FGFR3 Alterations Research Articles

Genetic Profiling of Non-Small Cell Lung Cancer in Moroccan Patients by Targeted Next-Generation Sequencing.

We retrospectively analyzed the next-generation sequencing (NGS) results from diagnosed NSCLC patients to identify and compare genomic alterations of NSCLC between Moroccan patients and the Cancer Genome Atlas (TCGA). We also aimed to investigate the distribution and frequency of concurrent genomic alterations. From December 2022 to December 2023, a retrospective study of 76 formalin-fixed paraffin-embedded (FFPE) samples have been profiled using the Oncomine™ Precision Assay on the Ion Torrent™ Genexus™ Integrated Sequencer across the panel of 50 key genes that are applicable for the selection of targeted therapy. Seventy of the 76 FFPE sequenced samples carried at least one genetic alteration in the tested genes. The study identified 234 genetic alterations in 18 genes. Targetable genetic alterations in EGFR, KRAS, MET, BRAF, ALK, RET and ROS1 were identified in 84.3% of tumors. EGFR and KRAS mutations were frequently reported, occurring in 24.3% and 22.9% of cases, respectively. The untargetable genetic alterations were found in 74.3% of the specimens in FGFR3, TP53, ERBB2, PIK3CA, CDKN2A, PDL1, FGFR1, PTEN, CHEK2 and ERBB3. There were additional uncommon/rare mutations in EGFR, BRAF, RET and ROS1. Comparing the prevalence of selected mutated genes in the NSCLC patients from the TCGA database identified substantial differences in EGFR (24.3%, vs14.97%), KRAS (22.9%, vs 25.99%), and TP53 (34.3%, vs 50.94%). ALK, ROS1, and RET gene rearrangements were detected in 4.3% of the 70 tumors tested. The ALK/RET/MET/ROS1/EML4 fusions were detected in 11.4% of samples. Co-alterations occurred in 67.1% of specimens. Co-occurring driver gene mutations were observed in 44.3%. TP53 mutations co-occurred driver gene mutations in 30% of tumors. Three cases (4.3%) harbored concurrent FGFR3, TP53, and PIK3CA alterations. Our results regarding the proportion of samples with actionable mutations demonstrate the value of NGS testing for NSCLC patients in a real-world clinical diagnostic setting.

Concordance in Oncogenic Alterations Between the Primary Tumor and Advanced Disease: Insights Into the Heterogeneity of Intrahepatic Cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICCA) is characterized by significant phenotypic and clinical heterogeneities and poor response to systemic therapy, potentially related to underlying heterogeneity in oncogenic alterations. We aimed to characterize the genomic heterogeneity between primary tumors and advanced disease in patients with ICCA. Biopsy-proven CCA specimens (primary tumor and paired advanced disease [metastatic disease, progressive disease on systemic therapy, or postoperative recurrence]) from two institutions were subjected to targeted next-generation sequencing. Overall concordance (oncogenic driver mutations, copy number alterations, and fusion events) and mutational concordance (only oncogenic mutations) were compared across paired samples. A subgroup analysis was performed on the basis of exposure to systemic therapy. Patients with extrahepatic CCA (ECCA) were included as a comparison group. Sample pairs from 65 patients with ICCA (n = 54) and ECCA (n = 11) were analyzed. The median time between sample collection was 19.6 months (range, 2.7-122.9). For the entire cohort, the overall oncogenic concordance was 49% and the mutational concordance was 62% between primary and advanced disease samples. Subgroup analyses of ICCA and ECCA revealed overall/mutational concordance rates of 47%/58% and 60%/84%, respectively. Oncogenic concordance was similarly low for pairs exposed to systemic therapy between sample collections (n = 50, 53% overall, 68% mutational). In patients treated with targeted therapy for IDH1/2 alterations (n = 6) or FGFR2 fusions (n = 3), there was 100% concordance between the primary and advanced disease specimens. In two patients, FGFR2 (n = 1) and IDH1 (n = 1) alterations were detected de novo in the advanced disease specimens. The results reflect a high degree of heterogeneity in ICCA and argue for reassessment of the dominant driver mutations with change in disease status.

Urine-based testing for patient selection and genomic characterization of patients with FGFR alteration-positive non–muscle-invasive bladder cancer (NMIBC) treated with TAR-210.

676 Background: TAR-210 is an intravesical drug delivery system that is designed to provide local, continuous release of erdafitinib. Its safety and efficacy are being evaluated in a first-in-human clinical study (NCT05316155) of patients with bladder cancer whose tumors harbor select FGFR alterations (alt). Toovercome tissue-based challenges in identifying susceptible FGFRalt to select patients for treatment with TAR-210, Janssen partnered with Predicine to use a proprietary urine cell-free DNA diagnostic assay (PredicineCARE). Validation of the urine assay to detect FGFRalt was previously demonstrated using urine samples collected in a highly controlled manner via a collaboration with Stratifyer Molecular Pathology GmbH, Cologne, Germany (Kim et al. ASCO GU 2023). However, evaluation of the urine assay for diagnostic screening in a real-world setting is currently lacking. Here, we report preliminary results of the urine assay for patient selection. We also report on the characterization of the urine-defined genomic landscape in screened patients. Methods: Enrollment was based on detection of prespecified FGFRalt from either tumor tissue obtained from previous biopsies (Qiagen Therascreen FGFR assay) or urine samples obtained prior to enrollment (PredicineCARE next-generation sequencing assay). Results: As of Jun 20, 2023, urine assay performance was compared to the tissue test from all screened patients with NMIBC (N=178). The proportions of samples that yielded results were 60% and 58% from tissue and urine, respectively, while the FGFRalt detection rates in the subsets that yielded results were 62% and 42%, respectively. FGFR3 S249C was the most frequent alteration detected in both tissue (48%) and urine (61%). For 36% of urine samples in which FGFRalt were detected, there was no corresponding tissue result. Of the disease-evaluable patients with high-risk (HR) NMIBC (N=11) or intermediate-risk (IR) NMIBC (N=15),18.2% and 33%, respectively, were enrolled based on urine assay alone due to insufficient tissue samples. A recurrence-free (RF) rate of 82% and a complete response (CR) rate of 87% were achieved at the first disease evaluation amongst patients with HR NMIBC and IR NMIBC, respectively. All patients (HR NMIBC, N=2, and IR NMIBC, N=5) enrolled by “urine only” were RF or achieved a CR. Based on the PredicineCARE panel, comprehensive genomic assessment of urine samples from all screened patients with NMIBC was performed. The prevalence of alterations detected was similar to that described in prior studies using tissue-based testing. Conclusions: Implementing a urine-based assay expands the molecular testing methods to identify additional patients that may respond to erdafitinib. Results justify further study. Clinical trial information: NCT05316155 .

