Fibroblast Growth Factor Receptor Research Articles

A phase I drug-drug interaction study to assess the effect of futibatinib on P-gp and BCRP substrates and of P-gp inhibition on the pharmacokinetics of futibatinib.

Futibatinib, an inhibitor of fibroblast growth factor receptor 1-4, is approved for the treatment of patients with advanced cholangiocarcinoma with FGFR2 fusions/rearrangements. In this phase I drug-drug interaction study, the effects of futibatinib on P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) substrates, and of P-gp inhibition on futibatinib pharmacokinetics (PK) were investigated in healthy adults aged 18-55 years. In part 1, 20 participants received digoxin (P-gp substrate) and rosuvastatin (BCRP substrate). Following a ≥10-day washout, futibatinib was administered for 7 days, with digoxin and rosuvastatin coadministered on the third day. In part 2, 24 participants received futibatinib. Following a ≥3-day washout, quinidine (P-gp inhibitor) was administered for 4 days, with futibatinib coadministered on day 4. Blood samples were collected predose and for 24 (futibatinib), 72 (rosuvastatin), and 120 h (digoxin) postdose. Urine samples (digoxin) were collected predose and for 120 h postdose. PK parameters were compared between treatments using analysis of variance. Coadministration with futibatinib had no effect on the PK of digoxin and rosuvastatin, and coadministration with quinidine had minimal effects on the PK of futibatinib. Differences in Cmax and AUC with and without futibatinib and quinidine, respectively, were <20%. The most common treatment-emergent adverse events were diarrhea (80%) and increased blood phosphorous (75%) in part 1 and prolonged electrocardiogram QT interval (38%) in part 2. The data show that futibatinib has no clinically meaningful effects on the PK of P-gp or BCRP substrates and that the effect of P-gp inhibition on futibatinib PK is not clinically relevant.

Affinity of Nintedanib Towards New Candidate Target for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive disease due to aggregation of fibroblasts on lung parenchyma. Nintedanib, an indolinone-derived tyrosine kinase inhibitor (TKi) has been approved for the treatment of IPF and it is a well-known inhibitor of platelet-derived growth factor (PDGF) receptor-α and -β, fibroblast growth factor (FGF) receptor-1–3 and vascular endothelial growth factor (VEGF) receptor-1–3. This study aims to evaluate the binding interaction between new therapeutic protein candidates for IPF such as autotaxin, galectin-3, interleukin-13, chitotriosidase-1, JNK, RhoE-ROCK-1, ROCK-2 against nintedanib. In this investigation we predicted, computed, and analyzed the binding interactions of the drug nintedanib using an in silico approach called molecular docking. Our docking studies demonstrated that RhoE-ROCK1 and autotaxin showed strong binding affinities towards nintedanib compared to known targets such as VEGFR2 and FGFR1. We can therefore hypothesize a further contribution of nintedanib to the improvement of pathology due to its affinity towards new targets in the pathogenesis of IPF. The next step will be to evaluate the effects of this affinity in vitro on specific cellular models.

FGFR1-mediated enhancement of foot-and-mouth disease virus entry

Foot-and-mouth disease virus (FMDV), a member of picornavirus, can enter into host cell via macropinocytosis. Although it is known that receptor tyrosine kinases (RTKs) play a crucial role in FMDV macropinocytic entry, the specific RTK responsible for regulating this process and the intricacies of RTK-mediated downstream signaling remain to be elucidated. Here, we conducted a screening of RTK inhibitors to assess their efficacy against FMDV. Our findings revealed that two compounds specifically targeting fibroblast growth factor receptor 1 (FGFR1) and FMS-like tyrosine kinase 3 (FLT3) significantly disrupted FMDV entry. Furthermore, additional evaluation through gene knockdown and overexpression confirmed the promotion effect of FGFR1 and FLT3 on FMDV entry. Interestingly, we discovered that the increasement of FMDV entry facilitated by FGFR1 and FLT3 can be ascribed to increased macropinocytic uptake. Additionally, in-depth mechanistic study demonstrated that FGFR1 interacts with FMDV VP3 and undergoes phosphorylation during FMDV entry. Furthermore, the FGFR1 inhibitor inhibited FMDV-induced activation of p21-activated kinase 1 (PAK1) on Thr212 and Thr423 sites. Consistent with these findings, the ectopic expression of FGFR1 resulted in a concomitant increase in phosphorylation level of PAK1 on Thr212 and Thr423 sites. Taken together, our findings represent the initial exploration of FGFR1's involvement in FMDV macropinocytic entry, providing novel insights with potential implications for the development of antiviral strategies.

