparation methods, the desmoplastic nature of the tumor, as well as the lack of communication among the multidisciplinary team. Recognizing these challenges and the lack of evidence-based guidelines for biomarker testing in iCCA, a multidisciplinary team of experts including interventional oncologists, a gastroenterologist, medical oncologists, and pathologists suggest best practices for optimizing tissue collection and biomarker testing in iCCA.

Clinical treatment of cholangiocarcinoma: an updated comprehensive review

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

Precision Medicine in Biliary Tract Cancer

Precision medicine has become a dominant theme in the treatment of biliary tract cancers (BTCs). Although prognosis remains poor, technologies for improved molecular characterization along with the US Food and Drug Administration approval of several targeted therapies have changed the therapeutic landscape of advanced BTC. The hallmark of BTC oncogenesis is chronic inflammation of the liver and biliary tract regardless of the anatomical subtype. Subtypes of BTC correspond to distinct molecular characteristics, making BTC a molecularly heterogenous collection of tumors. Collectively, up to 40% of BTCs harbor a potentially targetable molecular abnormality, and the National Comprehensive Cancer Network guidelines recommend molecular profiling for all patients with advanced BTC. Use of circulating tumor DNA, immunohistochemistry, and next-generation sequencing continues to expand the utility for biomarker-driven management and molecular monitoring of BTC. Improving outcomes using biomarker-agnostic treatment for nontargetable tumors also remains a priority, and combinational treatment strategies such as immune checkpoint inhibition plus chemotherapy hold promise for this subgroup of patients.

The current state of molecular profiling in gastrointestinal malignancies

This is a review of the current state of molecular profiling in gastrointestinal (GI) cancers and what to expect from this evolving field in the future. Individualized medicine is moving from broad panel testing of numerous genes or gene products in tumor biopsy samples, identifying biomarkers of prognosis and treatment response, to relatively noninvasive liquid biopsy assays, building on what we have learned in our tumor analysis and growing into its own evolving predictive and prognostic subspecialty. Hence, the field of GI precision oncology is exploding, and this review endeavors to summarize where we are now in preparation for the journey ahead.

Advances in the systemic treatment of therapeutic approaches in biliary tract cancer

INTRODUCTION

Biliary tract cancers (BTCs) are a rare and heterogenous group with an increasing incidence and high mortality rate. The estimated new cases and deaths of BTC worldwide are increasing, but the incidence and mortality rates in South East Asia are the highest worldwide, representing a real public health problem in these regions. BTC has a poor prognosis with a median overall survival <12 months. Thus, an urgent unmet clinical need for BTC patients exists and must be addressed.

RESULTS

The backbone treatment of these malignancies is chemotherapy in first- and second-line setting, but in the last decade a rich molecular landscape has been discovered, expanding conceivable treatment options. Some druggable molecular aberrations can be treated with new targeted therapies and have already demonstrated efficacy in patients with BTC, improving clinical outcomes, such as the FGFR2 or IDH1 inhibitors. Many other molecular alterations are being discovered and the treatment of BTC will change in the near future from our current clinical practice.

CONCLUSIONS

In this review we discuss the epidemiology, molecular characteristics, present treatment approaches, review the recent therapeutic advances, and explore future directions for patients with BTC. Due to the rich molecular landscape of BTC, molecular profiling should be carried out early. Ongoing research will bring new targeted treatments and immunotherapy in the near future.

Role of molecular genetics in the clinical management of cholangiocarcinoma

The incidence of cholangiocarcinoma (CCA) has steadily increased during the past 20 years, and mortality is increasing. The majority of patients with CCA have advanced or metastatic disease at diagnosis, and treatment options for unresectable disease are limited, resulting in poor prognosis. However, recent identification of targetable genomic alterations has expanded treatment options for eligible patients. Given the importance of early and accurate diagnosis in optimizing patient outcomes, this review discusses best practices in CCA diagnosis, with a focus on categorizing molecular genetics and available targeted therapies. Imaging and staging of CCAs are discussed, as well as recommended biopsy collection techniques, and molecular and genomic profiling methodologies, which have become increasingly important as molecular biomarker data accumulate. Approved agents targeting actionable genomic alterations specifically in patients with CCA include ivosidenib for tumors harboring IDH1 mutations, and infigratinib and pemigatinib for those with FGFR2 fusions. Other agents currently under development in this indication have shown promising results, which are presented here.

