FGFR Inhibitor Research Articles

Abstract 220: Thresholding response assessment in biliary tract cancer organoids to inform sensitivity to chemotherapy across molecular subtypes

Abstract Background: Cholangiocarcinoma (CCA) remains a highly morbid cancer for which accurate models. Patient-derived cancer organoid (PCOs) have been generated in CCA, however their utility in clinical prediction has not been validated. Z’ factoring often fails in assessing CCA organoid response. Prior analysis for organoid response has shown an effect size by Glass’s Delta (GΔ) of ≥1.25 in growth inhibition is predictive of clinical response. Here, we present subclonal organoid response across a diverse set of CCA models in response to therapy by growth and organoid level viability response. Methods: PCOs were expanded from the NCI’s Patient-Derived Model Repository (PDMR), tissue biopsy, and rapid autopsy. Organoid response was tracked from growth using Z-stacked high content imaging (Cytation5) with endpoint at 144h and stained using established viability markers, Caspase-3/7 (C3/7) and ToPro3. Treatment groups included media control, positive control of cycloheximide 200uM continuous, gemcitabine (gem) 10uM 24h, cisplatin (cis) 5uM 48h, combination gem+cis, and FGFR2 inhibitor futibatinib (futi) 300nM continuous. Results: Across models, PCO growth directly correlated with Z’ factor thresholding (R= 0.868). NCI PDMR organoids, CK11523 and CK10519 are IDH1mutant (mt), and both showed superior response to gem when compared to cis by growth (gem GΔ 1.18 and 0.44 v. cis GΔ 0.11 and 0.23) and C3/7 (gem GΔ 3.25 and 2.34 v. cis GΔ 1.46 and 0.33). BRCA1mt CCA was found to achieve modest growth inhibition with gem and gem+cis (GΔ 1.09 and 1.17) and yet significant increase in C3/7 (gem GΔ 1.68 and gem+cis GΔ 1.36) and ToPro3 (gem GΔ 1.65 and gem+cis GΔ 1.82). Despite this result, the patient developed early clinical recurrence after neoadjuvant gem+cis chemotherapy (<3 months). FGFR2-HPGDS fusion CCA achieved no meaningful difference in growth response with gem+cis (GΔ 0.94) or futi (GΔ 0.36). These findings were consistent with the clinical outcome of primary chemotherapy resistance and progression on futi. However, we observed increase in C3/7 positivity with both gem+cis (GΔ 2.11) and futi (GΔ 1.37). Conclusions: Primary resistance to both targeted and chemotherapy remains a formidable barrier to therapeutic development in CCA. While growth inhibition remains a validated marker of clinical response, further work is needed to understand thresholds for C3/7 and ToPro3 across physiologic drug dosing. This is the first report of modeling the novel FGFR2-HPGDS fusion CCA in organoids. Ongoing work is evaluating therapeutic sensitivity across prospective specimens of CCA in support of establishing thresholding for response to apoptosis (C3/7) and necrosis (ToPro3). Citation Format: Eleanor Riedl, Austin Stram, Md Shahadat Hossan, Ethan Samuel Lin, Jamie Warner, Luke Koeppel, Jeremy D. Kratz. Thresholding response assessment in biliary tract cancer organoids to inform sensitivity to chemotherapy across molecular subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 220.

The Irreversible FGFR Inhibitor KIN-3248 Overcomes FGFR2 Kinase Domain Mutations.

FGFR2 and FGFR3 show oncogenic activation in many cancer types, often through chromosomal fusion or extracellular domain mutation. FGFR2 and FGFR3 alterations are most prevalent in intrahepatic cholangiocarcinoma (ICC) and bladder cancers, respectively, and multiple selective reversible and covalent pan-FGFR tyrosine kinase inhibitors (TKI) have been approved in these contexts. However, resistance, often due to acquired secondary mutations in the FGFR2/3 kinase domain, limits efficacy. Resistance is typically polyclonal, involving a spectrum of different mutations that most frequently affect the molecular brake and gatekeeper residues (N550 and V565 in FGFR2). Here, we characterize the activity of the next-generation covalent FGFR inhibitor, KIN-3248, in preclinical models of FGFR2 fusion+ ICC harboring a series of secondary kinase domain mutations, in vitro and in vivo. We also test select FGFR3 alleles in bladder cancer models. KIN-3248 exhibits potent selectivity for FGFR1-3 and retains activity against various FGFR2 kinase domain mutations, in addition to being effective against FGFR3 V555M and N540K mutations. Notably, KIN-3248 activity extends to the FGFR2 V565F gatekeeper mutation, which causes profound resistance to currently approved FGFR inhibitors. Combination treatment with EGFR or MEK inhibitors potentiates KIN-3248 efficacy in vivo, including in models harboring FGFR2 kinase domain mutations. Thus, KIN-3248 is a novel FGFR1-4 inhibitor whose distinct activity profile against FGFR kinase domain mutations highlights its potential for the treatment of ICC and other FGFR-driven cancers.