Developing New Peptides and Peptide-Drug Conjugates for Targeting the FGFR2 Receptor-Expressing Tumor Cells and 3D Spheroids.

In this work, we utilized a biomimetic approach for targeting KATO (III) tumor cells and 3D tumoroids. Specifically, the binding interactions of the bioactive short peptide sequences ACSAG (A-pep) and LPHVLTPEAGAT (L-pep) with the fibroblast growth factor receptor (FGFR2) kinase domain was investigated for the first time. Both peptides have been shown to be derived from natural resources previously. We then created a new fusion trimer peptide ACSAG-LPHVLTPEAGAT-GASCA (Trimer-pep) and investigated its binding interactions with the FGFR2 kinase domain in order to target the fibroblast growth factor receptor 2 (FGFR2), which is many overexpressed in tumor cells. Molecular docking and molecular dynamics simulation studies revealed critical interactions with the activation loop, hinge and glycine-rich loop regions of the FGFR2 kinase domain. To develop these peptides for drug delivery, DOX (Doxorubicin) conjugates of the peptides were created. Furthermore, the binding of the peptides with the kinase domain was further confirmed through surface plasmon resonance studies. Cell studies with gastric cancer cells (KATO III) revealed that the conjugates and the peptides induced higher cytotoxicity in the tumor cells compared to normal cells. Following confirmation of cytotoxicity against tumor cells, the ability of the conjugates and the peptides to penetrate 3D spheroids was investigated by evaluating their permeation in co-cultured spheroids grown with KATO (III) and colon tumor-associated fibroblasts (CAFs). Results demonstrated that Trimer-pep conjugated with DOX showed the highest permeation, while the ACSAG conjugate also demonstrated reasonable permeation of the drug. These results indicate that these peptides may be further explored and potentially utilized to create drug conjugates for targeting tumor cells expressing FGFR2 for developing therapeutics.

Achondroplasia current concept of orthopaedic management.

Achondroplasia, the most common form of inherited disproportionate short stature, is caused by mutations in the fibroblast growth factor receptor 3 gene. The typical clinical features of achondroplasia include short stature, rhizomelic disproportion, joint hyperlaxity, spinal deformity and deformity of the upper and lower limbs. The latter are among the challenges of state-of-the-art orthopaedic treatment plans and significantly contribute to the burden of the disease in individuals with achondroplasia. Multidisciplinary preoperative individual decision-making concerning surgical interventions should be considered. New medical treatments for achondroplasia have been developed and (some) have been approved for clinical use in several countries. While the number of research articles on achondroplasia is increasing rapidly, many unknown or controversial orthopaedic topics remain. Furthermore, in view of new medical developments with improvements in growth and potentially other effects, the timing and algorithms of orthopaedic treatments (e.g. guided growth, limb lengthening and deformity correction) need to be re-evaluated. While standing height is the primary research focus in medical therapy, it is crucial to comprehensively assess orthopaedic parameters in this multifactorial disease. The current treatment of patients with achondroplasia requires specialised multidisciplinary centres with transitional care and individual orthopaedic counselling.

Exploring the Horizon: Anti-Fibroblast Growth Factor Receptor Therapy in Pancreatic Cancer with Aberrant Fibroblast Growth Factor Receptor Expression-A Scoping Review.

Pancreatic cancer is a highly lethal disease, often diagnosed at advanced stages, with a 5-year overall survival rate of around 10%. Current treatments have limited effectiveness, underscoring the need for new therapeutic options. This scoping review aims to identify and summarize preclinical and clinical studies on FGFR (Fibroblast Growth Factor Receptor) inhibitors, including tyrosine kinase inhibitors (TKIs) and FGFR-specific inhibitors, in pancreatic cancer with FGFR alterations. We included studies analyzing efficacy, safety, and survival outcomes in various populations. A comprehensive search across major databases identified 73 relevant studies: 32 preclinical, 16 clinical, and 25 from gray literature. The clinical trials focused primarily on efficacy (20 studies) and safety (14 studies), with fewer studies addressing survival outcomes. FGFR1 was the most studied alteration, followed by FGFR2 and FGFR4. Although FGFR alterations are relatively rare in pancreatic cancer, the available data, including promising real-life outcomes, suggest significant potential for FGFR inhibitors. However, more extensive research is needed to identify the correct genetic drivers and gather robust survival data. Ongoing and future trials are expected to provide more comprehensive insights, potentially leading to improved targeted therapies for pancreatic cancer patients with FGFR alterations.

