Biliary tract cancers (BTCs) are a histologically and molecularly diverse group of malignancies arising from the gallbladder and the ductal epithelium of the biliary tree. Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver malignancy in the United States. Surgical resection with negative margins is the only recognized curative treatment option for iCCA; however, most patients will present with advanced or unresectable disease. The clinical presentation is largely non-specific, with the characteristic symptoms of biliary malignancies being less frequent than extrahepatic cholangiocarcinoma. Clinical management in iCCA is heavily influenced by the molecular profile of individual tumors. Hence, pathologists must exercise caution to prevent tissue exhaustion during the diagnostic workup of iCCA and ensure the availability of tissue samples for molecular testing. Establishing standardized procedures for obtaining adequate tissue and using molecular testing is vital. Circulating tumor DNA (ctDNA) offers a potential alternative to tissue-based analysis, especially in cases with insufficient tissue samples. Drugs targeting alterations in NTRK, IDH1, BRAF, FGFR2, and HER2 are commonly utilized. Targeting the MDM2-p53 pathway represents an avenue for future investigations in advanced BTCs. Liver transplantation and locoregional therapies are treatment modalities that may represent curative intent treatments for patients with unresectable disease, and larger explorations are warranted. Akin to HCC, a multidisciplinary team-based approach is essential for patients with BTCs. Through this narrative review of literature, we provide an overview of the current management of iCCA with perspectives regarding future directions in the clinical management of iCCA. We also present patient perspectives regarding the importance of patient advocacy and access to advances in clinical research for patients with BTCs.

The selective inhibition of fibroblast growth factor receptors (FGFR) presents a significant challenge due to the high degree of sequence and the close structural similarity of the subtypes. Herein, we designed selective dual FGFR2/3 inhibitors based on the in-depth understanding of protein-ligand interaction contributions. We efficiently identified ISM7594 (4) with distinctive flexible hinge binder and a unique central core that potently inhibited FGFR2/3 and selectively spared FGFR1/4. The "magic methyl" effect played a crucial role in enhancing the activity. ISM7594 maintained strong activity against multiple FGFR2/3 mutants known to drive resistance to current drugs and broad-spectrum antiproliferative potency in cancer cells harboring diverse FGFR2/3 alterations, including FGFR2/3 amplification, fusion, and mutation types. The compound demonstrated robust tumor growth suppression, favorable pharmacokinetic profile, and pharmacodynamic effects. This study supports the preclinical development of ISM7594 and demonstrates its potential in advancing tissue-agnostic therapy for advanced solid tumors with FGFR2/3 aberrations and mutation resistance.

Biliary tract cancers (BTCs) are classified on the basis of their anatomical origin, and the feasibility of surgical resection depends on the tumor location and extent of progression. However, for unresectable BTCs, systemic therapy has been uniformly applied. Gemcitabine and cisplatin (GC) therapy and GC-based therapies were established as the first-line standard BTC treatment. However, no highly effective second-line therapy has been established, and the prognosis remains poor, highlighting the need for further therapeutic advancements. Meanwhile, the era of precision medicine has expanded the use of genetic testing, leading to the identification of actionable molecular targets in BTC. Several targeted therapies, including FGFR inhibitors and IDH1 inhibitors, have been developed, offering new second-line treatment options and the potential for first-line use in appropriate cases. Notably, the frequency of these genetic alterations varies depending on the tumor location, demonstrating the molecular heterogeneity of BTC. Therefore, it has been recognized that a tailored treatment approach for each BTC patient may be more effective than uniform systemic therapy. Consequently, although routine genetic testing before initiating systemic treatment is currently limited by the medical environment (e.g., cost, accessibility, regional differences), it is recommended in ESMO guideline and might be increasingly advocated. However, BTC harbors a wide range of genetic alterations, and numerous targeted therapies are being developed accordingly. This review provides an overview of the reported genetic alterations in BTC, the frequencies of these alterations, and the corresponding targeted therapies, emphasizing the evolving role of precision medicine in BTC treatment.

Fibroblast growth factor receptors (FGFRs; FGFR1, FGFR2, FGFR3, FGFR4) are frequently mutated oncogenes in solid cancers. The oncogenic potential of FGFR rearrangements and few hotspot point mutations is well established, but the majority of variants resulting from point mutations especially outside of the tyrosine kinase domain are currently considered variants of unknown significance (VUS).

Recurrent nonkinase domain FGFR VUS variants were collected from the Catalog of Somatic Mutations in Cancer and their oncogenic potential was assessed in vitro by different functional assays. We compiled published clinical and preclinical data on FGFR variants and compared the data with results from our functional assays and pathogenicity predictions of state-of-the-art artificial intelligence (AI) models.

We identified 12 novel FGFR extracellular small variants with potential driver function. Comparison of clinical and preclinical data on FGFR variants with pathogenicity predictions of state-of-the-art AI models showed limited usefulness of the AI predictions. Sensitivity profiles of activating FGFR variants to targeted inhibitors were recorded and showed good targetability of FGFR nonkinase domain variants.

