FGFR1 Research Articles

Abstract 3123: Preclinical characterization of AMB302/GQ1011, a first-in-class FGFR3 antibody-drug conjugate (ADC) with topoisomerase 1 inhibitor against diverse FGFR3 overexpression or alteration

Abstract Background: Molecular alterations of oncogene FGFR3 in various cancers include FGFR3 gene fusions, activating mutations, and overexpression as a driver mutation. AMB302/GQ1011 is a novel FGFR3-targeting ADC conjugated with an innovative topoisomerase I inhibitor (TopoIx) using intelligent Ligase-Dependent Conjugation (iLDC) technologies developed by GeneQuantum (GQ), providing high homogeneity, excellent druggability, and superior linker stability. Based on preclinical characterization, AMB302/GQ1011 exhibits impressive anti-tumor activities against bladder cancer (BC), head and neck squamous cell carcinoma (HNSCC), and glioblastoma (GBM) with either FGFR3 overexpression or FGFR3 alterations including gene fusions, demonstrating potential as a first-in-class FGFR3 ADC against FGFR3 relevant solid tumor indications. Methods: For biomarker analysis, patient tissue microarrays and tissue blocks were subjected to IHC staining for FGFR3 to assess its real-world intensity. To characterize AMB302/GQ1011, in vitro assays and ex vivo plasma stability were evaluated to confirm the anti-tumor effect and linker stability. In vivo anti-tumor effects of AMB302/GQ1011 were assessed on various CDX and PDX models with FGFR3 overexpression or alterations. The potential toxicity profile of AMB302/GQ1011 was evaluated in NHP via repeated intravenous infusions. Results: AMB302/GQ1011 conjugates a novel FGFR3-targeting antibody (Aimedbio Inc.) with TopoIx (GQ) via a cleavable linker through iLDC platform. In IHC analysis, we detected high and widespread FGFR3 expression in various tumors. In in vitro cytotoxicity assay, AMB302/GQ1011 showed excellent antitumor activity against FGFR3-expressing cells. In various CDX and PDX models with FGFR3 expression or alterations, AMB302/GQ1011 demonstrated superior efficacy compared with benchmark ADCs and FGFR pan-inhibitors. AMB302/GQ1011 dramatically prolonged survival in GBM orthotopic PDX models with F3-T3 fusion by >150% in combination with TMZ. Particularly, in combination with an immune checkpoint inhibitor (ICI), AMB302/GQ1011 exhibited an excellent synergistic antitumor effect. In a monkey toxicity study, AMB302/GQ1011 demonstrated a high tolerability up to 60 mg/kg dosing, without severe adverse effects. Conclusion: AMB302/GQ1011 demonstrated a potent antitumor efficacy in vitro and in vivo models with FGFR3 overexpression and alterations across various solid tumors. Notably, AMB302/GQ1011 suggests the potential for combination with ICI treatment. Moreover, AMB302/GQ1011 exhibited excellent tolerability at high doses in NHP, indicating its safety profile. Our data suggest that AMB302/GQ1011 has potential to become a first-in-class FGFR3-targeting ADC for solid tumors with FGFR3 overexpression or alterations. Citation Format: Byeongkwi Min, Sunghyun Lee, Wonsik Jung, Lina Wang, Yajun Sun, Hyejin Kim, Nam-Gu Her, Paul H. Song, Gang Qin, Do-Hyun Nam. Preclinical characterization of AMB302/GQ1011, a first-in-class FGFR3 antibody-drug conjugate (ADC) with topoisomerase 1 inhibitor against diverse FGFR3 overexpression or alteration [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 3123.

A case of treatment-resistant advanced gastric cancer with FGFR2 gene alteration successfully treated with pemigatinib.