Timeline of FDA-Approved Targeted Therapy for Cholangiocarcinoma

Simple Summary

Cholangiocarcinoma constitutes around 3% of gastrointestinal cancers, and mortality from this cancer has been rising in the recent decades. Many cases of cholangiocarcinoma are unfortunately discovered in their advanced stages which cannot be treated with surgical resection alone. Targeted therapy is a type of medical treatment that has garnered significant interest due to its ability to specifically target cancer cells while sparing normal healthy cells. A few targeted therapies have just recently been approved by the United States FDA for the treatment of cholangiocarcinoma specifically. This manuscript seeks to explore the timeline of targeted therapies with either FDA approval or FDA breakthrough therapy designation. The official approval of these therapies marks a new age for the treatment of cholangiocarcinoma and brings new options for clinicians across the nation for this unfortunate disease.

Abstract

Cholangiocarcinoma (CCA) represents approximately 3% of gastrointestinal malignancies worldwide and constitutes around 10–15% of all primary liver cancers, being only second to hepatocellular carcinoma. Mortality from CCA has been on the rise in recent decades, and in the United States alone there has been a 36% increase in CCA from 1999 to 2014, with over 7000 CCA mortalities since 2013. Targeted therapies, which have been gaining interest due to their greater specificity toward cancer cells, have only recently started gaining FDA approval for the treatment of CCA. In this manuscript, we will go through the timeline of current FDA-approved targeted therapies as well as those that have gained FDA breakthrough therapy designation.

Characterization of the Estrogen Response Helps to Predict Prognosis and Identify Potential Therapeutic Targets in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is an aggressive malignancy originating from the epithelium of the bile duct. The prognosis of patients is poor regardless of radical resection and chemoradiotherapy. The current classification and prognostic model of CCA are unable to satisfy the requirements for predicting the clinical outcome and exploring therapeutic targets. Estrogen signaling is involved in diverse cancer types, and it has long been established that CCA could be regulated by estrogen. In our study, estrogen response was identified to be significantly and stably correlated with poor prognosis in CCA. Employing several algorithms, CCA was classified into ES cluster A and B. ES cluster B was mainly composed of patients with fluke infection and overlapped with CCA cluster 1/2, and ES cluster A was mainly composed of patients without fluke infection and overlapped with CCA cluster 3/4. COMT and HSD17B1 were identified to be responsible for the differential estrogen response between ES clusters A and B, and the estrogen response may be correlated with the differentiation and cancer stemness of CCA at the single-cell level. Complement activation and the expression of C3 and C5, which are mainly expressed by CCA cells, were significantly downregulated in ES cluster B. An estrogen response risk score (ESRS) model was constructed to predict the prognosis of CCA, followed by a nomogram integrating ESRS and clinical features. Finally, altered pathways, applicable drugs and sensitivity to chemical drugs were analyzed specific to the estrogen response. In summary, our results provide insights into the role of the estrogen response in CCA progression as well as applicable drugs and potential therapeutic targets in estrogen metabolism, the complement system and ESRS-related pathways.

Changing Landscape of Systemic Therapy in Biliary Tract Cancer

Biliary tract cancers (BTC) are often diagnosed at advanced stages and have a grave outcome due to limited systemic options. Gemcitabine and cisplatin combination (GC) has been the first-line standard for more than a decade. Second-line chemotherapy (CT) options are limited. Targeted therapy or TT (fibroblast growth factor 2 inhibitors or FGFR2, isocitrate dehydrogenase 1 or IDH-1, and neurotrophic tyrosine receptor kinase or NTRK gene fusions inhibitors) have had reasonable success, but <5% of total BTC patients are eligible for them. The use of immune checkpoint inhibitors (ICI) such as pembrolizumab is restricted to microsatellite instability high (MSI-H) patients in the first line. The success of the TOPAZ-1 trial (GC plus durvalumab) is promising, with numerous trials underway that might soon bring targeted therapy (pemigatinib and infrigatinib) and ICI combinations (with CT or TT in microsatellite stable cancers) in the first line. Newer targets and newer agents for established targets are being investigated, and this may change the BTC management landscape in the coming years from traditional CT to individualized therapy (TT) or ICI-centered combinations. The latter group may occupy major space in BTC management due to the paucity of targetable mutations and a greater toxicity profile.