The collected results extend the spectrum of suitable FGFR variants for potential treatment with FGFR inhibitors in the context of clinical trials and beyond. Current AI models for variant pathogenicity prediction require further refinement for use in oncogenic decision making.

Predicting patients who will benefit from postoperative adjuvant chemotherapy is crucial for precision medicine. Therefore, this study comprehensively analyzed messenger RNA (mRNA) expression profiles to identify novel biomarkers and developed a prediction signature for postoperative adjuvant chemotherapy in patients with gastric cancer (GC).

Biomarkers were discovered by analyzing two publicly available genome-wide datasets from 343 patients with pathologic stages (pStages) II and III GC. A novel prediction signature was developed based on a quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay using 137 pStages II and III GC frozen tissue specimens.

Nine novel mRNAs were identified as candidate biomarkers in biomarker discovery, and a Gene Expression-based ADJuvant chemotherapy Response prediction for stages II and III GC (GEx-ADJ-Res) signature was developed using these candidate biomarkers and key clinicopathologic features by qRT-PCR assay. The GEx-ADJ-Res signature robustly predicted postoperative recurrence in clinical tissue samples (area under the curve [AUC], 0.84). The signature demonstrated sufficient potential for predicting response to postoperative adjuvant chemotherapy (AUC, 0.82) and was shown to be an independent predictor of postoperative recurrence and survival in multivariate analysis. Finally, the GEx-ADJ-Res signature was successfully validated using independent multi-institutional datasets (AUC, 0.91, 0.85, and 0.78, respectively).

We identified the novel mRNA biomarkers and developed a novel signature that allowed robust prediction of response to postoperative adjuvant chemotherapy in patients with GC. This signature could become a precision medicine tool in GC treatment.

Cholangiocarcinoma (CCA) is a type of cancer with few effective systemic therapies. Elucidation of the molecular landscape of the disease from genomic studies based on next-generation sequencing (NGS) has contributed to the introduction of new targeted therapies. One of these treatments consists of a class of small molecules that target members of the fibroblast growth factor receptors (FGFRs) family of receptor tyrosine kinases. We report here on a patient with a cholangiocarcinoma bearing an FGFR2 mutation. The patient was treated with 2 different FGFR inhibitors, as the first caused ocular toxicity. She obtained clinical benefits from both. This case illustrates the efficacy of FGFR inhibitors on cholangiocarcinoma with specific point mutations.

Advanced biliary tract cancers (ABCs) are a heterogeneous group of rare malignancies of the bile ducts and gall-bladder with a poor prognosis and limited treatment options. Cisplatin-gemcitabine (CISGEM) chemotherapy plus immunotherapy (durvalumab or pembrolizumab) is the current first-line standard of care (1L-SoC). ABCs frequently harbour actionable molecular alterations that suggest a high potential for benefit from molecular targeted therapies (MTTs). However, the assessment of potential first-line MTT treatments is hindered by the scarcity of ABCs harbouring a specific alteration and the time required to carry out tumour molecular profiling.

We detail here the design of SAFIR-ABC10, an international, randomised, phase III umbrella trial comparing the efficacy of sequential matched targeted therapy after four cycles (12 weeks) of 1L-SoC versus continued 1L-SoC in patients with ABC and an actionable molecular alteration [European Society for Medical Oncology (ESMO) Scale for Clinical Actionability of molecular Targets (ESCAT) tier I or II]. The primary study endpoint is progression-free survival. Besides initial tumour and circulating DNA next-generation sequencing analysis, sequential blood and tumour sampling will be carried out to identify biomarkers of prognosis, response and acquired resistance.

SAFIR-ABC10 is, to our knowledge, the first randomised, umbrella trial assessing the concept of precision medicine in ABC, the ideal setting for addressing this question with a high rate of targetable alterations.

While fibroblast growth factor receptor 2 (FGFR2) emerges as an appealing cancer therapeutic target, so far there is no selective FGFR2 inhibitor on the market. Here, we report the discovery of a series of new selective, irreversible FGFR2 inhibitors with compound BW710 being the representative. Compound BW710 potently inhibited the proliferation of BaF3-FGFR2 cells with an IC50 value of 2.8 nM, and was much less active against BaF3-FGFR1 and parental BaF3 cells with IC50 values of >1000 nM. Kinase selectivity profiling revealed that BW710 completely abolished FGFR2 enzymatic activity and was selective against other 75 tyrosine kinases including FGFR1, FGFR3, and FGFR4 at 1 μM. The covalent binding mode between BW710 and FGFR2 was confirmed by MS spectrometry. Further evaluation showed that BW710 potently suppressed the FGFR2 signaling and selectively inhibited FGFR2-driven cancer cell proliferation. Additionally, BW710 also displayed reasonable pharmacokinetic properties with an oral bioavailability of 29 % in mice. Taken together, this study provides a potent, selective and orally bioavailable FGFR2 inhibitor for further development of FGFR2-targeted therapeutic agents.

This study aimed to investigate the clinicomolecular profiles and the efficacy of human epidermal growth factor receptor 2 (HER2)-targeted therapy in HER2-amplified biliary tract cancer (BTC).