FGFR inhibitors in urothelial cancer: Contextualizing THOR within the new treatment landscape

As frontline treatment of advanced urothelial cancer (UC) evolves, optimal sequencing of subsequent therapies remains unclear. The phase 3 THOR trial compared the efficacy of erdafitinib to chemotherapy or immunotherapy in FGFR3/2-altered advanced UC. THOR offers valuable data informing sequencing strategies, reinforcing the need for molecular testing in UC.

FGFR-targeted therapeutics: clinical activity, mechanisms of resistance and new directions.

Fibroblast growth factor (FGF) signalling via FGF receptors (FGFR1-4) orchestrates fetal development and contributes to tissue and whole-body homeostasis, but can also promote tumorigenesis. Various agents, including pan-FGFR inhibitors (erdafitinib and futibatinib), FGFR1/2/3 inhibitors (infigratinib and pemigatinib), as well as a range of more-specific agents, have been developed and several have entered clinical use. Erdafitinib is approved for patients with urothelial carcinoma harbouring FGFR2/3 alterations, and futibatinib and pemigatinib are approved for patients with cholangiocarcinoma harbouring FGFR2 fusions and/or rearrangements. Clinical benefit from these agents is in part limited by hyperphosphataemia owing to off-target inhibition of FGFR1 as well as the emergence of resistance mutations in FGFR genes, activation of bypass signalling pathways, concurrent TP53 alterations and possibly epithelial-mesenchymal transition-related isoform switching. The next generation of small-molecule inhibitors, such as lirafugratinib and LOXO-435, and the FGFR2-specific antibody bemarituzumab are expected to have a reduced risk of hyperphosphataemia and the ability to overcome certain resistance mutations. In this Review, we describe the development and current clinical role of FGFR inhibitors and provide perspective on future research directions including expansion of the therapeutic indications for use of FGFR inhibitors, combination of these agents with immune-checkpoint inhibitors and the application of novel technologies, such as artificial intelligence.

Integration of CD4+ T cells and molecular subtype predicts benefit from PD-L1 blockade in muscle-invasive bladder cancer.

Muscle-invasive bladder cancer (MIBC) is a disease characterized by molecular and clinical heterogeneity, posing challenges in selecting the most appropriate treatment in clinical settings. Considering the significant role of CD4+ T cells, there is an emerging need to integrate CD4+ T cells with molecular subtypes to refine classification. We conducted a comprehensive study involving 895 MIBC patients from four independent cohorts. The Zhongshan Hospital (ZSHS) and The Cancer Genome Atlas (TCGA) cohorts were included to investigate chemotherapeutic response. The IMvigor210 cohort was included to assess the immunotherapeutic response. NCT03179943 was used to evaluate the clinical response to a combination of immune checkpoint blockade (ICB) and chemotherapy. Additionally, we evaluated genomic characteristics and the immune microenvironment to gain deeper insights into the distinctive features of each subtype. We unveiled four immune-molecular subtypes, each exhibiting distinct clinical outcomes and molecular characteristics. These subtypes include luminal CD4+ Thigh, which demonstrated benefits from both immunotherapy and chemotherapy; luminal CD4+ Tlow, characterized by the highest level of fibroblast growth factor receptor 3 (FGFR3) mutation, thus indicating potential responsiveness to FGFR inhibitors; basal CD4+ Thigh, which could benefit from a combination of ICB and chemotherapy; and basal CD4+ Tlow, characterized by an immune suppression microenvironment and likely to benefit from transforming growth factor-β (TGF-β) inhibition. This immune-molecular classification offers new possibilities for optimizing therapeutic interventions in MIBC.

Receptor-based pharmacophore modeling, molecular docking, synthesis and biological evaluation of novel VEGFR-2, FGFR-1, and BRAF multi-kinase inhibitors