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

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

Efficacy and safety results of FGFR1-3 inhibitor, tinengotinib, as monotherapy in patients with advanced, metastatic cholangiocarcinoma: Results from phase II clinical trial.

434 Background: Tinengotinib is a spectrum-selective multi-kinase inhibitor with unique binding properties to FGFR, potently inhibited FGFR2 fusion/rearrangement and acquired resistant mutations in pre-clinical models and in phase I trials that included cholangiocarcinoma (CCA) patients (pts). Here we present the efficacy and safety of tinengotinib in a phase II clinical trial. Methods: Eligible pts with advanced/metastatic CCA who had received ≥ 1 prior systemic chemotherapy therapy and ECOG PS 0 or 1 were treated with tinengotinib 10 mg QD. Four cohorts included: Cohort A1: FGFR2 fusion(s) with primary progression on previous FGFR inhibitor ( FGFRi), A2: FGFR2 fusion(s) with progression after prior response to FGFRi (acquired resistance); B: non-fusion FGFR alteration(s): C: FGFR wild-type ( FGFRwt). Primary endpoint was objective response rate (ORR) per RECIST v1.1. CTCAE V5.0 was used for safety assessments. Results: As of 7Aug2023, 48 pts with CCA were enrolled, 13 in Cohort A1, 10 in A2, 12 in B, 13 in C. Median age 61.5 [range 25-81] years old, 41.7% male, 58.3% had ≥ 3 lines of prior therapy. ECOG PS 0 in 47.9% pts. Among 35 pts with FGFR alterations, 80.0% had ≥ 1 prior FGFRi therapy, and 97.1% had prior chemotherapy. Forty (40) pts were efficacy evaluable. In A1, 1 out of 11 pts (9.1%) achieved PR with tumor reduction of 31.8%. In A2, 3 out of 8 pts (37.5%) achieved PR with tumor reduction of 40.7%, 47.0% and 54.6%. In B, 3 out of 9 pts (33.3%) achieved PR with tumor reduction of 36.5%, 48.6%, and 60.6%. No PR was observed in C. Overall DCR was 94.7% (18/19) in FGFR2 fusion/rearrangement pts (A1+A2), 88.9% (8/9) in other FGFR alterations pts (B), and 75% (9/12) in FGFRwt pts (C). Median progression-free survival (mPFS) was 5.26 months (95%CI, 2.86-9.10) in A1+A2, 5.98 months (95%CI, 1.87-NA) in B and 3.84 months (95% CI, 1.84-4.80) in C. Among 48 treated pts, treatment-related AEs (TRAEs) occurred in 45 (93.8%) pts, 14 (29.2%) in G1-2, 29 (60.4%) in G3 and 2 (4.2%) in G4. The most common G3 TRAEs were hypertension in 12 (25%), palmar-plantar erythrodysesthesia syndrome in 3 (6.3%), diarrhea in 3 (6.3%) and stomatitis in 3 (6.3%). One subject had G4 increased TSH and G4 increased lipase, and another subject had G4 posterior reversible encephalopathy syndrome. No G5 TRAE was observed. Conclusions: Tinengotinib has promising clinical benefit for FGFR2 fusion CCA after prior FGFRi and for non-fusion FGFR alterations. Tinengotinib-related toxicities were manageable. An ongoing randomized, controlled phase III study will evaluate the clinical efficacy, safety, and pharmacodynamic effect of Tinengotinib vs Physicians’ choice in subjects with FGFR2-altered refractory/relapsed CCA after prior chemotherapy and FGFRi therapy. Clinical trial information: NCT04919642 .

Association of FGFR2 structural alterations in intrahepatic cholangiocarcinomas with female gender and younger age.

537 Background: FGFR2 fusions and other rearrangements are targetable alterations due to the advent of FGFR2 kinase domain inhibitors, and are considerably more common in intrahepatic cholangiocarcinomas (iCCA) than other cancer types. Understanding clinical factors associated with FGFR2 fusions and other rearrangements may guide precision oncology efforts. Prior studies indicate that FGFR2 alterations are more common in younger patients, but it remains unknown whether other demographics are specifically associated with FGFR2 structural alterations. Here, we reviewed the frequency of FGFR2 structural alterations in 8,898 iCCA patients from the AACR Genie and the Foundation Medicine databases. Methods: We reviewed the Foundation Medicine (n= 7,934) and AACR GENIE database (n=964) for intrahepatic cholangiocarcinomas. We identified iCCAs with FGFR2 structural alterations and mutations in other common driver genes and analyzed their distribution by age and sex. Results: FGFR2 structural alterations were more frequent in female (10.4%) compared to male (6.4%) patients across both cohorts. FGFR2 structural alterations had an association with an odds ratio of 2.5 (95% CI 1.6-3.7) and 1.7 (95% CI-2.0) with the female gender in the AACR GENIE and Foundation Medicine databases, respectively. The frequency of FGFR2 fusions/rearrangement was highest during reproductive years (up to age 40) and subsequently declined with age. This decline was greater in females than males. Mutations in other genes associated with iCCA including non-fusion FGFR2 alterations, and mutations in ARID1A, KRAS, and TP53 were not associated with gender or age. Conclusions: Our results show that FGFR2 structural alterations are significantly enriched in younger female patients with iCCA. Clinical assessment of FGFR2 alterations should be prioritized in this patient population, and future clinical studies in this molecular subtype should ensure inclusive enrollment practices. Further research is warranted to determine if the pathogenesis of FGFR2 structural alterations are driven by female biology including the involvement of sex hormones and the potential impact on the development of acquired resistance to FGFR2 kinase inhibitors.

