Derazantinib (ARQ 087) in advanced or inoperable FGFR2 gene fusion-positive intrahepatic cholangiocarcinoma

Targeting FGFR2 Positive Gastroesophageal Cancer: Current and Clinical Developments

Despite recent advances in the systemic treatment of gastroesophageal cancers, prognosis remains poor. Comprehensive molecular analyses have characterized the genomic landscape of gastroesophageal cancer that has established therapeutic targets such as human epidermal growth factor receptor 2 (HER2), vascular endothelial growth factor receptor (VEGFR) and programmed death ligand 1 (PD-L1). The aberrant fibroblast growth factor receptor 2 (FGFR2) pathway is attractive for targetable therapy with FGFR inhibition based on preclinical data showing a pivotal role in the progression of gastric cancer (GC). FGFR2 amplification is the most common FGFR2 gene aberration in gastroesophageal cancer, and most associated with diffuse GC, which is often linked to poorer prognostic outcomes. There has been considerable progress with drug development focused on FGFR inhibition. At present, there is no approved FGFR inhibitor for FGFR2 positive gastroesophageal cancer. A selective FGFR2b monoclonal antibody bemarituzumab is currently being investigated in the first phase III randomized trial for patients with first line advanced GC, which may change the treatment paradigm for FGFR2b positive GC. The role of FGFR signalling, specifically FGFR2, is less established in oesophageal squamous cell cancer (ESCC) with a paucity of evidence for clinical benefit in these patients. Precision medicine is part of the wider approach in gastrointestinal cancers; however, it can be challenging due to heterogeneity and here circulating tumour DNA (ctDNA) for patient selection may have future clinical utility. In our review, we outline the FGFR pathway and focus on the developments and challenges of targeting FGFR2 driven gastroesophageal cancers.

Patient Selection Approaches in FGFR Inhibitor Trials-Many Paths to the Same End?

Inhibitors of fibroblast growth factor receptor (FGFR) signaling have been investigated in various human cancer diseases. Recently, the first compounds received FDA approval in biomarker-selected patient populations. Different approaches and technologies have been applied in clinical trials, ranging from protein (immunohistochemistry) to mRNA expression (e.g., RNA in situ hybridization) and to detection of various DNA alterations (e.g., copy number variations, mutations, gene fusions). We review, here, the advantages and limitations of the different technologies and discuss the importance of tissue and disease context in identifying the best predictive biomarker for FGFR targeting therapies.

Small-molecule inhibitors, immune checkpoint inhibitors, and more: FDA-approved novel therapeutic drugs for solid tumors from 1991 to 2021

The United States Food and Drug Administration (US FDA) has always been a forerunner in drug evaluation and supervision. Over the past 31 years, 1050 drugs (excluding vaccines, cell-based therapies, and gene therapy products) have been approved as new molecular entities (NMEs) or biologics license applications (BLAs). A total of 228 of these 1050 drugs were identified as cancer therapeutics or cancer-related drugs, and 120 of them were classified as therapeutic drugs for solid tumors according to their initial indications. These drugs have evolved from small molecules with broad-spectrum antitumor properties in the early stage to monoclonal antibodies (mAbs) and antibody‒drug conjugates (ADCs) with a more precise targeting effect during the most recent decade. These drugs have extended indications for other malignancies, constituting a cancer treatment system for monotherapy or combined therapy. However, the available targets are still mainly limited to receptor tyrosine kinases (RTKs), restricting the development of antitumor drugs. In this review, these 120 drugs are summarized and classified according to the initial indications, characteristics, or functions. Additionally, RTK-targeted therapies and immune checkpoint-based immunotherapies are also discussed. Our analysis of existing challenges and potential opportunities in drug development may advance solid tumor treatment in the future.

Peritoneal Seeding Is More Common in Gastric Cancer Patients with FGFR2 Amplification or High Tumor Mutation Burden

Fibroblast growth factor receptor-2 (FGFR2) gene alterations have been identified in solid tumors. FGFR2 amplification is found in 2−9% of gastric carcinomas. We hypothesized that FGFR2 could be associated with peritoneal seeding and studied 360 advanced gastric carcinoma patients; 222 (61.7%) were male, 246 (73.7%) had poorly differentiated histology, and 175 (48.6%) presented with peritoneal seeding. High tumor mutation burden (TMB) was observed in 44 (12.2%) patients, high microsatellite instability (MSI) was observed in 12 (3.33%) patients, ERBB2 amplification was observed in 44 (12.2%) patients, EBV positivity was observed in 10 (10/278; 3.6%) patients, and PD-L1 positivity was observed in 186 (186/264; 70.5%) cases. We found FGFR2 amplification in 26 (7.2%) patients, of which 12 (46.2%) were female and 22 (84.6%) had poorly differentiated histology. In these 26 cases, the copy number of FGFR2 amplification ranged from 3.7 to 274. Eighteen of them showed seeding, and this association was statistically significant (18/26, 69.2%; 157/334, 47%; p = 0.023). In addition, high TMB was significantly associated with seeding (p = 0.028; OR = 1.83). Poorly differentiated histology was significantly associated with seeding (p = 0.04) but not with FGFR2 amplification (p > 0.1). Seeding was frequent in gastric carcinoma patients with FGFR2 amplification, in patients with high TMB, or in those who were female. The subgroup of patients with FGFR2 amplification could be potential candidates for targeted therapeutic agents.