A receptor-based pharmacophore model describing the binding features required for the multi-kinase inhibition of the target kinases (VEGFR-2, FGFR-1, and BRAF) were constructed and validated. It showed a good overall quality in discriminating between the active and the inactive in a compiled test set compounds with F1 score of 0.502 and Mathew’s correlation coefficient of 0.513. It described the ligand binding to the hinge region Cys or Ala, the glutamate residue of the Glu-Lys αC helix conserved pair, the DFG motif Asp at the activation loop, and the allosteric back pocket next to the ATP binding site. Moreover, excluded volumes were used to define the steric extent of the binding sites. The application of the developed pharmacophore model in virtual screening of an in-house scaffold dataset resulted in the identification of a benzimidazole-based scaffold as a promising hit within the dataset. Compounds 8a-u were designed through structural optimization of the hit benzimidazole-based scaffold through (un)substituted aryl substitution on 2 and 5 positions of the benzimidazole ring. Molecular docking simulations and ADME properties predictions confirmed the promising characteristics of the designed compounds in terms of binding affinity and pharmacokinetic properties, respectively. The designed compounds 8a-u were synthesized, and they demonstrated moderate to potent VEGFR-2 inhibitory activity at 10 µM. Compound 8u exhibited a potent inhibitory activity against the target kinases (VEGFR-2, FGFR-1, and BRAF) with IC50 values of 0.93, 3.74, 0.25 µM, respectively. The benzimidazole derivatives 8a-u were all selected by the NCI (USA) to conduct their anti-proliferation screening. Compounds 8a and 8d resulted in a potent mean growth inhibition % (GI%) of 97.73% and 92.51%, respectively. Whereas compounds 8h, 8j, 8k, 8o, 8q, 8r, and 8u showed a mean GI% > 100% (lethal effect). The most potent compounds on the NCI panel of 60 different cancer cell lines were progressed further to NCI five-dose testing. The benzimidazole derivatives 8a, 8d, 8h, 8j, 8k, 8o, 8q, 8r and 8u exhibited potent anticancer activity on the tested cell lines reaching sub-micromolar range. Moreover, 8u was found to induce cell cycle arrest of MCF-7 cell line at the G2/M phase and accumulating cells at the sub-G1 phase as a result of cell apoptosis.

Resistance of HNSCC cell models to pan-FGFR inhibition depends on the EMT phenotype associating with clinical outcome

BackgroundFocal adhesion signaling involving receptor tyrosine kinases (RTK) and integrins co-controls cancer cell survival and therapy resistance. However, co-dependencies between these receptors and therapeutically exploitable vulnerabilities remain largely elusive in HPV-negative head and neck squamous cell carcinoma (HNSCC).MethodsThe cytotoxic and radiochemosensitizing potential of targeting 10 RTK and β1 integrin was determined in up to 20 3D matrix-grown HNSCC cell models followed by drug screening and patient-derived organoid validation. RNA sequencing and protein-based biochemical assays were performed for molecular characterization. Bioinformatically identified transcriptomic signatures were applied to patient cohorts.ResultsFibroblast growth factor receptor (FGFR 1–4) targeting exhibited the strongest cytotoxic and radiosensitizing effects as monotherapy and combined with β1 integrin inhibition, exceeding the efficacy of the other RTK studied. Pharmacological pan-FGFR inhibition elicited responses ranging from cytotoxicity/radiochemosensitization to resistance/radiation protection. RNA sequence analysis revealed a mesenchymal-to-epithelial transition (MET) in sensitive cell models, whereas resistant cell models exhibited a partial epithelial-to-mesenchymal transition (EMT). Accordingly, inhibition of EMT-associated kinases such as EGFR caused reduced adaptive resistance and enhanced (radio)sensitization to FGFR inhibition cell model- and organoid-dependently. Transferring the EMT-associated transcriptomic profiles to HNSCC patient cohorts not only demonstrated their prognostic value but also provided a conclusive validation of the presence of EGFR-related vulnerabilities that can be strategically exploited for therapeutic interventions.ConclusionsThis study demonstrates that pan-FGFR inhibition elicits a beneficial radiochemosensitizing and a detrimental radioprotective potential in HNSCC cell models. Adaptive EMT-associated resistance appears to be of clinical importance, and we provide effective molecular approaches to exploit this therapeutically.

Safety Profile and Adverse Event Management for Futibatinib, An Irreversible FGFR1-4 Inhibitor: Pooled Safety Analysis of 469 Patients.

Futibatinib, a covalently-binding inhibitor of fibroblast growth factor receptor (FGFR)1-4 gained approval for the treatment of refractory, advanced intrahepatic cholangiocarcinoma (iCCA) harboring an FGFR2 fusion/other rearrangement. An integrated analysis was performed to evaluate safety and provide guidance on the management of futibatinib-associated adverse events (AEs) in patients with unresectable/metastatic tumors, including iCCA. Data from three global phase I or II studies of futibatinib (NCT02052778; JapicCTI-142552) were pooled. AEs were graded per NCI CTCAE v4.03, where applicable. Safety was analyzed for patients receiving any futibatinib starting dose (overall population) and in those receiving the approved starting dose of 20 mg once every day. In total, 469 patients with one of 33 known tumor types were analyzed, including 318 patients who received futibatinib 20 mg every day. AEs of clinical interest (AECI; any grade/grade ≥3) in the overall population included hyperphosphatemia (82%/19%), nail disorders (27%/1%), hepatic AEs (27%/11%), stomatitis (19%/3%), palmar-plantar erythrodysesthesia syndrome (PPES; 13%/3%), rash (9%/0%), retinal disorders (8%/0%), and cataract (4%/1%). Median time to onset of grade ≥3 AECIs ranged from 9 days (hyperphosphatemia) to 125 days (cataract). Grade ≥3 hyperphosphatemia, hepatic AEs, PPES, and nail disorders resolved to grade ≤2 within a median of 7, 7, 8, and 28 days, respectively. Discontinuations due to treatment-related AEs were rare (2%), and no treatment-related deaths occurred. AE management included phosphate-lowering medication and dose adjustments. Futibatinib showed a consistent and manageable safety profile across patients with various tumor types. AECIs were mostly reversible with appropriate clinical management.