Structure-based drug-development study against fibroblast growth factor receptor 2: molecular docking and Molecular dynamics simulation approaches

Developing new therapeutic strategies to target specific molecular pathways has become a primary focus in modern drug discovery science. Fibroblast growth factor receptor 2 (FGFR2) is a critical signaling protein involved in various cellular processes and implicated in numerous diseases, including cancer. Existing FGFR2 inhibitors face limitations like drug resistance and specificity issues. In this study, we present an integrated structure-based bioinformatics analysis to explore the potential of FGFR2 inhibitors-like compounds from the PubChem database with the Tanimoto threshold of 80%. We conducted a structure-based virtual screening approach on a dataset comprising 2336 compounds sourced from the PubChem database. Primarily, the selection of promising compounds was based on several criteria, such as drug-likeness, binding affinities, docking scores, and selectivity. Further, we conducted all-atom molecular dynamics (MD) simulations for 200 ns, followed by an essential dynamics analysis. Finally, a promising FGFR2 inhibitor with PubChem CID:507883 (1-[7-(1H-benzimidazol-2-yl)-4-fluoro-1H-indol-3-yl]-2-(4-benzoylpiperazin-1-yl)ethane-1,2-dione) was screened out from the study. This compound indicates a higher potential for inhibiting FGFR2 than the control inhibitor, Zoligratinib. The identified compound, CID:507883 shows >80% structural similarity with Zoligratinib. ADMET analysis showed promising pharmacokinetic potential of the screened compound. Overall, the findings indicate that the compound CID:507883 may have promising potential to serve as a lead candidate against FGFR2 and could be further exploited in therapeutic development.

Real-world use of pemigatinib for the treatment of cholangiocarcinoma in the US.

Pemigatinib demonstrated efficacy in fibroblast growth factor receptor (FGFR)-altered cholangiocarcinoma (CCA) in the FIGHT-202 trial. However, limited real-world evidence exists on treatment patterns and outcomes in this setting. Patient characteristics, treatment patterns, and outcomes of US adults who received pemigatinib for unresectable, locally advanced or metastatic CCA were collected via retrospective physician-abstracted chart review. Results were summarized using descriptive statistics. Data from 120 patients (49.2% male; 55.0% White; 19.2% Hispanic; median age at initial pemigatinib prescription, 64.5 years) were collected from 18 physicians/practices. At the time of prescribing, 90.0% of patients had metastatic disease. FGFR2 testing was completed for 92.5% of patients; of those, all but one (result unknown) tested positive, and 95.5% were tested using next-generation sequencing. Pemigatinib was prescribed as second- and third-line therapy among 94.2% and 5.8% of patients, respectively. The most common starting dosage was 13.5mg daily for 14 days of 21-day cycles (87.5% of patients). Among 60 patients (50.0% of the full cohort) who discontinued pemigatinib during the 6.5-month median study follow-up period, 68.3% discontinued due to disease progression. The median real-world progression-free survival (rwPFS) from the date of pemigatinib initiation was 7.4 months (95% CI: 6.4-8.6), and the real-world overall response rate (rwORR) was 59.2% (95% CI: 50.0%-68.4%). This study complements the FIGHT-202 clinical trial by assessing the use of pemigatinib among a diverse population of patients with CCA under real-world conditions. Findings support the clinical benefit of pemigatinib demonstrated in FIGHT-202.