Validated UPLC-MS/MS Method for Determination of Futibatinib and Its Pharmacokinetics in Beagle Dogs

Futibatinib, a highly selective, irreversible potent fibroblast growth factor receptor (FGFR) inhibitor, has been proved to be effective in clinical trials of intrahepatic cholangiocarcinoma (ICCA) patients. An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to determine the concentration of futibatinib in beagle dog plasma was developed and validated for the study of pharmacokinetics. After the plasma protein was removed by acetonitrile precipitation, futibatinib was detected and derazantinib was used as the internal standard (IS). Futibatinib and IS were separated in an UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with acetonitrile and 0.1% formic acid as the mobile phase, and the flow rate was 0.3 mL/min. Under the positive ion condition of an electrospray spray ion (ESI+) source, multireaction detection was used, and the ion pairs for futibatinib and IS were m/z 418.99 ⟶ 295.97 and 468.96 ⟶ 382.00, respectively. Futibatinib had a good linear relationship in the linear range of 0.5∼100 ng/mL; the lower limit of quantification (LLOQ) was 0.5 ng/mL. The RSDs of the intraday and interday precision were all less than 10.70%, and the RE value of accuracy was between −3.87% and 3.28%. The extraction recovery of futibatinib was more than 80%, and the matrix effect was around 100%, and futibatinib was found to be stable under four experimental conditions. The new optimized and validated UPLC-MS/MS method was an effective tool to determine the concentration of futibatinib in plasma and has been successfully applied to the pharmacokinetics of futibatinib in beagle dogs. This method would also be used to study drug-drug interaction (DDI).

Functional Investigation of the Tumoural Heterogeneity of Intrahepatic Cholangiocarcinoma by In Vivo PET-CT Navigation: A Proof-of-Concept Study

Intra-tumoural heterogeneity (IH) is a major determinant of resistance to therapy and outcomes but remains poorly translated into clinical practice. Intrahepatic cholangiocarcinoma (ICC) often presents as large heterogeneous masses at imaging. The present study proposed an innovative in vivo technique to functionally assess the IH of ICC. Preoperative 18F-FDG PET-CT and intraoperative ultrasonography were merged to perform the intraoperative navigation of functional tumour heterogeneity. The tumour areas with the highest and the lowest metabolism (SUV) at PET-CT were selected, identified during surgery, and sampled. Three consecutive patients underwent the procedure. The areas with the highest uptake at PET-CT had higher proliferation index (KI67) values and higher immune infiltration compared to areas with the lowest uptake. One of the patients showed a heterogeneous presence of FGFR2 translocation within the samples. Tumour heterogeneity at PET-CT may drive biopsy to sample the most informative ICC areas. Even more relevant, these preliminary data show the possibility of achieving a non-invasive evaluation of IH in ICC, paving the way for an imaging-based precision-medicine approach.

Outcomes following FGFR Inhibitor Therapy in Patients with Cholangiocarcinoma

BACKGROUND

Sequencing efforts in patients with cholangiocarcinoma (CCA) have provided insights into molecular mechanisms including fibroblast growth factor receptor (FGFR) alterations. There is a lack of data on outcomes of patients following cessation of FGFR inhibitor (FGFRi) therapy.

OBJECTIVE

We describe the clinical outcomes following initial FGFRi treatment in CCA harboring FGFR alterations.

PATIENTS AND METHODS

We conducted a multicentric, retrospective analysis of patients with FGFR-altered CCA diagnosed between 2010 and 2021. Median overall survival (OS) and progression-free survival (PFS) analyses were performed using the Kaplan-Meier method.

RESULTS

We identified 88 advanced or metastatic CCA patients, 28 males (31.8%) and 60 females (68.2%), harboring FGFR alterations who received FGFRi. Median PFS on initial FGFRi was 6.6 months (95% confidence interval (CI): 5.5-8.3). Following cessation of first FGFRi therapy, 55% patients received systemic therapy as next line: 67% received chemotherapy or targeted treatment and 33% received another FGFRi. Median PFS for patients who received chemotherapy or targeted agent was 2.1 months (95% CI 1.6-5.7) and for patients who received a second FGFRi was 3.7 months (95% CI 1.5-not evaluable). OS was 2.0 months for patients who did not receive any therapy compared to 8.7 months with chemotherapy and 8.6 months with another FGFRi. In addition, one patient treated with pemigatinib developed FGFR2 M540_I541insMM alteration at time of resistance, which has not been functionally characterized and its effect on protein function remains unknown.

CONCLUSIONS

Understanding the mechanisms of resistance with FGFRi is essential to understand sequencing of treatments. In this study, patients received standard chemotherapy in the first line and were fit enough to be considered for subsequent therapy with an FGFRi. Almost half of the patients become ineligible to receive further systemic therapy following progression on FGFRi. As more agents are being introduced, detailed understanding of outcomes following treatment with an FGFRi, including subsequent FGFRi, is essential.

Electrolytes disturbances in cancer patients

PURPOSE OF REVIEW

Hypernatremia, hyperphosphatemia, hypocalcaemia, hyperkalaemia and hypermagnesemia are electrolytes disturbances that can arise in cancer patients in relation to unique causes that are related to the cancer itself or its treatment and can lead to delay or interruption of cancer therapy. This article summarizes these main causes, the proposed pathophysiology and the recommended management for these disturbances.

RECENT FINDINGS

There have been many cancer drugs approved in the field of oncology over the past several years and a subset of these drugs have been associated with electrolytes disturbances. This includes, for example, immune checkpoint inhibitor related hyperkalemia, fibroblast growth factor 23 inhibitor associated hyperphosphatemia and epidermal growth factor receptor inhibitor associated hypomagnesemia and hypocalcaemia.

SUMMARY

This article provides an updated review of certain electrolytes disturbance in cancer patients and allows clinicians to have a greater awareness and knowledge of these electrolyte abnormalities in efforts to early recognition and timely management.

Synergizing liver systemic treatments with interventional oncology: friend or foe?