This study was an international collaboration that used combined data from the prospective SCRUM-Japan GOZILA and MONSTAR-SCREEN in Japan and retrospective reviews in the United States; patients with advanced BTC who had received systemic therapy were included. The clinicomolecular profiles were evaluated in an exploratory cohort, whereas the efficacy of HER2-targeted therapy was assessed in a biomarker-selected cohort.

Of the 439 patients in the exploratory cohort, 43 (10%) had HER2 amplification. The frequencies of coalterations were higher in patients with HER2 amplification versus patients without HER2 amplification including HER2 mutations (26% v 5%, P < .001), TP53 mutations (84% v 61%, P = .003), and BRAF amplification (9% v 2%, P = .030). There were no KRAS mutations identified in patients with HER2-amplified BTC. No significant difference in overall survival (OS) was observed between patients with and without HER2 amplification (median, 17.7 v 16.9 months; hazard ratio [HR], 0.95 [95% CI, 0.65 to 1.40]). Of the 60 patients with HER2-amplified BTC in the biomarker-selected cohort (43 from Japan and 17 from the United States), the OS was significantly longer in 29 patients who received HER2-targeted therapy than in those who did not receive HER2-targeted therapy (median, 24.3 v 12.1 months; HR, 0.39 [95% CI, 0.23 to 0.82]). Multivariate analysis identified HER2-targeted therapy as an independent prognostic factor for OS (HR, 0.29 [95% CI, 0.14 to 0.58]; P < .001).

HER2 amplification was found in 10% of advanced BTC and was not identified as an independent prognostic factor for OS. Patients with HER2-amplified BTC derive significant benefit from HER2-targeted therapy.

The purpose of this review is to summarize the current knowledge of cholangiocarcinoma molecular biology and to suggest a framework for implementation of next-generation sequencing in all stages of liver transplantation. This is timely as recent guidelines recommend increased use of these technologies with promising results.

The main themes covered here address germline and somatic genetic alterations recently discovered in cholangiocarcinoma, particularly those associated with prognosis and treatment responses, and nascent efforts to translate these into contemporary practice in the peri-liver transplantation period.

Early efforts to translate molecular profiling to cholangiocarcinoma care demonstrate a growing number of potentially actionable alterations. Still lacking is a consensus on what biomarkers and technologies to adopt, at what scale and cost, and how to integrate them most effectively into care with the ambition of increasing the number of patients eligible for liver transplantation and improving their long-term outcomes.

Aberrant signaling through the fibroblast growth factor receptor (FGFR) due to activating somatic alterations has been associated with multiple malignancies. FGFR inhibitors (FGFRi) with distinct profiles recently entered standard of care. This work summarizes the experience of a dedicated clinical trial unit with FGFRi developed in the last decade within the context of clinical trials.

Demographic and clinical data were collected for patients enrolled in FGFR-targeting phase I to II trials conducted at Sarah Cannon Research Institute, United Kingdom between January 2012 and August 2023.

Fifty-four patients across seven trials were identified: 50% male; median age 55 years. An FGFR alteration was present in 81% of cases; rearrangements, amplifications, and mutations were present in 59%, 43%, and 9.1% of the cases, respectively, with coexisting alterations in 27%. The most frequent primary tumors were cholangiocarcinomas (31%), urothelial (15%), and colorectal (15%); 85% of the patients were FGFRi-naïve. The most common adverse events (AEs) were hyperphosphatemia (42%), dry mouth (35%), fatigue (24%), mucositis (24%), nail changes (22%), and palmar-plantar erythrodysesthesia (20%), with significant differences between pan-FGFRi and FGFR-2i. The rate of G3 AEs was 22%; no G4-5 events were observed. The median time on treatment was 3.5 months (0.2-72.8). Higher disease control rate was observed in the presence of any FGFR alteration, compared with all-comers (odds ratio [OR], 7; P = .0226). The objective response rate was 38%, 25%, and 25% in patients with gene rearrangements, amplification, and mutations, respectively. The median duration of response was 2.3 months (1.6-7.7). After a median follow-up time of 20 months (95% CI, 12.9 to 71.8), median progression-free survival (mPFS) was 3.2 months (95% CI, 1.9 to 4.6) and median overall survival was 13 months (95% CI, 6.4 to 19.6). PFS was significantly different by response, FGFR status, and tumor type. Patients who experienced a G2-3 AE were more likely to achieve a response (OR, 5.24; P = .0256).

FGFRi are effective treatment strategies for patients with advanced solid tumors harboring FGFR alterations, with manageable toxicities in most patients.