Cardiac Fibroblasts Produce Fibroblast Growth Factor 23 in Response to Hyperphosphatemia

Chronic Kidney Disease (CKD) is accompanied by pathologic cardiac remodeling, including cardiac hypertrophy and fibrosis. The decline in renal function results in elevations of serum concentrations of phosphate (hyperphosphatemia) and of the bone-derived hormone Fibroblast Growth Factor (FGF) 23. Clinical studies have shown that hyperphosphatemia and high circulating levels of FGF23 are associated with cardiovascular mortality in CKD. We previously found that FGF23 can directly target cardiac myocytes via FGF Receptor (FGFR) 4 and induce cardiac hypertrophy in rodents. Furthermore, decreasing serum FGF23 levels or pharmacological blockade of FGFR4 in rodent models of hyperphosphatemia and CKD reduces cardiac hypertrophy, but not cardiac fibrosis. To directly determine whether cardiac fibroblasts are resistant to FGF23 elevations, we isolated cardiac fibroblasts from adult mice and treated them with recombinant FGF23 protein, which did not induce proliferation, pro-fibrotic gene programs or differentiation into myofibroblasts. Similarly, cardiac fibroblasts isolated from mice receiving a high-phosphate diet did also not respond to FGF23, indicating that hyperphosphatemia does not prime cardiac fibroblasts for FGF23 responsiveness. However, cardiac fibroblasts derived from mice on high-phosphate diet produced and secreted FGF23. Our study suggests that cardiac fibroblasts are not a target but a source of FGF23 and that FGF23/FGFR4 signaling is a driver of cardiac hypertrophy but not fibrosis. Elevated phosphate appears to not only induce FGF23 production in bone but also in cardiac fibroblasts which in a paracrine manner might contribute to cardiac hypertrophy in scenarios of hyperphosphatemia, such as CKD.

Matching-Adjusted Indirect Comparison of the Efficacy and Safety of Erdafitinib vs Enfortumab Vedotin in Patients with Locally Advanced Metastatic Urothelial Carcinoma.

Background: For patients with locally advanced or metastatic urothelial carcinoma (la/mUC), prognosis is poor and effective treatment options are limited. Erdafitinib is an oral fibroblast growth factor receptor (FGFR) kinase inhibitor approved by the FDA for the treatment of adults with la/mUC harboring FGFR alterations whose disease progressed following at least 1 prior line of therapy, including a PD-1 or PD-L(1) inhibitor, based on the phase 3, randomized THOR trial (NCT03390504, Cohort 1). Objective: To compare the efficacy and safety of erdafitinib vs enfortumab vedotin-ejfv (EV) in the absence of head-to-head comparison via an anchored matching-adjusted indirect comparison (MAIC). Methods: An anchored MAIC was conducted according to the National Institute for Health and Care Excellence Decision Support Unit guidance, with physician's choice of chemotherapy (docetaxel/paclitaxel and vinflunine) as the common comparator. Individual patient data from THOR were adjusted to match published key eligibility criteria and average baseline characteristics of EV-301, such as Bellmunt risk score, liver or visceral metastases, primary site, among others. Erdafitinib was then indirectly compared with EV using the relative treatment effects for the reweighted THOR population and those published for EV-301. Results: After matching, the effective sample size for THOR was 126 patients. The MAIC-recalculated hazard ratio (95% credible interval) for erdafitinib vs EV was 0.92 (0.54, 1.57) for overall survival and 0.93 (0.55, 1.56) for progression-free survival, yielding Bayesian probabilities of erdafitinib being better than EV of 62.1% and 60.5%, respectively. For response outcomes, the MAIC-recalculated risk ratio was 1.49 (0.56, 3.90) for confirmed objective response rate and 2.89 (0.27, 30.33) for confirmed complete response with probabilities of 72.6% and 81.3% for erdafitinib being better than EV, respectively. For safety, MAIC-yielded risk ratios of 1.09 (0.99, 1.21) for any treatment-related adverse events, 0.86 (0.57, 1.28) for grade 3+ TRAEs, and 1.02 (0.98, 1.06) for any treatment-emergent adverse events. Conclusion: The MAIC indicates comparable efficacy of erdafitinib vs EV for overall survival and progression-free survival, with erdafitinib showing a higher probability of achieving deep responses. While erdafitinib is associated with slightly more adverse events compared with EV, these events seem to be less severe.