Interventional radiology techniques provide excellent local tumor control for small tumors in various organs, but several limitations can hamper the oncological outcomes such as the tumor size or the number of lesions. Technical improvements, optimal patient selection and combination with systemic therapies, including immune checkpoint inhibitors, have been successfully developed to overcome these barriers.In this setting, chemotherapy and targeted therapies aim to diminish the tumor burden in addition to local treatments, while immunotherapies may have a synergistic effect in terms of mechanism of action on the tumor cell as well as the immune environment, with multiple treatment combinations being available. Finally, interventional Rrdiology treatments often increase tumor antigen exposure to the immune system, and thus stimulate a specific antitumor immune response that can act beyond the treated site. Notwithstanding their many benefits, combination treatment may also result in complications, the most feared may be auto-immune-related adverse events.In early studies, several combined therapies have shown promising levels of safety and efficacy, particularly in hepatocellular carcinoma.This review provides a comprehensive and up-to-date overview of results of combined therapies for primary and secondary liver malignancies. Recent advances and future perspectives will be discussed.

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.

Pemigatinib for adults with previously treated, locally advanced or metastatic cholangiocarcinoma with FGFR2 fusions/rearrangements

Biliary tract cancers are a diverse and aggressive malignancy that carry a poor chance for curative treatment and significant associated mortality. Current first-line treatment only extends median overall survival to roughly 1 year and is associated with a significant adverse event profile. Recently, advancements in genetic sequencing have opened new avenues of targeted treatment. In cholangiocarcinoma, FGFR2 alterations have been shown to be present in roughly 10-15% of intrahepatic cholangiocarcinoma. Pemigatinib, a FGFR1-4 inhibitor, has been shown to significantly extend survival in the second-line setting to over 20 months in patients who harbor FGFR2 fusions. Here, we outline the development and future direction of pemigatinib and other FGFR2 inhibitors in the field of advanced biliary tract cancers.

Identification of a novel FGFR2-KIAA1217 fusion in esophageal gastrointestinal stromal tumours: A case report

Background

Gastrointestinal stromal tumours (GISTs) rarely arise in the esophagus. The clinical course and treatment options for esophageal GISTs are poorly understood because of their rarity. In general, the mutation spectrum of esophageal GISTs resembles that of gastric GISTs. Wild-type (WT) GISTs lacking KIT and PDGFRA gene mutations occasionally occur in adults; primary esophageal GISTs are commonly WT.

Case presentation

Herein, we report the case of a 41-year-old female patient who presented with a 1-week history of anterior upper chest pain. Chest computed tomography revealed a 3.7 cm × 2.8 cm × 6.7 cm soft tissue mass in the right posterior mediastinum adjacent to the esophagus. The patient underwent thoracoscopic mediastinal tumor resection and was subsequently diagnosed with an esophageal GIST. Neither KIT nor PDGFRA mutations were detected by Sanger sequencing; however, next-generation sequencing (NGS) identified an FGFR2-KIAA1217 gene fusion in the tumor tissue. No relapse was observed in this patient during the 8-month treatment-free follow-up period.

Conclusion

To the best of our knowledge, this report is the first to describe an FGFR2-KIAA1217 fusion in a patient with a quadruple WT esophageal GIST. When WT KIT/PDGFRA GISTS are suspected, intensive genetic analysis is recommended, and obtaining a better molecular characterization of these tumours might reveal novel therapeutic avenues.

Genomic mutation characteristics and prognosis of biliary tract cancer

BACKGROUND

The incidence of biliary system cancer is higher in the Chinese population than in the West. The overall prognosis of gallbladder cancer and cholangiocarcinoma is poor, and the current treatment is limited. In order to explore the pathogenesis of biliary tract cancers and potential targeted therapies, we mapped the mutation landscape of biliary tract cancer in the Chinese population and analyzed the molecular mechanism related to prognosis.

METHODS

A total of 59 formalin fixed paraffin-embedded (FFPE) tissue samples were obtained from patients with operable biliary tract cancer. We conducted targeted capture sequencing of 620 genes through high-throughput sequencing technology and analyzed the fusion information of 13 genes.

RESULTS

Mutations were detected in 88% samples, and the most frequent mutation base was C>T. Genes with higher single nucleotide variations (SNV) and copy number variations (CNV) frequency are TP53, KRAS, ARID1A, VEGFA, cyclin family related genes and cyclin-dependent kinase genes. Actionable mutations were detected in 59.3% samples, and germline mutations were detected in 22% samples. Patients with KRAS mutations, VEGFA pathway mutations and higher tumor mutation burden (TMB) may have poor prognosis.

CONCLUSIONS

We explored the mutation characteristics and prognostic mechanism of biliary tract cancers in the Chinese population. This study provides potential evidence for targeted therapy and immunotherapy of biliary tract cancers.

New developments in the biology of fibroblast growth factors

The fibroblast growth factor (FGF) family is composed of 18 secreted signaling proteins consisting of canonical FGFs and endocrine FGFs that activate four receptor tyrosine kinases (FGFRs 1-4) and four intracellular proteins (intracellular FGFs or iFGFs) that primarily function to regulate the activity of voltage-gated sodium channels and other molecules. The canonical FGFs, endocrine FGFs, and iFGFs have been reviewed extensively by us and others. In this review, we briefly summarize past reviews and then focus on new developments in the FGF field since our last review in 2015. Some of the highlights in the past 6 years include the use of optogenetic tools, viral vectors, and inducible transgenes to experimentally modulate FGF signaling, the clinical use of small molecule FGFR inhibitors, an expanded understanding of endocrine FGF signaling, functions for FGF signaling in stem cell pluripotency and differentiation, roles for FGF signaling in tissue homeostasis and regeneration, a continuing elaboration of mechanisms of FGF signaling in development, and an expanding appreciation of roles for FGF signaling in neuropsychiatric diseases. This article is categorized under: Cardiovascular Diseases > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology Congenital Diseases > Stem Cells and Development Cancer > Stem Cells and Development.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Advances in Diagnosis and Therapy for Bladder Cancer

Bladder cancer (BCa) is one of the most common and expensive urinary system malignancies for its high recurrence and progression rate. In recent years, immense amounts of studies have been carried out to bring a more comprehensive cognition and numerous promising clinic approaches for BCa therapy. The development of innovative enhanced cystoscopy techniques (optical techniques, imaging systems) and tumor biomarkers-based non-invasive urine screening (DNA methylation-based urine test) would dramatically improve the accuracy of tumor detection, reducing the risk of recurrence and progression of BCa. Moreover, intravesical instillation and systemic therapeutic strategies (cocktail therapy, immunotherapy, vaccine therapy, targeted therapy) also provide plentiful measures to break the predicament of BCa. Several exploratory clinical studies, including novel surgical approaches, pharmaceutical compositions, and bladder preservation techniques, emerged continually, which are supposed to be promising candidates for BCa clinical treatment. Here, recent advances and prospects of diagnosis, intravesical or systemic treatment, and novel drug delivery systems for BCa therapy are reviewed in this paper.

