Circulating tumor DNA molecular analyses and real-world evidence outcomes of FGFR2 amplified gastroesophageal cancers.

PURPOSE: In addition to the existing biomarkers HER2 and PD-L1, FGFR2b has become an area of interest for the development of new targeted-based treatment. Given that clinical evaluation of FGFR2 targeted therapy is underway, we sought to elucidate the genomic landscape of FGFR2amp in gastroesophageal cancer (GEC) using a circulating tumor DNA (ctDNA) platform. MATERIALS AND METHODS: We retrospectively evaluated the Guardant Health database from 2017 to 2022 for patients with GECs with Guardant360 ctDNA next-generation sequencing (NGS) performed. We assessed co-occurring genetic alterations for patients who harbored FGFR2amp versus FGFR2null. We also explored real-world evidence database with Guardant Health, publicly available genomic databases (MSK cohort using cBioPortal), and pooled clinical data from large-volume cancer centers for FGFR2amp GECs. RESULTS: Less than 4% of patients with GEC in the Guardant Health database were identified to be FGFR2amp. The most commonly co-occurring gene mutations were TP53, CTNNB1, CDH1, and RHOA. Upon interrogation of the MSK cohort, these same genes were not significant on tissue NGS in the FGFR2amp cohort of GEC. In the pooled institutional cohort, we noted that FGFR2amp tumors were most commonly involving the gastroesophageal junction (GEJ). The overall survival of these patients was noted at 13.1 months. CONCLUSION: FGFR2 is a validated target in GECs, and the contexture of FGFR2amp will be important in defining patient subgroups with responses to FGFR2-directed therapy. Using ctDNA to provide a more detailed genomic landscape in patients with GECs will allow the advancement of targeted therapy in the near future for these aggressive cancers.

FGFR2-amplified tumor clones are markedly heterogeneously distributed in carcinomas of the upper gastrointestinal tract.

BACKGROUND: FGFR2 is a therapy-relevant target in tumors of the upper gastrointestinal tract (GIT), and clinical trials are currently underway to test the efficacy of FGFR2 inhibitors. Tumor heterogeneity is one of the relevant causes of treatment failure. Almost nothing is known about the heterogeneous distribution of FGFR2-amplified clones in adenocarcinomas of the upper GIT. PATIENTS AND METHODS: To assess FGFR2 gene copy number alteration and intratumoral heterogeneity of upper GIT adenocarcinomas, we analyzed 893 patient-derived formalin-fixed paraffin-embedded tumor specimens, including primary operated and neoadjuvant-treated tumors (462 gastric carcinomas and 429 esophageal adenocarcinomas) as well as complementary lymph node and distant metastasis by fluorescence in situ hybridization. RESULTS: Twenty-six gastric tumors (5.6%) and 21 esophageal adenocarcinomas (4.9%) showed FGFR2 amplification. Overall, 93% of gastric carcinomas and 83% of esophageal carcinomas showed heterogeneous amplification. FGFR2 amplification was found in different histological growth patterns, including intestinal and diffuse type according to the Lauren classification. In the primary gastric carcinoma group, FGFR2 amplification was associated with poor prognosis (p = 0.005). CONCLUSION: Homogeneous FGFR2 amplification in tumors of the upper GIT is the exception. This has highly relevant implications in the nature of FGFR2 diagnostics (sufficient tumor cell number, determination of amplification at metastasis versus primary tumor, etc.) and on the response probability of appropriate inhibitors. It is relevant that the often poorly treatable and aggressive subtype of diffuse carcinomas (poorly cohesive carcinomas) also shows FGFR2 amplification and that an individualized therapy option with FGFR2 inhibitors could be an option in this group.

Gastric carcinosarcoma with FGFR2 amplification under long-term control with pazopanib: a case report and literature review.