Comprehensive genome profiling (CGP) is expected to widen the scope of cancer drug options by identifying the genes involved in carcinogenesis. However, a few patients can access recommended treatments following CGP. Herein, we report a case in which pemigatinib, a selective fibroblast growth factor receptor (FGFR) inhibitor, was used as last-line therapy to treat a patient with advanced gastric cancer exhibiting FGFR2 genomic alterations, as determined by CGP testing. The patient (male, 52years old) was diagnosed with advanced gastric cancer (cStage IV, cT4aN3M1 [LYM], por, HER2 0, microsatellite stable) and received docetaxel + cisplatin + S-1 (7 cycles), irinotecan + ramucirumab (11 cycles), and nivolumab (3 cycles), but experienced progressive disease (PD). Subsequently, FoundationOne Liquid CDx testing was conducted, revealing FGFR2 rearrangement and amplification; however, no clinical trials on genotype-matched therapies for FGFR2 alterations were available. After three cycles of TAS-102, the patient experienced PD and provided consent for the off-label use of pemigatinib. The Cancer Genomics Medical Committee of our hospital approved the self-funded treatment. The patient had markedly decreased CEA and CA19-9 levels after treatment initiation, but experienced PD after five courses. Over the treatment course, grade 1 hyperphosphatemia and onychomadesis were observed. To the best of our knowledge, this is the first reported case of pemigatinib therapy employed in a patient with advanced gastric cancer exhibiting FGFR2 gene alterations. This case could serve as a notable example of tumor-agnostic therapy to broaden treatment options for gastric cancer patients with rare genetic alterations.

Crouzon syndrome: features of clinical manifestations, management and outcomes in children

Syndromic craniosynostosis is a special group of hereditary pathologies. One of the syndromic craniosynostoses is Crouzon syndrome, an autosomal dominant pathology of the primary violation of the fusion of cranial sutures. It occurs with a frequency of 1:60,000 newborns. The disease leads to a number of secondary complications, such as exophthalmos, orthognathic problems, impaired vision, hearing, breathing, lag in neuropsychic development. The development of Crouzon syndrome is associated with a missense mutation in the fibroblast growth factor receptor-2 (FGFR2) gene. In modern medicine, a variant of Crouzon syndrome with black acanthosis is also known, the development of which is associated with a mutation in the FGFR3 gene. The similarity of clinical manifestations as with others syndromic craniosynostoses, also between 2 variants of Crouzon syndrome, leads to difficulties in differential diagnostic search. Knowledge and awareness of the full clinical presentation of this syndrome makes it possible to timely diagnose and treat, prevent possible severe complications and improve the quality of life of patients with Crouzon syndrome. This article describes 2 clinical cases with mutations in the FGFR2 and FGFR3 genes.

A comprehensive overview of selective and novel fibroblast growth factor receptor inhibitors as a potential anticancer modality.

The arrival of comprehensive genome sequencing has accelerated the understanding of genetically aberrant advanced cancers and target identification for possible cancer treatment. Fibroblast growth factor receptor (FGFR) gene alterations are frequent findings in various rare and advanced cancers refractive to mainstay chemo-therapy or surgical interventions. Several FGFR inhibitors have been developed for addressing these genetically altered FGFR-harboring malignancies, and some have performed well in clinical trials. In contrast, others are still being investigated in different phases of clinical trials. FDA has approved four anticancer agents such as erdafitinib, pemigatinib, infigratinib, and futibatinib, for clinical use in oncogenic FGFR-driven malignancies. These include cholangiocarcinoma, urothelial carcinoma, and myeloid/lymphoid malignancies. Pemigatinib is the only FGFR inhibitor globally approved (USA, EU, and Japan) and available as a targeted therapy for two types of cancer, including FGFR2 fusion or other rearrangements harboring cholangiocarcinoma and relapsed/refractory myeloid/lymphoid neoplasms with FGFR1 rearrangements. Myeloid/lymphoid neoplasm is the latest area of application added to the therapeutic armamentarium of FGFR inhibitors. Furthermore, futibatinib is the first-in-class covalent or irreversible pan-FGFR inhibitor that has received FDA approval for locally advanced or metastatic intrahepatic cholangiocarcinoma harboring FGFR2 gene aberrations. This review highlights the current clinical progress concerning the safety and efficacy of all the approved FGFR-TKIs (tyrosine kinase inhibitors) and their ongoing investigations in clinical trials for other oncogenic FGFR-driven malignancies.

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.

In Silico Approach to Molecular Profiling of the Transition from Ovarian Epithelial Cells to Low-Grade Serous Ovarian Tumors for Targeted Therapeutic Insights.