First-308: Phase III study of tinengotinib versus physician's choice in patients with FGFR-altered, chemotherapy- and FGFR inhibitor–refractory/relapsed cholangiocarcinoma.

TPS575 Background: Fibroblast growth factor (FGFR) alterations occur in 10-15% of adult patients with advanced intrahepatic cholangiocarcinoma (CCA) and 1-2% of adult patients with advanced extrahepatic cholangiocarcinoma. The first generation FGFR inhibitors (FGFRi) pemigatinib and futibatinib, have been approved for the treatment of advanced CCA with FGFR2 fusions or rearrangements after systemic chemotherapy. However, disease progression occurs within 6-9 months. Secondary polyclonal mutations in the FGFR kinase domain represent a prominent acquired resistance mechanism. Tinengotinib, a novel multi-kinase inhibitor with high potency against a variety of FGFR2 kinase domain mutations, has shown promising clinical benefit in subjects with FGFR-altered metastatic CCA who were heavily pretreated with chemotherapy and FGFRi(s) in phase I/II clinical trials. (NCT03654547, NCT04742959, NCT04919642). Methods: FIRST-308 is a phase III, randomized, global multicenter study to evaluate the efficacy and safety of oral tinengotinib versus Physician’s Choice in subjects with FGFR-altered, chemotherapy- and FGFRi-refractory/relapsed CCA. Approximately 200 subjects will be enrolled in US, Europe, and Asia. Key eligibility criteria include age ≥ 18 years, ECOG performance status 0 or 1, documentation of FGFR2 fusion/rearrangement gene status, prior treatment with at least one line of chemotherapy and exactly one prior FDA-approved FGFRi for unresectable or metastatic disease. The study includes Part A and Part B. The Part A is to select a dose for Part B. Eligible subjects will be randomized in a 2:2:1 ratio to receive tinengotinib 8 mg QD, tinengotinib 10 mg QD or Physician's Choice (FOLFOX or FOLFIRI) in Part A or 2:1 in Part B to receive the recommended Part B dose or Physician's Choice. The stratification factors at randomization include geographic region, prior lines of chemotherapy (1 or ≥ 2) and Physician’s choice. Tinengotinib will be administered orally QD in 28-day cycles. Subjects will continue to receive study treatment until confirmed disease progression, unacceptable toxicity, withdrawal of consent, or termination of study by Sponsor, whichever occurs first. For Part A, the primary endpoint is safety/tolerability; secondary endpoints include objective response rate (ORR), duration of response (DOR) and PK analysis. For Part B, the primary endpoint is progression-free survival (PFS); secondary endpoints include overall survival (OS), ORR, DOR, safety, quality of life and population PK. Exploratory endpoints will assess the correlations between baseline FGFR2 alterations by cfDNA and efficacy, and exposure-response in terms of efficacy and safety. Study is open for enrollment. Clinical trial information: NCT05948475 .

Real-world (RW) characteristics, treatment patterns, and outcomes of patients with cholangiocarcinoma (CCA) treated with pemigatinib.

444 Background: Pemigatinib demonstrated efficacy in fibroblast growth factor receptor (FGFR)–altered CCA in the FIGHT-202 trial; however, limited RW evidence exists on treatment patterns and outcomes in patients (pts) with CCA treated with pemigatinib. This study assessed characteristics, FGFR2 testing patterns, treatment patterns, and outcomes of pts treated with pemigatinib for locally advanced or metastatic CCA in the United States as part of routine clinical care. Methods: This retrospective, multisite cohort study included pts with a diagnosis of unresectable locally advanced or metastatic CCA who were initially prescribed pemigatinib on or after 04/17/2020. Eligible pts were ≥18 years at pemigatinib prescription and had ≥4 months (mo) of follow-up (unless <4 mo due to death). Pts who received pemigatinib as part of a clinical trial or those who received systemic therapy for another primary malignancy (other than cancer of unknown primary or hepatic cancer) were ineligible. Participating physicians from Cardinal Health’s Oncology Provider Extended Network—approximately 72% from community oncology practices—abstracted data from the medical records of eligible patients into electronic case report forms. Results were summarized using descriptive statistics. Results: Data from 120 pts (49% male; 55% White; 19% Hispanic; median age at pemigatinib prescription, 65 years) were collected from 18 physicians/practices. Testing for FGFR2 alterations was completed in 93% (n=111) of pts; of those, all but one patient (result unknown) tested positive, and 95% were tested using next-generation sequencing. At time of pemi prescription, 90% of pts had metastatic disease. Across all pts, 94% and 6% were prescribed pemigatinib as 2nd and 3rd line of therapy, respectively. The most common starting dosage was 13.5 mg daily for 14 days of 21-day cycle (87.5% of pts). Among the 60 pts who discontinued pemi during the 6.5-month median study follow-up period, 68% discontinued due to disease progression. Median RW progression-free survival (rwPFS) from date of pemigatinib initiation was 7.4 (95% CI: 6.4–8.6) mo. Among the 116 patients with tumor response data available, RW overall response rate (rwORR) was 61% (95% CI: 52% - 71%). Conclusions: This study complements the FIGHT-202 clinical trial by assessing the use of pemigatinib among a diverse population of patients with CCA under RW conditions. Secondarily, the rwORR and rwPFS from this study support the clinical benefit of pemigatinib demonstrated in FIGHT-202.