Biliary tract cancers (BTCs) constitute a heterogeneous group of malignancies with rising incidence and limited therapeutic options in advanced stages, leading to increased overall mortality. Extensive genomic profiling has identified key oncogenic drivers in BTCs that represent promising therapeutic targets and could change the treatment paradigm. Evidence suggests improved survival outcomes for patients with actionable molecular alterations who received matched targeted therapies. Human epidermal growth factor receptor 2 (HER2) is a receptor tyrosine kinase and proto-oncogene that has been extensively studied as a prognostic biomarker and a therapeutic target in multiple solid organ malignancies. Recent clinical trials on the combination of trastuzumab with tucatinib, FOLFOX, or pertuzumab for previously treated, HER2-positive, advanced BTCs have shown improved outcomes compared to current second-line therapies. Early evidence from observational studies on trastuzumab-containing regimens as first-line suggests promising efficacy. Furthermore, the recent tumor-agnostic approval of trastuzumab deruxtecan for HER2-positive solid tumors has formally introduced HER2-directed agents in the BTC therapeutic arsenal. This review aims to summarize the rapidly evolving landscape of HER2-directed agents for BTCs, highlighting current evidence of survival benefit. Beginning with a concise presentation of the structural and functional aspects of HER2, we detail the frequency and prognostic significance of HER2 alterations in BTCs and discuss all available preclinical and clinical data on anti-HER2 agents tested for BTCs.

Fibroblast growth factor receptor (FGFR) inhibitors have significantly improved outcomes for patients with FGFR-altered cholangiocarcinoma, leading to their regulatory approval in multiple countries. As with many targeted therapies, however, acquired resistance limits their efficacy. A comprehensive, multimodal approach is crucial to characterizing resistance patterns to FGFR inhibitors.

This study integrated data from six investigative strategies: cell-free DNA, tissue biopsy, rapid autopsy, statistical genomics, in vitro and in vivo studies, and pharmacology. We characterized the diversity, clonality, frequency, and mechanisms of acquired resistance to FGFR inhibitors in patients with FGFR-altered cholangiocarcinoma. Clinical samples were analyzed longitudinally as part of routine care across 10 institutions.

Among 138 patients evaluated, 77 met eligibility, yielding a total of 486 clinical samples. Patients with clinical benefit exhibited a significantly higher rate of FGFR2 kinase domain mutations compared with those without clinical benefit (65% versus 10%, P < 0.0001). We identified 26 distinct FGFR2 kinase domain mutations, with 63% of patients harboring multiple. While IC50 assessments indicated strong potency of pan-FGFR inhibitors against common resistance mutations, pharmacokinetic studies revealed that low clinically achievable drug concentrations may underly polyclonal resistance. Molecular brake and gatekeeper mutations predominated, with 94% of patients with FGFR2 mutations exhibiting one or both, whereas mutations at the cysteine residue targeted by covalent inhibitors were rare. Statistical genomics and functional studies demonstrated that mutation frequencies were driven by their combined effects on drug binding and kinase activity rather than intrinsic mutational processes.

Our multimodal analysis led to a model characterizing the biology of acquired resistance, informing the rational design of next-generation FGFR inhibitors. FGFR inhibitors should be small, high-affinity, and selective for specific FGFR family members. Tinengotinib, a novel small molecule inhibitor with these characteristics, exhibited preclinical and clinical activity against key resistance mutations. This integrated approach offers a blueprint for advancing drug resistance research across cancer types.

Cholangiocarcinoma (CCA) is a serious public health issue due to its insidious onset and dismal prognosis. The past few years have witnessed and highlighted the development of understanding and management of CCA. The combination of gemcitabine and cisplatin (GP) chemotherapy regimen with immunotherapy using immune checkpoint inhibitors has been considered the new standard first-line treatment alternative for advanced CCA. Notably, the proportion of patients with advanced CCA with targetable genetic mutations is approximately 40 %, and these patients may be considered for molecularly targeted therapy in the second-line treatment. In this review, we highlight the advances and progress in targeted therapies for advanced CCA, with special attention to data from Asian populations, including Chinese. In addition, we present in detail the phosphatase tension homolog (PTEN), a novel biomarker for both of first-line chemotherapy and second-line targeted therapy in advanced CCA, and its ability to forecast prognosis in patients with CCA. The mechanisms of rapid resistance to targeted agents warrant further investigation and address in light of the development of new targeted therapies. Precision medicine is gradually playing an increasing role in achieving optimal therapeutic outcomes.

The aim of the present study is to report the clinical results of patients with advanced intrahepatic cholangiocarcinoma (ICC) who received combination therapy of hepatic arterial infusion chemotherapy (HAIC), toripalimab and surufatinib.

The study cohort consisted of 28 patients with advanced ICC who were treated with HAIC (mFOLFOX6 regimen, Q3W) in combination with intravenous toripalimab (240 mg, Q3W) and oral surufatinib (150 mg, once daily). The cohort had 14 male and 14 female patients. The baseline characteristics of the study cohort were obtained. The tumor response and drug-associated toxicity were assessed and reported.

During the follow-up period (median follow-up time: 11.3 months; range: 4-19 months), four patients died of tumor progression. The objective response rate and disease control rate were 58% and 79%, respectively. The mPFS was 9.5 months, and the overall survival rate was 83.3%. The most frequent adverse events were nausea and vomiting (100%) and abdominal pain (85.7%). Serious complications related to death were not observed.

The combination treatment schedule for advanced ICC demonstrated positive efficacy and safety profiles.

This study provides promising clinical guidance for the treatment of advanced cholangiocarcinoma and is expected to modify the treatment strategy for this disease.