Matching-Adjusted Indirect Comparison of the Efficacy and Safety of Erdafitinib vs Enfortumab Vedotin in Patients with Locally Advanced Metastatic Urothelial Carcinoma

Background: For patients with locally advanced or metastatic urothelial carcinoma (la/mUC), prognosis is poor and effective treatment options are limited. Erdafitinib is an oral fibroblast growth factor receptor (FGFR) kinase inhibitor approved by the FDA for the treatment of adults with la/mUC harboring FGFR alterations whose disease progressed following at least 1 prior line of therapy, including a PD-1 or PD-L(1) inhibitor, based on the phase 3, randomized THOR trial (NCT03390504, Cohort 1). Objective: To compare the efficacy and safety of erdafitinib vs enfortumab vedotin-ejfv (EV) in the absence of head-to-head comparison via an anchored matching-adjusted indirect comparison (MAIC). Methods: An anchored MAIC was conducted according to the National Institute for Health and Care Excellence Decision Support Unit guidance, with physician’s choice of chemotherapy (docetaxel/paclitaxel and vinflunine) as the common comparator. Individual patient data from THOR were adjusted to match published key eligibility criteria and average baseline characteristics of EV-301, such as Bellmunt risk score, liver or visceral metastases, primary site, among others. Erdafitinib was then indirectly compared with EV using the relative treatment effects for the reweighted THOR population and those published for EV-301. Results: After matching, the effective sample size for THOR was 126 patients. The MAIC-recalculated hazard ratio (95% credible interval) for erdafitinib vs EV was 0.92 (0.54, 1.57) for overall survival and 0.93 (0.55, 1.56) for progression-free survival, yielding Bayesian probabilities of erdafitinib being better than EV of 62.1% and 60.5%, respectively. For response outcomes, the MAIC-recalculated risk ratio was 1.49 (0.56, 3.90) for confirmed objective response rate and 2.89 (0.27, 30.33) for confirmed complete response with probabilities of 72.6% and 81.3% for erdafitinib being better than EV, respectively. For safety, MAIC-yielded risk ratios of 1.09 (0.99, 1.21) for any treatment-related adverse events, 0.86 (0.57, 1.28) for grade 3+ TRAEs, and 1.02 (0.98, 1.06) for any treatment-emergent adverse events. Conclusion: The MAIC indicates comparable efficacy of erdafitinib vs EV for overall survival and progression-free survival, with erdafitinib showing a higher probability of achieving deep responses. While erdafitinib is associated with slightly more adverse events compared with EV, these events seem to be less severe.

Intraduodenal fecal microbiota transplantation ameliorates gut atrophy and cholestasis in a novel parenteral nutrition piglet model.

Total parenteral nutrition (TPN) provides lifesaving nutritional support intravenously; however, it is associated with significant side effects. Given gut microbial alterations noted with TPN, we hypothesized that transferring fecal microbiota from healthy controls would restore gut-systemic signaling in TPN and mitigate injury. Using our novel ambulatory model (US Patent: US 63/136,165), 31 piglets were randomly allocated to enteral nutrition (EN), TPN only, TPN + antibiotics (TPN-A), or TPN + intraduodenal fecal microbiota transplant (TPN + FMT) for 14 days. Gut, liver, and serum were assessed through histology, biochemistry, and qPCR. Stool samples underwent 16 s rRNA sequencing. Permutational multivariate analysis of variance, Jaccard, and Bray-Curtis metrics were performed. Significant bilirubin elevation in TPN and TPN-A versus EN (P < 0.0001) was prevented with FMT. IFN-G, TNF-α, IL-β, IL-8, and lipopolysaccharide (LPS) were significantly higher in TPN (P = 0.009, P = 0.001, P = 0.043, P = 0.011, P < 0.0001), with preservation upon FMT. Significant gut atrophy by villous-to-crypt ratio in TPN (P < 0.0001) and TPN-A (P = 0.0001) versus EN was prevented by FMT (P = 0.426 vs. EN). Microbiota profiles using principal coordinate analysis demonstrated significant FMT and EN overlap, with the largest separation in TPN-A followed by TPN, driven primarily by Firmicutes and Fusobacteria. TPN-altered gut barrier was preserved upon FMT; upregulated cholesterol 7 α-hydroxylase and bile salt export pump in TPN and TPN-A and downregulated fibroblast growth factor receptor 4, EGF, farnesoid X receptor, and Takeda G Protein-coupled Receptor 5 (TGR5) versus EN was prevented by FMT. This study provides novel evidence of prevention of gut atrophy, liver injury, and microbial dysbiosis with intraduodenal FMT, challenging current paradigms into TPN injury mechanisms and underscores the importance of gut microbes as prime targets for therapeutics and drug discovery.NEW & NOTEWORTHY Intraduodenal fecal microbiota transplantation presents a novel strategy to mitigate complications associated with total parenteral nutrition (TPN), highlighting gut microbiota as a prime target for therapeutic and diagnostic approaches. These results from a highly translatable model provide hope for TPN side effect mitigation for thousands of chronically TPN-dependent patients.