Abstract B083: The use of liquid biopsy in patients with advanced pancreatic cancer (PDAC) to guide enrollment in phase I clinical trials

Abstract Background: Therapeutic possibilities in PDAC remain poor and access to tumor tissue for molecular profiling is still a challenge. The era of circulating tumor DNA (ctDNA) or liquid biopsy facilitated molecular screening and treatment orientation in selected patients (pts). Patients and methods: Data from PDAC pts who underwent liquid biopsy at the Drug Development Department (DITEP) at Gustave Roussy were collected. The primary objective was to assess the ability of liquid biopsy to find molecular alterations (MA), orient and include pts in early phase clinical trials. We evaluated the progression-free survival (PFS) on matched therapy (PFS2) compared to PFS on prior therapy (PFS1). Treatment efficacy was considered by focusing on the percentage of patients with a PFS2 that was 1.5 times greater than the PFS1, based on a standard calculation (PFS2/PFS1), and a modified formula (mPFSr) with mPFSr = postPFS/prePFS with postPFS = PFS2 if PFS2 < 6 months and postPFS = 24 months if PFS2 > 6 months; prePFS = PFS1 if PFS1 > 2 months and prePFS = 2 months if PFS1 < 2 months. Results: Between January 2020 to November 2022, a total of 31 pts were included in the study. The main characteristics were as follow: median age of 62 years (32-81), median number of previous lines of treatment of 2 (0-4) and median ECOG Performance Status of 0 (0-2). Finally, 30 patients had a liquid biopsy at progression on their last treatment line. Targetable MA (FGFR, KRAS…) were found in 8 pts (27%), and 5 patients (17%) received a matched targeted therapy in an early phase clinical trial. FGFR alterations were the most frequent and 3 patients (60%) received FGFR inhibitors. From the 5 patients matched and treated, one patient (20%) had a PFS2/PFS1 ratio > 1.5 and three pts (60%) had an mPFSr > 1.5. With a median follow-up time of 12.3 months (9.2-NR), the overall response rate was 20%, the overall control rate was 100% and the median overall survival was not reached (8.5-NR months). Discussion: These results suggest that molecular profiling-matched therapy assessed by liquid biopsy could improve the therapeutic field in pancreatic cancer. However, only a small proportion of patients are matched and treated. Randomised trials are needed to confirm the value of this treatment method in pancreatic cancer. Citation Format: Octave Letissier, Cristina Smolenschi, Antoine Hollebecque, Damien Vasseur, Stéphane Champiat, Rastilav Bahleda, Anas Gazzah, Jean-Marie Michot, François-Xavier Danlos, Kaissa Ouali, Clémence Henon, Claudia Parisi, Linda Mahjoubi, Vincent Goldschmidt, Yohann Loriot, Christophe Massard, Arnaud Bayle, Antoine Italiano, Capucine Baldini, Santiago Aix Ponce. The use of liquid biopsy in patients with advanced pancreatic cancer (PDAC) to guide enrollment in phase I clinical trials [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B083.

Associations of TACSTD2/TROP2 and NECTIN-4/NECTIN-4 with molecular subtypes, PD-L1 expression, and FGFR3 mutational status in two advanced urothelial bladder cancer cohorts.

Treatment options for advanced urothelial carcinoma (aUC) rapidly evolved: besides immunomodulative therapeutic options and inhibitors targeting Fibroblast growth factor receptor (FGFR) alterations, two new antibody-drug conjugates (ADC), sacituzumab govitecan (SG) and enfortumab vedotin (EV), have been approved. However, little is known about the associations of specific aUC properties and the surface target expression of TROP2 and NECTIN-4. Our aim was to characterize associations of TACSTD2/TROP2 and NECTIN-4/NECTIN-4 protein and gene expression with morphomolecular and clinicopathological characteristics of aUC in two large independent cohorts. The TCGA BLCA (n = 405) and the CCC-EMN (n = 247) cohorts were retrospectively analysed. TROP2/TACSTD2 and NECTIN-4/NECTIN-4 are highly expressed at the protein and transcript level in aUC, and their expression status did not correlate with patient survival in both cohorts. NECTIN-4/NECTIN-4 expression was higher in luminal tumours and reduced in squamous aUCs. NECTIN-4 was negative in 10.6% of samples, and 18.4% of samples had low expression (H-score <15). The TROP2 negativity rate amounted to 6.5%. TACSTD2 and NECTIN-4 expression was reduced in neuroendocrine-like and/or protein-based double-negative tumours. TROP2- and NECTIN-4-negative tumours included one sarcomatoid and four neuroendocrine aUC. FGFR3 alterations and PD-L1 expression on tumour and immune cells did not associate with TROP2 or NECTIN-4 expression. TACSTD2/TROP2 and NECTIN-4/NECTIN-4 are widely expressed in aUC, independent of FGFR3 alterations or PD-L1 expression, thus representing a suitable target for ADC treatment in the majority of aUC. The expression loss was associated with aggressive morphomolecular aUC subtypes, i.e. neuroendocrine(-like) and sarcomatoid aUC.

FGFR Inhibitors in Urothelial Cancer: From Scientific Rationale to Clinical Development.