In recent years, treatment options for patients with advanced biliary tract cancer (BTC) have increased significantly due to the positive results from phase 2/3 clinical trials of immune checkpoint inhibitors, combined with chemotherapy, and molecularly targeted agents. These advances have led to the need for molecular testing to identify actionable alterations and patients amenable to targeted therapies. However, these improvements have brought with them many questions and challenges, including the identification of resistance mechanisms and therapeutic sequences. In this Series paper we aim to provide an overview of the current systemic treatment options for patients with BTC, highlighting disparities in access to innovative treatments and molecular testing across European countries, which lead to inequalities in the possibilities of treating patients with advanced BTC. We also discuss how ongoing European collaborative projects, such as the COST Action Precision-BTC-Network CA22125, supported by COST (European Cooperation in Science and Technology), linked to the European Network for the Study of Cholangiocarcinoma (ENSCCA), can help overcome these disparities and improve the current scenario.

Cholangiocarcinoma (CCA) is a diverse group of epithelial malignant tumors arising from the biliary tract, characterized by high molecular heterogeneity. It is classified into intrahepatic (iCCA) and extrahepatic CCA (eCCA) based on the location of the primary tumor. CCA accounts for approximately 15% of all primary liver cancers, with iCCA comprising 10-20% of all CCAs. iCCA is especially known for its characteristic aggressiveness and refractoriness, leading to poor prognosis. Despite the increasing global incidence and mortality rates, surgery remains the only available standard treatment approach for a subset (25%) of patients with early-stage, resectable iCCA. The paucity of effective systemic medical therapies restricts therapeutic options for patients with advanced or metastatic iCCA. In the past decade, advances in the understanding of the molecular complexity of these tumors have provided fruitful insights for the identification of promising new druggable targets and the development of feasible therapeutic strategies that may improve treatment outcomes for patients with iCCA. In this review, we aim to highlight critical up-to-date studies and medicinal chemistry aspects, focusing on novel targeted approaches utilizing promising candidates for molecular targeted therapy in iCCA. These candidates include aberrations in isocitrate dehydrogenase (IDH) 1/2, fibroblast growth factor receptor (FGFR), B-Raf proto-oncogene (BRAF), neurotrophic tyrosine receptor kinase (NTRK), human epidermal growth factor receptor 2 (HER2), and programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1). Furthermore, this review provides an overview of potential inhibitors aimed at overcoming acquired drug resistance in these actionable targets for iCCA.

Cholangiocarcinoma (CCA) is known for its high aggressiveness and dismal prognosis, whose effectiveness of systemic therapy remains limited. As a multi-target drug, lenvatinib has exhibited promising effects in many solid tumors. However, the therapeutic role of lenvatinib in CCA is rarely investigated. Here, the in vitro assays including EdU, colony formation, transwell, wound healing, and apoptosis analyses demonstrated that lenvatinib significantly inhibited the proliferation, migration, and invasion, while simultaneously inducing apoptosis of CCA cells. Mechanistically, lenvatinib downregulated the expression of FGF19 and inactivated the PI3K/AKT signaling pathway. Depletion of FGF19 enhanced the anti-tumor effects of lenvatinib, which was attributed to the inhibition of p-PI3K and p-AKT expression in CCA cells. In contrast, overexpression of FGF19 activated the PI3K/AKT signaling pathway, thereby impairing the inhibitory effects of lenvatinib against CCA. In addition, the AKT inhibitor, MK-2206, reinforced the lenvatinib-induced CCA inhibition. Notably, the in vivo experiment confirmed that the subcutaneous tumorigenicity of CCA cells in nude mice was weakened by lenvatinib. Lenvatinib markedly downregulated the expression of FGF19, p-AKT, Ki-67, vimentin, and VEGF in the xenograft tumor tissues. Collectively, these findings demonstrated that lenvatinib inhibits CCA progression by targeting the FGF19/PI3K/AKT signaling pathway. The present study provides novel experimental evidence for the potential clinical application of lenvatinib in CCA, which also highlights the promising role of targeting FGF19 in combined therapeutic approaches for CCA.

Biliary tract cancer (BTC) comprises a clinically diverse and genetically heterogeneous group of tumors along the intra- and extrahepatic biliary system (intrahepatic and extrahepatic cholangiocarcinoma) and gallbladder cancer with the common feature of a poor prognosis, despite increasing molecular knowledge of associated genetic aberrations and possible targeted therapies. Therefore, the search for even more precise and individualized therapies is ongoing and preclinical tumor models are central to the development of such new approaches.

The models described in the current review include simple and advanced in vitro and in vivo models, including cell lines, 2D monolayer, spheroid and organoid cultures, 3D bioprinting, patient-derived xenografts, and more recently, machine-perfusion platform-based models of resected liver specimens. All these models have individual advantages, disadvantages and limitations that need to be considered depending on the desired application.

In addition to potential cost limitations, availability of BTC cell types, time required for model establishment and growth success rate, the individual models differently reflect relevant characteristics such as tumor heterogeneity, spatial tumor-stroma microenvironment interactions, metabolic and nutritional gradients and immunological interactions. Therefore, a consequent combination of different models may be required to improve clinical study outcomes by strengthening the preclinical data basis.