BACKGROUND: Gastric carcinosarcoma is most frequently diagnosed at an advanced stage when the tumor is generally large with invasion into other organs, lymph node metastasis, and distant metastasis. Standard chemotherapy has not been established, and surgery is the only curative treatment. Here, we present a case of postoperative recurrence of gastric carcinosarcoma under long-term tumor control with pazopanib. CASE PRESENTATION: A 77-year-old man was referred to our hospital because of nausea and vomiting. Computed tomography and upper gastrointestinal endoscopy revealed a type 1 tumor arising from the gastric antrum and extending into the duodenal bulb. He underwent distal gastrectomy (D2) with Roux-en-Y reconstruction. Histopathologically, the tumor had mixed adenocarcinoma and sarcoma components. According to the tumor-node-metastasis classification, the diagnosis was primary gastric carcinosarcoma pT1bN1M0 stage IB. Liver metastasis was detected 2 months after surgery; multiple lung metastases were detected 17 month after surgery. A genomic profiling test was performed using liver specimens as the patient became refractory to chemotherapy commonly used for gastric cancer, and the test revealed FGFR2 amplification along with TP53 R209*, AKT3 N127D, NOTCH1 A2036T, and POLD1 M161I. The patient was treated with pazopanib (800 mg/daily), and the tumor growth was controlled for 11 months. CONCLUSIONS: We report a case of postoperative recurrence of gastric carcinosarcoma under long-term tumor control with pazopanib. This case suggested that pazopanib may be effective in treating gastric carcinosarcoma.

Novel targetable FGFR2 and FGFR3 alterations in glioblastoma associate with aggressive phenotype and distinct gene expression programs.

Prognostic molecular subgrouping of glioblastoma is an ongoing effort and the current classification includes IDH-wild-type and IDH-mutant entities, the latter showing significantly better prognosis. We performed a comparative integrated analysis of the FGFR glioblastoma subgroup consisting of 5 cases from a prospective 101-patient-cohort. FGFR alterations included FGFR2-TACC2 and FGFR2 amplifications arising in a multifocal IDH-mutant glioblastoma with unexpected 2.5-month patient survival, novel FGFR3 carboxy-terminal duplication and FGFR3-TLN1 fusion, and two previously described FGFR3-TACC3 fusions. The FGFR2 tumors showed additional mutations in SERPINE1/PAI-1 and MMP16, as part of extensive extracellular matrix remodeling programs. Whole transcriptomic analysis revealed common proliferation but distinct morphogenetic gene expression programs that correlated with tumor histology. The kinase program revealed EPHA3, LTK and ALK receptor tyrosine kinase overexpression in individual FGFR tumors. Paradoxically, all FGFR-fused glioblastomas shared strong PI3K and MAPK pathway suppression effected by SPRY, DUSP and AKAP12 inhibitors, whereas the FGFR2-TACC2 tumor elicited also EGFR suppression by ERRFI1 upregulation. This integrated analysis outlined the proliferation and morphogenetic expression programs in FGFR glioblastoma, and identified four novel, clinically targetable FGFR2 and FGFR3 alterations that confer aggressive phenotype and trigger canonical pathway feedback inhibition, with important therapeutic implications.

SPA: A Quantitation Strategy for MS Data in Patient-derived Xenograft Models.

With the development of mass spectrometry (MS)-based proteomics technologies, patient-derived xenograft (PDX), which is generated from the primary tumor of a patient, is widely used for the proteome-wide analysis of cancer mechanism and biomarker identification of a drug. However, the proteomics data interpretation is still challenging due to complex data deconvolution from the PDX sample that is a cross-species mixture of human cancerous tissues and immunodeficient mouse tissues. In this study, by using the lab-assembled mixture of human and mouse cells with different mixing ratios as a benchmark, we developed and evaluated a new method, SPA (shared peptide allocation), for protein quantitation by considering the unique and shared peptides of both species. The results showed that SPA could provide more convenient and accurate protein quantitation in human-mouse mixed samples. Further validation on a pair of gastric PDX samples (one bearing FGFR2 amplification while the other one not) showed that our new method not only significantly improved the overall protein identification, but also detected the differential phosphorylation of FGFR2 and its downstream mediators (such as RAS and ERK) exclusively. The tool pdxSPA is freely available at https://github.com/Li-Lab-Proteomics/pdxSPA.

High-level FGFR2 amplification is associated with poor prognosis and Lower response to chemotherapy in gastric cancers.