Precision Medicine Targeting FGFR2 Genomic Alterations in Advanced Cholangiocarcinoma: Current State and Future Perspectives

Although a relatively uncommon tumor, cholangiocarcinoma is on the rise globally. Of note, most patients are diagnosed with metastatic disease, and the prognosis is poor with cytotoxic chemotherapy. Strategies targeting specific genomic alterations have demonstrated promising activity in recent years and could represent a new therapeutic avenue for these patients. In this review, we will address the biology and clinical results of FGFR inhibition in intrahepatic cholangiocarcinoma, highlighting limitations associated with treatment and discussing the use of circulating tumor DNA to detect mechanisms of resistance.

Up-to-Date Pathologic Classification and Molecular Characteristics of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive primary liver malignancy with an increasing incidence worldwide. Recently, histopathologic classification of small duct type and large duct type iCCA has been introduced. Both these types of tumors exhibit differences in clinicopathological features, mutational profiles, and prognosis. Small duct type iCCA is composed of non-mucin-producing cuboidal cells, whereas large duct type iCCA is composed of mucin-producing columnar cells, reflecting different cells of origin. Large duct type iCCA shows more invasive growth and poorer prognosis than small duct type iCCA. The background liver of small duct type iCCA often shows chronic liver disease related to hepatitis B or C viral infection, or alcoholic or non-alcoholic fatty liver disease/steatohepatitis, in contrast to large duct type iCCA that is often related to hepatolithiasis and liver fluke infection. Cholangiolocarcinoma is a variant of small duct type iCCA composed of naïve-looking cuboidal cells forming cords or ductule-like structures, and shows better prognosis than the conventional small duct type. Fibrous tumor stroma, one of the characteristic features of iCCA, contains activated fibroblasts intermixed with innate and adaptive immune cells. The types of stroma (mature versus immature) are related to tumor behavior and prognosis. Low tumor-infiltrating lymphocyte density, KRAS alteration, and chromosomal instability are related to immune-suppressive tumor microenvironments with resistance to programmed death 1/ programmed death ligand 1 blockade. Data from recent large-scale exome analyses have revealed the heterogeneity in the molecular profiles of iCCA, showing that small duct type iCCA exhibit frequent BAP1, IDH1/2 hotspot mutations and FGFR2 fusion, in contrast to frequent mutations in KRAS, TP53, and SMAD4 observed in large duct type iCCA. Multi-omics analyses have proposed several molecular classifications of iCCA, including inflammation class and proliferation class. The inflammation class is enriched in inflammatory signaling pathways and expression of cytokines, while the proliferation class has activated oncogenic growth signaling pathways. Diverse pathologic features of iCCA and its associated multi-omics characteristics are currently under active investigation, thereby providing insights into precision therapeutics for patients with iCCA. This review provides the latest knowledge on the histopathologic classification of iCCA and its associated molecular features, ranging from tumor microenvironment to genomic and transcriptomic research.

Inhibition of FGFR2 enhances chemosensitivity to gemcitabine in cholangiocarcinoma through the AKT/mTOR and EMT signaling pathways

AIM

To investigate the oncogenic role of FGFR2 in carcinogenesis in cholangiocarcinoma (CCA) cells. In addition, the feasibility of using FGFR inhibitors in combination with standard chemotherapy was also explored for the chemosensitizing effect in CCA cells.