Activated FGFR2 signalling as a biomarker for selection of intrahepatic cholangiocarcinoma patients candidate to FGFR targeted therapies

FGFR inhibitors have been developed to inhibit FGFR activation and signal transduction; notwithstanding, currently the selection of intrahepatic cholangiocarcinoma (iCCA) patients for these drugs only relies on the detection of FGFR2 genetic alterations (GAs) in tumor tissues or circulating tumor DNAs, without concomitant assessment of FGFR2 signalling status. Accordingly, we performed multi-omic analyses of FGFR2 genes and FGFR2 signalling molecules in the tissue samples from 36 iCCA naïve patients. Gain-of-function FGFR2 GAs were detected in 7 patients, including missense mutations (n = 3; p.F276C, p.C382R and p.Y375C), translocations (n = 1) and copy number gain (n = 4; CNV ≥ 4). In contrast, among 29 patients with wild-type FGFR2, 4 cases showed activation of FGFR2 signalling, as they expressed the FGFR2 ligand FGF10 and phosphorylated FGFR2/FRS2α proteins; the remaining 25 cases resulted negative for activated FGFR2 signalling, as they lacked FGFR2 (n = 8) or phosphorylated FRS2α (n = 17) expression. Overall, we found that activation of FGFR2 signalling occurs not only in iCCA naïve patients with FGFR2 GAs, but also in a subgroup carrying wild-type FGFR2. This last finding entails that also this setting of patients could benefit from FGFR targeted therapies, widening indication of these drugs for iCCA patients beyond current approval. Future clinical studies are therefore encouraged to confirm this hypothesis.

Interventional Radiology Locoregional Therapies for Intrahepatic Cholangiocarcinoma.

Surgical resection remains the cornerstone of curative treatment for intrahepatic cholangiocarcinoma (iCCA), but this option is only available to a small percentage of patients. For patients with unresectable iCCA, systemic therapy with gemcitabine and platinum-based agents represents the mainstay of treatment; however, the armamentarium has grown to include targeted molecular therapies (e.g., FGFR2 inhibitors), use of adjuvant therapy, liver transplantation in select cases, immunotherapy, and locoregional liver-directed therapies. Despite advances, iCCA remains a challenge due to the advanced stage of many patients at diagnosis. Furthermore, given the improving options for systemic therapy and the fact that the majority of iCCA patients succumb to disease progression in the liver, the role of locoregional therapies has increased. This review will focus on the expanding role of interventional radiology and liver-directed therapies in the treatment of iCCA.

Discovery of lirafugratinib (RLY-4008), a highly selective irreversible small-molecule inhibitor of FGFR2

Fibroblast growth factor receptor (FGFR) kinase inhibitors have been shown to be effective in the treatment of intrahepatic cholangiocarcinoma and other advanced solid tumors harboring FGFR2 alterations, but the toxicity of these drugs frequently leads to dose reduction or interruption of treatment such that maximum efficacy cannot be achieved. The most common adverse effects are hyperphosphatemia caused by FGFR1 inhibition and diarrhea due to FGFR4 inhibition, as current therapies are not selective among the FGFRs. Designing selective inhibitors has proved difficult with conventional approaches because the orthosteric sites of FGFR family members are observed to be highly similar in X-ray structures. In this study, aided by analysis of protein dynamics, we designed a selective, covalent FGFR2 inhibitor. In a key initial step, analysis of long-timescale molecular dynamics simulations of the FGFR1 and FGFR2 kinase domains allowed us to identify differential motion in their P-loops, which are located adjacent to the orthosteric site. Using this insight, we were able to design orthosteric binders that selectively and covalently engage the P-loop of FGFR2. Our drug discovery efforts culminated in the development of lirafugratinib (RLY-4008), a covalent inhibitor of FGFR2 that shows substantial selectivity over FGFR1 (~250-fold) and FGFR4 (~5,000-fold) in vitro, causes tumor regression in multiple FGFR2-altered human xenograft models, and was recently demonstrated to be efficacious in the clinic at doses that do not induce clinically significant hyperphosphatemia or diarrhea.

FGFR3 mutated (FGFR3mut+) urothelial carcinoma of bladder (UCB) or upper tract (UTUC): A comparative genomic landscape study.