BACKGROUND: Recurrent FGFR2 amplification is observed in gastroesophageal cancers but clinical implications are unknown. We investigated the association of FGFR2 amplification with cytotoxic chemotherapy outcome in gastroesophageal cancer (GC) patients. METHODS: Between 2016 and 2018, we identified 1045 metastatic GC patients who received palliative fluoropyrimidine/platinum-based chemotherapy and underwent tumor genomic profiling at a tertiary hospital in Korea and two US cancer centers. We retrospectively identified FGFR2-amplified cases and abstracted clinicopathologic features and treatment outcomes. Cox proportional hazard regression model was used to evaluate the variables that demonstrated effects on progression free and overall survival PFS and OS. Descriptive statistics were used to correlate level of FGFR2 copy number amplification CNA and clinicopathological parameters. RESULTS: The incidence of FGFR2-amplified GC was 4.0 %. A total of 42 FGFR2-amplified GC patients were included and divided into high and lower FGFR2 amplification values. Fifteen patients had an FGFR2 CNA greater than 30, and 27 had a CNA of 30 or less. There was no significant differences between age, sex, tumor localization, Lauren classification, or tumor staging. After a median follow-up duration of 11.4 months, patients with high FGFR2 amplification had significantly poorer median PFS (3.2 vs. 4.8 months, hazard ratio (HR) 2.08, 95 % CI, 1.03-4.22, P = 0.042) and significantly shorter median OS (10.1 vs. 26.3 months, HR 2.99, 95 % CI = 1.05-8.49, P = 0.040) than the low FGFR2 amplification group. CONCLUSION: Recurrent FGFR2 amplification was observed in roughly 4.0 % of GC patients. High FGFR2 amplification was significantly associated with poor progression free survival and overall survival in GC patients. Clinical studies of FGFR2-directed therapies are warranted and should consider stratification by FGFR2 CNA.

Pathologic and prognostic impacts of FGFR2 amplification in gastric cancer: a meta-analysis and systemic review.

Fibroblast growth factor receptor-2 (FGFR2) gene is amplified in up to 15% of patients with gastric cancer (GC). However, the prognostic significance of FGFR2 amplification has been controversial. This meta-analysis was conducted to evaluate the clinicopathological impacts of FGFR2 amplification in patients with GC. We performed a systematic computerized search of the electronic databases of PubMed, PMC, EMBASE, Web of Science, and Google Scholar and selected studies assessing the correlation of FGFR2 amplification with pathologic features and/or prognosis in gastric adenocarcinoma. From eight studies, 2,377 patients were included in the pooled analysis of odds ratios (ORs) with 95% confidence intervals (CIs) for pathologic findings and hazard ratios (HRs) with 95% CIs for overall survival. FGFR2 amplification was significantly associated with LN metastasis (OR = 3.93, 95% CI: 2.22-6.96, p < 0.00001) and poorly differentiated adenocarcinoma (OR = 2.36, 95% CI: 1.03-5.39, p = 0.04). In addition, patients with GC harboring FGFR2 amplification showed significantly worse survival (HR = 2.09, 95% CI: 1.68-2.59, p < 0.00001), compared with patients with FGFR2-unamplified GC. In conclusion, this meta-analysis indicates that FGFR2 amplification is an adverse prognostic factor in patients with GC.

Bemarituzumab with modified FOLFOX6 for advanced FGFR2-positive gastroesophageal cancer: FIGHT Phase III study design.

Bemarituzumab is an afucosylated monoclonal antibody against FGFR2b (a FGF receptor) with demonstrated monotherapy clinical activity in patients with late-line gastric cancer whose tumors overexpress FGFR2b (NCT02318329). We describe the rationale and design of the FIGHT trial (NCT03343301), a global, randomized, double-blind, placebo-controlled Phase III study evaluating the role of bemarituzumab in patients with previously untreated, FGFR2b-overexpressing advanced gastroesophageal cancer. Patients are randomized in a blinded fashion to the combination of mFOLFOX6 and bemarituzumab or mFOLFOX6 and placebo. Eligible patients are selected based on the presence of either FGFR2b protein overexpression determined by immunohistochemistry or FGFR2 gene amplification determined by circulating tumor DNA. The primary end point is overall survival, and secondary end points include progression-free survival, objective response rate and safety.

FGFR2 amplification is predictive of sensitivity to regorafenib in gastric and colorectal cancers in vitro.