MAIN METHODS

Five CCA cell lines were used to screen FGFR2 expression by Western immunoblotting. Two CCA cell lines, KKU-100 and KKU-213A, were knocked down of the FGFR2 gene using siRNA. Cell viability was assessed by the MTS cell proliferation assay. Reproductive cell death was assessed by clonogenic assay. The effects on cell migration and invasion were analyzed by the Transwell chamber method. Cell cycle analysis was performed by flow cytometry. Cell angiogenesis was assessed by HUVEC tube formation and human angiogenesis antibody array analysis. Proteins associated with proliferative and metastatic properties were evaluated by Western blotting.

KEY FINDINGS

Knockdown of FGFR2 suppressed cell growth and colony formation in CCA cells in association with G2/M cell cycle arrest and downregulation of STAT3, cyclin A and cyclin B1. Silencing FGFR2 enhanced the suppressive effect of gemcitabine (Gem) on cell migration and invasion. The combination of infigratinib, an FGFR inhibitor, and Gem, interrupted cell growth, migration, and invasion via downregulation of FGFR/AKT/mTOR pathways and the EMT-associated proteins vimentin and slug. Moreover, the combination also suppressed tube formation together with decreased expression of the proangiogenic factor VEGF.

SIGNIFICANCE

Inhibition of FGFRs by infigratinib enhanced the antitumor effect of Gem in CCA cells through downregulation of the FGFR/AKT/mTOR, FGFR/STAT3 and EMT signaling pathways.

Roles of fusion genes in digestive system cancers: dawn for cancer precision therapy

For advanced and advanced tumors of the digestive system, personalized, precise treatment could be a lifesaving medicine. With the development of next-generation sequencing technology, detection of fusion genes in solid tumors has become more extensive. Some fusion gene targeting therapies have been written into the guidelines for digestive tract tumors, such as for neurotrophic receptor tyrosine kinase, fibroblast growth factor receptor 2. There are also many fusion genes being investigated as potential future therapeutic targets. This review focuses on the current detection methods for fusion genes, fusion genes written into the digestive system tumor guidelines, and potential fusion gene therapy targets in different organs to discuss the possibility of clinical treatments for these targets in digestive system tumors.

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.

Precision approaches for cholangiocarcinoma: Progress in clinical trials and beyond

INTRODUCTION

Although a relatively uncommon tumor, the incidence of intrahepatic cholangiocarcinoma is rising globally. Unfortunately, most patients are diagnosed with locally advanced or metastatic disease with poor prognosis. Strategies targeting genomic alterations and incorporation of precision medicine will represent a new therapeutic avenue for these patients.

AREAS COVERED

In this review article we addressed clinical trials in cholangiocarcinoma with FGFR, IDH, BRAF and ErbB2 targeted therapies. We also reviewed mechanisms of resistance to precision medicine and possible future strategies to overcome clonal evolution. Articles selected for this review were based on reported studies indexed in PubMed (2010-2021).

EXPERT OPINION

Pemigatinib, infigratinib and futibatinib could eventually be incorporated in the landscape of first-line systemic treatment for advanced cholangiocarcinoma with FGFR2 fusions or rearrangements after the ongoing phase III trials. Circulating tumor DNA could be used as a dynamic tool for evaluating mechanisms of resistance and prediction of response in patients treated with directed therapy.

Combination therapies for targeting FGFR2 fusions in cholangiocarcinoma

Fibroblast growth factor receptor 2 (FGFR2) fusion proteins (FFs) are oncogenic drivers in 10-15% of intrahepatic cholangiocarcinoma (iCCA). FGFR-specific inhibitors provide temporary benefit in FF⁺ unresectable patients. Recent work with mouse iCCA models has documented the necessary role of RAS-ERK downstream to FFs and provided examples of preclinical experimentation aimed at improving FF targeting in iCCA.