This paper aims to elucidate the differentially coexpressed genes, their potential mechanisms, and possible drug targets in low-grade invasive serous ovarian carcinoma (LGSC) in terms of the biologic continuity of normal, borderline, and malignant LGSC. We performed a bioinformatics analysis, integrating datasets generated using the GPL570 platform from different studies from the GEO database to identify changes in this transition, gene expression, drug targets, and their relationships with tumor microenvironmental characteristics. In the transition from ovarian epithelial cells to the serous borderline, the FGFR3 gene in the "Estrogen Response Late" pathway, the ITGB2 gene in the "Cell Adhesion Molecule", the CD74 gene in the "Regulation of Cell Migration", and the IGF1 gene in the "Xenobiotic Metabolism" pathway were upregulated in the transition from borderline to LGSC. The ERBB4 gene in "Proteoglycan in Cancer", the AR gene in "Pathways in Cancer" and "Estrogen Response Early" pathways, were upregulated in the transition from ovarian epithelial cells to LGSC. In addition, SPP1 and ITGB2 genes were correlated with macrophage infiltration in the LGSC group. This research provides a valuable framework for the development of personalized therapeutic approaches in the context of LGSC, with the aim of improving patient outcomes and quality of life. Furthermore, the main goal of the current study is a preliminary study designed to generate in silico inferences, and it is also important to note that subsequent in vitro and in vivo studies will be necessary to confirm the results before considering these results as fully reliable.

Role of vosoritide drug on children's with achondroplasia

Achondroplasia is a genetic condition with an autosomal dominant inheritance pattern. It is caused by detrimental heterozygous FGFR3 gene mutations. Gain-of-function mutations in the FGFR3 gene impair chondrocyte differentiation and proliferation, which has a negative impact on the formation of new bone. Vosoritide, also known as voxzogo, is the first pharmacological intervention to receive approval for the treatment of achondroplasia. This therapeutic agent has been sanctioned for administration via at-home injections, which are to be performed under the supervision of a proficient nurse.

Real-World Data and Clinical Implications of Next-Generation Sequencing (NGS)-Based Analysis in Metastatic Breast Cancer Patients.

Over the last two decades, the use of Next-Generation Sequencing (NGS) in medical oncology has increased the likelihood of identifying druggable mutations that may be potentially susceptible to targeted treatments. The European Society for Medical Oncology (ESMO) currently does not recommend the use of the NGS test to determine the therapeutic course of patients with metastatic breast cancer (mBC) in daily clinical practice. However, the aim of this work is to evaluate the potential contribution of the NGS test in selecting targeted therapies for patients with mBC. Data were retrospectively collected from 101 patients diagnosed with metastatic breast cancer and treated at the Modena Cancer Center between January 2015 and April 2022. A NGS test was performed on the tumor tissue of each patient at the Laboratory of Molecular Pathology of the University Hospital of Modena. This study analyzed the clinical-pathological characteristics and mutational profile of the population using NGS tests, with a focus on actionable mutations that could be targeted in advanced stages of clinical development. The indicator of this study was to quantify the actionable mutations that resulted in a change of cancer treatment. In total, 101 patients with metastatic breast cancer were analyzed, including 86 with luminal phenotype, 10 who were HER2-positive and 5 who were triple-negative. Median age was 52 years. NGS analysis was conducted on 47 samples of primary breast cancer, 52 on metastatic sites of disease and 2 on liquid biopsies. A total of 85 gene mutations were found. The most common mutations were identified in the PIK3CA (47%), FGFR (19%) and ERBB2 genes (12%), and to a lesser extent in other genes. Of the 61 patients with pathogenic mutations, 46 (75%) had at least one actionable mutation. Of these, nine received treatment with a molecular target drug: eight patients with a mutation of the PIK3CA gene were treated with alpelisib and fulvestrant; one patient with FGFR1/2 amplifications received TAS120. Median PFS for these patients was 3.8 months. The study results show that using the NGS test on cancer tissue of metastatic breast cancer could influence the therapeutic choices, considering the small sample size and limited follow-up. About 9% of the study population had their therapy modified based on the results of NGS. The growing number of detectable mutations and increased accessibility of the test may lead to a greater number of potential therapeutic implications for the NGS assay. Perspectives suggest that NGS analysis can be implemented in daily clinical practice, particularly in contexts where a Molecular Tumor Board (MTB) is active.