In the past decade, the treatment of metastatic urothelial cancer (mUC), including bladder cancer (BC), has transformed significantly with the introduction of diverse therapies, such as immune checkpoint inhibitors, targeted therapies, and antibody-drug conjugates. This change is partly due to advancements in genomic understanding, particularly next-generation sequencing, which has identified numerous mutations in UC. 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. In 2019, erdafitinib became pivotal for the treatment of mUC, particularly in patients with specific FGFR alterations. Recent studies have highlighted the benefits of combining erdafitinib with immunotherapy, thereby broadening the treatment options. Ongoing investigations exist on its use in non-muscle-invasive BC and in combination with drugs such as enfortumab vedotin in mUC. Other FGFR-targeted agents are under development; however, overcoming FGFR resistance and ensuring the safety of combination therapies remain major hurdles. FGFR3 mutations are particularly prevalent in BC, a heterogeneous form of UC, and account for a considerable proportion of new cancer diagnoses annually. Approximately half of these cancers have FGFR3 mutations, with gene rearrangements being a common feature. These FGFR3 genomic alterations often occur independently of mutations in other BC oncogenes, such as TP53 and RB1. 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.

Comprehensive characterization of genomic features and clinical outcomes following targeted therapy and secondary cytoreductive surgery in OCCC: a single center experience.

Ovarian clear cell carcinoma (OCCC) is associated with chemoresistance. Limited data exists regarding the efficacy of targeted therapies such as immune checkpoint inhibitors (ICI) and bevacizumab, and the role of secondary cytoreductive surgery (SCS). We retrospectively analyzed genomic features and treatment outcomes of 172 OCCC patients treated at our institution from January 2000 to May 2022. Next-generation sequencing (NGS) was performed where sufficient archival tissue was available. 64.0% of patients were diagnosed at an early stage, and 36.0% at an advanced stage. Patients with advanced/relapsed OCCC who received platinum-based chemotherapy plus bevacizumab followed by maintenance bevacizumab had a median first-line progression-free survival (PFS) of 12.2 months, compared with 9.3 months for chemotherapy alone (hazard ratio=0.69; 95% confidence interval [CI]=0.33, 1.45). In 27 patients who received an ICI, the overall response rate was 18.5% and median duration of response was 7.4 months (95% CI=6.5, 8.3). In 17 carefully selected patients with fewer than 3 sites of relapse, median PFS was 35 months (95% CI=0, 73.5) and median overall survival was 96.8 months (95% CI=44.6, 149.0) after SCS. NGS on 58 tumors revealed common mutations in ARID1A (48.3%), PIK3CA (46.6%), and KRAS (20.7%). Pathogenic alterations in PIK3CA, FGFR2, and NBN were associated with worse survival outcomes. Median tumor mutational burden was 3.78 (range, 0-16). All 26 patients with available loss of heterozygosity (LOH) scores had LOH <16%. Our study demonstrates encouraging outcomes with bevacizumab and ICI, and SCS in select relapsed OCCC patients. Prospective trials are warranted.

Precision medicine for KRAS wild-type pancreatic adenocarcinomas

BackgroundKRAS mutation is the most common molecular alteration in pancreatic adenocarcinoma (PDAC), and around 10% of patients harbor KRAS wild-type tumors (KRASWT). MethodsA retrospective chart review of clinical/molecular data was performed including all PDAC patients with a determined KRAS status (tumor molecular profiling on tissue or liquid biopsy). Results342 patients were included with 54 KRASWT PDAC (16%) compared to 288 patients with KRASm PDAC. Median age was 61 years [IQR:54.0;67.0] and 164 pts (48%) were female. At diagnosis, KRASWT patients (63%) were more frequently diagnosed at a non-metastatic stage compared to KRASm patients (41%) (p = 0.003). Regarding metastatic sites, liver was less frequent in KRASWT (39%, p < 0.0001).Median overall survival (mOS) from initial diagnosis was significantly higher in the KRASWT group compared to KRASm (50.8 months, CI95% [32.0-NR] vs 21.1 months, CI95% [18.9–23.4] (p < 0.004 after adjustment on age, ECOG and stage at diagnosis). In first-line systemic treatment, (mostly FOLFIRINOX) progression-free survival (PFS) was also higher in KRASWT.Based on ESCAT classification, a putative actionable alteration (ESCAT I-III) was identified in 19 (36%) KRASWT pts and 46 (16%) KRASm patients (p < 0.0001) with more alterations in FGFR2, BRAF(V600E), NRTK and more MSI tumors. KRASWT harbored also fewer alterations in TP53, CDKN2A, and SMAD4. 12 KRASWT patients received a molecularly-matched treatment with clinical benefit and improved outcomes compared to KRASm patients. ConclusionsKRASWT patients display distinct disease characteristics and outcomes with prolonged overall survival. KRASWT patients also harbor more actionable molecular alterations, leading to higher survival rates after receiving molecularly matched treatments.

A new subtype of diffuse midline glioma, H3 K27 and BRAF/FGFR1 co-altered: a clinico-radiological and histomolecular characterisation

Diffuse midline gliomas (DMG) H3 K27-altered are incurable grade 4 gliomas and represent a major challenge in neuro-oncology. This tumour type is now classified in four subtypes by the 2021 edition of the WHO Classification of the Central Nervous System (CNS) tumours. However, the H3.3-K27M subgroup still appears clinically and molecularly heterogeneous. Recent publications reported that rare patients presenting a co-occurrence of H3.3K27M with BRAF or FGFR1 alterations tended to have a better prognosis. To better study the role of these co-driver alterations, we assembled a large paediatric and adult cohort of 29 tumours H3K27-altered with co-occurring activating mutation in BRAF or FGFR1 as well as 31 previous cases from the literature. We performed a comprehensive histological, radiological, genomic, transcriptomic and DNA methylation analysis. Interestingly, unsupervised t-distributed Stochastic Neighbour Embedding (tSNE) analysis of DNA methylation profiles regrouped BRAFV600E and all but one FGFR1MUT DMG in a unique methylation cluster, distinct from the other DMG subgroups and also from ganglioglioma (GG) or high-grade astrocytoma with piloid features (HGAP). This new DMG subtype harbours atypical radiological and histopathological profiles with calcification and/or a solid tumour component both for BRAFV600E and FGFR1MUT cases. The analyses of a H3.3-K27M BRAFV600E tumour at diagnosis and corresponding in vitro cellular model showed that mutation in H3-3A was the first event in the oncogenesis. Contrary to other DMG, these tumours occur more frequently in the thalamus (70% for BRAFV600E and 58% for FGFR1MUT) and patients have a longer overall survival with a median above three years. In conclusion, DMG, H3 K27 and BRAF/FGFR1 co-altered represent a new subtype of DMG with distinct genotype/phenotype characteristics, which deserve further attention with respect to trial interpretation and patient management.