Chimeric transcripts observed in non-canonical FGFR2 fusions with partner genes' breakpoint located in intergenic region in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a fatal bile duct cancer with dismal prognosis and limited therapeutic options. FGFR family fusion have been identified in many diseases, and FGFR2 fusion is a validated oncogenic driver in ICC. At present, a variety of fusion forms have been reported, including gene-gene, gene-intergenic, and intergenic-intergenic fusion. Here, by performing RNA- and DNA-sequencing analysis, FGFR2 fusions were found in 10.1% of ICC, including 4 gene-intergenic fusions. We confirmed that the non-canonical rearrangements can generate chimeric transcripts, and used conventional splicing mechanism to explain the event. Our study provides possible target therapy for these 4 patients and possibility analysis scheme for similar situation.

The state of therapy modalities in clinic for biliary tract cancer

Biliary tract cancers (BTCs) include intrahepatic cholangiocarcinoma (iCCA), perihilar and distal cholangiocarcinoma (pCCA and dCCA), and gallbladder carcinoma based on the epithelial site of origin. BTCs are highly aggressive tumors associated with poor prognosis due to widespread metastasis and high recurrence. Surgery is the typical curative-intent treatment, yet the cornerstone of cure depends on the anatomical site of the primary tumor, and only a minority of patients (approximately 30%) has an indication necessitating surgery. Similarly, only a small subset of carefully selected patients with early iCCA who are not candidates for liver resection can opt for liver transplantation. Chemotherapy, target therapy, and immunotherapy are the main treatment options for patients who have advanced stage or unresectable disease. The genetic background of each cholangiocarcinoma subtype has been accurately described based on whole gene exome and transcriptome sequencing. Accordingly, precision medicine in targeted therapies has been identified to be aimed at distinct patient subgroups harboring unique molecular alterations. Immunotherapy such as immune checkpoint inhibitors (ICIs) was identified as antitumor responses in a minority of select patients. Current studies indicate that immunotherapy of adoptive cell therapy represents a promising approach in hematological and solid tumor malignancies, yet clinical trials are needed to validate its effectiveness in BTC. Herein, we review the progress of BTC treatment, stratified patients according to the anatomic subtypes of cholangiocarcinoma and the gene drivers of cholangiocarcinoma progression, and compare the efficacy and safety of chemotherapy, targeted therapy, and immunotherapy, which will be conducive to the design of individualized therapies.

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

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.

Prognostic impact of FGFR2/3 alterations in patients with biliary tract cancers receiving systemic chemotherapy: the BITCOIN study

AIM

FGFR2 rearrangements have been identified as a novel therapeutic target of biliary tract cancer (BTC). However, reliable prevalence estimates of this molecular alteration and its prognostic role have not been fully elucidated.

METHODS

A retrospective mono-institutional series of 286 patients affected by locally advanced or metastatic BTC (183 intrahepatic cholangiocarcinomas, 67 extrahepatic cholangiocarcinomas, 36 gallbladder carcinomas) was profiled by means of targeted DNA/RNA next-generation sequencing, immunohistochemistry and fluorescence in situ hybridisation for FGFR2/3, ERBB2, NTRK alterations, IDH1/2 and BRAF mutations and DNA mismatch repair complex proteins alterations/microsatellite instability.

RESULTS

FGFR2 rearrangements, amplifications and point mutations were detected in 15 (5.2%), 1 and 3 cases, respectively. FGFR3 alterations were observed in 5 (1.7%) cases. IDH1/2 were mutated in 35/223 cases (15.7%). A total of 9/258 (3.5%) and 6/260 (2.3%) BTCs had ERBB2 and BRAF gene alterations, respectively. Two cases (2/242; 0.8%) had NTRK1 amplifications but no rearrangement was found. A deficit of mismatch repair protein expression was identified in 9/237 cases (3.8%). At multivariate analysis, age, ECOG performance status, number of metastatic sites, tumour stage, FGFR2/3 alterations and IDH1/2 mutations were prognostic factors of overall survival.

CONCLUSIONS

These data provide a strong proof - challenged with a robust and detailed multivariate model - that FGFR2/3 aberrations (including FGFR2 rearrangements) and IDH1/2 mutations can be prognostic for better survival in patients with BTC . The recognition and the measurement of their prognostic impact could be of primary importance for the correct interpretation of currently available data and in the design of new therapeutic trials.

FIGHT-101, a first-in-human study of potent and selective FGFR 1-3 inhibitor pemigatinib in pan-cancer patients with FGF/FGFR alterations and advanced malignancies

BACKGROUND

The phase I/II FIGHT-101 study (NCT02393248) evaluated safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of pemigatinib, a potent and selective fibroblast growth factor receptor (FGFR) 1-3 inhibitor, as monotherapy or in combination therapy, for refractory advanced malignancies, with and without fibroblast growth factor (FGF) and receptor (FGFR) gene alterations.