Cancers of the digestive system are major contributors to global cancer-associated morbidity and mortality, accounting for 35% of annual cases of cancer deaths. The etiologies, molecular features, and therapeutic management of these cancer entities are highly heterogeneous and complex. Over the last decade, genomic and functional studies have provided unprecedented insights into the biology of digestive cancers, identifying genetic drivers of tumor progression and key interaction points of tumor cells with the immune system. This knowledge is continuously translated into novel treatment concepts and targets, which are dynamically reshaping the therapeutic landscape of these tumors. In this review, we provide a concise overview of the etiology and molecular pathology of the six most common cancers of the digestive system, including esophageal, gastric, biliary tract, pancreatic, hepatocellular, and colorectal cancers. We comprehensively describe the current stage-dependent pharmacological management of these malignancies, including chemo-, targeted, and immunotherapy. For each cancer entity, we provide an overview of recent therapeutic advancements and research progress. Finally, we describe how novel insights into tumor heterogeneity and immune evasion deepen our understanding of therapy resistance and provide an outlook on innovative therapeutic strategies that will shape the future management of digestive cancers, including CAR-T cell therapy, novel antibody-drug conjugates and targeted therapies.

Fibroblast growth factor receptors (FGFRs) are a highly conserved family of transmembrane receptor tyrosine kinases with multiple roles in the regulation of key cellular processes. Specific FGFR mutations have been observed in several types of cancers, including gastric carcinoma and cholangiocarcinoma. Dose escalation data of 24 Japanese patients with solid tumors treated with Tasurgratinib (previously known as E7090), a potent, selective FGFR1-3 inhibitor, was reported in a phase I, first-in-human, single-center study. Based on the safety, pharmacokinetic, and pharmacodynamic profiles observed in this study, the recommended dose of 140 mg once daily was selected for the expansion part (Part 2), a multicenter expansion of the dose-finding study restricted to patients with tumors harboring FGFR gene alterations. Safety and preliminary efficacy were assessed in Part 2. Pharmacodynamic pharmacogenomic markers (serum phosphate, FGF23, and 1,25-(OH)2-vitamin D, circulating tumor DNA) and pharmacokinetic profiles were also evaluated. A total of 16 patients were enrolled in Part 2, six with cholangiocarcinoma and 10 with gastric cancer. The most common treatment-emergent adverse events were hyperphosphatemia, palmar-plantar erythrodysesthesia syndrome, and paronychia. Five partial responses (83.3%) in cholangiocarcinoma patients and one partial response (11.1%) in gastric cancer patients were observed; median progression-free survival was 8.26 months (95% confidence interval [CI] 3.84, not evaluable [NE]) and 3.25 months (95% CI 0.95, 4.86), and overall survival was 22.49 months (95% CI 6.37, NE) and 4.27 months (95% CI 2.23, 7.95), respectively, in the two groups. In conclusion, Tasurgratinib 140 mg has a tolerable safety profile with good clinical efficacy in patients with cholangiocarcinoma harboring FGFR2 gene rearrangements.

Cutaneous squamous cell carcinoma (cSCC) is an increasingly common malignancy of the skin and the leading cause of death from skin cancer in adults over the age of 85. Fibroblast growth factor receptor 2 (FGFR2) has been identified as an important effector of signaling pathways that lead to the growth and development of cSCC. In recent years, there have been numerous studies evaluating the role FGFR2 plays in multiple cancers, its contribution to resistance to anticancer therapy, and new drugs that may be used to inhibit FGFR2. This review will provide an overview of our current understanding of FGFR2 and potential mechanisms in which we can target FGFR2 in cSCC. The goals of this review are the following: (1) to highlight our current knowledge of the role of FGFR2 in healthy skin and contrast this with its role in the development of cancer; (2) to further explain the specific molecular mechanisms that FGFR2 uses to promote tumorigenesis; (3) to describe how FGFR2 contributes to more invasive disease; (4) to describe its immunosuppressive effects in skin; and (5) to evaluate its effect on current anticancer therapy and discuss therapies on the horizon to target FGFR2 related malignancy.

Among solid tumors, cholangiocarcinoma (CCA) emerges as one of the most difficult to eradicate. The silent and asymptomatic nature of this tumor, particularly in its early stages, as well as the high heterogeneity at genomic, epigenetic, and molecular levels delay the diagnosis, significantly compromising the efficacy of current therapeutic options and thus contributing to a dismal prognosis. Extensive research has been conducted on the molecular pathobiology of CCA, and recent advances have been made in the classification and characterization of new molecular targets. Both targeted therapy and immunotherapy have emerged as effective and safe strategies for various types of cancers, demonstrating potential benefits in advanced CCA. Furthermore, the deeper comprehension of the cellular and molecular components in the tumor microenvironment (TME) has opened up possibilities for new innovative treatment methods. This review discusses recent evidence in the characterization and molecular biology of CCA, highlighting novel possible druggable targets.

