P1, N=30, Recruiting, National Cancer Institute (NCI) | Trial completion date: Oct 2024 --> Sep 2025 | Trial primary completion date: Oct 2024 --> Sep 2025

Several FGFR inhibitors have been studied or are in development, and erdafitinib is the sole inhibitor to achieve regulatory approval...In this review, we describe known mechanisms of FGFR inhibitor resistance, including gatekeeper mutations, domain mutations, and the development of new mutations. In addition, we discuss management strategies, including ongoing clinical trials evaluating FGFR inhibitors, antibody-drug conjugates, and combination therapies with immune checkpoint inhibitors that may provide additional treatment options for localized and metastatic urothelial carcinoma.

We believe that FGFR4 overexpression and complex formation with HER2 can serve as molecular markers to assist clinicians in identifying trastuzumab-resistant tumors. Our results suggest that FGF401 combined with trastuzumab as adjuvant therapy for patients with trastuzumab-resistant breast cancer may be a potential new treatment strategy.

Dysregulated FGFR4 activates the AKT/RYR2 axis, leading to tumor proliferation, invasion, and altered lipid metabolism in TNBC. FGFR4 inhibition could potentially serve as a novel therapeutic strategy for TNBC treatment.

In addition, both morphological and molecular subtypes are associated with immunological and other molecular characteristics that could be relevant for modern immunotherapies or antibody-drug conjugates, e.g. in the form of PD-L1 and NECTIN-4 status. With the pending approval of erdafitinib (FGFR3 inhibitor), molecular tumour boards for patients with metastatic urothelial carcinoma will also become more important in the future.

For example, erdafitinib is approved for treating locally advanced or metastatic urothelial cancer patients with FGFR2/FGFR3 mutations, and pemigatinib is approved for treating cholangiocarcinoma with FGFR2 fusion/rearrangement. Various detection methods, such as polymerase chain reaction, next-generation sequencing, fluorescence in situ hybridization, and immunohistochemistry, are available, and their selection should be based on diagnostic and treatment decision-making needs. Our developed expert consensus aims to standardize the diagnosis and treatment process for FGFR gene mutations and facilitate the practical application of FGFR inhibitors in clinical practice.

We found that, consistent with other Fgfr4 knockout animal models, the fgfr4 mutant fish developed normally; however, homozygous fgfr4 mutant zebrafish were significantly smaller than wildtype fish at three months post fertilization. These fgfr4 knockout zebrafish lines are a valuable tool to study the role of FGFR4 in vertebrate development and its viability as a potential therapeutic target in pediatric and adult cancers, as well as other diseases.

Collaboration between nephrologists and oncologists is crucial for optimizing treatment benefits and managing side effects. Further research is warranted to refine management strategies and to understand the clinical implications of hyperphosphatemia.

Among these therapies, erdafitinib, a pan-fibroblast growth factor receptor (FGFR) inhibitor for specific FGFR2 and FGFR3 alterations, is the only targeted therapy approved till now...Ongoing investigations exist on its use in non-muscle-invasive BC and in combination with drugs such as enfortumab vedotin in mUC...This review emphasizes the importance of FGFR inhibition in UC and the optimization of its use in clinical practice. Moreover, it underscores the ongoing efforts to evaluate combination strategies and early treatment testing to enhance the effectiveness of targeted therapies for UC.

P1, N=35, Completed, Vanderbilt-Ingram Cancer Center | Active, not recruiting --> Completed | Trial completion date: Sep 2024 --> Mar 2024

On this basis, the present review aims at providing an overview of recently explored connections between the FGF/FGFR system and c-Myc oncoprotein, sustaining the therapeutic potential of targeting the FGF/FGFR/c-Myc axis in MM by using inhibitors targeting FGF ligands or FGF receptors. Importantly, the provided findings may represent the rationale for using FDA approved FGFR TK inhibitors (i.e. Pemigatinib, Futibatinib, Erdafitinib) for the treatment of MM patients presenting with an aberrant activation of this axis.

Erdafitinib (Erda) was nano-sized and encapsulated in PLTs to construct nano-Erda@PLT... PLTs-camouflaged nano-vehicles enable nano-Erda-mediated tumor immunotherapy through the induction of pyroptosis. These findings introduce a novel approach in exploring nanomaterial-mediated pyroptosis for cancer immunotherapy.

The characterization of metastatic tumour samples can improve response prediction to immunotherapy, the anti-NECTIN4 antibody-drug conjugate enfortumab vedotin and the FGFR inhibitor erdafitinib. Routine metastatic biopsy can thus improve the precision of identifying driver druggable alterations, thus improving treatment selection for patients with mUC.