Cholangiocarcinoma: Recent Advances in Molecular Pathobiology and Therapeutic Approaches.

Cholangiocarcinomas (CCA) pose a complex challenge in oncology due to diverse etiologies, necessitating tailored therapeutic approaches. This review discusses the risk factors, molecular pathology, and current therapeutic options for CCA and explores the emerging strategies encompassing targeted therapies, immunotherapy, novel compounds from natural sources, and modulation of gut microbiota. CCA are driven by an intricate landscape of genetic mutations, epigenetic dysregulation, and post-transcriptional modification, which differs based on geography (e.g., for liver fluke versus non-liver fluke-driven CCA) and exposure to environmental carcinogens (e.g., exposure to aristolochic acid). Liquid biopsy, including circulating cell-free DNA, is a potential diagnostic tool for CCA, which warrants further investigations. Currently, surgical resection is the primary curative treatment for CCA despite the technical challenges. Adjuvant chemotherapy, including cisplatin and gemcitabine, is standard for advanced, unresectable, or recurrent CCA. Second-line therapy options, such as FOLFOX (oxaliplatin and 5-FU), and the significance of radiation therapy in adjuvant, neoadjuvant, and palliative settings are also discussed. This review underscores the need for personalized therapies and demonstrates the shift towards precision medicine in CCA treatment. The development of targeted therapies, including FDA-approved drugs inhibiting FGFR2 gene fusions and IDH1 mutations, is of major research focus. Investigations into immune checkpoint inhibitors have also revealed potential clinical benefits, although improvements in survival remain elusive, especially across patient demographics. Novel compounds from natural sources exhibit anti-CCA activity, while microbiota dysbiosis emerges as a potential contributor to CCA progression, necessitating further exploration of their direct impact and mechanisms through in-depth research and clinical studies. In the future, extensive translational research efforts are imperative to bridge existing gaps and optimize therapeutic strategies to improve therapeutic outcomes for this complex malignancy.

Prenatal diagnosis and phenotypic analysis of two fetuses harboring heterozygous deletions of SHOX gene

To explore the clinical manifestations of two fetuses harboring heterozygous deletions of the SHOX gene. Two pregnant women who had presented at the Prenatal Diagnosis Center of Nanjing Drum Tower Hospital respectively on June 24, 2022 and July 27, 2022 were selected as the study subjects. In case 1, prenatal ultrasonography had shown short femur and intrauterine growth retardation of the fetus. Case 2 had a history of spontaneous abortions due to structural chromosomal aberrations. Fetus 1 had undergone a test for the FGFR3 gene, and both fetuses were subjected to single nucleotide polymorphism-based microarray (SNP array) analysis. After excluding the influence of FGFR3 gene variant, fetus 1 was found to harbor a heterozygous 883 kb deletion at Xpter or Ypter, whilst fetus 2 was found to harbor a 5.75 Mb deletion in the Xpter region. Both deletions have encompassed the SHOX gene. The origin of the deletion in fetus 1 was unknown, whilst that in fetus 2 was inherited from its mother. Fetus 1 has been delivered at term with a normal phenotype, and fetus 2 was not born yet. The intrauterine and postnatal phenotypes of fetuses may be predicted by combining the ultrasound finding, parental phenotype and results of CMA, and the results can facilitate genetic counseling and decision making over the pregnancy.

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.

Global Expanded Access Program for Pemigatinib in Patients with Previously Treated Locally Advanced or Metastatic Cholangiocarcinoma and Fibroblast Growth Factor Receptor Gene Alterations.