FGFR3 alterations in bladder cancer: Sensitivity and resistance to targeted therapies.

In this review, we revisit the pivotal role of fibroblast growth factor receptor 3 (FGFR3) in bladder cancer (BLCA), underscoring its prevalence in both non-muscle-invasive and muscle-invasive forms of the disease. FGFR3 mutations in up to half of BLCAs play a well-established role in tumorigenesis, shaping distinct tumor initiation patterns and impacting the tumor microenvironment (TME). Emphasizing the importance of considering epithelial-mesenchymal transition profile and TME status, we revisit their relevance in predicting responses to immune checkpoint inhibitors in FGFR3-mutated BLCAs. This writing highlights the initially promising yet transient efficacy of the FGFR inhibitor Erdafitinib on FGFR3-mutated BLCA, stressing the pressing need to unravel resistance mechanisms and identify co-targets for future combinatorial studies. A thorough analysis of recent preclinical and clinical evidence reveals resistance mechanisms, including secondary mutations, epigenetic alterations in pathway effectors, phenotypic heterogeneity, and population-specific variations within FGFR3 mutational status. Lastly, we discuss the potential of combinatorial treatments and concepts like synthetic lethality for discovering more effective targeted therapies against FGFR3-mutated BLCA.

FGFR1 governs iron homeostasis via regulating intracellular protein degradation pathways of IRP2 in prostate cancer cells

The acquisition of ectopic fibroblast growth factor receptor 1 (FGFR1) expression is well documented in prostate cancer (PCa) progression, notably in conferring tumor growth advantage and facilitating metastasis. However, how FGFR1 contributes to PCa progression is not fully revealed. Here we report that ectopic FGFR1 in PCa cells promotes transferrin receptor 1 (TFR1) expression and expands the labile iron pool (LIP), and vice versa. We further demonstrate that FGFR1 stabilizes iron regulatory proteins 2 (IRP2) and therefore, upregulates TFR1 via promoting IRP2 binding to the IRE of TFR1. Deletion of FGFR1 in DU145 cells decreases the LIP, which potentiates the anticancer efficacy of iron chelator. Intriguingly, forced expression of IRP2 in FGFR1 depleted cells reinstates TFR1 expression and LIP, subsequently restoring the tumorigenicity of the cells. Together, our results here unravel a new mechanism by which FGFR1 drives PCa progression and suggest a potential novel target for PCa therapy.

Inhibiting FGFR by toadflax reverses erlotinib resistance in nonsmall cell lung cancer

This study aims to demonstrate the effect of toadflax (bufalin) on erlotinib resistance in nonsmall cell lung cancer (NSCLC) by inhibiting the fibroblast growth factor receptor (FGFR). The microfluidic mobility transferase and caliper mobility-shift assays were employed to detect the FGFR inhibition by bufalin and the binding reversibility. Further, the inhibitory effects of bufalin were determined in HCC827 and HCC827/ER cells in vitro, investigating relative FGFR overexpression by quantitative reverse transcriptase-PCR (RT-qPCR) and FGFR downstream proteins, that is, FGFR substrate 2 (FRS2), extracellular signal-regulated kinase (ERK), and S6 by western blot analysis. Finally, HCC827/ER-inoculated xenograft tumors were constructed to observe the effects of bufalin and bufalin + erlotinib intervention on tumor growth. Bufalin inhibited FGFR by reversibly binding to FGFR1. In addition, the western blot analysis indicated a significant reduction in the expression levels of FGFR, FRS2, ERK, and S6 proteins in HCC827 and HCC827/ER cells, increasing the expression levels of apoptotic caspase-3 and poly-(ADP-ribose) polymerase proteins. Bufalin + erlotinib combination significantly inhibited the apoptosis of HCC827/ER cells and subsequent tumor growth in vivo. In addition, FGFR overexpression significantly reversed the sensitivity of bufalin to HCC827/ER cells, promoting the value-addition of HCC827/ER cells. Further, bufalin + erlotinib significantly reduced the growth of erlotinib-resistant HCC827/ER tumors, induced apoptosis, and inhibited the expression of FGFR and p-ERK proteins. These findings indicated that bufalin could reverse the erlotinib resistance in NSCLC by inhibiting the FGFR expression.