The concept of precision oncology, the application of targeted drugs based on comprehensive molecular profiling, has revolutionized treatment strategies in oncology. This review summarizes the current status of precision oncology in glioblastoma (GBM), the most common and aggressive primary brain tumor in adults with a median survival below 2 years. Targeted treatments without prior target verification have consistently failed. Patients with BRAF V600E-mutated GBM benefit from BRAF/MEK-inhibition, whereas targeting EGFR alterations was unsuccessful due to poor tumor penetration, tumor cell heterogeneity, and pathway redundancies. Systematic screening for actionable molecular alterations resulted in low rates (< 10%) of targeted treatments. Efficacy was observed in one-third and currently appears to be limited to BRAF-, VEGFR-, and mTOR-directed treatments. Advancing precision oncology for GBM requires consideration of pathways instead of single alterations, new trial concepts enabling rapid and adaptive drug evaluation, a focus on drugs with sufficient bioavailability in the CNS, and the extension of target discovery and validation to the tumor microenvironment, tumor cell networks, and their interaction with immune cells and neurons.

Although there have been significant advances in the early detection and treatment of gallbladder cancer (GBC), it is still considered a leading cause of morbidity and mortality. Molecular profiling of tumors is generally performed using samples obtained during surgery or biopsy. However, tissue genotyping has its limitations as it only provides a single snapshot and is susceptible to spatial selection bias due to the tumor heterogeneity. Over the past decade, there has been a remarkable transition from invasive diagnostic methods to non-invasive alternatives, including liquid biopsy, for cancer diagnosis and monitoring. Liquid biopsies have ushered in a new era in clinical oncology, enabling convenient tumor sampling, continuous monitoring through repeated analysis, development of personalized treatment regimens, and assessment of therapy resistance. While peripheral blood is the primary medium for these biopsies, other biological fluids, including urine, saliva, and bile, also serve as valuable sources of information. Currently, the focus of blood-based biopsy analyses is on four main sources of biomarkers for cancer detection and stratification: circulating tumor DNA (ctDNA) or circulating free DNA (cfDNA), circulating tumor cells (CTCs), and extracellular vesicle (EVs). There are over 300 clinical trials either ongoing or actively recruiting participants to investigate the diagnostic and prognostic applications of ctDNA/cfDNA in the context of cancer. This review outlines the current standard of care for individuals with GBC, anticipates future treatment developments, and evaluates the potential applications of liquid biopsies in various clinical contexts. The review addresses ctDNA/cfDNA, CTC, and circulating microRNA and highlights their prospective roles in management of GBC.

Cholangiocarcinoma (CCA) is a malignant tumor originating in the bile duct and its branching epithelium. Due to its high heterogeneity, there are no specific clinical indications at the early stage, the diagnosis is often in advanced CCA. With surgical resection, the 5-year postoperative survival rate (long-term survival rate) is very poor. The regimen of gemcitabine combined with platinum has been used as the first-line chemotherapy for advanced patients. In recent years, targeted therapy for a variety of malignant tumors has made great progress, showing good efficacy and safety in advanced CCA. However, the current targeted therapy of CCA still has many challenges, such as adverse reactions, drug resistance, and individual differences. Therefore, the researches need to further explore the targeted therapy mechanism of CCA malignancies in depth, develop more effective and safe drugs, and accurately formulate plans based on patient characteristics to further improve patient prognosis in the future. This article reviews the recent progress of targeted therapy for CCA, aiming to provide a strategy for the research and clinical work of targeted therapy for CCA.

Since fibroblast growth factor receptor inhibitors (FGFRi) are used for treatment of intrahepatic cholangiocarcinoma (iCCA), understanding potential complications following longer-term use in clinical practice settings is warranted. This study describes cataract formation or progression as a complication of FGFRi use for the treatment of iCCA, even after treatment discontinuation.

To describe cases of cataract formation or worsening in patients with iCCA treated with FGFRi and to characterize the ophthalmologic features, risk factors, and outcomes for FGFRi-associated cataracts.

This retrospective case series study used data from patients with iCCA harboring FGFR2 aberrations who received FGFRi in clinical trials or as standard therapy from the University of California, San Francisco, Hepatobiliary Tissue Bank and Registry. Data were collected from patient visits between February 2015 and October 2021, and this retrospective investigation was conducted from September 6, 2022, to May 4, 2023. Data analysis was conducted from May 5, 2023, to September 6, 2023.

Use of an FGFRi for the treatment of iCCA.

The primary outcome was designated as development of a new or worsening cataract after FGFRi initiation. Statistical analysis for the association between cataract formation and clinical covariates was performed using unpaired t tests and Fisher exact tests. A single bivariate logistic regression model was used to examine total duration of FGFRi therapy and age at the conclusion of FGFRi therapy as predictors of cataract development.

A total of 18 patients were included in the study; median (range) patient age was 54 (27-81) years, and 13 patients (72%) were female. Nine patients (50%) developed a cataract or had cataract progression in at least 1 eye after initiation of FGFRi. Of 17 eyes with cataract, 8 eyes (47%) required cataract surgery. One patient rapidly developed a cataract associated with phacomorphic glaucoma, which required urgent surgery. The median (range) time to cataract onset or worsening from initiation of FGFRi was approximately 18 (1-23) months. Five of 9 patients (56%) who developed cataracts or had cataract progression were diagnosed with new or worsening cataracts after discontinuation of FGFRi. Patients who developed cataracts had longer median (range) duration of FGFRi treatment compared with patients who did not develop cataracts (13 months [2-26] vs 5 months [1-11]; odds ratio, 1.01; 95% CI, 1.00-1.02; P = .02).