Pemigatinib is a fibroblast growth factor receptor-2 (FGFR2) inhibitor approved for use in patients with previously treated cholangiocarcinoma (CCA) and FGFR2 fusions or rearrangements. This ongoing global Expanded Access Program (EAP) allows physicians in regions where pemigatinib is not commercially available to request pemigatinib for patients with locally advanced or metastatic CCA who, in the physician's opinion, could benefit from pemigatinib treatment. Eighty-nine patients from Europe, North America, and Israel were treated from January 2020 through September 2021. Patients had FGFR gene fusions (68.5%), rearrangements (12.4%), translocations (5.6%), amplifications (2.2%), and other alterations (11.2%). Median duration of treatment in the EAP was 4.0 months (range, 0.1 to 13.6 months). The most frequently reported adverse event (AE) was hyperphosphatemia (22.5%); the most common serious AE was cholangitis (3.4%). Treatment discontinuation was associated with reports of AEs for seven patients (7.9%). AEs associated with pemigatinib were consistent with those observed in clinical trials. Efficacy was not assessed in this EAP. However, some patients remained on treatment for up to a year, suggesting that they observed a benefit from treatment. Patients with CCA should undergo molecular testing to identify those who could benefit from targeted treatments such as pemigatinib.

Comprehensive Examination of Cholangiocarcinoma Patients Treated with Novel Targeted Therapies after Extended Molecular Profiling on Liquid Biopsies.

Cholangiocarcinoma (CCA) is associated with poor outcomes and limited treatment options, leading to increased use of targeted therapies for its management. Here, we performed one of the largest single-centre reviews evaluating outcomes following personalised targeted agents in CCA patients. All consecutive CCA patients receiving systemic therapy between January 2010 and April 2023 at UCLH were included. The primary objective of this study was to evaluate treatment response, survival outcomes and predictors of clinical benefit in CCA patients treated with molecularly guided therapies. Patient demographic factors, disease characteristics and survival outcomes were evaluated using the Kaplan-Meier method and Cox proportional-hazards models. Of the 227 consecutive CCA patients, 162 (71%) had molecular profiling, of whom 56 (35%) were eligible and 55 received molecular-targeted treatment. CCA histological classifications comprised intrahepatic (N = 32), extrahepatic (N = 11), hilar (N = 4) and unknown (N = 9) subtypes. Most patients received targeted agents based on genomic profiling in a second treatment line setting (N = 34). Frequently observed genomic alterations occurred in the FGFR2 (N = 21), IDH1 (N = 7) and BRCA2 (N = 6) genes. Median progression-free survival (PFS) following first-, second- and third-line systemic therapy and overall survival (OS) were 8.44 (95% CI, 7.49-12.78), 5.65 (95% CI, 3.71-7.13), 5.55 (2.79-12.58) and 29.01 (24.21-42.91) months, respectively. CCA subtype and FGFR/BRCA molecular aberration status were not associated with PFS or OS. However, a prior CCA-related surgical history was predictive of OS (p = 0.02). Stratification by best overall response to second-line targeted agents demonstrated an association with PFS (p = 0.002) and OS (p = 0.02). Duration of treatment with second-line targeted therapy was associated with OS (p < 0.001). Patients receiving targeted therapeutics achieved promising outcomes, especially those attaining a favourable treatment response and those receiving targeted agents for longer periods. Liquid biopsies can reliably provide information on extended molecular profiling to aid patient selection for personalised therapies.

Investigating FGFR2 gene as a blood-based epigenetic biomarker in gastric cancer.

Gastric adenocarcinoma is a prevalent form of cancer that often remains undetected in its early stages due to the lack of specific symptoms. This delayed diagnosis leads to poor clinical outcomes, underscoring the need for an effective and non-invasive method for early detection. Recent advances in cancer epigenetics have led to the identification of biomarkers that have the potential to revolutionize the early detection and monitoring of this disease. One such promising biomarker is the methylation of the FGFR2 promoter. This study aims to measure the methylation levels of a specific CpG site in the FGFR2 promoter gene in DNA extracted from blood leukocytes from patients with intestinal metaplasia, gastric cancer, and healthy control. The CpG site of the FGFR2 gene promoter was identified in its control region. Methylation alteration of the selected FGFR2 CpG site was determined through the (methylation-sensitive restriction enzyme) MSRE-qPCR. Genomic DNA was extracted from one hundred twenty-five participants. The normal group had mean methylation levels of 93.23 ± 4.929%, while the IM group had a level of 69.85 ± 27.15%. In GC patients, the levels varied, with 25.96 ± 18.98% in the intestinal type and 28.30 ± 16.07% in the diffuse type. The methylation levels in the IM and GC patients were significantly lower than those in the normal control group. However, no significant difference was observed between the methylation status of the intestinal type of GC and the diffuse type. The Receiver operating characteristic (ROC) curve analysis showed that FGFR2 CpG methylation levels in GC patients compared to normal controls had a high sensitivity of 100% and specificity of 100%, with a cut-off of < 74.25%; when GC patients were compared to IM patients, the sensitivity was 85%, and the specificity was 80%, with a cut-off < 44.45%. The potential of the FGFR2 methylation status as a non-invasive biomarker lies in its ability to be detected in blood leukocytes, which makes it a promising tool for the early detection of intestinal metaplasia and gastric cancer. This could significantly improve the detection and management of these gastric conditions.