Ocular surface adverse reactions of antitumor-targeted drugs

With the extensive application of targeted drugs, the survival rate of cancer patients has been significantly improved. However, adverse reactions to the drugs have also become apparent, especially those affecting the ocular surface, which can severely impact patients' vision and quality of life. The article systematically analyzes a variety of targeted drugs, including epidermal growth factor receptor inhibitors, human epidermal growth factor receptor 2 inhibitors, fibroblast growth factor receptor inhibitors, selective estrogen receptor modulators, vascular endothelial growth factor receptor inhibitors, aromatase inhibitors, proteasome inhibitors, antibody-drug conjugates, Bruton's tyrosine kinase inhibitors, FMS-like tyrosine kinase 3 inhibitors, and cyclin-dependent kinase inhibitors, and discusses their adverse reactions on the ocular surface. The review emphasizes the role of clinicians in monitoring and managing patients' ocular surface health and the importance of early diagnosis and intervention to ensure that patients receive optimal visual protection while undergoing antitumor treatment.

Deciphering the prognostic value of FGFR2b/2c isoform expression levels in advanced esophagogastric cancer through whole-transcriptome sequencing.

53 Background: Fibroblast growth factor receptor (FGFR) isoform switching from FGFR2b to FGFR2c has been implicated in epithelial-to-mesenchymal transition and enhanced invasive potential in various malignancies and potentially be involved in resistance mechanisms to FGFR2b targeted therapy (e.g., bemarituzumab). This study sought to investigate the potential of respective FGFR2 isoform expression evaluation utilizing whole-transcriptome sequencing (WTS) and its correlation with therapeutic efficacy and clinical outcomes in patients with advanced G/GEJ cancer. Methods: Patients with advanced G/GEJ cancer who received systemic therapy at the National Cancer Center Hospital East between May 2021 and September 2023, and were enrolled in the immunological profiling study (UMIN000019129) and MONSTAR-SCREEN-2 (UMIN000043899) were included. FGFR2 protein and RNA expression were assessed via immunohistochemistry (IHC) and WTS with Caris MI Profile, respectively. FGFR2b and FGFR2c isoforms were distinguished by the detection of their respective splice junctions using WTS data. The FGFR2b/(2b+2c) ratio was stratified into FGFR2b-dominat and -containing subtypes using the median value. The log-rank test was used to discern differences in overall survival (OS). Results: Among the 129 patients, 21 (16.3%) exhibited FGFR2-positivity by IHC (staining intensity 2+ or 3+≥1% membranous staining of tumor cells), and a significant correlation was observed between FGFR2 IHC status and RNA expression levels (TPM: transcript per million) in WTS (FGFR2-positive, median TPM=11.1; FGFR2-negative, median TPM=4.7; P=0.002). The distribution of FGFR2b/(2b+2c) ratio (median, 0.89) was: 10.9% (0≤x&lt;0.2), 5.4% (0.2≤x&lt;0.4), 7.0% (0.4≤x&lt;0.6), 12.4% (0.6≤x&lt;0.8), 43.4% (0.8≤x&lt;1.0), and 20.9% (x=1.0). Among 58 patients treated with 1st line therapy, no significant difference in treatment response was observed between the FGFR2b-dominat (67.9%) and FGFR2c-containing subtypes (53.3%) (P=0.259). Overall, the FGFR2c-containing subtype was associated with significantly shorter OS compared to the FGFR2b-dominat subtype (median OS, 10.1 vs. 17.9 months; hazard ratio, 1.72; 95% confidence interval, 1.03-2.86; log-rank P=0.037). Conclusions: Our findings underscore the substantial concordance between IHC and WTS analysis of FGFR2, the feasibility of distinguishing FGFR2 isoforms using WTS, and the prognostic implications of FGFR2c isoform in patients with advanced G/GEJ cancer. Further analysis is warranted in patients receiving FGFR2b targeted treatment.

Mathematical Modeling of Tumor Immune Interactions: The Role of Anti-FGFR and Anti-PD-1 in the Combination Therapy.