540 Background: Activating DNA sequence genomic alterations (GA) in the FGFR3 gene including short variant (SV) mutations and kinase domain activating gene rearrangements/fusions (RE-FUS) are known drivers and relevant precision treatment targets for pts with UC. THOR trial showed a significant overall survival benefit with erdafitinib (FGFR inhibitor) vs (taxane or vinflunine) in patients (pts) with advanced UCB or UTUC. PROOF-302 trial showed higher frequency of FGFR3 GA in UTUC (30%) vs UCB (13%). We sought to explore differences in frequency of FGFR3 alterations and the genomic landscapes of FGFR3-altered UCB and UTUC. Methods: 10,402 UCB and 2,325 UTUC (combined ureter and renal pelvis) underwent hybrid capture-based comprehensive genomic profiling (CGP) using a hybrid capture-based to assess all classes of GA and measure MSI status, TMB level, genomic ancestry, genomic signature, germline mutations and HRD score. PD-L1 was determined by IHC (Dako 22C3 using the TPS system. Results were compared using the Fisher Exact method with the Benjamini-Hochberg adjustment. Results: FGFR3mut+ status was significantly more frequent in UTUC than in UBC (24.9% vs 17.7%; p<.0001) (Table). UCB pts were more often male than UTUC (P=.0003). Age (71-72 yrs), EUR ancestry (85%) and GA/tumor (8.9-9.0) were similar. The number of GA/case and the frequency of EUR ancestry were similar. Targetable GA in ERBB2 and PIK3CA were more frequent in FGFR3mut+ UBC vs FGFR3mut+ UTUC. GA in PTEN, TSC1 and MTAP currently associated with clinical trials were similar in UBC and UTUC. The KEGG ERBB and VEGF signaling pathways were more frequently identified in UCB (p=0.036) and the MMR pathway more frequently identified in UTUC (p=0.014). The HRD signature was similar in both groups (2.3-3.1%). Anti-PD(L)1 putative biomarkers included a significantly higher frequency of MSI-high status in UTUC vs UCB but no significant difference in TMB or PD-L1 expression levels. Conclusions: Although histologically similar, the genomic landscape of FGFR3mut+ UTUC has notable differences with FGFR3mut+ UCB. Limitations include lack of clinical data annotation. The findings may impact of clinical trial designs for UCB and UTUC, including evaluating combinations of anti-FGFR3 with other agents. [Table: see text]

Sequencing of erdafitinib (erda) and enfortumab vedotin (EV) in patients (pts) with fibroblast growth factor receptor (FGFR2/3) altered (alt) advanced urothelial cancer (aUC): Analysis of UNITE database.

616 Background: The optimal therapy sequencing in aUC with FGFR2/3 alt is unclear. FGFR inhibition may increase Nectin-4 expression. We hypothesized that outcomes with EV would be more favorable when given after E compared to before E in pts with aUC harboring FGFR2/3 genomic alt. Methods: Pts with FGFR2/3 alts who received EV only (EVo), E then EV (E->EV), or EV then E (EV->E) were included. Overall survival (OS) measured from E or EV start (based on agent given first) and progression-free survival (PFS) measured from EV start were assessed with KM method and group comparison by log rank test with Cox proportional hazards regression model. Variables with p ≤0.2 were included in multivariate analysis (MVA). Wilcoxon rank sum and Fisher’s exact test were used to compare continuous and categorical variables, respectively. Observed response rate (ORR) was compared between groups using χ2 test. Results: Among 633 pts from 16 US sites, 487 had NGS data, and 94 (19%) had FGFR2/3 alterations with 24 receiving E->EV, 15 EV->E, and 55 EVo. Median age: 72 yrs; 87% Caucasian, 65% primary bladder tumor, 73% pure urothelial histology, 76% BMI <30, 83% ECOG PS 0-1, 60% visceral metastases (mets) with 23% liver mets, 93% prior IO, and 63% prior Plt. Pts treated with E->EV vs EV->E had similar baseline characteristics, but at EV start ECOG PS 0-1 was 93% in EV->E vs 67% in E->EV (p=0.04). ORR to EV for E->EV pts was 32% (CI- 12%-51%) vs 67% (CI 54%-91%) for EV->E pts (p=0.04). ORR for EVo was 49%. Median OS was 21 months (mo) E->EV, 19 mo EV->E, and 12 mo EVo; median PFS was 5, 5, 6 mo, respectively. Univariate analysis (UVA) and MVA results are shown in Table. In MVA, longer OS was seen in pts who received both EV and E vs EVo. Conclusions: We showed longersurvival in pts with FGFR2/3 alt aUC who received both EV and E regardless of sequence, which may reflect guarantee-time bias. Additional limitations include retrospective nature, modest sample size, no central scan review, lack of data for pts who received E only, selection and confounding biases. Larger prospective studies are needed to determine optimal sequencing and putative biomarkers. [Table: see text]