Long Non-coding RNA DANCR in Cancer: Roles, Mechanisms, and Implications

Long non-coding RNA (lncRNA) DANCR (also known as ANCR)—differentiation antagonizing non-protein coding RNA, was first reported in 2012 to suppress differentiation of epithelial cells. Emerging evidence demonstrates that DANCR is a cancer-associated lncRNA abnormally expressed in many cancers (e.g., lung cancer, gastric cancer, breast cancer, hepatocellular carcinoma). Increasing studies suggest that the dysregulation of DANCR plays critical roles in cancer cell proliferation, apoptosis, migration, invasion, and chemoresistance in vitro and tumor growth and metastasis in vivo. Mechanistic analyses show that DANCR can serve as miRNA sponges, stabilize mRNAs, and interact with proteins. Recent research reveals that DANCR can be detected in many body fluids such as serum, plasma, and exosomes, providing a quick and convenient method for cancer monitor. Thus DANCR can be used as a promising diagnostic and prognostic biomarker and therapeutic target for various types of cancer. This review focuses on the role and mechanism of DANCR in cancer progression with an emphasis on the clinical significance of DANCR in human cancers.

Targeted Therapy for Advanced or Metastatic Cholangiocarcinoma: Focus on the Clinical Potential of Infigratinib

Cholangiocarcinoma is one of the most aggressive cancers, with a 5-year survival rate of 11-44% after surgical resection. However, there is no established systemic therapy after failure of the gemcitabine plus cisplatin first-line therapy with exception of FOLFOX. Fibroblast growth factor receptor (FGFR) genomic aberrations have been detected in cholangiocarcinoma, and targeting these genomic aberrations with FGFR inhibitors has shown remarkable clinical benefits in advanced cholangiocarcinoma. In this article, we provide up-to-date information on the clinical development of selective FGFR inhibitors in advanced cholangiocarcinoma, focusing on infigratinib. In a Phase 1 trial, infigratinib showed a safe profile. In a following Phase 2 trial, infigratinib showed remarkable efficacy in advanced cholangiocarcinoma with FGFR2 fusions or rearrangements, and the Food and Drug Administration (FDA) approved infigratinib for cholangiocarcinoma in May 2021 largely based on tumor response and duration of response. Currently infigratinib is on a Phase 3 trial (PROOF301) as a first-line setting compared to the GEMCIS therapy in advanced cholangiocarcinoma. Given that the FGFR genomic aberrations including FGFR2 fusions are rarely accompanied with other targetable mutations, infigratinib and other FGFR inhibitors are continuously expected to be the novel targeted agents in cholangiocarcinoma harboring these aberrations. Acquired resistance to infigratinib was reported in several recent studies which could potentially be a barrier to overcome. Active clinical trials including PROOF301 are expected to elucidate the clinical benefits of infigratinib in this disease. Infigratinib combined with immunotherapy is also a potential future direction of investigation in cholangiocarcinoma.

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.

The Evolving Role of FGFR2 Inhibitors in Intrahepatic Cholangiocarcinoma: From Molecular Biology to Clinical Targeting

Intrahepatic cholangiocarcinoma (iCCA) is an anatomically and biologically distinct entity with a rising incidence and a poor prognosis on conventional treatments. Surgery followed by adjuvant chemotherapy is a potentially curative option in resectable cases, while palliative-intent chemotherapy is the standard-of-care in the advanced setting. Technological advances through massive parallel sequencing have enabled a deeper understanding of disease biology with the identification of several druggable molecular vulnerabilities in nearly 50% of cases. Among them, gene fusions involving the fibroblast growth factor receptor 2 (FGFR2) are the most therapeutically exploited so far with a number of Phase II clinical trials investigating FGFR2 inhibitors showing unprecedented efficacy results in this molecular subgroup. Over the last year, these efforts have culminated in the US FDA-approval of pemigatinib and infigratinib, the first two oral selective FGFR2 targeted agents for previously treated, locally advanced or metastatic iCCA driven by FGFR2 fusion or rearrangements. While first-line Phase III trials are currently underway to test these targeted approach against standard-of-care chemotherapy, translational studies are trying to better understand primary and secondary resistance mechanisms in order to optimize FGFR2 blockade in iCCA. In this article, we extensively reviewed the current evidence on the biological rationale, as well as preclinical and clinical development of FGFR inhibitors in iCCA.