Bladder cancer poses a significant global health burden with high incidence and recurrence rates. This study addresses the therapeutic challenges in advanced bladder cancer, focusing on the competitive mechanisms of ligand or drug binding to receptors. We developed a refined mathematical model that integrates the dynamics of tumor cells and immune responses, particularly targeting fibroblast growth factor receptor 3 (FGFR3) and immune checkpoint inhibitors (ICIs). This study contributes to understanding combination therapies by elucidating the competitive binding dynamics and quantifying the synergistic effects. The findings highlight the importance of personalized immunotherapeutic strategies, considering factors such as drug dosage, dosing schedules, and patient-specific parameters. Our model further reveals that ligand-independent activated-state receptors are the most essential drivers of tumor proliferation. Moreover, we found that PD-L1 expression rate was more important than PD-1 in driving the dynamic evolution of tumor and immune cells. The proposed mathematical model provides a comprehensive framework for unraveling the complexities of combination therapies in advanced bladder cancer. As research progresses, this multidisciplinary approach contributes valuable insights toward optimizing therapeutic strategies and advancing cancer treatment paradigms.

Retraction Note: Fibroblast growth factor receptor 1 is principally responsible for fibroblast growth factor 2-induced catabolic activities in human articular chondrocytes

Retraction Note: Fibroblast growth factor receptor 1 is principally responsible for fibroblast growth factor 2-induced catabolic activities in human articular chondrocytes

35 Efficacy of treatments post-lenvatinib in patients with advanced renal cell carcinoma (aRCC)

Abstract Background Lenvatinib is a tyrosine kinase inhibitor (TKI) that targets both vascular endothelial growth factor (VEGF) receptor and fibroblast growth factor receptor. It has demonstrated efficacy both in the upfront and refractory disease settings. However, there is a lack of data surrounding the efficacy of TKIs post-lenvatinib exposure. In this study, we investigate the activity of therapies post-lenvatinib in patients with aRCC. Methods We conducted a retrospective analysis utilizing the International Metastatic Database Consortium (IMDC). Patients having received treatment post-lenvatinib exposure were eligible and divided into two cohort: patients post-1st line lenvatinib (2nd line cohort) and patients post-2nd line lenvatinib (3rd line cohort). The primary objective was objective response rate (ORR) and time to treatment failure (TTF). ORR was summarized with 95% two-sided exact binomial confidence interval. TTF was defined as time from treatment initiation to drug cessation for any reason censored at the date of last follow-up. Results Overall, 84 patients received 1st line lenvatinib of whom 43 (51%) remain on therapy, 20 (24%) received 2nd line treatment, and 21 (25%) received no subsequent treatment. The median duration of prior lenvatinib was 9.7 months. All patients received 1st line pembrolizumab + lenvatinib (ORR 50%, median TTF 19.7 months). Reason for lenvatinib discontinuation was progression (50%), progression + toxicity (20%), toxicity (15%), or other (15%). For the 2nd line cohort, median age was 61 years, most patients were male (85%), had prior nephrectomy (75%), clear cell histology (85%), and were IMDC intermediate/poor risk (55%). 2nd line therapy regimens included TKI monotherapy (80%), TKI-IO (5%), and other (15%). The median follow up from 2nd-line treatment initiation was 4.9 months. The ORR to 2nd line treatment was 5% (95% CI 0.2-25) and median TTF was 5.8 months (95% CI 1.9-14.9). Of 2nd line lenvatinib-exposed patients (n=84), 24 (29%) remain on treatment, 34 (40%) received 3rd line treatment, and 26 (31%) did not receive additional therapy. The median duration of prior lenvatinib was 5.9 months. Most patients received 2nd line everolimus + lenvatinib (97%) (ORR 31%, median TTF 9.2 months). Reason for lenvatinib discontinuation was progression (59%), progression + toxicity (9%), toxicity (12%), or other (21%). For the 3rd line cohort, median age was 67 years, most patients were male (68%), had prior nephrectomy (88%), clear cell histology (68%), and were IMDC intermediate/poor risk (77%). 3rd line treatments included TKI alone (50%), IO-TKI (38%), and other (12%). The median follow up from 3rd-line treatment initiation was 14.9 months. The ORR to 3rd line treatment was 12% (95% CI 3.3-27) and median TTF was 2.8 months (95% CI 1.9-7.4). Conclusions In this analysis, we demonstrate modest activity of TKI-based therapy post-lenvatinib exposure. Our study highlights the need for improved treatment options for patients progressing on lenvatinib-based therapies.