Abstract IA006: Clinical activity of lirafugratinib (RLY-4008), a highly selective FGFR2 inhibitor, in patients with advanced FGFR2-altered solid tumors: The ReFocus study

Abstract Background: Oncogenic FGFR2 alterations (fusions/rearrangements [f/r], amplifications, mutations) drive multiple solid tumors. Pan-FGFR inhibitors have validated FGFR2 as an actionable target in cholangiocarcinoma (CCA), however, activity has been limited by off-isoform toxicity and on-target resistance. Lirafugratinib (RLY-4008), the first highly selective FGFR2 inhibitor, was studied in ReFocus, an ongoing Phase I/II study (NCT04526106) in advanced FGFR2-altered solid tumor patients (pts). Previously, we defined the RP2D, confirmed the selective mechanism that minimizes off-isoform toxicity (FGFR1-hyperphosphatemia; FGFR4-diarrhea), and reported efficacy in CCA pts with FGFR2 f/r. Here, we report initial efficacy and safety from pts with solid tumors other than CCA treated at the RP2D. Methods: Pts with advanced solid tumors and FGFR2 alterations identified per local testing enrolled and received lirafugratinib orally. Key objectives were investigator-assessed objective response rate (ORR), duration of response (DOR), and safety. Efficacy was analyzed in pts with measurable disease, no prior FGFRi therapy and an opportunity for ³1 post-baseline imaging assessment. Safety was analyzed in all pts. Results: As of 09May23, 98 pts with solid tumors other than CCA (21 tumor types) were enrolled and treated at the RP2D. Fifty-three percent of pts had ³3 prior therapies; 19% had prior FGFRi therapy. Median treatment exposure was 8.3 weeks (range: 0.1–55.7). Of 79 FGFRi-naïve pts, 61 were evaluable; 18 unevaluable (1 nonmeasurable; 17 ongoing pending imaging). Twenty had f/r with an ORR of 40% (8/20, 7 confirmed/5 ongoing) and DOR from 8-50+ weeks. Twenty-seven had amplification with an ORR of 33% (9/27, 7 confirmed/5 ongoing) and DOR from 8-32+ weeks. Pts with breast (n=7), lung (n=3), and pancreatic (n=5) cancer with FGFR2 f/r or amplification had confirmed ORRs of 43%, 67%, and 40%, respectively. Response varied by mutation with ORR 14.3% (2 [N549K; C382R]/14; both confirmed, 1 ongoing) with DOR each of 40+ weeks. Most common treatment-related adverse events (TRAEs, all grades; grade 3) were stomatitis (50%; 10%), nail toxicities (44%; 4%), and palmar-plantar erythema (45%; 5%). Typical off-isoform TRAEs for pan-FGFR inhibitors were uncommon, including hyperphosphatemia (16%; 0%) and diarrhea (9%; 1%). One percent of pts discontinued treatment because of TRAEs. No grade 4/5 TRAEs were observed. Conclusion: Beyond CCA, lirafugratinib demonstrates promising initial efficacy in multiple tumor types with diverse FGFR2 alterations including f/r, amplification, and select mutations. Together with lirafugratinib’s differentiated safety profile (minimal off-isoform toxicity), these efficacy data validate FGFR2 as a tumor agnostic target sensitive to selective FGFR2 inhibition. Pivotal development across solid tumors continues in Phase 2 of ReFocus. Additional/updated data will be presented at the conference. Citation Format: Alison M Schram, Vivek Subbiah, Chih-Yi (Andy) Liao, Victor Moreno, Roda Desamparados, Mariano Ponz-Sarvise, Efrat Dotan, Philippe Alexandre Cassier, Irene Moreno, Andreas Varkaris, Richard D Kim, Elena Garralda, Frans Opdam, David Tai, Antoine Italiano, Do-Youn Oh, Lipika Goyal, Elisa Fontana, Jia Liu, Myrto Boukovala, Francois Ghiringelli, Mitesh J Borad, Hani Babiker, Zhaohui Jin, Michael Millward, Jeffrey Yachnin, Suneel Deepak Kamath, Jermaine M. Coward, Changhoon Yoo, Robin Kate Kelley, Vaibhav Sahai, John Bridgewater, Christoph Springfield, Vaia Florou, Anthony El-Khoueiry, Ferry Eskens, Bruce Lin, Scott Paulson, Giuseppe Curigliano, Meredith Murphy, Alicia Deary, Fabien Ricard, Kai Yu Jen, Florence (Tianhui) Ramirez, Rick E. Blakesley, Oleg Schmidt-Kittler, Brenton G. Mar, Joon Oh Park, Antoine Hollebecque. Clinical activity of lirafugratinib (RLY-4008), a highly selective FGFR2 inhibitor, in patients with advanced FGFR2-altered solid tumors: The ReFocus study [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr IA006.