PATIENTS AND METHODS

Eligible, molecularly unselected patients with advanced malignancies were included in part 1 (dose escalation; 3 + 3 design) to determine the maximum tolerated dose. Part 2 (dose expansion) evaluated the recommended phase II dose in tumors with or where FGF/FGFR activity is relevant.

RESULTS

Patients (N = 128) received pemigatinib 1-20 mg once daily intermittently (2 weeks on/1 week off; n = 70) or continuously (n = 58). No dose-limiting toxicities were reported. Doses ≥4 mg were pharmacologically active (maximum tolerated dose not reached; recommended phase II dose 13.5 mg once daily). The most common treatment-emergent adverse event (TEAE) was hyperphosphatemia (75.0%; grade ≥3, 2.3%); the most common grade ≥3 TEAE was fatigue (10.2%). Dose interruption, dose reduction, and TEAE-related treatment discontinuation occurred in 66 (51.6%), 14 (10.9%), and 13 (10.2%) patients, respectively. Overall, 12 partial responses were achieved, most commonly in cholangiocarcinoma (n = 5) as well as in a broad spectrum of tumors including head and neck, pancreatic, gallbladder, uterine, urothelial carcinoma, recurrent pilocytic astrocytoma, and non-small-cell lung cancer (each n = 1); median duration of response was 7.3 months [95% confidence interval (CI) 3.3-14.5 months]. Overall response rate was highest for patients with FGFR fusions/rearrangements [n = 5; 25.0% (95% CI 8.7% to 49.1%)], followed by those with FGFR mutations [n = 3; 23.1% (95% CI 5.0% to 53.8%)].

CONCLUSIONS

Pemigatinib was associated with a manageable safety profile and pharmacodynamic and clinical activity, with responses seen across tumors and driven by FGFR fusions/rearrangements and mutations. These results prompted a registrational study in cholangiocarcinoma and phase II/III trials in multiple tumor types demonstrating the benefit of precision therapy, even in early phase trials.

An Insight into the Novel Immunotherapy and Targeted Therapeutic Strategies for Hepatocellular Carcinoma and Cholangiocarcinoma

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) constitute highly malignant forms of primary liver cancers. Hepatocellular and bile duct carcinogenesis is a multiplex process, caused by various genetic and epigenetic alterations, the influence of environmental factors, as well as the implication of the gut microbiome, which was undervalued in the previous years. The molecular and immunological analysis of the above malignancies, as well as the identification of the crucial role of intestinal microbiota for hepatic and biliary pathogenesis, opened the horizon for novel therapeutic strategies, such as immunotherapy, and enhanced the overall survival of cancer patients. Some of the immunotherapy strategies that are either clinically applied or under pre-clinical studies include monoclonal antibodies, immune checkpoint blockade, cancer vaccines, as well as the utilization of oncolytic viral vectors and Chimeric antigen, receptor-engineered T (CAR-T) cell therapy. In this current review, we will shed light on the recent therapeutic modalities for the above primary liver cancers, as well as on the methods for the enhancement and optimization of anti-tumor immunity.

Genomic alterations in cholangiocarcinoma: clinical significance and relevance to therapy

Improving the survival of patients with cholangiocarcinoma (CCA) has long proved challenging, although the treatment of this disease nowadays is on advancement. The historical invariability of survival outcomes and the limited number of agents known to be effective in the treatment of this disease has increased the number of studies designed to identify genetic targetable hits that can be efficacious for novel therapies. In this respect, the increasing feasibility of molecular profiling starting either from tumor tissue or circulating cell-free DNA (cfDNA) has led to an increased understanding of CCA biology. Intrahepatic CCA (iCCA) and extrahepatic CCA (eCCA) display different and typical patterns of actionable genomic alterations, which offer opportunity for therapeutic intervention. This review article will summarize the current knowledge on the genomic alterations of iCCA and eCCA, provide information on the main technologies for genomic profiling using either tumor tissue or cfDNA, and briefly discuss the main clinical trials with targeted agents in this disease.

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.

FDFT1/FGFR2 rearrangement: A newly identified anlotinib-sensitive FGFR2 variant in cholangiocarcinoma

According to previous reports,10-16% of patients with clinically advanced cholangiocarcinoma develop FGFR2 fusions or rearrangements. Treatment with FGFR2-specific inhibitors (tyrosine kinase inhibitors, TKIs) has proven effective for patients with cholangiocarcinoma. In this study, we report a case of advanced cholangiocarcinoma, in which the patient was unable to tolerate the adverse effects of standard first-line chemotherapy. Genetic testing suggested the presence of a novel variant resulting from FDFT1/FGFR2 rearrangement. Owing to poor accessibility and high price, only a limited number of patients with advanced cholangiocarcinoma have access to TKIs and precision targeted therapy in China. Anlotinib is a novel small-molecule multi-target TKI developed independently in China. It has a broad target spectrum, including FGFR, and can effectively inhibit tumor angiogenesis and tumor cell proliferation, thereby achieving an anti-tumor effect. Here, the patient was prescribed anlotinib. After treatment, the tumor size continued to shrink, and no significant adverse effects were reported. The finding suggested that anlotinib may be effective in patients with FDFT1/FGFR2 rearrangement and could serve as a novel treatment option for affected patients in future.

EGFR Inhibition Potentiates FGFR Inhibitor Therapy and Overcomes Resistance in FGFR2 Fusion-Positive Cholangiocarcinoma

FGFR inhibitors are approved for the treatment of advanced cholangiocarcinoma harboring FGFR2 fusions. However, the response rate is moderate, and resistance emerges rapidly due to acquired secondary FGFR2 mutations or due to other less-defined mechanisms. Here, we conducted high-throughput combination drug screens, biochemical analysis, and therapeutic studies using patient-derived models of FGFR2 fusion-positive cholangiocarcinoma to gain insight into these clinical profiles and uncover improved treatment strategies. We found that feedback activation of EGFR signaling limits FGFR inhibitor efficacy, restricting cell death induction in sensitive models and causing resistance in insensitive models lacking secondary FGFR2 mutations. Inhibition of wild-type EGFR potentiated responses to FGFR inhibitors in both contexts, durably suppressing MEK&sol;ERK and mTOR signaling, increasing apoptosis, and causing marked tumor regressions in vivo. Our findings reveal EGFR-dependent adaptive signaling as an important mechanism limiting FGFR inhibitor efficacy and driving resistance and support clinical testing of FGFR&sol;EGFR inhibitor therapy for FGFR2 fusion-positive cholangiocarcinoma.