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&lt;.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]

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 &gt; 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 .

PROOF 301: Results of an early discontinued randomized phase 3 trial of the oral FGFR inhibitor infigratinib vs. gemcitabine plus cisplatin in patients with advanced cholangiocarcinoma (CCA) with an FGFR2 gene fusion/rearrangement.

516 Background: Infigratinib (BGJ398), an oral inhibitor of fibroblast growth factor receptor (FGFR)1-3 with demonstrated clinical activity and a manageable adverse event profile in a phase 2 study in patients with previously treated, unresectable or metastatic CCA with an FGFR2 fusion or other rearrangement, represented one of the few targeted treatment options after progression on first-line therapy, as per FDA conditional approval. The confirmatory phase III trial PROOF 301 of infigratinib versus gem/cis as frontline treatment of FGFR2 Gene Fusions/Translocations CCA was early discontinued. Here we report the efficacy and safety in the patients accrued prior to termination. Methods: Eligible patients were randomized 2:1 to infigratinib 125 mg on days 1-21 of a 28-day cycle vs intravenous gemcitabine (1000 mg/m2) + cisplatin (25 mg/m2) on days 1 and 8 of a 21-day cycle. The primary endpoint was progression-free survival (PFS), confirmed by blinded independent central review (BICR). Secondary endpoints included overall survival (OS), investigator determined PFS, overall response rate (ORR), best overall response (BOR), disease control rate (DCR), duration of response (DOR), and safety and tolerability. Crossover to the investigational arm was permitted at progression. Results: Over 40 months, a total of 1127 patients were pre-screened at 120 sites and 48 enrolled. In a 2:1 randomization, 29 patients received infigratinib and 19 received gem/cis. Upon progression, 2 patients crossed over from gem/cis to infigratinib. Median PFS (95% CI) by BICR was 7.4 (5.4, not evaluable [NE]) and 8.0 (3.4, NE) months with infigratinib and chemotherapy, respectively. The ORRs by BICR were 37.9 % with infigratinib and 15.8 % with gem/cis. Grade 3–4 adverse events occurred in 79.3% and 58.8% patients treated with infigratinib and chemotherapy. Conclusions: Infigratinib showed a preliminary signal of efficacy in the first-line treatment of FGFR2-rearranged CCA, but due to early termination of the study, the power is insufficient to draw conclusions regarding its efficacy in comparison to gem/cis. This study highlights the challenge of performing confirmatory studies in biomarker-selected subpopulations of rare tumors and the importance of exploring alternative approaches to delivering confirmatory data for regulatory purposes. Clinical trial information: NCT03773302 .

Mutational analysis of consanguineous families and their targeted therapy against dwarfism

Dwarfism is a medical term used to describe individuals with a height-vertex measurement that falls below two standard deviations (−2SD) or the third percentile for their gender and age. Normal development of growth is a complicated dynamic procedure that depends upon the coordination of different aspects involving diet, genetics, and biological aspects like hormones in equilibrium. Any severe or acute pathologic procedure may disturb the individual’s normal rate of growth. In this research, we examined four (A–D) Pakistani consanguineous families that exhibited syndromic dwarfism, which was inherited in an autosomal recessive pattern. The genomic DNA of each family member was extracted by using phenol-chloroform and Kit methods. Whole Exome Sequencing (WES) of affected family members (IV-11, III-5, IV-4 and III-13) from each group was performed at the Department of Medical Genetics, University of Antwerp, Belgium. After filtering the exome data, the mutations in PPM1F, FGFR3, ERCC2, and PCNT genes were determined by Sanger sequencing of each gene by using specific primers. Afterward, FGFR3 was found to be a suitable drug target among all the mutations to treat achondroplasia also known as disproportionate dwarfism. BioSolveIT softwares were used to discover the lead active inhibitory molecule against FGFR3. This research will not only provide short knowledge to the concerned pediatricians, researchers, and family physicians for the preliminary assessment and management of the disorder but also provide a lead inhibitor for the treatment of disproportionate dwarfism. Communicated by Ramaswamy H. Sarma