With deepening understanding of the biology of bladder cancer, novel diagnostics, and improved drug delivery methods, we posit that FGFR inhibition will lead the way in advancing precision treatment of bladder cancer.

The drug may exert toxic effects on retinal pigment epithelium, which may be seen through interval OCTs and visualization of the interdigitation zone. Therefore, pronunciation of the ellipsoid and interdigitation zone on OCT may allow for surveillance of early manifestations of erdafitinib-induced retinal toxicity.

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. 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.

The European Association of Urology (EAU), National Comprehensive Cancer Network, and European Society for Medical Oncology guidelines recommend PD-L1 and FGFR testing for patients with locally advanced bladder cancer or upper tract urothelial cancer (UTUC) according to specific eligibility criteria; positive results indicate therapy with immune checkpoint inhibitors or erdafitinib, respectively. The EAU guidelines recommend PD-L1 testing for subsequent adjuvant therapy in high-risk UC, and germline DNA sequencing in patients with UTUC positive for DNA mismatch repair alterations.

This study utilized pharmacokinetic methods to propose a new formulation of erdafitinib combined with sertraline or duloxetine. The findings suggest that this combination has potential for clinical co-administration based on a database analysis, thereby providing a novel strategy for anti-tumor treatment with fibroblast growth factor receptor (FGFR) inhibitors.

Further molecular studies showed that such an effect of Erdafitinib and Stattic was associated with their concurrently inhibitory effect on FGFR1 and STAT3 signaling in LUSC cells. Therefore, the findings of this study indicated that the concurrent use of Erdafitinib and Stattic is a promising therapeutic approach for the treatment of FGFR1-positive LUSC.

For instance, roblitinib induces ferroptosis of trastuzumab-resistant human epidermal growth factor receptor 2 (HER2)-positive breast cancer cells by diminishing fibroblast growth factor receptor 4 (FGFR4) expression, thereby augmenting the susceptibility of these cells to HER2-targeted therapies. In tamoxifen-resistant breast cancer cells, Fascin exacerbates their resistance by repressing solute carrier family 7 member 11 (SLC7A11) expression, which in turn heightens their responsiveness to tamoxifen. In recent years, Chinese herbs extracts and therapeutic drugs have been demonstrated to elicit ferroptosis in breast cancer cells by modulating a spectrum of regulatory factors pertinent to ferroptosis, including SLC7A11, glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long chain family member 4 (ACSL4), and heme oxygenase 1 (HO-1). Here, we review the roles and mechanisms of Chinese herbal extracts and therapeutic drugs in regulating ferroptosis in breast cancer, providing potential therapeutic options for anti-breast cancer.

We present the case of a patient with a FGFR3-TACC3 fusion-positive IDH-WT GB that at its second recurrence was treated with the FGFR inhibitor erdafitinib through a compassionate use program. Although no objective response was achieved, an overt deceleration in tumor growth was evidenced and the patient remained on treatment for 5.5 months.

Our study demonstrates that FGFR4 is a prospective target for CAR-T cell therapy in rhabdomyosarcoma without serious on-target off-tumor toxicity. FGFR4 CAR-T cells with the iCasp9 suicide gene system as a safety switch to limit toxicity may broaden the clinical applications of cellular therapy.

Furthermore, novel forms of application for instillation therapy, such as the TAR device, in combination with gemcitabine or erdafitinib are being investigated in clinical trials in order to extend the duration of action of the active substance on the urothelium. Thus, there are now many developments that could make bladder-preserving therapy with comparable survival data possible as an alternative to BCG or in the event of BCG failure. In the future, it will be necessary to clarify how BCG response can be predicted by using molecular markers and how to define risk groups that should primarily be given an alternative therapy to BCG.

Moreover, N5 demonstrated favorable pharmacokinetic characteristics with a bioavailability of 74.8% when administered intraperitoneally and effectively suppressed the growth of SNU16 xenograft tumors, exhibiting greater potency compared to the parental inhibitor Erdafitinib. This study lays the groundwork for developing and potentially applying therapeutic agents targeting FGFR2 degradation.

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.

Erdafitinib demonstrated efficacy in a population of Asian patients in selected advanced solid tumors, particularly in those with advanced FGFR-altered cholangiocarcinoma. Treatment was tolerable with no new safety signals.

In summary, this study offers key insights into drug-induced network remodeling and the role of protein expression heterogeneity in targeted therapy responses. These findings underscore the utility of computational network modeling for designing cell type-selective combination therapies and enhancing precision cancer treatment.