SIGNIFICANCE

We demonstrate that feedback activation of EGFR signaling limits the effectiveness of FGFR inhibitor therapy and drives adaptive resistance in patient-derived models of FGFR2 fusion-positive cholangiocarcinoma. These studies support the potential of combination treatment with FGFR and EGFR inhibitors as an improved treatment for patients with FGFR2-driven cholangiocarcinoma.

Fibroblast Growth Factor Receptor 1-4 Genetic Aberrations as Clinically Relevant Biomarkers in Squamous Cell Lung Cancer

Fibroblast growth factor receptor (FGFR) inhibitors (FGFRis) are a potential therapeutic option for squamous non-small cell lung cancer (Sq-NSCLC). Because appropriate patient selection is needed for targeted therapy, molecular profiling is key to discovering candidate biomarker(s). Multiple FGFR aberrations are present in Sq-NSCLC tumors-alterations (mutations and fusions), amplification and mRNA/protein overexpression-but their predictive potential is unclear. Although FGFR1 amplification reliability was unsatisfactory, FGFR mRNA overexpression, mutations, and fusions are promising. However, currently their discriminatory power is insufficient, and the available clinical data are from small groups of Sq-NSCLC patients. Here, we focus on FGFR aberrations as predictive biomarkers for FGFR-targeting agents in Sq-NSCLC. Known and suggested molecular determinants of FGFRi resistance are also discussed.

Robust Response to Futibatinib in a Patient With Metastatic FGFR-Addicted Cholangiocarcinoma Previously Treated Using Pemigatinib

Futibatinib is a novel FGFR inhibitor currently under investigation as a second-line treatment for locally advanced or metastatic cholangiocarcinoma harboring FGFR2 gene fusions and rearrangements. As FGFR-targeted therapies move into the frontline setting, sequencing of these drugs remains undetermined. To date, no study has investigated the use of futibatinib in the context of pemigatinib resistance. We describe a 50-year-old woman with metastatic FGFR-aberrant intrahepatic cholangiocarcinoma who showed a robust response to futibatinib for 23.6 months, having previously benefited from pemigatinib. Futibatinib was safely used despite her history of decompensated cirrhosis and significant cytopenias. We observed a reduction in CA 19-9 level and a partial radiographic response on futibatinib. Serial next-generation sequencing and cell-free DNA testing proved crucial to making appropriate treatment decisions.

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.

Validation and Characterization of FGFR2 Rearrangements in Cholangiocarcinoma with Comprehensive Genomic Profiling

Cholangiocarcinoma (CCA) is a heterogeneous biliary tract cancer with a poor prognosis. Approximately 30% to 50% of patients harbor actionable alterations, including FGFR2 rearrangements. Pemigatinib, a potent, selective fibroblast growth factor receptor (FGFR) FGFR1-3 inhibitor, is approved for previously treated, unresectable, locally advanced or metastatic CCA harboring FGFR2 fusions/rearrangements, as detected by a US Food and Drug Administration-approved test. The next-generation sequencing (NGS)-based FoundationOneCDx (F1CDx) was US Food and Drug Administration approved for detecting FGFR2 fusions or rearrangements. The precision and reproducibility of F1CDx in detecting FGFR2 rearrangements in CCA were examined. Analytical concordance between F1CDx and an externally validated RNA-based NGS (evNGS) test was performed. Identification of FGFR2 rearrangements in the screening population from the pivotal FIGHT-202 study (NCT02924376) was compared with F1CDx. The reproducibility and repeatability of F1CDx were 90% to 100%. Adjusted positive, negative, and overall percentage agreements were 87.1%, 99.6%, and 98.3%, respectively, between F1CDx and evNGS. Compared with evNGS, F1CDx had a positive predictive value of 96.2% and a negative predictive value of 98.5%. The positive percentage agreement, negative percentage agreement, overall percentage agreement, positive predictive value, and negative predictive value were 100% for F1CDx versus the FIbroblast Growth factor receptor inhibitor in oncology and Hematology Trial-202 (FIGHT-202) clinical trial assay. Of 6802 CCA samples interrogated, 9.2% had FGFR2 rearrangements. Cell lines expressing diverse FGFR2 fusions were sensitive to pemigatinib. F1CDx demonstrated sensitivity, reproducibility, and high concordance with clinical utility in identifying patients with FGFR2 rearrangements who may benefit from pemigatinib treatment.

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

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

Targeted Therapies for Perihilar Cholangiocarcinoma

Perihilar cholangiocarcinoma (pCCA) is the anatomical sub-group of biliary tract cancer (BTC) arising between the second-order intrahepatic bile ducts and the cystic duct. Together with distal and intrahepatic cholangiocarcinoma (dCCA and iCCA; originating distal to, and proximal to this, respectively), gallbladder cancer (GBC) and ampulla of Vater carcinoma (AVC), these clinicopathologically and molecularly distinct entities comprise biliary tract cancer (BTC). Most pCCAs are unresectable at diagnosis, and for those with resectable disease, surgery is extensive, and recurrence is common. Therefore, the majority of patients with pCCA will require systemic treatment for advanced disease. The prognosis with cytotoxic chemotherapy remains poor, driving interest in therapies targeted to the molecular nature of a given patient's cancer. In recent years, the search for efficacious targeted therapies has been fuelled both by whole-genome and epigenomic studies, looking to uncover the molecular landscape of CCA, and by specifically testing for aberrations where established therapies exist in other indications. This review aims to provide a focus on the current molecular characterisation of pCCA, targeted therapies applicable to pCCA, and future directions in applying personalised medicine to this difficult-to-treat malignancy.