Targeting FGFR3 signaling and drug repurposing for the treatment of SLC26A2-related chondrodysplasia in mouse model

BackgroundMutations in Slc26a2 cause a spectrum of autosomal-recessive chondrodysplasia with a significant and negligible influence on the quality of life. It has been reported that Slc26a2 deficiency triggers the ATF6 branch of the UPR, which may, in turn, activate the negative regulator of the FGFR3 signaling pathway. However, the correlation between the deletion of Slc26a2 and the augmentation of downstream phosphorylation of FGFR3 has not been investigated in vivo. MethodsFirst, we constructed Slc26a2 and Fgfr3 double knockout mouse lines and observed gross views of the born mice and histological staining of the tibial growth plates. The second approach was to construct tamoxifen-inducible Cre-ERT2 mouse models to replicate SLC26A2-related non-lethal dysplastic conditions. Pharmacological intervention was performed by administering the FGFR3 inhibitor NVP-BGJ398. The effect of NVP-BGJ398 on chondrocytes was assessed by Alcian blue staining, proliferation, apoptosis, and chondrocyte-specific markers and then verified by western blotting for variations in the downstream markers of FGFR3. The growth process was detected using X-rays, micro-CT examination, histomorphometry staining of growth plates, and immunofluorescence. ResultsGenetic ablation of Fgfr3 in embryonic Slc26a2-deficient chondrocytes slightly attenuated chondrodysplasia. Subsequently, in the constructed mild dysplasia model, we found that postnatal intervention with Fgfr3 gene in Slc26a2-deficient chondrocytes partially alleviated chondrodysplasia. In chondrocyte assays, NVP-BGJ398 suppressed the defective phenotype of Slc26a2-deficient chondrocytes and restored the phosphorylation downstream of FGFR3 in a concentration-dependent manner. In addition, in vivo experiments showed significant alleviation of impaired chondrocyte differentiation, and micro-CT analysis showed a clear improvement in trabecular bone microarchitectural parameters. ConclusionOur results suggested that inhibition of FGFR3 signaling pathway overactivation and NVP-BGJ398 has promising therapeutic implications for the development of SLC26A2-related skeletal diseases in humans. The translational potential of this articleOur data provide genetic and pharmacological evidence that targeting FGFR3 signaling via NVP-BGJ398 could be a route for the treatment of SLC26A2-associated skeletal disorders, which promisingly advances translational applications and therapeutic development.

The frequency of NRAS mutation in stool samples of Iranian colorectal cancers compared to Finnish patients

Abstract Background: Stools from colorectal cancer patients are noninvasive samples that could be used to compare the frequency of hotspot mutations between two different ethnic cohorts. Materials and Methods: We collected stool samples from the Iranian cohort (52 patients and 49 controls) and the Finnish cohort (40 patients and 14 controls). Following stool DNA extraction, we used the AmpliSeq Colon and Lung Cancer panel to prepare DNA libraries before sequencing. Results: The Iranian cohort exhibited 35 hotspot mutations in the BRAF, ERBB4, FBXW7, FGFR1, FGFR3, KRAS, MAP2K, MET, NRAS, PIK3C, SMAD4, and TP53 genes. In the Finnish cohort, 13 hotspot mutations were found in the AKT1, APC, KIT, KRAS, SMO, STK11, and TP53 genes. Mutations in NRAS and FGFR3 were observed only in the Iranian cohort, while APC mutations were exclusive for the Finnish cohort. Conclusion: Genes involved in MAPK and PI3K-MAPK pathways showed a higher frequency of mutations in Iranian patients which may have therapeutic implications.