Diverse landscape of dermatologic toxicities from small-molecule inhibitor cancer therapy

BACKGROUND

Advances in molecular biology and genetics have contributed to breakthrough treatments directed at specific pathways associated with the development of cancer. Small-molecule inhibitors (Nibs) aimed at a variety of cellular pathways have been efficacious; however, they are associated with significant dermatologic toxicities.

METHODS

We conducted a comprehensive review of dermatologic toxicities associated with Nibs categorized into the following five groups: (a) mitogen-activated protein kinase; (b) growth factor/multi-tyrosine kinase; (c) cell division/DNA repair; (d) signaling associated with myeloproliferative neoplasms; and (e) other signaling pathways. Prospective phase I, II, or III clinical trials, retrospective literature reviews, systematic reviews/meta-analyses, and case reviews/reports were included for analysis.

RESULTS

Dermatologic toxicities reviewed were associated with every class of Nibs and ranged from mild to severe or life-threatening adverse skin reactions. Inflammatory reactions manifesting as maculopapular, papulopustular/acneiform, and eczematous lesions were frequent types of dermatologic toxicities seen with Nibs. Squamous cell carcinoma with keratoacanthoma-like features was associated with a subset of Nibs. Substantial overlap in dermatologic toxicities was found between Nibs.

CONCLUSIONS

Dermatologic toxicities from Nibs are diverse and may overlap between classes of Nibs. Recognition of the various types of toxicities from Nibs is critical for patient care in the era of "oncodermatology/dermatopathology."

A Novel Combination of Bevacizumab with Chemotherapy Improves Therapeutic Effects for Advanced Biliary Tract Cancer: A Retrospective, Observational Study

BACKGROUND

Biliary tract cancer (BTC) is a heterogenous collection of biliary tract cancer at different primary sites, and the prognosis of advanced BTC is dismal. Systemic chemotherapy with gemcitabine and cisplatin (GC) has been the reference regimen since 2010. How to improve therapeutic effects of GC regimen is an urgent mission at present.

METHODS

Bevacizumab with a reduced dosage and modified schedule (10 mg/Kg/triweekly, 1 day before GS at the first 2 cycles) was combined with standard GC for patients with advanced BTC. Tumor response was assessed using Response Evaluation Criteria in Solid Tumors version 1.1 every 2 months. Kaplan-Meier curves were estimated for time-to-treatment failure (TTF), progression-free survival (PFS) and overall survival (OS).

RESULT

A total of thirty cases of advanced BTC accepted this treatment, and the overall response rate (ORR) was 50.0%, and the disease control rate was 80.0% for all patients. The median TTF was 5.8 months, the median PFS was 8.4 months, and the median OS was 13.6 months. Most responses were noted at the first evaluation. Adverse effects (AEs) were mostly tolerable.

CONCLUSIONS

After modifying the schedule, adding bevacizumab to a traditional GC regimen could increase the ORR with a shorter time-to-response, a better PFS and OS than GC alone but without the addition of AE. This regimen can be applied to patients with advanced BTC, especially those who are with a big tumor burden and who need a rapid response.

The Application of Inorganic Nanoparticles in Molecular Targeted Cancer Therapy: EGFR Targeting

Epidermal growth factor receptor (EGFR) is an anticancer drug target for a number of cancers, such as non-small cell lung cancer. However, unsatisfying treatment effects, terrible side-effects, and development of drug resistance are current insurmountable challenges of EGFR targeting treatments for cancers. With the advancement of nanotechnology, an increasing number of inorganic nanomaterials are applied in EGFR-mediated therapy to improve those limitations and further potentiate the efficacy of molecular targeted cancer therapy. Given their facile preparation, easy modification, and biosecurity, inorganic nanoparticles (iNPs) have been extensively explored in cancer treatments to date. This review presents an overview of the application of some typical metal nanoparticles and nonmetallic nanoparticles in EGFR-targeted therapy, then discusses and summarizes the relevant advantages. Moreover, we also highlight future perspectives regarding their remaining issues. We hope these discussions inspire future research on EGFR-targeted iNPs.

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.