Development and Multicentre Validation of the Modena Score to Predict Survival in Advanced Biliary Cancers Undergoing Second-Line Chemotherapy

Background

The role of second-line chemotherapy in advanced biliary cancers (ABCs) has only recently been established in phase III randomized trial and the optimal selection of patients most likely to benefit from it remains challenging.

Methods

A cohort of 98 ABC treated second-line chemotherapy was used as a developmental dataset to identify covariates independently associated with overall survival (OS). Kaplan–Meier analysis was used to investigate the association between variables and OS and those retaining statistically significance were combined in a multiplexed score.

Results

The following pretreatment variables were independently associated with OS: ECOG PS > 0, peritoneal disease, LDH > 430 UI/L, albumin <3.5 gr/dL, gamma-GT >100 UI/L, sodium <140 mEq/L, absolute lymphocyte count <1000/mmc, and PFS to first-line <6 months. Based on these results, a scoring system was developed that identified three subgroups with statistically different OS: low-risk (mOS 18 months), intermediate-risk (mOS 9.4 months) and high-risk (mOS 2.9 months) (p < 0.001). The prognostic model was both internally and externally validated in a multicentre cohort of 120 ABCs.

Conclusion

The Modena score is a multiplexed scoring system capable of accurately risk-stratified ABCs treated with second-line chemotherapy. Based on its reproducibility, usability and generalizability, it has the potential for assisting therapeutic decision-making in the clinic and risk-stratification in future trials.

Prognostic and Predictive Molecular Markers in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common primary liver cancer and subsumes a heterogeneous group of malignant tumors arising from the intra- or extrahepatic biliary tract epithelium. A rising mortality from CCA has been reported worldwide during the last decade, despite significant improvement of surgical and palliative treatment. Over 50% of CCAs originate from proximal extrahepatic bile ducts and constitute the most common CCA entity in the Western world. Clinicopathological characteristics such as lymph node status and poor differentiation remain the best-studied, but imperfect prognostic factors. The identification of prognostic molecular markers as an adjunct to traditional staging systems may not only facilitate the selection of patients who would benefit the most from surgical, adjuvant or palliative treatment strategies, but may also be helpful in defining the aggressiveness of the disease and identifying patients at high-risk for tumor recurrence. The purpose of this review is to provide an overview of currently known molecular prognostic and predictive markers and their role in CCA.

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.

Chemoresistance and resistance to targeted therapies in biliary tract cancer: what have we learned?

INTRODUCTION

Biliary tract cancer (BTC), including intra- and extrahepatic cholangiocarcinoma and gallbladder cancer, is a rare and highly difficult to manage human malignancy. Besides late diagnosis and associated unresectability, frequently observed unresponsiveness toward and recurrence following chemotherapy or targeted therapy essentially contribute to the dismal prognosis of BTC patients.

AREAS COVERED

The review provides an update on individual mechanisms involved resistance of BTC toward conventional chemotherapy as well as targeted therapies. We review the distinct mechanisms of pharmacoresistance (MPRs) which have been defined in BTC cells on a molecular basis and examine the specific consequences for the various approaches of chemo-, targeted or immunomodulatory therapies.

EXPERT OPINION

Based on currently available experimental and clinical data, the present knowledge about these MPRs in BTCs are summarized. While some possible tactics for overcoming these mechanisms of resistance have been investigated, a BTC-specific and efficient approach based on comprehensive in vitro and in vivo experimental systems is not yet available. Additionally, a reliable monitoring of therapy-relevant cellular changes needs to be established which allows for choosing the optimal drug (combination) before and/or during pharmacological therapy.

Futibatinib, an Irreversible FGFR1-4 Inhibitor, in Patients with Advanced Solid Tumors Harboring FGF/FGFR Aberrations: A Phase I Dose-Expansion Study

Futibatinib, a highly selective, irreversible FGFR1-4 inhibitor, was evaluated in a large multihistology phase I dose-expansion trial that enrolled 197 patients with advanced solid tumors. Futibatinib demonstrated an objective response rate (ORR) of 13.7%, with responses in a broad spectrum of tumors (cholangiocarcinoma and gastric, urothelial, central nervous system, head and neck, and breast cancer) bearing both known and previously uncharacterized FGFR1-3 aberrations. The greatest activity was observed in FGFR2 fusion/rearrangement-positive intrahepatic cholangiocarcinoma (ORR, 25.4%). Some patients with acquired resistance to a prior FGFR inhibitor also experienced responses with futibatinib. Futibatinib demonstrated a manageable safety profile. The most common treatment-emergent adverse events were hyperphosphatemia (81.2%), diarrhea (33.5%), and nausea (30.4%). These results formed the basis for ongoing futibatinib phase II/III trials and demonstrate the potential of genomically selected early-phase trials to help identify molecular subsets likely to benefit from targeted therapy. SIGNIFICANCE: This phase I dose-expansion trial demonstrated clinical activity and tolerability of the irreversible FGFR1-4 inhibitor futibatinib across a broad spectrum of FGFR-aberrant tumors. These results formed the rationale for ongoing phase II/III futibatinib trials in cholangiocarcinoma, breast cancer, gastroesophageal cancer, and a genomically selected disease-agnostic population.This article is highlighted in the In This Issue feature, p. 275.