The antibody was highly effective in suppressing growth of FGFR3-driven tumor models, providing efficacy comparable to that of the FDA-approved TKI erdafitinib. Thus, this bispecific antibody may provide an effective approach for broad and highly selective inhibition of oncogenic FGFR3 variants. Significance: Development of a bispecific antibody that broadly inhibits gain-of-function FGFR3 variants provides a therapeutic strategy to target tumors with oncogenic FGFR3 point mutations and fusions, a particularly difficult case for antibody blockade.

Adverse events were consistent with the known erdafitinib safety profile; no new safety signals emerged. Thus, repeated dosing of erdafitinib had no clinically meaningful effect on the pharmacokinetics of midazolam or metformin.

Bicistronic CARs (BiCisCAR) targeting both FGFR4 and CD276, containing two distinct co-stimulatory domains, have superior prolonged persistent and invigorated anti-tumor activities compared to the optimized FGFR4-specific CAR and the other BiCisCAR with the same 4-1BB co-stimulatory domain. Our study thus lays down the proof-of-principle for a CAR T-cell therapy targeting both FGFR4 and CD276 in RMS.

Current clinical trials, including those evaluating FGFR inhibitors like erdafitinib, lucitanib, and dovitinib, have demonstrated mixed outcomes, underscoring the complexity of FGFR signaling in breast cancer. In conclusion, targeting FGFR signaling in ER+ breast cancer presents both challenges and opportunities. A deeper understanding of the molecular mechanisms and resistance pathways is crucial for the successful integration of FGFR inhibitors into clinical practice, aiming to improve outcomes for patients with endocrine-resistant breast cancer.

P2, N=90, Recruiting, Spanish Oncology Genito-Urinary Group

P2, N=316, Active, not recruiting, Janssen Research & Development, LLC | Trial completion date: Sep 2024 --> Mar 2025

In the Japanese subgroup, erdafitinib showed improved survival and response compared to chemotherapy, with no new safety concerns. These results support erdafitinib as a treatment option for Japanese mUC patients with FGFR alterations, and early FGFR testing after diagnosis of mUC should be considered.

Covalent docking and covalent molecular dynamics (MM/MDcov) simulations combined with thermodynamic binding free energy calculations were performed, and the results were compared against known potent and selective covalent EGFR and FGFR4 inhibitors with available X-ray crystal structures, Afatinib and BLU9931, respectively. The findings of this study identified that curcumin, syringolin A and andrographolide-but not eupalmerin acetate or deoxyelephantopin -could be viable dual EGFR and FGFR4 covalent irreversible inhibitors and could be implemented in HCC combination therapy protocols alone or in conjunction with other chemotherapeutic agents. Investigations of this study conclusively indicate dual blockade of EGFR and FGFR4 may be a promising future therapeutic strategy for enhanced management of HCC.

The present study is the first to demonstrate that Erdafitinib powerfully induces ferroptosis in UM by orchestrating the ferritinophagy and lysosome biogenesis via modulating the FGFR1/mTORC1/TFEB signaling. Consequently, Erdafitinib emerges as a strong candidate for clinical trial investigation, and FGFR1 emerges as a novel and promising therapeutic target in the treatment of UM.

Erdafitinib is currently the only Food and Drug Administration (FDA)-approved targeted therapy for aUC...This review summarizes the current understanding of molecular alterations associated with aUC targeted therapy. It also comprehensively discusses the related interventions for treatment in clinical research and the potential of using novel targeted drugs in combination therapy.

Based on reflex molecular analysis performed on consecutive advanced/metastatic BCs, we found FGFR alterations to be present in approximately 17% of UCs, with FGFR3 being more frequently altered than FGFR1 and FGFR2 genes. These patients could gain clinical benefits from receiving a FGFR inhibitor such as erdafitinib which is an approved drug to treat FGFR-altered BCs lacking response to chemotherapy. Future studies will include a larger cohort to assess the correlation of FGFR alterations with histologic subtypes of invasive UC.

Overall, our study revealed FGF19/FGFR4 as a new mechanism involved in the drug resistance of prolactinomas, and combination therapy targeting the pathway could be helpful for the treatment of BRC-induced drug-resistant prolactinomas.

In this study, we designed several PROTACs with different E3 ligands based on LY2874455...In summary, we identified 28e as a novel selective degrader of FGFR2 with high potency and high potential to overcome resistance to gatekeeper mutation. The discovery of 28e provides new evidence for the strategy of pan-inhibitor-based development of selective degrading agents.

This study provides pre-clinical evidence that single PI3K, FGFR, and CDK4/6, inhibitors exhibit promising anti-NB activity and when combined lower doses of the drugs could be also used in spheroid NB-cultures, supporting the pursuit of further in vitro and in vivo studies in preparation for future potential clinical use.

P2, N=35, Active, not recruiting, National Cancer Institute (NCI) | Trial completion date: Jun 2024 --> Dec 2025