Abstract B129: A bispecific antibody inhibits FGFR3 dimerization and is highly effective in FGFR3-driven tumor models

Abstract Background: The receptor tyrosine kinase (RTK) FGFR3 is frequently mutated in bladder cancer (~15-20% in muscle invasive bladder cancer, MIBC) and is a validated therapeutic target. Oncogenic alterations in FGFR3 include point mutations in the extracellular domain (S249C, R248C, G372C, Y375C) and gene fusions that place an oligomerization domain from a fusion partner at the FGFR3 C-terminus (e.g., FGFR3-TACC3). Although pan-FGFR tyrosine kinase inhibitors (TKI) have demonstrated clinical efficacy, toxicity and acquired resistance limit the benefit of these agents. While antibody-based therapy can offer superior selectivity compared to TKIs, conventional ligand-blocking antibodies are usually ineffective inhibitors of constitutively active RTKs. Further, the existence of multiple oncogenic variants of FGFR3 presents an additional challenge for antibody-mediated blockade. Results: We generated a tetravalent bispecific FGFR3xFGFR3 antibody that potently inhibits both FGFR3 point mutants and fusions with better efficacy than the conventional antibodies that we produced and a clinical-stage comparator antibody. Mechanistically, our bispecific antibody binds FGFR3 through two different epitopes located in immunoglobulin-like domains D1 and D2/3 respectively. It potently blocks the dimerization of FGFR3 S249C, the most common oncogenic variant, inhibiting receptor phosphorylation and downstream signaling. Additionally, our bispecific antibody inhibits the function of FGFR3 gatekeeper mutations (V557M/L) that are resistant to TKIs. In FGFR3-driven tumor models, our antibody is highly effective, providing efficacy similar to that of the FDA-approved TKI erdafitinib. Conclusion: We have characterized the properties of a tetravalent bispecific FGFR3xFGFR3 antibody that shows strong anti-tumor activity in models driven by FGFR3 S249C as well as by FGFR3-TACC3 fusion, outperforming a conventional antibody that was previously in clinical development. The activity of the bispecific antibody is superior to the mixture of the two parental antibodies and results from strong inhibition of FGFR3 dimerization. Our bispecific antibody provides a novel approach to achieve selective and potent inhibition of multiple oncogenic variants of FGFR3 in bladder cancer, including FGFR3 variants that are resistant to FGFR TKIs. Citation Format: Yan Yang, Naga Suhasini Avvaru, Zaoli Jiang, Nina Liu, Michael Rosconi, Bojie Zhang, Yinyin Li, Erica Ullman, John Chia-Yang Lin, Yang Shen, Christopher Daly. A bispecific antibody inhibits FGFR3 dimerization and is highly effective in FGFR3-driven tumor models [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B129.

Abstract LB_B04: Deciphering FGFR3-TACC3 oncogenic fusions

Abstract Chromosomal rearrangements of the fibroblast growth factor receptor (FGFR) genes that give rise to fusions are one of several mechanisms by which the FGF/FGFR signaling axis can become deregulated and result in enhanced signaling in cancer. We have previously identified truncation of exon (E) 18 of FGFR2 as a potent single-driver alteration in cancer, independently of the rearrangement (RE) partner. In contrast, the same does not appear to hold true for its E18-truncated ortholog FGFR3. We mined human oncogenomic datasets from Hartwig Medical Foundation (&amp;gt;2,500 WGS profiles) and Foundation Medicine (&amp;gt;200,000 hybrid-capture panel-seq profiles) for alterations affecting FGFR3. Examination of the structural variants affecting FGFR3 uncovered that 85% of all E18-truncating FGFR3 REs involved transforming acidic coiled-coil-containing protein 3 (TACC3) as the downstream fusion partner gene, while REs with intergenic regions and other known protein-encoding genes were much less frequent. Additionally, there was a clear predominance of self-interacting domains (95%) among all FGFR3 RE partners, with the coiled-coil domain being the most recurrent, suggesting enhanced receptor dimerization and downstream signaling capacity for the majority of the FGFR3 fusions. Our findings led to the generation of a compendium of FGFR3 structural variants which we then functionally tested. In vitro testing of mouse mammary epithelial cells expressing Fgfr3ΔE18-Tacc3E7-E16 fusion variants showed that both E18-truncation and a fusion partner were required for 3D outgrowth and signaling induction. In vivo evaluation of the oncogenic capacity of Fgfr3 variants using somatic delivery of lentiviruses to the mouse mammary gland via intraductal injection and lung via intratracheal injection found that Fgfr3ΔE18-Tacc3E7-E16 fusion variants rapidly induced mammary and lung tumor formation in wild-type and Wap-Cre;Cdh1F/F, and in wild-type and Trp53F/F mice, respectively. In contrast, Fgfr3full-length(FL), Fgfr3ΔE18 and Fgfr3FL–Tacc3E7-E16 were non-tumorigenic. Noteworthy, mammary tumors driven by Fgfr3ΔE18-Tacc3E7-E16 fusions were sensitive to the FGFR inhibitor AZD4547 during a drug intervention study. In summary, our findings show that E18-truncating FGFR3 alterations are recurrent across human cancers and, as opposed to FGFR2 E18-truncating alterations, FGFR3 appears to depend both on E18-truncation and an additional fusion partner with dimerizing capacity. Notably, TACC3 is the most recurrent 3’ fusion partner across all FGFR3 E18-truncating alterations, and somatic tumor modeling has shown that Fgfr3ΔE18-Tacc3 fusions drive mouse mammary and lung tumorigenesis, and are sensitive to FGFR targeted therapy. Citation Format: Julia Yemelyanenko, Jinhyuk Bhin, Sjoerd Klarenbeek, Ji-Ying Song, Catrin Lutz, Marieke van de Ven, Shridar Ganesan, Lodewyk F. A. Wessels, Daniel Zingg, Jos Jonkers. Deciphering FGFR3-TACC3 oncogenic fusions [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_B04.