Cholangiocarcinoma Insights: Established Foundations and Cutting-Edge Innovations from Dr. James Cleary’s Pioneering Research

This paper provides insights into the conventional understanding of biliary tract malignancies, with a specific focus on cholangiocarcinoma (CCA). We then delve into the groundbreaking ideas presented by Dr. James Cleary. CCA, originating from biliary tree cells, manifests diverse subtypes contingent upon anatomical localization and differentiation status. These variants exhibit discrete genetic aberrations, yielding disparate clinical phenotypes and therapeutic modalities. Intrahepatic, perihilar, and distal CCAs intricately involve distinct segments of the biliary tree, further categorized as well-differentiated, moderately differentiated, or poorly differentiated adenocarcinomas based on their histological differentiation. Understanding the etiological factors contributing to CCA development assumes paramount importance. Stratifying these factors into two groups, those unrelated to fluke infestations (e.g., viral hepatitis and fatty liver conditions) and those associated with fluke infestations (e.g., chronic liver inflammation), facilitates predictive modeling. The epidemiology of CCA exhibits global variability, with Southeast Asia notably displaying higher incidences attributed primarily to liver fluke infestations. Jaundice resulting from bile duct obstruction constitutes a prevalent clinical manifestation of CCA, alongside symptoms like malaise, weight loss, and abdominal pain. Diagnostic challenges arise due to the symptomatic overlap with other biliary disorders. Employing comprehensive liver function tests and imaging modalities such as computed tomography assumes a pivotal role in ensuring accurate diagnosis and staging. However, the definitive confirmation of CCA necessitates a biopsy. Treatment modalities, predominantly encompassing surgical resection and radiation therapy, hold curative potential, although a considerable subset of patients is deemed unresectable upon exploration. Challenges intensify, particularly in cases classified as cancer of unknown origin, underscoring the imperative for early intervention. Advancements in genomic sequencing have revolutionized precision medicine in CCA. Distinct genomic markers, including fibroblast growth factor receptor 2 (FGFR2) alterations and isocitrate dehydrogenase 1 (IDH1) mutations, have emerged as promising therapeutic targets. FGFR2 alterations, encompassing mutations and rearrangements, play pivotal roles in oncogenesis, with FGFR inhibitors demonstrating promise despite identified resistance mechanisms. Similarly, IDH1 inhibitors face challenges with resistance, despite encouraging early clinical trial results, prompting exploration of novel irreversible inhibitors. Dr. James Cleary’s illuminating discourse underscores the significance of diverse FGFR2 alterations and the potential of IDH1 inhibition in reshaping the treatment landscape for CCA. These findings unveil critical avenues for targeted therapeutic interventions, emphasizing the critical need for ongoing research to optimize outcomes in this challenging cancer subtype, incorporating innovative insights from Dr. Cleary.

The anti-tumor effects of AZD4547 on ovarian cancer cells: differential responses based on c-Met and FGF19/FGFR4 expression

BackgroundThe FGF/FGFR signaling pathway plays a critical role in human cancers. We analyzed the anti-tumor effect of AZD4547, an inhibitor targeting the FGF/FGFR pathway, in epithelial ovarian cancer (EOC) and strategies on overcoming AZD4547 resistance.MethodsThe effect of AZD4547 on cell viability/migration was evaluated and in vivo experiments in intraperitoneal xenografts using EOC cells and a patient-derived xenograft (PDX) model were performed. The effect of the combination of AZD4547 with SU11274, a c-Met-specific inhibitor, FGF19-specific siRNA, or an FGFR4 inhibitor was evaluated by MTT assay.ResultsAZD4547 significantly decreased cell survival and migration in drug-sensitive EOC cells but not drug-resistant cells. AZD4547 significantly decreased tumor weight in xenograft models of drug-sensitive A2780 and SKOV3ip1 cells and in a PDX with drug sensitivity but not in models with drug-resistant A2780-CP20 and SKOV3-TR cells. Furthermore, c-Met expression was high in SKOV3-TR and HeyA8-MDR cells, and co-administration of SU11274 and AZD4547 synergistically induced cell death. In addition, expressions of FGF19 and FGFR4 were high in A2780-CP20 cells. Combining AZD4547 with FGF19 siRNA or with a selective FGFR4 inhibitor led to significantly reduced cell proliferation in A2780-CP20 cells.ConclusionsThis study showed that AZD4547 has significant anti-cancer effects in drug-sensitive cells and PDX models but not in drug-resistant EOC cells. In drug-resistant cells, the expression level of c-Met or FGF19/FGFR4 may be a predictive biomarker for AZD4547 treatment response, and a combination strategy of drugs targeting c-Met or FGF19/FGFR4 together with AZD4547 may be an effective therapeutic strategy for EOC.