Although regorafenib has demonstrated survival benefits in patients with metastatic colorectal and gastrointestinal stromal tumors, no proven biomarker has been identified for predicting sensitivity to regorafenib. Here, we investigated preclinical activity of regorafenib in gastric and colorectal cancer cells to identify genetic alterations associated with sensitivity to regorafenib. Mutation profiles and copy number assays of regorafenib target molecules indicated that amplification of fibroblast growth factor receptor 2 (FGFR2) was the only genetic alteration associated with in vitro sensitivity to regorafenib. Regorafenib effectively inhibited phosphorylation of FGFR2 and its downstream signaling molecules in a dose-dependent manner and selectively in FGFR2-amplified cells. Regorafenib induced G1 arrest (SNU-16, KATO-III) and apoptosis (NCI-H716); however, no significant changes were seen in cell lines without FGFR2 amplification. In SNU-16 mice xenografts, regorafenib significantly inhibited tumor growth, proliferation, and FGFR signaling compared to treatment with control vehicle. Regorafenib effectively abrogates activated FGFR2 signaling in FGFR2-amplified gastric and colorectal cancer and, therefore, might be considered for integration into treatment in patients with FGFR2-amplified gastric and colorectal cancers.

Acquired resistance to LY2874455 in FGFR2-amplified gastric cancer through an emergence of novel FGFR2-ACSL5 fusion.

BACKGROUND: Fibroblast growth factor 2 (FGFR2) amplification, occurring in ~2-9% of gastric cancers (GC), is associated with poor overall survival. RESULTS: RNA sequencing identified a novel FGFR2-ACSL5 fusion in the resistant tumor that was absent from the matched pre-treatment tumor. The FGFR2-amplified PDC line was sensitive to FGFR inhibitors whereas the PDC line with concomitant FGFR2 amplification and FGFR2-ACSL5 fusion exhibited resistance. Additionally, the FGFR2-amplified GC PDC line, which was initially sensitive to FGFR2 inhibitors, subsequently also developed resistance. MATERIALS AND METHODS: We identified an FGFR2-amplified patient with GC, who demonstrated a dramatic and long-term response to LY2874455, a pan-FGFR inhibitor, but eventually developed an acquired LY2874455 resistance. Following resistance development, an endoscopic biopsy was performed for transcriptome sequencing and patient-derived tumor cell line (PDC) establishment to elucidate the underlying molecular alterations. CONCLUSIONS: FGFR inhibitors may function against FGFR2-amplified GC, and a novel FGFR2-ACSL5 fusion identified by transcriptomic characterization may underlie clinically acquired resistance. IMPLICATIONS FOR PRACTICE: Poor treatment response represents a substantial concern in patients with gastric cancer carrying multiple FGFR2 gene copies. Here, we show the utility of a general FGFR inhibitor for initial response prior to treatment resistance and report the first characterization of a potential resistance mechanism involving an FGFR2-ACSL5 fusion protein.

Amplification of FGFR2 Gene in Patients with Advanced Gastric Cancer Receiving Chemotherapy: Prevalence and Prognostic Significance.

BACKGROUND: Fibroblast growth factors and their receptors regulate key cellular functions, such as proliferation, differentiation and survival. Herein, we studied the prevalence and prognostic role of fibroblast growth factor receptor 2 (FGFR2) amplification in patients with advanced gastric cancer (AGC) who received systemic chemotherapy. PATIENTS AND METHODS: The gene copy number of FGFR2 was investigated in 80 patients with AGC who received systemic chemotherapy. FGFR2 gene status was assessed by dual-color fluorescence in-situ hybridization. RESULTS: Among 80 patients, FGFR2 amplification was observed in seven cases (11.5%). Patients with FGFR2 amplification had significantly shorter overall survival (OS) than did those without FGFR2 amplification (9.1 vs. 16.5 months; p=0.037). In multivariate analysis, disease status and number of metastatic sites were associated with worse OS (p=0.015 and p=0.009, respectively). FGFR2 amplification tended to be correlated with a poorer outcome (p=0.080). CONCLUSION: FGFR2 amplification tended to result in a shorter survival period compared to cases without amplification.