Population Pharmacokinetics Analysis of Pemigatinib in Patients With Advanced Malignancies

Pemigatinib is a fibroblast growth factor receptor 1–3 inhibitor used to treat cholangiocarcinoma. A compartmental population pharmacokinetics model was developed using data from 318 patients with cancer enrolled in a phase 1 dose‐escalation/dose‐expansion study, a phase 1 Japanese PK bridging study, and a phase 2 cholangiocarcinoma study. The final model for pemigatinib was a 2‐compartment disposition model with first‐order absorption and linear elimination. All fixed‐ and random‐effect parameters were estimated with good precision, and no apparent biases in the overall model fit were observed. For females, the estimated typical pemigatinib absorption rate constant (k_a) and oral clearance (CL/F) were estimated (1.49 L/h and 10.3 L/h, respectively). For males, the typical apparent clearance and k_a are 19.0% higher and 56.5% lower, respectively, compared with females. Typical apparent volume of distribution of the central compartment (V_c/F) and peripheral compartment for a 73.3‐kg patient was estimated to be 122.0 L and 80.1 L, respectively; both increased with body weight. Phosphate binder coadministration decreases typical pemigatinib CL/F by 14.1%. Proton pump inhibitor coadministration increases typical pemigatinib apparent Vc/F by 24.4%. Phosphate binders and sex contribute a <20% change to CL/F. The impact of the investigated covariates on pemigatinib pharmacokinetics are not clinically significant.

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.

Unmet needs in the treatment of intrahepatic cholangiocarcinoma harboring FGFR2 gene rearrangements

Intrahepatic cholangiocarcinoma, a malignancy of the intrahepatic bile ducts, is the second most common primary liver malignancy and has been rising in incidence over the past several decades. Given its poor prognosis and diagnosis at a late stage, novel therapies are urgently needed to improve outcomes. Intrahepatic cholangiocarcinoma harbors a high rate of targetable mutations, spurring an increased interest in drug development in this disease. FGFR2 gene rearrangements occur in approximately 10-16% of these tumors and this underscores the importance of next generation sequencing in this population. There are now several FGFR inhibitors in development, and these agents may help improve outcomes for these patients. However, both primary and secondary resistance remain a challenge.

ESMO Scale for Clinical Actionability of Molecular Targets driving targeted treatment in patients with cholangiocarcinoma

Purpose: Treatment options for advanced cholangiocarcinoma are limited and prognosis is poor. Cholangiocarcinomas are highly heterogeneous at the molecular level, with divergent patterns between intrahepatic and extrahepatic forms, intrahepatic being particularly rich in actionable alterations. We compared survival in patients with advanced cholangiocarcinoma harboring alterations matched to targeted drugs, with patients harboring non-actionable alterations. Experimental design: Patients with cholangiocarcinoma treated between 2011 and 2020 at one institution, with available molecular analyses, were retrospectively reviewed. Genomic alteration actionability was classified according to the ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT) and correlated with efficacy endpoints. Results: Of 327 patients included, 78.9% had intrahepatic cholangiocarcinoma, 97.9% had received chemotherapy for metastatic disease. Actionable molecular alterations per ESCAT were identified in 184 patients (56.3%), including IDH1 mutations and FGFR2 fusions (23.1% and 8.0% of intrahepatic cholangiocarcinoma patients, respectively). Median overall survival in 50 patients with ESCAT I-IV alterations who received matched therapy (48 with intrahepatic cholangiocarcinoma) was 22.6 months (95%CI:20.1-32.8), compared to 14.3 months (95%CI:11.9-18.1) in 130 patients without actionable ESCAT alterations (HR=0.58, 95%CI:0.40-0.85; P=0.005). Among patients receiving matched targeted therapy, median progression-free survival was longer for patients with alterations classified as ESCAT I-II compared to ESCAT III-IV (5.0 versus 1.9 months; HR=0.36, 95%CI:0.15-0.87; P=0.02). Conclusions: ESCAT represents a tool to guide clinicians in fine-tuning use of molecular profiling data to choose matched targeted therapies. Our data demonstrate that targeted treatment administered per alteration actionability according to ESCAT is associated with improved survival in cholangiocarcinoma, particularly in ESCAT I-II intrahepatic cholangiocarcinoma.

Novel and emerging targets for cholangiocarcinoma progression: therapeutic implications

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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.

Treatment of Intrahepatic Cholangiocarcinoma-A Multidisciplinary Approach

Simple Summary

This review discusses multimodality treatment strategies for intrahepatic cholangiocarcinoma (iCC). Surgical resection remains the only potentially curative therapeutic option and the central cornerstone of treatment. Adjuvant systemic treatment will be recommended after resection or in the palliative setting. Increasing knowledge of phenotypic subclassification and molecular profiling allows investigation of targeted therapies as (neo-)adjuvant treatment. High-dose brachytherapy, internal radiation therapy, and transarterial chemoembolization are among the interventional treatment options being evaluated for unresectable iCC. Given the multiple options of multidisciplinary management, any treatment strategy should be discussed in a multidisciplinary tumor board and treatment should be directed by a specialized treatment center.

Abstract

Intrahepatic cholangiocarcinoma (iCC) is distinguished as an entity from perihilar and distal cholangiocarcinoma and gallbladder carcinoma. Recently, molecular profiling and histopathological features have allowed further classification. Due to the frequent delay in diagnosis, the prognosis for iCC remains poor despite major technical advances and multimodal therapeutic approaches. Liver resection represents the therapeutic backbone and only curative treatment option, with the functional residual capacity of the liver and oncologic radicality being deciding factors for postoperative and long-term oncological outcome. Furthermore, in selected cases and depending on national guidelines, liver transplantation may be a therapeutic option. Given the often advanced tumor stage at diagnosis or the potential for postoperative recurrence, locoregional therapies have become increasingly important. These strategies range from radiofrequency ablation to transarterial chemoembolization to selective internal radiation therapy and can be used in combination with liver resection. In addition, adjuvant and neoadjuvant chemotherapies as well as targeted therapies and immunotherapies based on molecular profiles can be applied. This review discusses multimodal treatment strategies for iCC and their differential use.