Dual-Hit Strategy for Therapeutic Targeting of Pancreatic Cancer in Patient-Derived Xenograft Tumors.

Paracrine activation of pro-fibrotic hedgehog (HH) signaling in pancreatic ductal adenocarcinoma (PDAC) results in stromal amplification that compromises tumor drug delivery, efficacy, and patient survival. Interdiction of HH-mediated tumor-stroma crosstalk with smoothened (SMO) inhibitors (SHHi) "primes" PDAC patient-derived xenograft (PDX) tumors for increased drug delivery by transiently increasing vascular patency/permeability, and thereby macromolecule delivery. However, patient tumor isolates vary in their responsiveness, and responders show co-induction of epithelial-mesenchymal transition (EMT). We aimed to identify the signal derangements responsible for EMT induction and reverse them and devise approaches to stratify SHHi-responsive tumors noninvasively based on clinically-quantifiable parameters. Animals underwent diffusion-weighted magnetic resonance (DW-MR) imaging for measurement of intratumor diffusivity. In parallel, tissue-level deposition of nanoparticle probes was quantified as a marker of vascular permeability/perfusion. Transcriptomic and bioinformatic analysis was employed to investigate SHHi-induced gene reprogramming and identify key "nodes" responsible for EMT induction. Multiple patient tumor isolates responded to short-term SHH inhibitor exposure with increased vascular patency and permeability, with proportionate increases in tumor diffusivity. Nonresponding PDXs did not. SHHi-treated tumors showed elevated FGF drive and distinctly higher nuclear localization of fibroblast growth factor receptor (FGFR1) in EMT-polarized tumor cells. Pan-FGFR inhibitor NVP-BGJ398 (Infigratinib) reversed the SHHi-induced EMT marker expression and nuclear FGFR1 accumulation without compromising the enhanced permeability effect. This dual-hit strategy of SMO and FGFR inhibition provides a clinically-translatable approach to compromise the profound impermeability of PDAC tumors. Furthermore, clinical deployment of DW-MR imaging could fulfill the essential clinical-translational requirement for patient stratification.

Clinical management of intrahepatic cholangiocarcinoma: surgical approaches and systemic therapies.

Intrahepatic cholangiocarcinoma (ICCA) is a rare and aggressive malignant tumor that arises from the biliary tracts in the liver. Upfront surgery with adjuvant capecitabine in patients with resectable disease is often the standard treatment. Unfortunately, only 20% of patients present with resectable disease and many individuals will develop recurrence or metastatic disease after curative-intent resection. Patients with advanced or metastatic ICCA often require multidisciplinary care with a combination of cytotoxic chemotherapy, targeted therapy, and/or locoregional therapies. Gemcitabine plus cisplatin is currently first line therapy for advanced or metastatic ICCA. In recent years, efforts have been focused to develop more effective targeted therapy, most commonly with FGFR and IDH inhibitors for ICCA. Despite these efforts, ICCA still carries a poor prognosis. We herein review the current clinical management of ICCA focusing on surgical technique and systemic therapies.

Hyperglycemia activates FGFR1 via TLR4/c-Src pathway to induce inflammatory cardiomyopathy in diabetes

Protein tyrosine kinases (RTKs) modulate a wide range of pathophysiological events in several non-malignant disorders, including diabetic complications. To find new targets driving the development of diabetic cardiomyopathy (DCM), we profiled an RTKs phosphorylation array in diabetic mouse hearts and identified increased phosphorylated fibroblast growth factor receptor 1 (p-FGFR1) levels in cardiomyocytes, indicating that FGFR1 may contribute to the pathogenesis of DCM. Using primary cardiomyocytes and H9C2 cell lines, we discovered that high-concentration glucose (HG) transactivates FGFR1 kinase domain through toll-like receptor 4 (TLR4) and c-Src, independent of FGF ligands. Knocking down the levels of either TLR4 or c-Src prevents HG-activated FGFR1 in cardiomyocytes. RNA-sequencing analysis indicates that the elevated FGFR1 activity induces pro-inflammatory responses via MAPKs–NFκB signaling pathway in HG-challenged cardiomyocytes, which further results in fibrosis and hypertrophy. We then generated cardiomyocyte-specific FGFR1 knockout mice and showed that a lack of FGFR1 in cardiomyocytes prevents diabetes-induced cardiac inflammation and preserves cardiac function in mice. Pharmacological inhibition of FGFR1 by a selective inhibitor, AZD4547, also prevents cardiac inflammation, fibrosis, and dysfunction in both type 1 and type 2 diabetic mice. These studies have identified FGFR1 as a new player in driving DCM and support further testing of FGFR1 inhibitors for possible cardioprotective benefits.