While this retrospective case series study cannot prove cause and effect conclusively due to the study design, study results highlight cataract formation or progression as a potential adverse effect of FGFRi therapy, supporting consideration of periodic eye examinations in patients who have received this treatment.

Infigratinib, an FGFR1-3 selective oral tyrosine kinase inhibitor, has shown clinical activity in cancers with FGFR alterations. The pharmacokinetics (PK) of infigratinib and its major metabolites have been characterized in global populations. This study examined the PK profile of infigratinib and its metabolites in Chinese patients. In this phase II, open-label, single-arm study in China, patients with advanced gastric cancer (GC) or gastroesophageal junction adenocarcinoma (GEJ) harboring FGFR2 gene amplification received 125 mg infigratinib orally once daily in a "3 weeks on, 1 week off" schedule for 28-day cycles. Plasma PK parameters were calculated with a non-compartmental model. Data were available from 21 patients (19 GC and two GEJ). After a single dose, peak infigratinib plasma concentration was reached at a median time of 3.1 h, with geometric mean Cmax of 85.9 ng/mL and AUC0-t of 637 h*ng/mL. After 21-day dosing, geometric mean infigratinib Cmax,ss of 204 ng/mL was reached at a median of 4.0 h; geometric mean AUC0-24,ss was 3060 h*ng/mL. The geometric mean Rac,Cmax (%CV) and Rac,AUC0-24 (%CV) of infigratinib was 2.5 (113.8) and 5.1 (138.2), respectively. A steady state of infigratinib was reached after continuous dosing for 15 days. The metabolites accounting for >10% of infigratinib were BHS697 and CQM157. The PK profiles of infigratinib and its metabolites in Chinese patients with GC or GEJ were largely consistent with known PK profiles of infigratinib from global populations.

Cholangiocarcinoma (CCA) is a highly aggressive form of liver cancer and is an increasing cause of cancer-related death worldwide. Despite its increasing incidence globally and alarming mortality, treatment options for CCA have largely remained unchanged, stressing the importance of developing new effective therapies. YAP activation is common in CCA, and its major transcriptional signaling partners are the TEAD proteins. CA3 is a small-molecule YAP-TEAD disrupter discovered utilizing a TEAD reporter assay. Utilizing CCA, gastric cancer cell lines, and patient-derived xenograft models (PDX), we demonstrate that CA3 is effective in inducing cell death and delaying tumor growth in both FGFR2 fusion and wild-type models. CA3 was associated with on-target decreases in YAP-TEAD target gene expression, TEAD reporter activity, and overall TEAD levels. Hippo pathway signaling was not altered as there was no change in YAP phosphorylation status in the cells exposed to CA3. RNA sequencing of gastric cancer and CCA models demonstrated upregulation of an androgen receptor-mediated transcriptional program following exposure to CA3 in five unique models tested. Consistent with this upstream regulator analysis, CA3 exposure in CCA cells was associated with increased AR protein levels, and combinatorial therapy with CA3 and androgen receptor blockade was associated with increased cancer cell death. CA3 behaves functionally as a YAP-TEAD disrupter in the models tested and demonstrated therapeutic efficacy. Exposure to CA3 was associated with compensatory androgen receptor signaling and dual inhibition improved the therapeutic effect.

This multicenter phase II basket trial investigated the efficacy, safety, and pharmacokinetics of Debio 1347, an investigational, oral, highly selective, ATP-competitive, small molecule inhibitor of FGFR1-3, in patients with solid tumors harboring a functional FGFR1-3 fusion.

Eligible adults had a previously treated locally advanced (unresectable) or metastatic biliary tract (cohort 1), urothelial (cohort 2), or another histologic cancer type (cohort 3). Debio 1347 was administered at 80 mg once daily, continuously, in 28-day cycles. The primary endpoint was the objective response rate. Secondary endpoints included duration of response, progression-free survival, overall survival, pharmacokinetics, and incidence of adverse events.

Between March 22, 2019, and January 8, 2020, 63 patients were enrolled and treated, 30 in cohort 1, 4 in cohort 2, and 29 in cohort 3. An unplanned preliminary statistical review showed that the efficacy of Debio 1347 was lower than predicted, and the trial was terminated. In total, 3 of 58 evaluable patients had partial responses, representing an objective response rate of 5%, with a further 26 (45%) having stable disease (≥6 weeks duration). Grade ≥3 treatment-related adverse events occurred in 22 (35%) of 63 patients, with the most common being hyperphosphatemia (13%) and stomatitis (5%). Two patients (3%) discontinued treatment due to adverse events.

Debio 1347 had manageable toxicity; however, the efficacy in patients with tumors harboring FGFR fusions did not support further clinical evaluation in this setting. Our transcriptomic-based analysis characterized in detail the incidence and nature of FGFR fusions across solid tumors. See related commentary by Hage Chehade et al., p. 4549.