Efficacy of futibatinib, an irreversible fibroblast growth factor receptor inhibitor, in FGFR-altered breast cancer

Several alterations in fibroblast growth factor receptor (FGFR) genes have been found in breast cancer; however, they have not been well characterized as therapeutic targets. Futibatinib (TAS-120; Taiho) is a novel, selective, pan-FGFR inhibitor that inhibits FGFR1-4 at nanomolar concentrations. We sought to determine futibatinib’s efficacy in breast cancer models. Nine breast cancer patient–derived xenografts (PDXs) with various FGFR1-4 alterations and expression levels were treated with futibatinib. Antitumor efficacy was evaluated by change in tumor volume and time to tumor doubling. Alterations indicating sensitization to futibatinib in vivo were further characterized in vitro. FGFR gene expression between patient tumors and matching PDXs was significantly correlated; however, overall PDXs had higher FGFR3-4 expression. Futibatinib inhibited tumor growth in 3 of 9 PDXs, with tumor stabilization in an FGFR2-amplified model and prolonged regression (> 110 days) in an FGFR2 Y375C mutant/amplified model. FGFR2 overexpression and, to a greater extent, FGFR2 Y375C expression in MCF10A cells enhanced cell growth and sensitivity to futibatinib. Per institutional and public databases, FGFR2 mutations and amplifications had a population frequency of 1.1%–2.6% and 1.5%–2.5%, respectively, in breast cancer patients. FGFR2 alterations in breast cancer may represent infrequent but highly promising targets for futibatinib.

Oncogenic activation revealed by FGFR2 genetic alterations in intrahepatic cholangiocarcinomas

BackgroundExcept for gene fusions, FGFR2 genetic alterations in intrahepatic cholangiocarcinomas (ICCs) have received limited attention, leaving patients harboring activating FGFR2 gene mutations with inadequate access to targeted therapies.Experimental designWe sought to survey FGFR2 genetic alterations in ICC and pan-cancers using fluorescence in situ hybridization and next-generation sequencing. We conducted an analysis of the clinical and pathological features of ICCs with different FGFR2 alterations, compared FGFR2 lesion spectrum through public databases and multicenter data, and performed cellular experiments to investigate the oncogenic potential of different FGFR2 mutants.ResultsFGFR2 gene fusions were identified in 30 out of 474 ICC samples, while five FGFR2 genetic alterations aside from fusion were present in 290 ICCs. The tumors containing FGFR2 translocations exhibited unique features, which we designated as the “FGFR2 fusion subtypes of ICC”. Molecular analysis revealed that FGFR2 fusions were not mutually exclusive with other oncogenic driver genes/mutations, whereas FGFR2 in-frame deletions and site mutations often co-occurred with TP53 mutations. Multicenter and pan-cancer studies demonstrated that FGFR2 in-frame deletions were more prevalent in ICCs (0.62%) than in other cancers, and were not limited to the extracellular domain. We selected representative FGFR2 genetic alterations, including in-frame deletions, point mutations, and frameshift mutations, to analyze their oncogenic activity and responsiveness to targeted drugs. Cellular experiments revealed that different FGFR2 genetic alterations promoted ICC tumor growth, invasion, and metastasis but responded differently to FGFR-selective small molecule kinase inhibitors (SMKIs).ConclusionsFGFR2 oncogenic alterations have different clinicopathological features and respond differently to SMKIs.

PATH-30. GLIOMAS WITH FGFR ONCOGENIC ALTERATIONS: CLINICO-PATHOLOGICAL FEATURES, MANAGEMENT AND OUTCOMES IN PEDIATRIC, ADOLESCENT AND YOUNG ADULT PATIENTS.

Abstract INTRODUCTION Fibroblast growth factor receptor (FGFR1-4) pathway alterations are rare in pediatric cancers (1-3%) but are enriched in certain specific subtypes of difficult to treat pediatric and AYA brain tumors. Some of the common oncogenic alterations include structural variants (fusions, duplications), mutations and amplifications. METHODS We describe here the clinico-pathological features and therapeutic outcomes of pediatric and AYA patients (ages 0-39yrs) with FGFR pathway altered gliomas diagnosed in the past 10yrs (2013-2023). Data was collected from review of patient charts. RESULTS We identified 13 patients with gliomas harboring an oncogenic FGFR alteration. Median age at diagnosis was 16yrs (range, 6-30yrs) and was more common in males (M: F-3:1). Seizures were the most common presenting symptom (N=5/13, 38%); all of these patients had cortical tumors, which were resected and seizures were adequately controlled. A biopsy only approach was done in more than half (N=7/13, 54%) of the patients. Pathological diagnosis included low grade glio-neuronal tumors in all but one of the patients, who had a high-grade glioma (Pilocytic astrocytoma N=6, Diffuse astrocytoma N=2, glio-neuronal tumors N=2, PLNTY N=2). FGFR alterations included oncogenic fusions (FGFR1-TACC1=1, FGFR2-TACC1=1, FGFR2-CTNNA3=2, FGFR3-TACC3=1), tandem duplications (FGFR1-TKD-ITD=3) and mutations (FGFR1- N546K=2, K654E=1, K656E=2). Co-occurring mutations were seen in 4 patients (H3.3-K27M=1, PIK3CA-E545K=1, PTPN11-G503V=1, PTPN11-E69K=1). Patients with symptomatic residual tumors (N=6, 46%) were treated with targeted therapies (Erdafitinib=3, Trametinib=1, Ponatinib / Everolimus=1, Dasatinib=1) and two patients received Radiation therapy. Erdafitinib was discontinued in one patient due to intra-tumoral bleed. Rest of the patients are tolerating the targeted therapy well and all of the patients are alive. CONCLUSION In summary, cortical tumors bearing FGFR alterations present with refractory seizures and are eminently treatable with surgical resection. Targeted therapy with FGFR specific inhibitors is tolerated well and updated response assessment of our patients will be presented in the meeting.