Development of a stemness-related prognostic index to provide therapeutic strategies for bladder cancer

Bladder cancer (BC) is a heterogeneous disease with varying clinical outcomes. Recent evidence suggests that cancer progression involves the acquisition of stem-like signatures, and assessing stemness indices help uncover patterns of intra-tumor molecular heterogeneity. We used the one-class logistic regression algorithm to compute the mRNAsi for each sample in BLCA cohort. We subsequently classified BC patients into two subtypes based on 189 mRNAsi-related genes, using the unsupervised consensus clustering. Then, we identified nine hub genes to construct a stemness-related prognostic index (SRPI) using Cox regression, LASSO regression and Random Forest methods. We further validated SRPI using two independent datasets. Afterwards, we examined the molecular and immune characterized of SRPI. Finally, we conducted multiply drug screening and experimental approaches to identify and confirm the most proper agents for patients with high SRPI. Based on the mRNAsi-related genes, BC patients were classified into two stemness subtypes with distinct prognosis, functional annotations, genomic variations and immune profiles. Using the SRPI, we identified a specific subgroup of BC patients with high SRPI, who had a poor response to immunotherapy, and were less sensitive to commonly used chemotherapeutic agents, FGFR inhibitors, and EGFR inhibitors. We further identified that dasatinib was the most promising therapeutic agent for this subgroup of patients. This study provides further insights into the stemness classification of BC, and demonstrates that SRPI is a promising tool for predicting prognosis and therapeutic opportunities for BC patients.

Pivotal single-arm, phase 2 trial of tasurgratinib for patients with fibroblast growth factor receptor (FGFR)-2 gene fusion-positive cholangiocarcinoma (CCA).

471 Background: CCA represents ~3% of all gastrointestinal malignancies globally; it is particularly prevalent in Asian countries. Additionally, FGFR2 gene fusions occur in ~13% of intrahepatic CCA cases. Tasurgratinib (E7090) is an orally available selective inhibitor of FGFR 1–3; the recommended dose is 140 mg per day per the dose-escalation part of a first-in-human phase 1 study. In this pivotal phase 2 study, this regimen was evaluated in patients (pts) with FGFR2 fusion-positive CCA. Methods: Japanese and Chinese pts with surgically unresectable advanced or metastatic CCA were treated with tasurgratinib 140 mg PO daily. FGFR2 gene fusion was confirmed by fluorescence in situ hybridization performed in central laboratories; ≥ 1 prior chemotherapy regimen including a gemcitabine-based combination was required; pts treated with FGFR2 inhibitors were excluded. The primary endpoint was objective response rate (ORR; complete response [CR] + partial response [PR]). Secondary endpoints included duration of response (DOR), time to response (TTR), disease control rate (DCR; CR + PR + stable disease [SD]), clinical benefit rate (CBR; CR + PR + SD lasting ≥ 23 weeks), progression-free survival (PFS), overall survival (OS), and safety. The study was considered successful if the lower limit of the ORR 90% CI was > 15% in a planned population. Tumor responses were measured every 8 weeks by RECIST v1.1 per independent imaging review. Adverse event (AE) severity was measured per CTCAE v4.03. Results: 63 Pts (Japanese: n = 28; Chinese: n = 35) were treated (median age: 55 years); 23 pts (37%) had received 1 prior regimen, all others had received ≥ 2. By the data cutoff date (March 15, 2023), 55 pts discontinued treatment (disease progression, n = 48; adverse events, n = 4; pt choice, n = 2; loss of clinical benefit, n = 1). 19 Pts (30%) had a PR; 31 pts (49%) had SD and 13 (21%) had SD for ≥ 23 weeks. The ORR was 30% (2-sided 90% CI 20.7–41.0; 95% CI 19.2–43.0); the DCR was 79% (95% CI 67.3–88.5); the CBR was 51% (95% CI 37.9–63.6). The median [m]TTR / DOR for responders were 1.87 mos (IQR 1.77–2.10; range 1.6–14.7) / 5.6 mos (95% CI 3.7–9.3; range 1.0+–14.8+). The mPFS / OS were 5.4 mos (95% CI 3.7–5.6) / 13.1 mos (95% CI 10.8–17.4). 61 Pts (97%) had ≥ 1 treatment-related AE (TRAE), most commonly hyperphosphatemia (n = 51; 81%); 18 pts (29%) had ≥ 1 grade ≥ 3 TRAE, most commonly lipase increased (n = 4; 6%). 34 Pts (54%) had a dose reduction and 18 (29%) had treatment interruption due to TRAEs. 4 Pts (6%) had a fatal AE, none related to treatment. Conclusions: Tasurgratinib had promising antitumor activity in pts with CCA harboring FGFR2 gene fusion and who received ≥ 1 prior chemotherapy regimen. The primary endpoint (ORR) met the study’s predefined success criteria. Tasurgratinib had a manageable safety profile consistent with previous reports and with the known pharmacological profile of FGFR inhibitors. Clinical trial information: NCT04238715 .